Seating arrangement

Abstract

A seating arrangement includes a back arrangement movable between upright and reclined positions, a linkage arrangement including a first link member comprising a portion of a seat arrangement, a second link member supported on a base, flexibly resilient front link members extending between forward portions of the first and second link members and being integral with the second link member, and a rigid rear link member extending between rearward portions of the first and second link members including a separate piece from the first or second link members, wherein the rearward portion of the first link member extends laterally in a first plane when the back arrangement is upright, and laterally in a second plane when the back arrangement is reclined, where the second plane is angled with respect to the first plane, and is positioned farther away from the base when the back arrangement is reclined than when upright.

Description

TECHNICAL FIELD

Various embodiments relate to a seating arrangement, and in particular to a seating arrangement that includes various combinations of a pair of flexibly resilient shell members, a flexibly resilient support member and a rigid support member that cooperate to form a deformable and flexibly resilient support arrangement, and an active back arrangement having a movement that may be separated from movement of an associated seat support arrangement.

BRIEF SUMMARY

In one embodiment, a seating arrangement includes a base, and a back arrangement and a seat arrangement each supported by the base on a linkage arrangement, wherein the back arrangement is movable between a generally upright position and a reclined position. The linkage arrangement includes a horizontally-extending first link member comprising at least a portion of the seat arrangement, the first link including a forward portion and a rearward portion, a second link member supported on the base, a pair of flexibly resilient front link members extending between the forward portion of the first link member and a forward portion of the second link member, the front link members being integral with the second link member, and a rigid rear link member extending between the rearward portion of the first link member and the second link member, the rear link member including a separate piece from the first link member or the second link member, wherein the rearward portion of the first link member extends laterally in a first plane when the back arrangement is in the generally upright position, and the rearward portion of the first link member extends laterally in a second plane when the back arrangement is in the reclined position, wherein the second plane is angled with respect to the first plane, and wherein the rearward portion of the first link member is positioned farther away from the base when the back arrangement is in the reclined position than when the back arrangement is in the generally upright position.

In another embodiment, a seating arrangement includes a base, a back arrangement and a seat arrangement each supported by the base on a linkage arrangement, the back arrangement including a vertically-extending back portion and a forwardly-extending portion, the back arrangement movable between a generally upright position and a reclined position. The linkage arrangement includes a horizontally-extending first link member comprising at least a portion of the seat arrangement, a second link member supported on the base having a longitudinally-extending axis, a pair of flexibly resilient front link members extending between the forward portion of the first link member and a forward portion of the second link member, and a rigid rear link member extending between the first link member and the second link member and having a second longitudinally-extending axis, wherein the rear link member and the forwardly-extending portion of the back arrangement are non-pivotally fixed together such that an angle therebetween remains constant as the back arrangement moves between the generally upright and reclined positions.

In yet another embodiment, a seat and back arrangement to be positioned on a surface includes a seat member, a back member, and a four-bar assembly. The four-bar assembly includes a substantially rigid bottom link having a front end and a rear end, a portion of the bottom link configured to be grounded with respect to the surface, a top link having a front end and a rear end, a portion of the top link configured to support a front portion of the seat member, the top link including a left side and a right side, a substantially rigid rear link extending between the rear end of the bottom link and the rear end of the top link, the rear link including a top end and a bottom end, the top end connected to a rear portion of the seat member, a first articulation location between the rear end of the bottom link and the bottom end of the rear link, a second articulation location between the rear end of the top link and the top end of the rear link, a front link assembly including a left front link and a right front link, the left front link connecting the front end of the bottom link to the front end of the top link at the left side of the top link, and the right front link connecting the front end of the bottom link to the front end of the top link at the right side of the top link, wherein both the left front link and right front links are flexible along a length thereof, and wherein the front link assembly is integrally formed with the bottom link, and wherein the rear link is non-pivotally connected to the back member to move therewith.

Various embodiments of the seating arrangements described here may provide a platform with the proper fit and function for comfortably supporting a seated user and may reduce or shift costs by reducing associated part counts, manufacturing costs, and labor costs. The seating arrangement includes an uncomplicated, durable, and visually appealing design capable of a long operating life, and particularly well adapted for the proposed use.

These and other features, advantages, and objects of various embodiments will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of a seating arrangement;

FIG. 2 is a cross-sectional side elevational view of the embodiment of the seating arrangement shown in FIG. 1 taken along the line II-II, FIG. 1;

FIG. 3 is a cross-sectional perspective view of the embodiment of the seating arrangement shown in FIG. 1 taken along the line II-II, FIG. 1;

FIG. 4a is a cross-sectional side elevational view of the embodiment of the seating arrangement shown in FIG. 1 shown in an upright position in solid line and in a reclined position in dashed line;

FIG. 4b is an enlarged cross-sectional side elevational view of another embodiment of a seating arrangement;

FIG. 5 is an enlarged perspective view of a first embodiment of a stop arrangement, wherein the associated seating arrangement is in a fully forward position;

FIG. 6 is an enlarged perspective view of the first embodiment of a stop arrangement, wherein the associated seating arrangement is in a fully reclined position;

FIG. 7 is an enlarged perspective view of an alternative embodiment of the stop arrangement, wherein the associated seating arrangement is shown in a fully reclined position;

FIG. 8 is an enlarged perspective view of the alternative embodiment of the stop arrangement, wherein the associated seating arrangement is shown in a fully forward position;

FIG. 9 is a perspective view of another embodiment of a seating arrangement;

FIG. 10 is a cross-sectional side elevational view of the embodiment of the seating arrangement shown in FIG. 9 taken along the line X-X, FIG. 9;

FIG. 11 is a cross-sectional perspective view of the embodiment of the seating arrangement shown in FIG. 9 taken along the line X-X, FIG. 9;

FIG. 12 is a bottom perspective view of yet another embodiment of the seating arrangement;

FIG. 13 is a bottom perspective view of still yet another embodiment of the seating arrangement, wherein the seating arrangement is in an upright position;

FIG. 14 is a bottom perspective view of the embodiment of the seating arrangement of FIG. 13, wherein the seating arrangement is in a reclined position;

FIG. 15 is a cross-sectional view of another embodiment of a seating arrangement;

FIG. 16 is a perspective view of yet another embodiment of a seating arrangement including a plurality of edge members;

FIG. 17 is a perspective view of another embodiment of a seating arrangement;

FIG. 18 is a cross-sectional view of the embodiment of the seating arrangement shown in FIG. 17 taken along the line XVIII-XVIII, FIG. 17;

FIG. 19 is a cross-sectional perspective view of the embodiment of the chair assembly shown in FIG. 17 taken along the line XVIII-XVIII, FIG. 17;

FIG. 20 is a cross-sectional side elevational view of yet another embodiment of the chair assembly;

FIG. 21 is a cross-sectional perspective view of the embodiment of the chair assembly shown in FIG. 20;

FIG. 22 is a perspective view of another embodiment of a seating arrangement;

FIG. 23 is a cross-sectional front perspective view of the embodiment of the seating arrangement shown in FIG. 22 taken along the line XXIII-XXIII, FIG. 22;

FIG. 24 is a rear perspective view of the embodiment of the seating arrangement shown in FIG. 22;

FIG. 25 is a side elevational view of the embodiment of the seating arrangement shown in FIG. 22 with a back arrangement in an upright position in solid line and in a reclined position in dashed line;

FIG. 26 is a rear perspective view of another embodiment of the seating arrangement;

FIG. 27 is a rear perspective view of yet another embodiment of the seating arrangement;

FIG. 28 is a front perspective view of still another embodiment of the seating arrangement;

FIG. 29 is an enlarged perspective view of a recline limiting arrangement of the seating arrangement of FIG. 28;

FIG. 30 is a perspective view of another embodiment of a seating arrangement;

FIG. 31 is a side elevational view of the embodiment of the seating arrangement shown in FIG. 30 with a back assembly shown in an upright position in solid line and a reclined position in dashed line;

FIG. 32 is a perspective view of a back shell member;

FIG. 33 is a perspective view of the back shell member;

FIG. 34 is a cross-sectional side elevational view of the embodiment of the chair shown in FIG. 30, taken along the line XXXIV-XXXIV, FIG. 30;

FIG. 35 is a perspective view of the embodiment of the chair shown in FIG. 30 with a fabric cover removed;

FIG. 36A is a cross-sectional side elevational view of the embodiment of the chair shown in FIG. 30, taken along the line XXXIVA-XXXIVA, FIG. 35, with the back assembly shown in the upright position;

FIG. 36B is a cross-sectional side elevational view of the embodiment of the chair shown in FIG. 30, taken along the line XXXIVA-XXXIVA, FIG. 35, with the back assembly shown in the reclined position;

FIG. 37 is a cross-sectional side elevational view of the embodiment of the chair shown in FIG. 30, taken along the line XXXVII-XXXVII, FIG. 35;

FIG. 38 is a perspective view of a stop member;

FIG. 39 is an exploded perspective view of another alternative embodiment of a seating arrangement;

FIG. 40 is an exploded perspective view of an accessory supporting arrangement;

FIG. 41 is an exploded perspective view of another alternative embodiment of a seating arrangement;

FIG. 42 is a cross-sectional side view of the seating arrangement of FIG. 41;

FIG. 43 is a top perspective view of a seating arrangement;

FIG. 44 is a front perspective view of the seating arrangement of FIG. 43;

FIG. 45 is a rear perspective view of the seating arrangement of FIG. 43;

FIG. 46 is a front elevational view of the seating arrangement of FIG. 43;

FIG. 47 is a rear elevational view of the seating arrangement of FIG. 43;

FIG. 48 is a first side elevational view of the seating arrangement of FIG. 43;

FIG. 49 is a second side elevational view of the seating arrangement of FIG. 43;

FIG. 50 is a top plan view of the seating arrangement of FIG. 43;

FIG. 51 is a bottom plan view of the seating arrangement of FIG. 43;

FIG. 52 is a top perspective view of a seating arrangement;

FIG. 53 is a front perspective view of the seating arrangement of FIG. 52;

FIG. 54 is a rear perspective view of the seating arrangement of FIG. 52;

FIG. 55 is a front elevational view of the seating arrangement of FIG. 52;

FIG. 56 is a rear elevational view of the seating arrangement of FIG. 52;

FIG. 57 is a first side elevational view of the seating arrangement of FIG. 52;

FIG. 58 is a second side elevational view of the seating arrangement of FIG. 52;

FIG. 59 is a top plan view of the seating arrangement of FIG. 52; and

FIG. 60 is a bottom plan view of the seating arrangement of FIG. 52.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of description herein, the terms “upper,” “lower,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the various seating embodiments as oriented in FIGS. 1, 9, 17 and 22. However, it is to be understood that certain embodiments may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are exemplary embodiments of the concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. The various embodiments disclosed herein may be utilized within and incorporated into various seating arrangements, including office chairs, general office seating, vehicle seating, home seating, aircraft seating, stadium seating, theater seating, and the like.

The reference numeral 10 (FIG. 1) generally designates an embodiment of a seating arrangement. In the illustrated example, the seating arrangement 10 is provided in the form of an office chair assembly and includes a cantered base or support assembly 12 supported above a ground or floor surface 14, a seat arrangement 16 and a back arrangement 18 each supported above the base assembly 12, and a pair of arm assemblies 20. The seating arrangement 10 (FIGS. 2 and 3) includes a front or first shell member 22 covered by a fabric layer 24 (FIG. 1) and a rear or second shell member 26. The shell members 22, 26 may be formed as a single, integral piece or comprise multiple, individual components. The shell members 22, 26 each comprise a flexibly resilient polymer material such as any thermoplastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any thermal set material, including, for example, epoxies; or any resin-based composites, including, for example, carbon fiber or fiberglass, thereby allowing each of the shell members 22, 26 to conform and move in response to forces exerted by a user. Other suitable materials may also be utilized, such as metals, including, for example, steel or titanium; plywoods; or composite material including plastics, resin-based composites, metals and/or plywood. A variety of other suitable energy-storing materials may also be utilized. In some embodiments, shell members 22, 26 may comprise the same material or materials, while in certain embodiments, shell members 22, 26 may each comprise a different material or materials.

The front shell member 24 includes a horizontally-extending bottom or first portion or first link member 28, a vertically-extending upper or second portion 30 extending upwardly from the first portion 28, and an arcuately-shaped transition portion 32 extending between the first portion 28 and the second portion 30. The first portion 28 includes a forward portion 34, a rearward portion 36 and a central portion 38 located therebetween and extending laterally across the first portion 28. A pair of laterally-extending reliefs or apertures 40 are located within the central portion 38 and divide the forward portion 34 from the rearward portion 36 as further described below. The second portion 30 includes a lower portion 44, an upper portion 46 and a mid-portion 48 located therebetween that may be arcuately-shaped and forwardly convex so as to support the lumbar region of a user's back. It is noted that the front shell member 24 may alternatively be referred to herein as the forward shell member, the first shell member, the support member or support shell member, and the top shell or shell member.

The rear shell member 26 includes a horizontally-extending bottom or first portion or second link member 50 supported by a height adjustable pneumatic cylinder 12a at a connection point 12b, a vertically-extending upper or second portion 52 extending upwardly from the first portion 50, and an arcuately-shaped transition portion 54 extending between the first portion 50 and the second portion 52. Preferably, the rear shell member 26 comprises carbon fiber, however, other materials may also be utilized as described above. The second portion 52 of the rear shell member 26 includes a lower portion 56, an upper portion 58 and a mid-portion 60 located therebetween that may be arcuately-shaped and forwardly convex. The upper portion 58 of the second portion 52 of the rear shell member 26 is connected to the upper portion 46 of the second portion 30 of the front shell member 22 at a location 62, such as by sonic welding, an adhesive, integral molding, mechanical fasteners, and the like. It is noted that the rear shell member 26 may alternatively be referred to herein as the rearward shell member, the second shell member, the bottom shell or shell member, or the control arrangement. The front shell member 22 and the rear shell member 26 are configured so as to define a gap 64 between at least a portion of the upper portion 30 and upper portion 52, between the mid-portion 48 and the mid-portion 60, between the lower portion 44 and the lower portion 56, between the transition portion 32 and the transition portion 54, and/or between the first portion 28 and first portion 50. In certain embodiments, the front shell member 22 and the rear shell member 26 may be connected at the lower portions or mid-portions of their respective second portions 30 and 52 or at their respective transition portions 21 and 54. For example, the front shell member 22 and the rear shell member 26 may be connected at their respective lower portions 44 and 56 such that seating arrangement 10 essentially has a single shell second portion with a gap 64 between the first portions 28 and 50.

The seating arrangement 10 further includes a laterally-extending, flexibly resilient forward support member 66, and a laterally-extending, rigid rearward support member 68, each extending between the first portion 28 of the front shell member 22 and the first portion 50 of the rear shell member 26. In the illustrated example, the forward support member 66 is integral and forms a single-piece with the first portion 50 of the rear shell member 26, while the rearward support member 68 is formed as and is a separate piece from the front shell member 22 and the rear shell member 26. However, either or both the forward support member 66 and the rearward support member 68 may be formed integrally with or as a separate piece from the front shell member 22 and/or the rear shell member 26. In the present example, the rearward support member 68 preferably comprises a rigid, relatively lightweight carbon fiber, however, other material or materials may also be utilized depending on the application, including those listed above with respect to the front and rear shell members 22, 26. The rearward support member 68 includes a body portion 70, an upper flange 72 secured to a bottom surface 74 of the first portion 28 at a location 74a, and a lower flange 76 secured to an upper surface 78 of the first portion 50 at a location 78a. The upper flange 72 and the lower flange 76 are secured to the first portion 28 and the first portion 50 by sonic welding, an adhesive, mechanical fasteners, friction fit and the like. Both the forward support member 66 and the rearward support member 68 angle forwardly from bottom to top, while the forward support member 66 includes a V-shaped notch or aperture 80 extending therethrough. In certain embodiments, the forward support member 66 may include one or more apertures, notches, or slots of varying shapes in order to promote a desired flexibility of the support member. Similarly, in some embodiments, the forward support member 66 may be a solid member shaped to promote a desired flexibility. The various configurations of the rear shell member as described herein, whether provided as a single, integral, one-piece unit or as a multiple-piece assembly allows the rear shell member to act as a control member to control various recline movements and support characteristics of the front shell member.

In operation, a user can move or recline the back arrangement 18 (FIG. 4a), including the second portion 30 of the front shell member 22 and the second portion 52 of the rear shell member 26, from an upright position A to a reclined position B by flexing the front shell member 22 and the rear shell member 26. The first portion or first link member 28, the first portion or second link member 50, the forward support member or third link member 66 and the rearward support member or fourth link member 68 cooperate to form a four-bar linkage arrangement such that movement of the second portion 30 of the first shell member 22 and the second portion 52 of the rear shell member 26 from the upright position A to the reclined position B causes the first portion 28 of the front shell member 22 to move rearward and to a reclined position. It is contemplated that the four-bar linkage arrangement as used and described herein is inclusive of linkage arrangements comprising additional linkage members, such as five-bar linkage arrangements, six-bar linkage arrangements, and the like. FIG. 4 illustrates in solid line the first portion 28 of the front shell member 22 in a substantially horizontal orientation C when not acted upon by external forces, such as a force exerted by a seated user. The apertures or reliefs 40 allow the rearward portion 36 to rotate more rapidly and to a greater recline angle than the forward portion 34 during recline of the back arrangement 18. Specifically, the forward portion 34 is moved from the position C to a rearward and reclined position D, while the rearward portion 36 of the first portion 28 is moved from the position C to a rearward and more reclined position E. In certain embodiments, apertures 40 may be positioned in first portion 28, either in the central portion 38, forward portion 34, or rearward portion 36, so as to achieve a desired rotation and recline angle during the recline of back arrangement 18. It is further noted that the rearward support member 68 remains rigid or substantially rigid during the entire recline movement of the seating arrangement 10, while most deformation of the front shell member 22 and the rear shell member 26 occurs in a portion 82 of the rear shell member 26 just forward of the location at which the rearward support member 68 is connected to the rear shell member 26, in the central portion 38 of the first portion 28 of the first shell member 22, and in the forward support member 66. Further, in some instances, the fourth link 68 may include at least a portion of the back arrangement 18. In various embodiments, the thickness of one or more links may be determined to achieve a desired performance characteristic, including for example, the flexibility of the link. Further, in certain embodiments, the thickness of a link may vary along the length of the link to achieve a desired flexibility or rigidity across the link or in a localized portion of the link. For example, the first link member 28, the second link member 50 and the forward link member 66 may all be more flexible than the rear link member 68 to achieve the desired flexibility of the four-bar linkage. In some embodiments, the various links may be more flexible in a particular portion or localized area of the link such that the links are generally flexible in the localized area and are generally not flexible or less flexible in any other area of the link. An example of this embodiment is illustrated in FIG. 4b where certain portions of the first link member 28, the second link member 50, and the third link member 66 include certain portions with a reduced relative thickness. Specifically, in the illustrated example, the first link member 28 includes an area of reduced thickness or flexing region or flexing zone 29 located in the central portion thereof, the second link member 50 includes an area of reduced thickness or flexing region or flexing zone 51 positioned rearward of the location at which the fourth link member attaches to the second link member 50, and the third link member 66 includes an area of reduced thickness or flexing region or flexing zone 67. It is noted that the relative areas of reduced thickness may extend along a short distance or the majority of the length of the associated link depending upon the support and bending characteristics desired.

The seating arrangement 10 further includes a support member 84 (FIGS. 1-3) at least partially located within an interior space 86 defined by the four-bar linkage arrangement, namely, the first link member 28, the second link member 50, the third link member 66 and the fourth link member 68. In the illustrated example, the support member 84 includes an open, loop-shaped body portion 88, the forward portion of which extends into the interior space 86, and the rearward portion of which is configured to support the arm assemblies 20. As best illustrated in FIG. 2, each arm assembly 20 includes an arm support member 92 integrally formed with and extending upwardly from the rear portion of the body portion 88 of the support member 84. An arm cap 94 is secured to an upper end of the arm support member 92 and may be movable adjustable with respect thereto. As best illustrated in FIG. 4, it is noted that the support member 84 and the arm assemblies 20 are grounded and remain substantially stationary as the back arrangement 18 is moved from the upright position A to the reclined position B.

The reference numeral 10a (FIG. 5) generally designates another embodiment of a seating arrangement, having a stop arrangement 100. Since the seating arrangement 10a is similar to the previously described seating arrangement 10, similar parts appearing in FIGS. 1-4 and FIGS. 5 and 6 respectively are represented by the same, corresponding reference numeral, except for the suffix “a” in the numerals of the latter. In the illustrated example, the stop arrangement 100 includes a bushing assembly 102 positioned between the body portion 88a and the rearward support member 68a. The bushing assembly 102 includes an elastically deformable bushing member 104, a sleeve member 106 extending about the bushing member 104, and a stop link 108 slidably extending through a centrally disposed aperture 110 of the bushing member 104 and having a first end fixably coupled to the rearward support member 68a and a second end 112 slidably received within an interior of the body portion 88a of the support member 84a. A stop plate 114 is affixed to the second end 112 of the stop link 108.

In operation, the bushing member 104 is compressed between the body portion 88a of the support member 84a and the rearward support member 68a as the back arrangement is moved in a forward direction from the reclined position to a fully forward upright position, thereby limiting the forward movement of the back arrangement. As the back arrangement is moved from the upright position to the reclined position, the stop link 108 is drawn from within an interior of the body portion 88a until the stop plate 114 abuts an inner surface 116 of the body portion 88a, thereby limiting movement of the rearward support member 68a and thus the rearward movement of the back assembly from the upright position toward the reclined position.

The reference numeral 10b (FIGS. 7 and 8) generally designates another embodiment of a seating arrangement, having a stop arrangement 100b. Since the seating arrangement 10b is similar to the previously described seating arrangement 10a, similar parts appearing in FIGS. 5 and 6 and FIGS. 7 and 8 respectively are represented by the same, corresponding reference numeral, except for the suffix “b” in the numerals of the latter. In the illustrated example, the stop arrangement 100b includes a stop member 120 located within the interior space 86b. The stop member 120 is secured to an upper surface 78b of the first portion 50b of the rear shell member 26b and extends upwardly therefrom into the interior space 86b positioned between the first link member 28b, the second link member 50b, the third link member 66b and the fourth link member 68b. The stop member 120 includes an upper or first stop surface 122 and a forward or second stop surface 124. A stop bracket 126 is secured to the bottom surface 74b of the first portion or first link member 28b, and includes a first portion 128 extending substantially parallel with the first portion or first link member 28b, and a second portion 130 extending orthogonally downward from the first portion 128. Elastically deformable abutment pads 132 are attached to the first portion 128 and the second portion 130.

In operation, the stop member 120 is configured to abut the pad 132 attached to the first portion 128 as the back assembly is moved from the reclined position toward a fully forward position, thereby limiting the amount of forward travel of the first portion or first link member 28b and the back assembly 12 in the forward direction. The stop member 120 is further configured such that the forward stop surface 124 contacts the pad 132 attached to the second portion 130 when the back arrangement is moved from the upright position to the reclined position, thereby limiting the amount of rearward travel of the first portion or first link member 28b and the back arrangement in the rearward direction.

The reference numeral 200 (FIG. 9) generally designates another embodiment of a seating arrangement. In the illustrated example, the seating arrangement or chair assembly 200 includes a cantered base assembly 202 abutting a floor surface 204, a seat assembly 206 and a back assembly 208 each supported above the base assembly 202, and a pair of arm assemblies 210. In the illustrated example, the chair assembly 200 (FIGS. 10 and 11) includes a front or a first shell member 214 and a rear or second shell member 212. The shell members 212, 214 may be formed as a single, integral piece or comprise multiple, individual components. The shell members 212, 214 each comprise a flexibly resilient polymer material such as any thermal plastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any thermal set material, including, for example, epoxies; or any resin-based composites, including, for example, carbon fiber or fiberglass, thereby allowing each of the shell members 212, 214 to conform and move in response to forces exerted by a user. Although a polymer material is preferred, other suitable materials may also be utilized, such as metals, including, for example, steel or titanium; plywood; or a composite material including plastics, resin-based composites, metals and/or plywood. A variety of other suitable energy-storing materials may also be utilized.

The rear shell member 212 includes a horizontally-extending bottom or first portion 216, a vertically-extending upper or second portion 218 extending upwardly from the first portion 216, and an arcuately-shaped transition portion 230 extending between the first portion 216 and the second portion 218. In the illustrated example, the first portion 216 is supported by a support plate 232 that abuts a bottom surface 234 of the first portion 216, and which is in turn supported by a column 236 of the pedestal assembly 202. In the illustrated example, the column 236 comprises a pneumatic height adjustment cylinder. The second portion 218 of the rear shell member 212 includes a lower portion 238, an upper portion 240 and an arcuately-shaped, forwardly convex mid-portion 242 located therebetween.

The front shell member 214 includes a horizontally-extending bottom or first portion 244, a vertically-extending upper or second portion 246 extending upwardly from the first portion 244, and an arcuately-shaped transition portion 248 extending between the first portion 244 and the second portion 246. The first portion 244 includes a forward portion 250 and a rearward portion 252, while the second portion 246 includes a lower portion 254, an upper portion 256 and an arcuately-shaped, forwardly convex mid-portion 258 located therebetween and configured to support the lumbar region of a user's back. The upper portion 256 of the second portion 246 of the front shell member 214 is connected to the upper portion 240 of the second portion 218 of the rear shell member 212 at a location 260, such as by sonic welding, an adhesive, integral molding, mechanical fasteners, and the like. The second shell member 212 and the first shell member 214 are configured so as to define a gap 262 between at least a portion of the upper portion 256 and the upper portion 240, between the mid-portion 258 and the mid-portion 242, between the lower portion 254 and the lower portion 238, between the transition portion 248 and the transition portion 230, and between the second portion 246 and the second portion 218.

The chair assembly 200 further includes a pair of laterally-extending, flexibly resilient support members, including a forward support member 262 and a rearward support member 264, each extending between the second portion 246 of the first shell member 214 and the second portion 218 of the second shell member 212. In the illustrated example, the forward support member 262 and the rearward support member 264 are integrally formed within a single spring member 266, however, the forward support member 262 and the rearward support member 264 may be formed as separate pieces, or as integral portions of the second shell member 212 and/or the first shell member 214. In the present example, the spring member 266 comprises a single sheet of metal material shaped to include the forward support member 262, the rearward support member 264, a support portion 268 attached to an underside or bottom surface 270 of the second portion 246 of the first shell member 214, and a pair of connection portions 272 extending rearwardly from the associated forward support member 262 and rearward support member 264. The connection portions 272 are secured to a spring stop member 274 which is described below. Alternatively, the connection portions 272 of the spring member 266 may be attached directly to an upper surface 276 of the second portion 218 of the second shell member 212. In the illustrated example, the connection portion 272 associated with the rearward support member 264 is attached to an upper surface of the spring stop member 274, while the connection portion 272 of the forward support member 262 is attached to and spaced from the upper surface of the spring stop member 274 by a spacer member 278 that is in turn attached to the upper surface of the spring stop member 274.

In operation, a user can move or recline the second portion 218 of the second shell member 212 and the second portion 246 of the first shell member 214 from an upright position A to a reclined position B by flexing the second shell member 212 and the first shell member 214. Movement of the second portion 218 of the second shell member 212 and the second portion 246 of the first shell member 214 from the upright position A to the reclined position B causes the first portion 244 of the first shell member 214 to move from a first position C to a rearward and reclined position D. Specifically, the first portion 216 of the second shell member 212, the first portion 244 of the first shell member 214, the forward support member 262 and the rearward support member 264 cooperate to form a flexible or deformable four-bar linkage allowing movement of the second portion 246 of the first shell member 214 to the first position C to the reclined position D. In some embodiments, the forward support member 262 and the rearward support member 264 are each more flexible than the second portion 246 of the first shell member 214, and the second portion 246 of the first shell member 214 is more flexible than the second portion 218 of the second shell member 212. In other embodiments, the various thicknesses of the links or members comprising the deformable four-bar linkage may vary so as to provide specific support and bending characteristics as previously described. It is noted that the deformable four-bar linkage does not include specific pivot assemblies and the components typically associated therewith, thereby reducing the complexity of the overall system. The spring member 266 is configured to return the four-bar linkage to the original position once the external force is removed. In the illustrated example, the forward support member 262 and the rearward support member 264 are substantially the same length, however as noted above, the connection portion 272 of the forward support member 262 is spaced from the spring stop member 274 or the upper surface 276 of the second portion 218 of the second shell member 212 by the spacer member 278, thereby effectively changing the moment arm length of the forward support member 262. As a result, the forward portion 250 of the second portion 246 of the first shell member 214 rises at a greater rate than the rearward portion 258 of the second portion 246 as the second portion 246 of the first shell member 214 is moved from the first position C to the reclined position D.

The spring stop member 274 includes a body portion 280 attached to the upper surface 276 of the second portion 218 of the second shell member 212, a forward stop portion 282 extending angularly forward and upward from the body portion 280, and a rearward stop portion 284 extending angularly rearward and upward from the body portion 280. The forward stop portion 282 is configured such that the forward support member 262 contacts the forward stop portion 282 thereby limiting the forward movement of the forward support member 262. In the illustrated example, the forward stop portion 282 is substantially flexible, thereby providing a spring effect or cushioning to the forward movement of the forward support member 262. However, the forward stop portion 282 may also comprise a substantially rigid material. The rearward stop portion 284 includes an arcuately-shaped upper end 286, and a mid-portion 288 that includes a vertically-extending slot 290. In operation, the upper end 286 is configured to abut the transition portion 248 of the first shell member 214, thereby limiting the rearward travel of the transition portion 248 with respect to the transition portion 230. In the illustrated example, the upper end 286 and the mid-portion 288 of the spring stop member 274 are flexibly resilient, so as to provide a soft-stop or cushioning to the rearward motion of the transition portion 248 to the transition portion 230.

A spacer 292 is positioned between the transition portion 230 of the second shell member 212 and the transition portion 248 of the first shell member 214. In the illustrated example, the spacer 292 includes an arcuately-shaped body portion 294 having a rearwardly-facing arcuately-shaped abutment surface 296, wherein the abutment surface 296 is complementary to the shape of the transition portion 230 of the second shell member 212. The spacer 292 further includes an arm portion 298 and a forward abutment portion 300 located at a distal end of the arm portion 298. The forward abutment portion 300 includes a forwardly-facing arcuately-shaped forward abutment surface 302 that abuts and is complementary to the shape of the transition portion 248 of the first shell member 214. The forward abutment portion 300 is secured to the transition portion 248 of the first shell member 214 by a plurality of mechanical fasteners such as bolts 304. In operation, the abutment surface 296 is spaced from the transition portion 230 of the second shell member 212 when the second shell member 212 and the first shell member 214 are in the upright position A. The abutment surface 296 moves rearwardly toward the transition portion 230 of the second shell member 212 as the second shell member 212 and the first shell member 214 are moved from the upright position A toward the reclined position B, until the abutment surface 296 abuts the transition portion 230, thereby reducing the total amount of flexure possible of the second shell member 212 and the first shell member 214 and maintaining a structural shape to the transition portion 230 and the transition portion 248. The spacer 292 further includes a stop member 306 extending upwardly from a forward end of the body portion 294 and received within the slot 290 of the mid-portion 288 of the spring stop member 274. The stop member 306 abuts an upper end of the slot 290, thereby providing a limit to the rearward recline of the second shell member 212 and the first shell member 214.

Alternatively, a chair assembly 200c (FIG. 12) may be provided with a pair of reinforcement plates that structurally support and secure the connection portion 272c of the spring member 266c to the second portion 246c of the first shell member 214a. Since the chair assembly 200c is similar to the previously described chair assembly 200, similar parts appearing in FIGS. 9-11 and in FIG. 12 respectively are represented by the same, corresponding reference numeral, except for the suffix “c” in the numerals of the latter. As illustrated, the chair assembly 200c includes an upper reinforcement or support plate 308 positioned above the connection portion 272c of the spring member 266c, and a lower or second support plate 310 positioned below the connection portion 272c of the spring stop member 274c, thereby sandwiching the connection portion 272c therebetween. The plates 308, 310 and the second portion 272c of the spring member 266c are coupled to the first portion 244c of the second shell member 214a by a plurality of mechanical fasteners such as bolts 312. The plate 308 may also be configured to support the arm assemblies 210c.

Another alternative embodiment is illustrated in FIG. 13, wherein the chair assembly 200d includes an upright stop member 314. Since the chair assembly 200d is similar to the previously described chair assembly 200, similar parts appearing in FIGS. 9-11 and FIG. 13 are respectively represented by the same, corresponding reference numeral, except for the suffix “d” in the numerals of the latter. The upright stop member 314 includes a substantially rectangular block-shaped body portion 316 having a proximal end 318 secured to the first portion 216d of the second shell member 212d, and a distal portion 320. The upright stop member 314 further includes a pair of stop members such as pins 322 extending laterally outward from the distal portion 320. As best illustrated in FIG. 13, the body portion 294d of each of the spacers 292d are spaced from the associated pins 322 when the second shell member 212d and the first shell member 214d are in the upright position. As best illustrated in FIG. 14, the spacers 292d rotate rearwardly with the transition portion 248d of the first shell member 214d until an upper surface 324 of the body portion 294d of each of the spacers 292d contacts or abuts the pins 320, thereby preventing the second shell member 212d and the first shell member 214d from further reclining.

In another alternative embodiment, a chair assembly 200e (FIG. 15) includes an alternative stop arrangement 326. In the illustrated example, the chair assembly 200e is similar to the chair assembly 200, with the most notable exception being an alteration to the rearward stop arrangement. Since the chair assembly 200e is similar to the chair arrangements 200, 200c, similar elements appearing in FIGS. 1-4 and FIG. 15 are represented by the same corresponding reference numeral, except for the suffix “e” in the numerals of the latter. The stop arrangement 326 includes a mounting member 328 fixedly secured to the first portion 216e and a stop member 330 secured to a distal end 332 of the mounting member 328. In operation, the rearward support member 264e abuts the stop member 330, thereby limiting rearward “recline” of the chair back.

In still another alternative embodiment, a chair assembly 200f (FIG. 16) includes a plurality of flexibly resilient edge members 334. Since the chair assembly 200f is similar to the previously described chair assembly 200, similar parts appearing in FIGS. 9-11 and FIG. 16, respectively are represented by the same, corresponding reference numeral, except for the suffix “f” in the numerals of the latter. In the illustrated example, the bottom or first portion 216f of the second shell member 212f provides a trough-like shape and includes sidewalls 336 and a front wall 338. The plurality of edge members 334 extend between the sidewalls 336 and/or the front wall 338 and the first portion 244f of the first shell member 214f. Each edge member 334 comprises a flexibly resilient polymer material and is positioned so as to contact an inside surface of the sidewalls 336 and/or the front wall 338 and the bottom surface of the second portion 244f of the second shell member 214f, and are secured thereto by a plurality of mechanical fasteners such as screws 340. In some embodiments, edge members 334 may be formed integrally with second shell member 212f and/or first shell member 214f. The edge members 334 may or may not be provided with a plurality of longitudinally-extending slots 342, which may alter the performance of the members. For example, increasing the number and/or size of the slots 342 may increase the flexibility of the members 334. The edge members 334 may additionally provide a surface between the second shell member 212f and the first shell member 214f to support an associated cover member (not shown), as well as to prevent access to the gap 262f between the second shell member 212f and the first shell member 214f.

The reference numeral 400 (FIG. 17) generally designates another embodiment of a seating arrangement. In the illustrated example, the seating arrangement 400 includes a cantered base assembly 402 abutting a floor surface 404, a seat assembly 406 and a back assembly 408 supported above the base assembly 402, and a pair of arm assemblies 410.

The chair assembly 10 includes a rear or second shell member 422 (FIGS. 18 and 19) and a front or first shell member 424. The shell members 422, 424 may be formed as a single integral piece or comprise multiple, individual components. In the illustrated example, the shell members 422, 424 each comprise one or more flexibly resilient polymer materials such as any thermal plastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any thermal set material, including, for example, epoxies; or any resin-based composites, including, for example, carbon fiber or fiberglass, thereby allowing each of the shell members 422, 424 to conform and move in response to forces exerted by a user. Although a polymer material is preferred, other suitable materials may also be utilized, such as metals, including, for example, steel or titanium; plywood; or a composite material including plastics, resin-based composites, metals and/or plywood. A variety of other suitable energy-storing materials may also be utilized.

The rear shell member 422 includes a horizontally-extending bottom or first portion 426, a vertically-extending upper or second portion 428 extending upwardly from the first portion 426, and a transition portion 429 extending between the first portion 426 and the second portion 428. In the illustrated example, the first portion 426 is supported by a support plate 430 that abuts a bottom surface 432 of the first portion 426, and which is in turn supported by a column 434 of the pedestal assembly 402. The second portion 428 of the rear shell member 422 includes a lower portion 436, an upper portion 438 and a mid-portion 440 located therebetween. The upper portion 438 of the rear shell member 422 is separated from the mid-portion 440 by a gap 442, thereby allowing the upper portion 438 to move independently from the mid-portion 440, as described below.

The front shell member 424 includes a first portion or seat shell member 444 and a second portion or back support member 446. The seat shell member 444 includes a forward portion 448, a rearward portion 450, an upper surface 452 configured to support a seated user, and a lower surface 454 opposite the upper surface 452. The back support member 446 includes a lower portion 456, an upper portion 458 and a mid-portion 460 located therebetween. The mid-portion 440 of the rear shell member 422 and the mid-portion 460 of the back support member 446 are coupled together by a laterally-extending rib 462 that extends forwardly from a forward surface 464 of the rear shell member 422 and rearwardly from a rearward surface 466 of the back support member 446. The rearward portion 450 of the seat shell member 444 is coupled to the second portion 428 of the rear shell member 422 by a link member 468. In the illustrated example, the link member 468 is integrally formed with both the rear shell member 422 and the seat shell member 444, however, each of these components may be formed as individual, single pieces. A lower end of the lower portion 456 of the back support member 446 extends through an aperture or slot 470 formed within the link member 468 and couples to an underside 472 of the link member 468 after passing through the aperture 470.

The seating arrangement 400 further includes a pair of laterally-extending, flexibly resilient support members including a forward support member 474 and a rearward support member 476 each extending between the seat shell member 444 and the second portion of the rear shell member 422. In the illustrated example, the support members 474, 476 are integrally formed with the seat shell member 444 and the rear shell member 422, and extend from the lower surface 454 of the seat shell member 444 to an upper surface 478 of the first portion 426 of the rear shell member 422, however each of these components may comprise individual pieces. The first portion 426 of the rear shell member 422, the seat shell member 444 and the pair of support members 474, 476 cooperate to define a deformable four-bar linkage allowing movement of the seating arrangement 400 as described below. In the illustrated example, the front support member 474 is slightly longer than the rear support member 476, the relevance of which is also described below.

In operation, a user can move or recline the second portion 428 of the rear shell member 422 from an upright position A to a reclined position B by flexing the rear shell member 422 and the front shell member 424. Movement of the second portion 428 of the rear shell member 422 from the upright position A to the reclined position B causes the seat shell member 444 to move from a first position C to a rearward and reclined position D. Specifically, the link member 468 draws the seat shell member 444 rearwardly with the second portion 428 of the rear shell member 422 as the second portion 428 of the rear shell member 422 is moved from the upright position A to the reclined portion B. As noted above, the front support member 474 is slightly longer than the rear support member 476, thereby causing the forward portion 448 of the seat shell member 444 to vertically raise at a rate slightly faster than the rearward portion 450 of the seat shell member 440 as the seat shell member 444 is moved from the first position C to the reclined position D. It is also noted that the upper portion 438 of the rear shell member 422 and the upper portion 458 of the back support member 446 tend to recline about a pivot point located forwardly of the gap 442 at a slightly greater rate than the rate of recline of the mid-portion 440 of the rear shell member 422 and the mid-portion 460 of the back support member 446 as the rear shell member 422 and the back support member 446 are moved between the upright position A and the reclined position B.

As best illustrated in FIG. 18, the mid-portion 460 of the back support member 446 may be compressed or moved separately from movement of the seat shell member 444. As noted above, a lowermost end of the lower portion 456 of the back support member 446 extends through the aperture or slot 470 of the link member 468. This configuration effectively decouples certain movements of the back support member 446 from movements of the seat shell member 444. For example, a force F may be exerted to the mid-portion 460 of the back support member 446 thereby flexing the back support member 446 rearwardly. In this instance, the position of the seat shell member 444 remains relatively constant as the back support member 446 is allowed to move within the aperture or slot 470.

In yet another embodiment, a seating arrangement 400g (FIGS. 20 and 21) includes a lowermost end of the lower portion 456g of the back support member 446g extending through the slot 470g of the link member 468g and attached to a forward surface 482 of the rear shell member 422g. Similar to the embodiment as described above, this arrangement effectively decouples movement or compression of the mid-portion 460g of the back support member 446g from movement of the seat shell member 444g, such that the back support member 446g can be compressed without moving the seat shell member 444g.

The reference numeral 500 (FIG. 22) generally designates another embodiment of a seating arrangement. In the illustrated example, the seating arrangement or chair assembly 500 includes a cantered base assembly 502 abutting a floor surface 504, a seat arrangement 506 and a back arrangement 508 each supported above the base assembly 502, and a pair of arm assemblies 510. In the illustrated example, the chair assembly 500 (FIG. 23) includes a rear or second shell member 512 and a front or first shell member 514. The shell members 512, 514 may be formed as a single, integral piece or comprise multiple, individual components. The shell members 512, 514 each comprise one or more flexibly resilient polymer materials such as any thermal plastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any thermal set material, including, for example, epoxies; or any resin-based composites, including, for example, carbon fiber or fiberglass, thereby allowing each of the shell members 512, 514 to conform and move in response to forces exerted by a user. Although a polymer material may be preferred, other suitable materials may also be utilized, such as metals, including, for example, steel or titanium; plywood; or a composite material including plastics, resin-based composites, metals and/or plywood. A variety of other suitable energy-storing materials may also be utilized.

The second shell member 512 includes a horizontally-extending bottom or first portion 516, a vertically-extending upper or second portion 518 extending upwardly from the first portion 516, and an arcuately-shaped transition portion 520 extending between the first portion 516 and the second portion 518. In the illustrated example, the first portion 516 is supported by a column 522 of the pedestal assembly 502.

The first portion 516 of the second shell member 512 includes a bottom wall 524 having a forward portion 526 and a rearward portion 528, a pair of sidewalls 530 extending angularly upward and laterally from the bottom wall 524, and a front wall 532 extending angularly upward and forwardly from the bottom wall 524. The upper or second portion 518 of the second shell member 512 includes a lower portion 534, an upper portion 536 and a mid-portion 538 located therebetween.

The rear or second shell member 512 further includes a U-shaped aperture 540 that includes a laterally-extending base portion 542 and a pair of forwardly-extending arm portions 544. In the illustrated example, the base portion 542 of the aperture 540 is positioned proximate the rearward portion 528 of the bottom wall 524 of the first portion 516 and proximate the transition portion 540, while the arm portions 544 extend forwardly from the base portion 542 and are located proximate the bottom wall 524 and proximate the sidewalls 530. The arm portions 544 angle or flare outwardly from one another from the base portion 542 to a distal end 546 of each of the arm portions 544. The second shell member 512 further includes an aperture 548 that extends from the transition portion 520 into the lower portion 534 of the second portion 518.

The first shell member 514 includes a horizontally-extending bottom or first portion 550, a vertically-extending upper or second portion 552 extending upwardly from the first portion 550, and an arcuately-shaped transition portion 554 extending between the first portion 550 and the second portion 552. The first portion 550 includes a forward portion 556 and a rearward portion 558, while the second portion 552 includes a lower portion 560, an upper portion 562, and an arcuately-shaped, forwardly convex mid-portion 564 located therebetween and configured to support the lower area of a user's back. The upper portion 562 of the second portion 552 of the first shell member 514 is connected to the upper portion 536 of the second portion 518 of the second shell member 512 at a location 566, such as by sonic welding, an adhesive, integral molding, mechanical fasteners, and the like. The second shell member 512 and the first shell member 514 are configured so as to define a gap 568 between at least a portion of the upper portion 562 and the upper portion 536, between the mid-portion 564 and the mid-portion 538, between the lower portion 560 and the lower portion 534, between the transition portion 554 and the transition portion 520, and between the second portion 552 and the second portion 518.

In operation, the second portion 518 (FIG. 25) of the second shell member 512 and the second portion 552 of the first shell member 514 are movable or reclinable from an upright position A to a reclined position B. The configuration of the U-shaped aperture 540 allows the first shell member 514 to deflect as the second shell member 512 is moved from the upright position A to the reclined position B. In the illustrated example, a portion 570 of the second shell member 512 located immediately rearwardly of the aperture adjacent to the base portion 542 of the aperture 540 travels downwardly as the second portion 518 of the second shell member 512 moves from the upright position A to the reclined position B. It is further noted that the location and configuration of the aperture 548 within the transition portion 520 and the second portion 518 of the second shell member 512 allows portions of the second shell member 512 located laterally outward of the aperture 548 to more easily flex as the second portion 518 of the second shell member 512 is moved from the upright position A to the reclined position B.

The reference numeral 500h (FIG. 26) generally designates another embodiment of a seating arrangement. Since the chair assembly 500h is similar to the previously described chair assembly 500, similar parts appearing in FIGS. 22-25 and FIG. 26 respectively are represented by the same, corresponding reference numeral, except for the suffix “h” in the numerals of the latter. In the illustrated example, the chair assembly 500h is similar to the chair assembly 500 with the most notable exception being the replacement of the aperture 548 of the chair assembly 500 with a plurality of apertures 574. The plurality of apertures 574 includes a pair of arcuately-shaped apertures 576 that extend both vertically and laterally from a first end 578 located within the lower portion 534h of the second portion 518h of the second shell member 514h, and a second end 580 located within the transition portion 520h of the second shell member 514h. As illustrated, the apertures 574 sweep downwardly and outwardly from the first ends 578 to the second ends 580. An upwardly-concave, arcuately-shaped second aperture 582 extends laterally across the transition portion 520h and includes a first end 584 and a second end 586 respectively located proximate the second ends 580 of the corresponding apertures 576. The second aperture 582 also includes a center portion 588 extending vertically upward from the arcuate portion of the second aperture 582 and along a centroidal axis of the first shell member 214h. The plurality of apertures 574 cooperate to define a pair of downwardly-extending tabs 590. The plurality of apertures 574 serve to increase the flexibility of the lower portion 534h of the second portion 518h of the second shell member 512h and the transition portion 520h as the second shell member is moved between an upright and reclined position, similar to the upright position A and the reclined position B illustrated in FIG. 25.

The reference numeral 500i (FIG. 27) generally designates another embodiment of a seating arrangement 500. Since the chair assembly 500i is similar to the previously described chair assembly 500, similar parts appearing in FIGS. 22-24 and FIG. 27 respectively are represented by the same, corresponding reference numeral, except for the suffix “i” in the numerals of the latter. The chair assembly 500i is similar to the chair assembly 500 with the most notable exception being the inclusion of an upper aperture 592 and a structural reinforcement and biasing assembly 594. In the illustrated example, the upper aperture 592 extends across and comprises the majority of the upper portion 536i of the second portion 518i of the second shell member 512i and extends downwardly into the mid-portion 538i of the second portion 518i of the second shell member 512i. The structural reinforcement and biasing assembly 592 includes a flexibly resilient rod 596 extending vertically between the upper portion 536i and a mounting plate 598. In the illustrated example, an upper end 600 of the rod 596 is attached to the upper portion 536i of the second portion 518i of the second shell member 512i by a mechanical fastener 602, while a second end 604 of the rod 596 is attached to the mounting plate 598 positioned either above or below the bottom wall 524i of the first portion 516i of the second shell member 512i. The rod 596 may also be attached along the length thereof to the mid-portion 538i of the second portion 518i of the second shell member 512i by a mechanical fastener 606. In operation, the rod 596 serves to structurally reinforce the second portion 518i of the second shell member 512i as well as to bias the second portion 518i of the second shell member 512i from a reclined position to an upright position, similar to the reclined position B and upright position A illustrated in FIG. 25.

The reference numeral 500j (FIG. 28) generally designates yet another embodiment of a seating arrangement 500. Since the chair assembly 500j is similar to the previously described chair assembly 500, similar parts appearing in FIGS. 22-24 and FIG. 28 respectively are represented by the same, corresponding reference numeral, except for the suffix “j” in the numerals of the latter. The chair assembly 500j is similar to the chair assembly 500 with the most notable exception being the inclusion of a structural reinforcement and biasing assembly 608. The structural reinforcement and biasing assembly 608 includes a pair of generally L-shaped, flexibly resilient biasing members 610 each having a generally horizontally-extending first portion 612 and generally vertically-extending second portion 614. Each first portion 612 includes a downwardly-turned distal end 616 welded to an attachment plate 618 that is secured to a support plate 620 that is in turn secured to the first portion 516j of the second shell member 512j by a plurality of mechanical fasteners such as bolts 622. A distal end 624 of the second portion 614 of each of the biasing members 610 is attached to the mid-portion 538j of the second portion 518j of the second shell member 512j by a plurality of mechanical fasteners such as bolts 626. In operation, the biasing members 610 serve to structurally reinforce the second portion 518j of the second shell member 512j as well as to bias the second portion 518j of the second shell member 512j from a reclined position and to an upright position, similar to the reclined position B and the upright position A illustrated in FIG. 25.

The structural reinforcement and biasing assembly 608 further includes a tilt limiting arrangement 630 (FIG. 29) that limits the rearward recline range of the second portion 518j of the second shell member 512j. Each biasing member 610 further includes an arcuately-shaped transition portion 632 positioned between the first portion 612 and the second portion 614. Each transition portion 632 includes an arcuately-shaped, downwardly and forwardly extending abutment or stop member 634. In operation, the ends of the stop members 634 are spaced from a stop plate 636, attached to the support plate 620, when the second portion 518j of the second shell member 512j is in the upright position. During recline, the ends of the stop members 634 contact or abut the stop plate 636 thereby limiting the rearward recline of the second portion 518j of the second shell member 512j.

The reference numeral 700 (FIG. 30) generally designates another embodiment of a seating arrangement. In the illustrated example, the seating arrangement or chair assembly 700 includes a cantered base assembly 702 abutting a floor surface 704, a seat assembly 706 and a back assembly 708 each supported above the base assembly 702, and a pair of arm assemblies 710. In the illustrated example, the chair assembly 700 (FIG. 31) includes a front or a first shell member 714 and a rear or second shell member 712. The shell members 712, 714 may be formed as a single, integral piece or comprise multiple, individual components. In the illustrated example, the first shell member 714 includes a single, integral piece, while the second shell member 712 includes a two-piece construction as described below. The shell members 712, 714 each comprise a flexibly resilient polymer material such as any thermal plastic, including, for example, nylon, glass-filled nylon, polypropylene, acetyl, or polycarbonate; any thermal set material, including, for example, epoxies; or any resin-based composites, including, for example, carbon fiber or fiberglass, thereby allowing each of the shell members 712, 714 to conform and move in response to forces exerted by a user. Although a polymer material is preferred, other suitable materials may also be utilized, such as metals, including, for example, steel or titanium; plywood; or a composite material including plastics, resin-based composites, metals and/or plywood. A variety of other suitable energy-storing materials may also be utilized.

The rear shell member 712 includes a horizontally-extending bottom or first portion 716, a vertically-extending upper or second portion 718 extending upwardly from the first portion 716, and an arcuately-shaped transition portion 720 extending between the first portion 716 and the second portion 718. In the illustrated example, the rear shell member 712 comprises a two-part construction having a first portion 722 and a second portion 724 each having one portion of a lap joint 726. Specifically, the lap joint 726 includes a first portion 728 integral with the first portion 722 of the rear shell member 712 and a second portion 730 integral with the second portion 724 of the rear shell member 712, where the first portion 722 and the second portion 724 each cantilever and overlap with one another to form the lap joint 726. In assembly, a column 732 (FIGS. 31 and 34) of the pedestal assembly 702 is received through an aperture 734 of the first portion 722 and an aperture 736 of the second portion, and the first portion 728 and the second portion 730 of the lap joint 726 are held in connection by a lower coupler 738 and an upper coupler 740 as described below. It is noted that while the embodiment illustrated in FIG. 32 shows a two-piece rear shell member 712, alternate embodiments may include more than two pieces, or an integral, single-piece construction.

The front shell member 714 (FIGS. 31 and 35) includes a horizontally-extending bottom or first portion 744, a vertically-extending upper or second portion 746 extending upwardly from the first portion 744, and an arcuately-shaped transition portion 748 extending between the first portion 744 and the second portion 746. The first portion 744 includes a forward portion 750 and a rearward portion 752, while the second portion 746 includes a lower portion 754, an upper portion 756 and an arcuately-shaped, forwardly convex mid-portion 758 located therebetween and configured to support the lumbar region of a user's back. An intermediate portion 759 of the second portion 746 of the front shell member 714 located between the upper portion 756 and the mid-portion 758 is connected to an upper portion 761 of the second portion 718 of the rear shell member 712, such as by sonic welding, an adhesive, integral molding, mechanical fasteners, and the like. The rear shell member 712 and the front shell member 714 are configured so as to define a gap 762 therebetween.

The front shell member 714 further includes a pair of laterally-spaced slots 764 extending in a fore-to-aft direction from a mid-portion of the second portion 746 to the intermediate portion 759 of the second portion 746, with the fore end of each slot 764 ending in an aperture 766, thereby dividing the front shell member 714 into an inner portion 768 and outer portion 770. The division of the inner portion 768 from the outer portion 770 allows the inner portion 768 to flex separately from the outer portion 770 during recline of the back assembly 708 from an upright position A to a recline position B. As best illustrated in the FIGS. 36A and 36B, the flexing of the front shell member 714 during recline is such that the inner portion 768 flexes less than the outer portion 770 such that the outer portion 770 descends relative to the inner portion 768, thereby allowing additional flexibility in the front shell member 714 while providing adequate support for the seated user via the inner portion 768. The differentiation of flexure of the inner portion 768 and the outer portion 770 causes the second portion 746 of the front shell member 714 to move from the reclined position toward the upright position and exert an increased pressure to the back of a seated user as the force exerted on the inner portion 768 is increased, such as the force exerted by the weight of a seated user.

The front shell member 714 (FIGS. 35 and 37) further includes a pair of C-shaped reliefs or apertures 772 each defining a tab 774. Each tab 774 has a laterally-extending flexing region 776 of relatively reduced thickness thereby promoting flexure of each tab 774 in this region as described below.

The chair assembly 700 (FIGS. 30 and 31) further includes a pair of laterally-extending support members or linkage members, including a forward support or linkage member 778 and a rearward support or linkage member 780, each extending between the second portion 746 of the forward shell member 714 and the second portion 716 of the rear shell member 712. In the illustrated example, the forward support member 778 is flexibly resilient along the length thereof, while the rearward support member 780 is relatively rigid. The forward support member 778 is integrally formed within the back shell member 716 and rigidly attached to the front shell member 714, while the rearward support member 780 is rigidly attached to the rear shell member 712, however, the forward support member 778 and the rearward support member 780 may be formed as separate pieces, or as integral portions of the rear shell member 712 and/or the front shell member 714. Further, in the illustrated example, the inner portion 768 cooperates with the forward support member 778 and the rearward support member 780 to form a control mechanism that synchronizes the rearward movement of the first portion 744 of the front shell member 714 with reclining movement of the second portion 746 of the front shell member 714 as further described below.

In the present example, the first portion 716 (FIGS. 34, 37) of the rear shell member 712 includes a laterally-extending flexing region 782 of relatively reduced thickness located fore of the attachment location of the rearward support member 780 with the rear shell member 712. The forward support member 778 includes a laterally-extending flexing region 784 of relatively reduced thickness located at a lower end of the forward support member 778 such that flexure of the forward support member 778 is concentrated in the flexing region 782 while the remainder of the forward support member may be relatively rigid and may remain relatively straight. The forward support member 778 connects to each of the tabs 774 aft of the flexing region 776. Referring to FIGS. 36A and 36B, it is noted that the rearward support member 780 remains rigid during recline, while the second portion 746, the first portion 716 and the forward support member 778 flex, with the flexing regions or flexing zones 776, 782, 784 flexing a greater amount than the remainder of each of the associated components. As previously noted, the various thicknesses of the linkages or members comprising the overall supporting four-bar linkage may be varied so as to provide specific support and bending characteristics previously described. It is further noted that this configuration provides adequate flexure to the front shell member 714 while allowing an outer perimeter edge 785 of the front shell member to remain continuous and without breaks or reliefs, thereby providing a continuous aesthetic edge, while simultaneously reducing or eliminating wear of a supported cover assembly 787 (FIGS. 30 and 34) typically caused by repeated flexing of a supporting chair surface. In the illustrated example, the cover assembly 787 includes a flexible resilient substrate layer 791 supported by the front shell member 714 and comprising a thermal plastic, a foam layer 793 molded to the substrate layer 791, and a fabric cover 795 thermally set to the foam layer 793. Alternatively, the fabric cover may be wrapped about the foam layer 793 and secured to an underside of the substrate layer 791 by separate mechanical fasteners such as staples (not shown) or to integral fasteners (not shown) integrally molded with the substrate layer 791, and/or secured about the foam layer 793 and the substrate layer 791 by a drawstring arrangement (not shown). In the illustrated example, the foam layer 793 and the fabric cover 795 are both continuous and free from irregularities along the edges thereof, such as apertures, reliefs, cut-outs, stitching, pleats, and the like. In an alternative embodiment, the continuous outer perimeter edge 785 of the front shell member 714 may provide an uninterrupted edge about which to wrap the fabric cover 795. In another alternative arrangement, a separate outermost shell (not shown) comprising a molded thermal plastic may replace the cover assembly 787 and provide an outer, user supporting surface eliminating the need for a fabric-type cover.

The chair assembly 700 further includes a recline stop arrangement 790 (FIG. 34). In the illustrated example, the stop arrangement 790 includes a stop member 792 (FIG. 38) having a cylindrical body portion 794 that receives an upper end of the column 732 therein, a flange 796 that extends about the body portion 794 and that cooperates with the lower coupler 738 to couple the first portion 722 and the second portion 724 of the rear shell member 712 together such that the stop member 792 functions as the upper coupler 740 as previously described, and a stop arm 798 extending rearwardly from the body portion 794. The stop arm 798 extends through an aperture 802 in a front wall 804 of the rearward support member 780 such that a pair of stops 800 located at a distal end of the stop arm 798 are located within an interior space or cavity 806 of the rearward support member 780 defined between the front wall 804 and a rear wall 808.

Alternatively, the aperture 802 and the interior space may be lined with a plastic bushing member 809. The stop arm 798 and stops 800 cooperate to form a control rod. In operation, the rearward recline of the back assembly 708 from the upright position A toward the reclined position B is limited by the stops 800 abutting the rear wall 808, while a forward tilting of the chair back 708 from the reclined position B toward the upright position A is limited by the stops 800 abutting the front wall 804. It is noted that the present configuration provides a relatively open chair structure such that the components comprising the four-bar linkage, the arm support structure and portions of the recline limiting arrangement are viewable, while the abutting stop components are concealed from view and within the existing supporting structures and specifically a component of the four-bar linkage. As best illustrated in FIGS. 30 and 39, the arm support members 820 are integral with and supported by a cover portion 822 configured to aesthetically cover the stop arrangement 792. The arm support members 820 and cover portion 822 may be removed from the chair assembly 700 and alternatively replaced with a cover member 824, thereby providing an armless embodiment of the chair assembly on the same underlying platform.

Alternatively, the arm assemblies 710, the arm support members 820 and the cover portion 822 may be replaced by an accessory supporting arrangement 830 (FIG. 40) that includes a support portion 832 configured as a housing to aesthetically cover the stop arrangement 792, and a chair accessory such as an arm assembly 834, or a leg assembly 836 configured to support the chair assembly 700 above a floor surface in place of the support assembly 702. While an arm assembly 834 and a leg assembly 936 are provided as examples, other chair accessories are also contemplated, such as tablet supports, work surfaces, beverage holders, and the like. In the illustrated example, the support portion 832 includes the first portion 838 of a releasable coupling arrangement, while the accessory includes the second portion 840 of the coupling arrangement, thereby allowing multiple accessories to be interchangeably supported from the same underlying support structure.

The reference numeral 900 (FIG. 41) generally designates another embodiment of a seating arrangement. In the illustrated example, the seating arrangement or chair assembly 900 is similar to the chair assembly 700 previously described with the most notable exceptions being the inclusion of a first structural reinforcement member 902, a second structural reinforcement member 904, and the construction of the front shell member 914 via a multi-layer over-molding process. In the illustrated example, the chair assembly 900 includes the front or first shell member 914, and a rear or second shell member 912, where the front shell member 914 is covered by a substrate layer 905 and a fabric cover assembly 907.

The rear shell member 912 is similar to the rear shell member 712 of the chair assembly 700 and includes a horizontally-extending bottom or first portion 916 (FIG. 42), a vertically-extending upper or second portion 918 extending upwardly from the first portion 916, and an arcuately-shaped transition portion 920 extending between the first portion 916 and the second portion 918. In the illustrated example, the rear shell member 912 comprises an integral, single-piece construction. In assembly, a pneumatic height adjustable column 932 is received through an aperture 934 of the rear shell member 912.

The front shell member 914 (FIGS. 41 and 42) includes an outer shell member 922 having a horizontally-extending bottom or first portion 944, a vertically-extending upper or second portion 946 extending upwardly from the first portion 944, and an arcuately-shaped transition portion 948 extending between the first portion 944 and the second portion 946. The first portion 944 includes a forward portion 950 and a rearward portion 952, while the second portion 946 includes a lower portion 954, an upper portion 956 and an arcuately-shaped, forwardly convex mid-portion 958 located therebetween and configured to support the lumbar region of a user's back. The front shell member 914 further includes a pair of laterally-spaced slots 964 extending in a fore-to-aft direction similar to the slots 764 of the chair assembly 700 as previously described.

The front shell member 914 further includes an inner shell portion 924 having a horizontally-extending bottom or first portion 960, a vertically-extending upper or second portion 962, and an arcuately-shaped transition portion 964 extending between the first portion 960 and the second portion 962. In assembly, the inner shell portion 924 is over-molded over the outer shell member 922 such that the inner shell portion 924 covers or overlaps with at least a portion of the bottom portion 944, the upper portion 946 and transition portion 948. The inner shell portion 924 is preferably positioned with respect to the outer shell member 922 such that the inner shell portion 924 covers the apertures 964 of the outer shell member 922. Preferably, the inner shell portion 924 comprises a material that is more flexible than the material from which the outer shell member 922 is constructed, more preferably the inner shell portion 924 and outer shell member 922 each comprise a thermoplastic polymer, and most preferably, the outer shell member 922 comprises polyethylene terephthalate or polybutylene terephthalate, and the inner shell portion 924 comprises a thermoplastic polyolefin.

The chair assembly 900 further includes the structural reinforcement member 902 located in the transition portion 948 of the front shell member 914. In the illustrated example, the structural reinforcement member 902 is arcuately-shaped to match the arcuate shape of the transition portion 948. The reinforcement member 902 comprises a relatively stiff material, such as metal, and extends through the transition portion 948, such that the reinforcement member 902 prevents the angle between the bottom portion 944 and the upper portion 946 from increasing as the upper portion 946 is moved from the upright position to the reclined position, thereby concentrating compliance or bending in the control arrangement forward of the transition portion 948.

The chair assembly 900 further includes the structural reinforcement member 904 extending between the tabs 972 that are similar to the tabs 774 of the chair assembly 700. The reinforcement member 904 overlaps with an area of the bottom portion 944 of the shell member 914 so as to disperse forces transmitted between the rear shell 912 and the front shell 914 in the vicinity of the tabs 972.

A seating arrangement embodiment is illustrated in a variety of views, including a top perspective view (FIG. 43), a front perspective view (FIG. 44), a rear perspective view (FIG. 45), a front elevational view (FIG. 46), a rear elevational view (FIG. 47), a first side elevational view (FIG. 48), a second side elevational view (FIG. 49), a top plan view (FIG. 50) and a bottom plan view (FIG. 51).

Another seating arrangement embodiment is illustrated in a variety of views, including a top perspective view (FIG. 52), a front perspective view (FIG. 53), a rear perspective view (FIG. 54), a front elevational view (FIG. 55), a rear elevational view (FIG. 56), a first side elevational view (FIG. 57), a second side elevational view (FIG. 58), a top plan view (FIG. 59) and a bottom plan view (FIG. 60). The seating arrangement embodiments illustrated in FIGS. 43-60 may include all, some or none of the features shown and described herein.

It is noted that in each of the aforedescribed embodiments, the seating arrangement is configured such that some, many, or all of the components may be visible from an exterior of the seating arrangements subsequent to the seating arrangements being completely manufactured and assembled, such that the visible components form an outer aesthetic appearance of the seating arrangement, or alternatively may be enclosed within an interior of the chair assembly such that the components are not visible to the casual observer. Specifically, components such as the forward support member, the rearward support member, the support member, as well as the stop arrangements as described are at least partially visible from an exterior of the chair, and cooperate to form an overall outer aesthetic thereof. Certain embodiments may include some, many, or all of the components described herein. For example, an embodiment may include one or more apertures, one or more of the stop systems, and/or components or materials selected for performance purposes, e.g., to bias the seat arrangement to an upright position or for material strength requirements. In some embodiments, a selection of a particular component may influence the selection of various other components. For example, using a particular aperture or apertures may dictate what type of components or materials should be used for performance purposes and vice versa.

Various embodiments of the seating arrangements described herein may provide a platform with the proper fit and function for comfortably supporting a seated user that may also reduce or shift costs, for example by reducing associated part counts, manufacturing costs, and labor costs. Certain aspects of the seating arrangements may include an uncomplicated, durable, and visually appealing design capable of a long operating life, and particularly well adapted for the proposed use.

In the foregoing description, it will be readily appreciated by those skilled in the art that modifications may be made to the described embodiments without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.

Claims

1. A seating arrangement, comprising: a base; anda back arrangement and a seat arrangement each supported via the base on a linkage arrangement, wherein the back arrangement is moveable between a generally upright position and a reclined position;the linkage arrangement comprising: a horizontally-extending first link member comprising at least a portion of the seat arrangement, the first link member including a forward portion and a rearward portion;a second link member supported on the base;a pair of flexibly resilient front link members extending between the forward portion of the first link member and a forward portion of the second link member, the front link members being a single, integral piece with the second link member; anda rigid rear link member extending between the rearward portion of the first link member and the second link member, the rear link member including a separate piece from the first link member or the second link member;wherein the rearward portion of the first link member extends fore-to-aft in a first plane when the back arrangement is in the generally upright position, and the rearward portion of the first link member extends fore-to-aft in a second plane when the back arrangement is in the reclined position, wherein the second plane is angled with respect to the first plane, and wherein the rearward portion of the first link member is positioned farther away from the base when the back arrangement is in the reclined position than when the back arrangement is in the generally upright position.

2. The seating arrangement of claim 1, wherein a majority of a length of the flexibly resilient front links flex when the back arrangement moves from the upright position to the reclined position.

3. The seating arrangement of claim 1, wherein a gap extends between the first link member and the second link member.

4. The seating arrangement of claim 3, wherein the arrangement further includes an armrest assembly that is connected to the linkage arrangement within the gap.

5. The seating arrangement of claim 1, wherein the back arrangement is coupled to the base through the second link member.

6. The seating arrangement of claim 1, wherein the seating arrangement further includes a stop member assembly configured to limit movement of the back arrangement between the substantially upright position and the reclined position.

7. The seating arrangement of claim 6, wherein a portion of the stop member assembly is visible from an exterior of the seating arrangement.

8. The seating arrangement of claim 6, wherein the stop member assembly includes a tilt stop that is coupled to the base.

9. The seating arrangement of claim 6, wherein the stop member assembly engages the second link member and the rear link member.

10. The seating arrangement of claim 1, wherein the first link member, second link member, front link members, and rear link member cooperate to define a pass-through therebetween.

11. The seating arrangement of claim 1, wherein the first, second, front and rear link members cooperate to define a four-bar linkage assembly.

12. The seating arrangement of claim 1, wherein the rear link member is fixedly connected to a portion of the back arrangement to move therewith.

13. The seating arrangement of claim 1, wherein the first link member moves upwardly and rearwardly with respect to the base as the back arrangement moves from the upright position to the reclined position.

14. The seating arrangement of claim 1, wherein the second link member and the first link member comprise the same material.

15. A seating arrangement, comprising: a base;a back arrangement and a seat arrangement each supported via the base on a linkage arrangement, the back arrangement including a vertically-extending back portion and a forwardly-extending portion, the back arrangement moveable between a generally upright position and a reclined position where the back arrangement and the seat arrangement are coupled to the base at a first position;the linkage arrangement comprising:a horizontally-extending first link member comprising at least a portion of the seat arrangement;a second link member supported on the base having a longitudinally-extending axis;a pair of flexibly resilient front link members extending between the forward portion of the first link member and a forward portion of the second link member; anda rigid rear link member extending between the first link member and the second link member and having a second longitudinally-extending axis, where the rear link member is non-pivotably coupled to the second link member, wherein the rear link member and the forwardly-extending portion of the back arrangement are non-pivotally fixed together such that an angle therebetween remains constant as the back arrangement moves between the generally upright and reclined positions, and wherein the rigid rear link member is coupled to the first link member at a second position that is located entirely rearward of the first position.

16. The seating arrangement of claim 15, wherein the rear link extends forwardly from the second link member to the first link member.

17. The seating arrangement of claim 15, wherein the front link member extends forward from the second link member to the first link member.

18. The seating arrangement of claim 15, further comprising: an arm assembly that includes a support, a pair of arm support members extending laterally outward from the support, and a pair of arm pads supported by the arm support members, and wherein the support is centrally located across a width of the seating arrangement.

19. The seating arrangement of claim 15, further comprising: an arm assembly that includes a pair of arm support members and a pair of arm pads supported by the arm support members, wherein the arm support members wrap about laterally spaced outer edges of the seat arrangement from positions located beneath the seat arrangement.

20. The seating arrangement of claim 15, wherein the first link member, the second link member, the front link members and the rear link member cooperate to define a pass-through therebetween.

21. The seating arrangement of claim 20, further comprising: an arm assembly supported between the first link member and the second link member.

22. A seat and back arrangement to be positioned on a surface, the seat and back arrangement comprising: a seat member;a back member; anda four-bar assembly, comprising: a substantially rigid bottom link having a front end and a rear end, a portion of the bottom link configured to be grounded with respect to the surface;a top link having a front end and a rear end, a portion of the top link configured to support a front portion of the seat member, the top link including a left side and a right side;a rear link extending between the rear end of the bottom link and the rear end of the top link, the rear link including a top end and a bottom end, the top end connected to a rear portion of the top link wherein the rear link member is substantially rigid along an entire length thereof;a first articulation location between the rear end of the bottom link and the bottom end of the rear link, wherein outer side edges of the rear link are located between and spaced inwardly from the left and right sides of the top link in a lateral direction;a second articulation location between the rear end of the top link and the top end of the rear link;a front link assembly including a left front link and a right front link, the left front link connecting the front end of the bottom link to the front end of the top link at the left side of the top link, and the right front link connecting the front end of the bottom link to the front end of the top link at the right side of the top link, wherein both the left front link and right front links are flexible along a length thereof, and wherein the front link assembly is integrally formed with the bottom link; andwherein the rear link is non-pivotally connected to the back member to move therewith.

23. A seating arrangement that comprises the seat and back arrangement of claim 20, and further comprising: an armrest that includes an armrest support member having vertically-extending portions disposed along outer lateral sides of the seat arrangement.

24. The seating arrangement of claim 23, wherein the armrest support member includes at least one laterally-extending cross-member positioned between the bottom link and the top link.

25. The seating arrangement of claim 24, wherein the vertically-extending portions extend forwardly from the cross-member.

26. A seating arrangement, comprising: an upwardly extending back arrangement movable between an upright position and a reclined position; anda seat arrangement, comprising: a first link member that includes a substantially horizontal portion, the substantially horizontal portion having a forward portion and a rearward portion and configured to support a seated user thereon;a second link member spaced from the first link member;a third link member operably coupled to the forward portion of the substantially horizontal portion of the first link member and to the second link member, the third link member being substantially flexible along a majority of a length thereof; anda fourth link member having a first end connected to the rearward portion of the substantially horizontal portion of the first link member and a second end connected to the second link member, the fourth link member being substantially rigid along a majority of a length of the fourth link member; andwherein the first link member, the second link member, the third link member and the fourth link member cooperate to form a linkage arrangement, and wherein the seat arrangement moves in a rearward direction as the back arrangement is moved between the upright position and the reclined position, wherein the first and second ends of the fourth link member are spaced a first distance from one another when the back arrangement is in the upright position and at a second distance from one another when the back arrangement is in the reclined position, wherein the first and second distances are substantially the same, and wherein the third link member flexes along the length of the third link member and the fourth link member remains generally straightand unrotated relative to at least a portion of the back arrangement as the back arrangement moves between the upright and reclined positions.

27. The seating arrangement of claim 26, wherein the back arrangement includes a back portion extending upwardly and rearwardly from the second link member and configured to support a back of the seated user.

28. The seating arrangement of claim 27, wherein the seating arrangement further includes a curved transition portion between the second link member and the back portion, wherein the second end of the fourth link member is connected to the second link member at a position forward of the transition portion.

29. The seating arrangement of claim 27, wherein the second link member, the back portion and the transition portion are an integral, single piece.