Patent Application
20240099464
This invention relates to a chair and related components. More particularly, the invention relates to a rocking mechanism and/or to a seat shell with a compliant structure and/or to a recline mechanism.
Many existing rocking and reclining chairs have bulky mechanisms to provide the rocking or the reclining motion. Such mechanisms can be unsightly, or are aesthetically more acceptable in pedestal-type task chairs than in household chairs such as dining chairs.
Dining chairs are traditionally upright, rigid chairs, with four legs, often chosen for their aesthetic appeal. Such chairs typically provide very little ergonomic support to an occupant. In addition to meal-time use, household dining chairs are often used for extended periods of time by household members, for example for working at a laptop at the table, making ergonomic support desirable.
Further, complex mechanisms of the type found in task chairs can be prohibitively expensive to apply to household chairs such as dining chairs and other chairs that are bought in large numbers such as meeting chairs, where the purchase of multiple chairs is necessary and a lower cost is desirable.
In this specification where reference has been made to patent specifications, other external documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.
It is an object of at least preferred embodiments of the present invention to address at least one of the disadvantages outlined above and/or to at least provide the public with a useful alternative.
In accordance with a first aspect of the present invention, there is provided a chair support shell comprising an integral back portion, seat portion, and joining portion between the back portion and the seat portion. At least a major portion of the support shell comprises a compliant structure. The compliant structure has a plurality of cells interconnected by a plurality of resilient members. The compliant structure provides compliance in the seat portion, compliance in the back portion, and compliance in the joining portion. The compliant structure enables recline of the back portion relative to the seat portion.
In an embodiment, the cells and the resilient members define a plurality of voids. In an embodiment, the voids are Y-shaped. The Y-shaped voids may be provided in a series of offset rows and/or columns. Alternatively, the voids may be a different shape.
In an embodiment, the cells are substantially triangular, for example, equilateral, scalene, or isosceles triangles in plan view. A plurality of the resilient members may extend from each cell. In an embodiment, three of the resilient members extend from each cell. For example, three of the resilient members may extend from each corner of a triangular cell at approximately 120 degrees to each other.
An occupant-facing surface of the cells may have a recess. Additionally or alternatively, the non occupant-facing surface of the cells may comprise a recess. The recess in the non-occupant-facing surface may be deeper than the recess in the occupant-facing surface.
The resilient members may be substantially straight or they may be curved. The thickness of the resilient members may be constant or may vary, and may have a filet/radius where they join the cells.
In an embodiment, the cells and resilient members together define an auxetic structure; that is, a structure having a negative Poisson's ratio. In such an embodiment, the auxetic behaviour is in the plane of the structure.
In an embodiment, the support shell is configured to cause deformation of the joining portion, as the back portion is reclined. The support shell may, for example, be configured to cause contraction and/or extension of the joining portion in a first direction and/or a second orthogonal direction, as the back portion is reclined. The support shell may be configured to cause contraction and/or extension of the joining portion in both the first direction and second orthogonal direction, as the back portion is reclined.
In an alternative embodiment, the back portion may not be reclinable relative to the seat portion. In that embodiment, the compliant structure may be provided soley to provide compliance and occupant comfort in the seat portion, back portion, and/or the joining portion between the seat portion and back portion.
In an embodiment, the support shell comprises a single piece of injection moulded plastic.
The support shell may comprise a solid perimeter portion that is substantially non-compressible and substantially non-extendible, such that a length of the perimeter is substantially unchanged as the back portion reclines or flexes, or as the seat portion flexes. The solid perimeter could extend around the entire perimeter of the shell or could only extend around a portion of the perimeter of the shell.
In an embodiment, the compliant structure comprises resilient members of differing thicknesses, the thicknesses being selected to provide regions of greater and/or lesser compliance within the compliant structure. In such an embodiment, thicker resilient members are provided in regions where less compliance is desirable and thinner resilient members are provided in regions where more compliance is desirable. Alternatively or additionally, the compliant structure may comprise resilient members of differing lengths, the lengths being selected to provide regions of greater and lesser compliance in the compliant structure. In such an embodiment, shorter resilient members are provided in regions where less compliance is desirable and longer resilient members are provided in regions where more compliance is desirable.
The shell may comprise solid, substantially non-compressible attachment regions for attachment to a chair support structure. For example, for attachment to a back support, seat support, transom, or base. The solid attachment regions may comprise areas of the compliant structure where the voids are ‘filled in’. Additionally or alternatively, the shell may comprise structural regions for other purpose(s). For example, the structural regions may comprise solid regions or relatively stiff regions, to provide reduced compliance in the structural regions. The structural regions may be solid and/or may be relatively thick. The structural regions may comprise lifting regions or straps to assist with lifting the seat portion as the back portion is reclined and/or may comprise regions to provide occupant support.
In accordance with a second aspect of the present invention, there is provided a chair comprising the support shell as described above in relation to the first aspect.
The chair may comprise a chair support structure and a recline mechanism coupling the back portion of the shell to the chair support, the recline mechanism facilitating recline of the back portion relative to the chair support structure. Part of the total recline of the back portion of the shell may be provided by the compliance and flex in the support shell, and part of the recline may be provided by the recline mechanism.
In an embodiment, the chair further comprises a rocking mechanism that couples the seat portion of the shell to the chair support to facilitate rocking motion of the shell relative to the chair support.
An occupant-facing surface and/or an opposite surface of the support shell may be upholstered.
In accordance with a third aspect of the present invention, there is provided a chair comprising a support shell having a seat portion and a back portion, a transom, and a recline mechanism. The recline mechanism comprises: a resilient front support member having a first end operatively attached to the transom and a second end operatively attached to a front part of the seat portion; and a back support arm having a lower end operatively rigidly attached to the transom, an upper end operatively rigidly attached to the back portion, and a flex region having a rearward flexibility that is greater than the rearward flexibility of the rest of the back support arm. The back portion is reclinable relative to the seat portion and a rear part of the seat portion is configured to lift as the shell back portion reclines.
In an embodiment, the back support arm is attached to a lumbar and/or upper portion of the back portion. The chair may comprise a single back support arm, two back support arms, or more than two back support arms.
In an embodiment, the recline mechanism comprises two resilient front support members. The front support member second ends may be positioned more laterally outward than the first ends. The recline mechanism may comprise a single front support member, two front support members, or more than two front support members.
In an embodiment, the back support arm flex region(s) comprise a series of transverse notches or slots, said notches or slots providing the greater rearward flexibility. The notches or slots may be provided on a front side of the back support arm(s). In an alternative embodiment, portion(s) of the back support arm may comprise thinned or necked region(s) to provide the greater rearward flexibility.
In an embodiment, the back support arm upper end(s) is/are operatively rigidly attached to a lumbar portion of the back portion. Alternatively, the back support arm upper end(s) may be rigidly attached to the upper portion of the back portion. The back support arm(s) may be integral with back portion of shell, or may be a separate member mechanically attached to the back shell.
The back support arm may be directly bolted or otherwise attached to the transom, or it may be attached via a back arm or transom extension. In an alternative form, the back support arm may be integrally moulded with the transom.
In an embodiment, the seat lift is partially controlled by a length and stiffness of the front support member(s).
In an embodiment, at least a major portion of the support shell comprises a compliant structure, the compliant structure having a plurality of cells interconnected by a plurality of resilient members. The compliant structure, in combination with the support arms, may enable recline of the back portion relative to the seat portion.
The chair may comprise the support shell as described above in relation to the first aspect.
In accordance with a fourth aspect of the present invention, there is provided a chair comprising a base, a transom supported on the base, a seat portion and a back portion supported on the transom, and a rocking mechanism configured to enable the transom to rock forward and rearward relative to the base. The rocking mechanism comprises a concave rock surface provided on the base; a convex rock surface operatively provided on the transom and arranged to be in rolling contact with the concave rock surface, the convex rock surface having a radius of curvature less than a radius of curvature of the concave rock surface; and complementary engagement features operatively provided on the transom and on the base.
In an embodiment, the rocking mechanism comprises at least one biasing member acting between the transom and the base to bias the transom to a neutral position, wherein the transom can be rocked forwards and/or rearwards from the neutral position. In an alternative embodiment, the biasing member(s) may not be provided, and the transom may return to the neutral position under the influence of gravity and/or the weight of a chair occupant.
In an embodiment, the engagement features comprise at least one tooth provided on one of the base and the transom, and a complementary recess or teeth provided on the other one of the transom, wherein the tooth is seated in the complementary recess or between the teeth when the transom is in a neutral position, and configured such that rocking the transom forwards or rearwards moves the tooth away from its seated position.
In an embodiment, the engagement features comprise a plurality of teeth provided on one of the base and the transom, and complementary recesses and/or teeth provided on the other one of the base and the transom. In an embodiment, at least one of the teeth is seated in a complementary recess and/or between the teeth when the transom is in a neutral position, and configured such that rocking the transom forward or rearwards moves the at least one of the teeth away from its seated position. The teeth may be provided by a gear on the transom, and the recesses and/or teeth may be provided by a curved array of recesses and/or teeth on the base, the gear being in rolling contact with the curved array of recesses and/or teeth. In an embodiment, the convex rock surface is adjacent the gear and the concave rock surface is adjacent the curved array of recesses and/or teeth.
The gear may be a spur gear. Alternatively, other types of tooth profile or gear could be used.
The curved array of recesses and/or teeth may be provided by a curved rack.
In an embodiment, the rocking mechanism comprises two laterally spaced coaxial gears and two respective laterally spaced curved arrays of recesses and/or teeth. Such an embodiment may further comprise two convex rock surfaces and two concave rock surfaces, each concave and convex rock surface being adjacent to a respective one of the gears or curved arrays of recesses and/or teeth.
In an embodiment, the spur gear is a partial spur gear. In an embodiment, the spur gear teeth have varying profiles. Alternatively the teeth profiles may all be the same. In an embodiment, the spur gear teeth have an involute profile to encourage rolling contact between teeth.
The or each convex rock surface may have a radius of curvature that is substantially the same as a pitch radius of the spur gear(s), and the or each concave rock surface may have a radius of curvature that is substantially the same as a pitch radius of the curved array(s) of recesses and/or teeth.
In an embodiment, the convex rock surface(s) is/are concentric with the spur gear(s), and the concave rock surface(s) is/are concentric with the curved rack(s).
In an embodiment, a forward portion of the gear(s) is substantially in line with a rear portion of the gear(s), and a forward portion of the curved array(s) of recesses and/or teeth is substantially in line with a rear portion of the curved array(s) of recesses and/or teeth. In an alternative configuration, a portion of the gear(s) may be offset from another portion of the gear(s). Similarly, a portion of the curved array(s) may be offset from another portion of the curved array(s). For example, a front portion of the gear(s) and curved array(s) may be positioned laterally outwardly of a rear portion of the gear(s) and curved array(s), or a front portion of the gear(s) and curved array(s) may be positioned laterally inwardly of a rear portion of the gear(s) and curved array(s).
In an embodiment, running/gear surfaces of teeth of the gear(s) and/or of the curved array(s) are parallel to each other, but the gear(s) and the curved array(s) are angled.
In an alternative embodiment, the engagement features comprise high friction surface(s) on the convex and/or concave surfaces. The convex rock surface may comprise a single tooth, the concave rock surface may comprise a complementary recess, and the convex and/or concave surfaces may have a high friction surface to reduce or eliminate slip between the contacting surfaces.
In an embodiment, the convex and concave rock surfaces each have a constant radius of curvature.
In an embodiment, the radius of curvature of each of the convex and concave rock surfaces varies along the surface. For example, the radius of curvature of each of the convex and concave rock surfaces may be smaller at a rear of the surfaces than at a front of the surfaces.
In an embodiment, the at least one biasing member comprises a front spring and a rear spring, the springs acting between the transom and the base. The rocking mechanism may comprise two front springs and two rear springs. The rocking mechanism may comprise more than two front springs and/or more than two rear springs. The front spring(s) may be symmetrical with the rear spring(s), in a side view, about a frontal plane that is coincident with the neutral contact point. Alternatively, the front and rear spring(s) may be asymmetric.
In an embodiment, the springs may be configured to act only in tension, only in compression, or both in tension and in compression. For example, the springs may be configured to act only in tension. In that configuration, the front spring(s) will resist rearward rock and the rear spring(s) will resist forward rock. In an alternative configuration, the springs may be configured to act only in compression. In that configuration, the front spring(s) will resist forward rock and the rear spring(s) will resist rearward rock. The springs may act in one direction and lose contact or decouple in the opposite direction.
A spring rate of the front spring(s) may be the same as or different to a spring rate of the rear spring(s). For example, in one embodiment, the spring rate of the front spring(s) is about twice the spring rate of the rear spring(s).
In an embodiment, the biasing member(s) comprise coil spring(s). Alternatively the biasing member(s) could comprise one or more leaf springs or springs in the form of resilient blocks or members.
In an embodiment, the chair further comprises a forward and/or rear stop to limit rock of the transom relative to the base. The stop may comprise a curved slot provided on the base or the transom, and a pin provided on the other of the base or the transom, the pin being slidable in the slot between a front limit position and a rear limit position. In an alternative embodiment, the stop(s) may be provided by different features, such as by resilient stop blocks or members that compress to provide a soft stop. The forward and/or rear stop may be incorporated into a forward and/or rear spring. Alternatively, the chair may comprise rigid geometric limit(s).
In an embodiment, the seat portion and the back portion are movably mounted on the transom. The back portion may be reclinable relative to transom and the seat portion. For example, the seat portion and back portion may be mounted on the transom by way of the recline mechanism described above in relation to the third aspect.
The term ‘comprising’ as used in this specification and claims means ‘consisting at least in part of’. When interpreting statements in this specification and claims which include the term ‘comprising’, other features besides the features prefaced by this term in each statement can also be present. Related terms such as ‘comprise’ and ‘comprised’ are to be interpreted in a similar manner.
It is intended that reference to a range of numbers disclosed herein (for example, 1 to 10) also incorporates reference to all rational numbers within that range (for example, 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9 and 10) and also any range of rational numbers within that range (for example, 2 to 8, 1.5 to 5.5 and 3.1 to 4.7) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.
This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.
As used herein the term C(s)′ following a noun means the plural and/or singular form of that noun.
As used herein the term ‘and/or’ means ‘and’ or ‘or’, or where the context allows both.
The invention consists in the foregoing and also envisages constructions of which the following gives examples only.
The present invention will now be described by way of example only and with reference to the accompanying drawings in which:
The figures illustrate preferred forms of the chair and rocking and reclining mechanisms from various different angles. An arrow marked “F” has been inserted into the figures where appropriate to indicate a forward direction of the chair. Accordingly the terms forward, rearward, left side, and right side (or similar) should be construed with reference to the forward direction F of the chair, not necessarily with reference to the orientation shown in the particular figure.
Referring to
The rocking mechanism 17 comprises two curved, convex rock surfaces 18 that are provided on an underside of the transom 11 (
The two convex rock surfaces 18 are co-axial with each other and laterally spaced apart, with one convex surface positioned at or towards a left side of the transom 11 and the other convex surface positioned at or towards a right side of the transom 11. Similarly, the two concave rock surfaces 21 are co-axial with each other and spaced apart, with one concave surface positioned at or towards a left side of the transom 11 and the other concave surface positioned at or towards a right side of the transom 11, aligned with and receiving the respective convex surfaces 18.
Complementary engagement features are operatively provided on the transom and on the base to help control movement of the rock surfaces relative to each other. Referring to
The spur gears 23 are partial spur gears, with each spur gear 23 comprising an externally geared arcuate convex surface that extends around an arc of less than 360 degrees, preferably less than 180 degrees. In the embodiment shown, the arcuate geared surface extends through an arc of about 120 degrees.
The concave curved rack 25 extends through an arc of less than 180 degrees. In the embodiment shown, the curved rack 25 extends through an arc of about 120 degrees. The involute teeth 24 on the spur gear 23 are sized and shaped to engage the teeth 26 on the curved rack.
In the form shown, a longitudinal axis of the convex rock surfaces, concave rock surfaces, gears, and curved racks lie in respective planes, so that a front portion of each convex rock surface is in line with a rear portion of that convex rock surface, a front portion of each concave rock surface is in line with a rear portion of that concave rock surface, a front portion of each gear is in line with a rear portion of that gear, and a front portion of each rack is in line with a rear portion of that rack. In an alternative configuration shown in
In this embodiment, a portion of each rack is offset from another portion of that rack. For example, in the form shown in
Similarly, a portion of each rock surface is offset from another portion of that rock surface. In the form shown, the front portion 1021a of each concave rock surface is offset from the rear portion 1021b of that concave rock surface. The front portion 1018a of each convex rock surface is offset from the rear portion 1018b of that convex rock surface. The front portions of the rock surfaces may be positioned laterally inwardly of the rear portions of the rock surfaces, or the front portions of the rock surfaces may be positioned laterally outwardly of the rear portions of the rock surfaces. Different configurations could be used on opposite sides of the chair. A laterally extending intermediate region 1018c, 1021c is advantageously provided on each rock surface so that there is contact between the convex and concave rock surfaces throughout the rocking motion.
Front and rear biasing members in the form of coil springs 27, 29 act between the transom 11 and the upper part 3a of the base 3, and are configured to bias the transom 11 to a neutral position shown in
The front springs 27 are angled with their upper ends 27a positioned more rearward than their lower ends 27b. The rear springs 29 are angled with their upper ends 29a positioned more forward than their lower ends 29b. In the embodiment shown, when viewed from the side of the chair, the front springs 27 are symmetrical with the rear spring(s) 29 about a frontal plane P that is coincident with the neutral contact point N (
Referring to
The pitch diameter PD2 of the curved rack 25 is larger than the pitch diameter PD1 of the spur gear 23 such that not all of the spur gear teeth 24 are fully engaged with the curved rack 25 at any position of the spur gear 23. This enables the spur gear 23 to roll along the rack 25. In the exemplary embodiment shown, the pitch diameter PD2 of the curved rack 25 is 145 mm, and the pitch diameter PD1 of the spur gear 23 is 125 mm. However, the absolute pitch diameters PD1, PD2 may be larger or smaller, and the difference between the diameters may be larger or smaller.
Referring to
In the forward rocked position of
To move from the forward rocked position (a relatively high energy state) towards the neutral position (a lower energy position), the seat shell tilts about the contact point C.
In the rear rocked position shown in
To move from the rearward rocked position (a relatively high energy state) towards the neutral position (a lower energy position), the seat shell 5 tilts about the contact point C.
The spring rate of the front springs 27 may be the same as the spring rate of the rear springs 29. Alternatively, the front and rear springs 27, 29 may have different spring rates to provide different forward and rearward rock resistances.
In the exemplary embodiment shown, the spring rate of each front spring 27 is about twice the spring rate of each rear spring: 29.3 N/mm for the front springs 27, and 14.5 N/mm for the rear springs 29.
Forward and rear stops constrain the maximum forward and rearward rock of the transom 11 relative to the base 3. As shown in
As shown in
Preferred embodiments of the rocking mechanism have been described by way of example only and modifications may be made thereto without departing from the scope of the invention. For example, the slot 31 could be provided on the transom 11 and the pin 33 may be provided on the base 3. Alternatively, rather than a slot and pin arrangement, rocking could be limited by separate forward and rear stops provided between the transom 11 and base 3, for example, ledges or projections that engage in the maximum rock positions, or resilient stop blocks that compress to provide a soft stop.
In the embodiment shown, the convex surfaces 18, concave rock surfaces 21, spur gears 23, and curved racks 25 are located in parallel vertical forward/rearward extending planes. Alternatively, they could be orientated in inwardly or outwardly angled non-parallel planes. The planes may be symmetric.
In an alternative embodiment, the chair 1 may comprise only a single convex rock surface 18 and a corresponding single concave rock surface 21. The single set of rock surfaces may be centrally or otherwise positioned. As a further alternative, the chair 1 may comprise more than two sets of rock surfaces.
The spur gear radius of curvature and the rack curvature may vary along the surface of the rack 25 and gear 23. For example, the spur gear 23 may be a partial elliptic gear or other irregularly shaped gear, and the curved rack 25 may have a partial elliptical shape, or other irregularly curved shape. In one embodiment, the pitch diameter of the spur gears 23 and curved racks 25 (and the radius of curvature of the convex and concave rock surfaces 18, 21) may be smaller towards a rear and/or towards the front of the surfaces and larger in a middle portion such that the curved rack 25 is steeper towards the front and rear of the rack. That would create a larger difference between the energy state in the forward and rearward positions to increase the resistance to rock at greater forwards and rearwards rock. Increasing the resistance towards the front and rear rock limits minimises the feeling of hitting a hard/sudden stop at the end of the range of motion.
In embodiments where one or more of the of the spur gears 23, curved racks 25, concave surfaces 21, and convex surfaces 18 have a varying radius of curvature, the pitch diameter PD2 of the curved rack 25, is larger than the pitch diameter PD1 of the spur gear 23 at least at the point of the rack 25 in contact with the spur gear 23 in the neutral position. The pitch diameter PD2 of the curved rack 25 is larger than the pitch diameter PD1 of the spur gear 23 at each point of contact through the rock motion.
The rocking mechanism described employs coil springs 27, 29 as the biasing members. However, alternatively the biasing members may comprise leaf springs, or springs in the form of elastic bands, resilient blocks, or other suitable biasing means.
The inserts 127a, 129a are positioned in complementary apertures in the transom 11. The inserts may comprise regions that are free of material to enhance spring function, with examples described below with reference to
The seat frame and transom 11 can then be fitted to the base 3, with the insert 127a, 129a received between spaced apart side walls 22 of the base. A locking pin 30 is inserted through apertures in the side walls 22 and in the resilient insert 127a, 129a, to hold the assembly together. The locking pin may be a snap fit with one of the side walls 22, or may be located in position by another feature such as a nut for example. However, the assembly of the spring arrangement is preferably tool-less or requires minimal tool use for assembly.
The chair may be provided with any suitable number of springs. In the form shown, the chair is provided with two front springs 127 and two rear springs 129, positioned at or toward respective sides of the base 3. Alternatively, the chair may comprise a single front spring and/or a single rear spring, more than two springs at one or each location, or any other suitable configuration.
The springs also act as ‘soft’ rock stops, with the pins 30 and inserts 127a, 129a limiting the forward or rearward rocking of the chair. That is, the forward and/or rear rock stop is incorporated into the forward and/or rear spring 127, 129.
The rocking resistance of the springs 127, 129 may be customisable. For example, the spring inserts could be swapped out for heavy or light, and/or large or small users. The spring inserts can also be configured so that the front springs 127 have a different spring rate from the rear springs 129. For example, the spring inserts 127a, 129a may be configured to provide a greater resistance to rearward rocking than to forward rocking, as described above for the coil springs.
Rather than having identical profiles, the profiles of the spur gear teeth 24 and/or the rack teeth 26 may vary. For example, if the profiles of the rolling surfaces are other than constant radii, the tooth profile would vary.
As a further alternative embodiment, rather than a spur gear 23 and curved rack 25, different complementary engagement features could be used. The engagement features could be provided on the rock surfaces or on adjacent surfaces. For example, as shown in
As a further alternative, the tooth or teeth could be provided on the base 3 and the complementary recess provided on the transom 11.
The springs of the chair may be configured to act only in tension, only in compression, or both in tension and in compression. For example, the springs may be configured to act only in tension. In that configuration, the front spring(s) will resist rearward rock and the rear spring(s) will resist forward rock. In an alternative configuration, the springs may be configured to act only in compression. In that configuration, the front spring(s) will resist forward rock and the rear spring(s) will resist rearward rock. The springs may act in one direction and lose contact or decouple in the opposite direction.
In an alternative configuration, the ends of the springs could be operatively connected to the transom 11 and the projections could instead by provided on the chair base 3.
Any of the springs described herein may be configured so that when the chair is in a neutral position, the springs have a small amount of preload.
Referring to
The thickness, shape, dimensions, and/or material of the front support members 39 may be selected to provide the desired amount of resilience. For example, the members 39 may be thin so that they are more flexible and provide little resistance to movement of the front portion of the shell 5, or may be thicker so that they are less flexible and provide more resistance to movement of the front portion of the shell 5. That may provide stiffer recline of the shell and/or a smaller extent of recline.
The front ends 39a of the front support members are positioned more laterally outward relative to the transom 11 than the rear ends 39b, which are positioned more medially. This may assist with providing a wider support beneath the seat, reducing finger traps, and improved aesthetics. Alternatively, the front support members could be parallel or inward-facing.
The rear part of the seat portion 9 is not connected to the transom 11.
The back portion 7 of the seat shell 5 is attached to the transom 11 by way of two upright back support arms 35. Each back support arm 35 has a lower end 35b rigidly attached to the transom 11 via a back extension 41, and an upper end 35a rigidly attached to an upper part of the back portion 7. Part of each back support arm 35 at or below a lower part of the back portion 7, below the flex region 37 is spaced from the back portion 7. A top transverse cross bar 43 joins the tops 35a of the back support arms 35 to minimise movement of the back support arms 35 towards and away from each other.
The back support arms 35 may be directly bolted or otherwise attached to the transom 11, or may be attached via a back arm or transom extension.
Each back support arm 35 has a flex region 37 positioned near a lower part of the back portion 7. The flex regions 37 each comprise a series of slots 38 or notches extending from a front surface of the back support arm 35, part way through the thickness of the back support arm. For example, the notches may extend from a front surface of the back support arm to about half way through the thickness of the support arm. The slots 38 or notches increase the local flexibility of the back support arm near the slots 38 to increase the rearward flexibility of the flex regions 37 compared to the rest of the back support arms 35. The flex regions 37 may also be more flexible than the rest of the back support arms 35 in a forwards direction. Alternatively, the slots or notches may be positioned in a rear surface of the back support arm, with there being sufficient space between upper and lower portions of the notches that they can close to enable rearward flexing.
At least a portion of the seat shell 5 is resilient such that the back portion 7 can resiliently recline relative to the seat portion 9; for example via a joining or intermediate region 8 between the back portion 7 and seat portion 9. As the back portion 7 is reclined relative to the seat portion 9, the back support arms 35 flex at their flex regions 37 to allow the recline.
As the back portion 7 is reclined, the rear part of the seat portion 9 lifts, deforming the resilient front support members 39. The lower portion of the back support arms 35 are spaced from the back portion 7 helps facilitate the seat lift. In addition, the back support arms 35 comprise a substantially non-compressible or stretchable material, which prevents extension of the back portion 7 during recline, encouraging seat lift.
The maximum lift of the rear of the seat portion 9 and the force required to lift the rear of the seat 9 is partially controlled by the length and stiffness of the front support members 39. The maximum lift of the rear of the seat portion 9 and the force required to lift the rear of the seat 9 is predominantly controlled by the compliance or flexibility of the seat portion. In addition, the weight force of an occupant seated in the chair 1 opposes the seat lift thereby providing some weight compensation of the recline force. That is, a greater rearward force is required to recline the back portion 7 relative to the transom 11 for a heavier occupant compared to the recline force required to recline the back portion 7 for a lighter occupant.
In combination, the rock and recline mechanisms provide a smooth transition between rocking and reclining motions. When the occupant leans back in the chair 1, the back portion 7 initially remains substantially upright relative to the seat portion 9 and the chair will rock rearward. As the seat portion 5 rocks rearward and the rock resistance increases, the back portion 7 will recline relative to the seat portion 9 as the rock resistance becomes greater than the recline resistance. The rock and recline mechanisms may be configured with a desired point in the rocking motion at which back portion starts reclining, for example, at a forward, intermediate, or rearward position in the rocking motion.
The support frame 15 forms a supportive understructure for the seat shell 5, providing load support to the occupant on seat portion when back portion is not reclined. The support frame 15 may be substantially rigid or may be resiliently flexible. In one form, the flexibility of the support frame 15 is less than the flexibility of the seat portion 9. The support frame 15 is coupled to the seat portion 9 at a front part of the support frame 15, but not at a rear portion of the frame 15 to enable the rear portion of the seat portion 9 to raise away from the support frame 15 as the seat portion 9 lifts during recline of the back portion 7. The chair 1 may comprise a cowling or other cover (not shown) to prevent fingers becoming caught between the support frame 15 and the seat portion 9.
The exemplary embodiment of
A major part of the seat shell 105 comprises a compliant structure 45. In one form, at least a major part of the back portion 107, seat portion 109, and intermediate joining region 108 of the seat shell 105 comprises the compliant structure 45. In one form, substantially the entire seat shell 105 comprises the compliant structure. The compliant structure 45 consists of a plurality of members or cells 47 interconnected by a plurality of resilient connectors 49. In the exemplary embodiment, the cells 47 are substantially triangular. In some embodiments, at least some of the cells may have three substantially equal length sides and substantially equal included angles between adjacent sides. In other embodiments, at least some of the cells may have sides and/or included angles that differ. Three connectors 49 extend from each cell 47, one connector 49 from each apex of each triangular cell 47, and each attach to a further cell 47 such that each cell 47 in the compliant structure 45 is connected to three other cells 47.
The resilient connectors 49 for a given cell 47 may be orientated at approximately 120° to each other. The angles may vary depending on the curvature/shape of the shell. For example, as shown in
The resilient connectors 49 are substantially straight but alternatively could be curved. The ends of the resilient connectors 49 may be filleted or have a radius where they join the cells 47 for manufacturing purposes, or to reduce stress concentrations.
The cells 47 and the resilient members 49 together define a plurality of voids 51 which, in the form shown, are Y-shaped. As shown in
The cells 47 and resilient members 49 together define a structure that displays auxetic characteristics. That is, the structure 45 has a negative Poisson's ratio in the plane of the structure, with compression in a first direction V causing the structure to also contract in a second orthogonal direction H and extension in a first direction V causing the structure to also expand in a second orthogonal direction H (
The compliant structure 45 provides compliance in the seat and back portions 109, 107, for comfort. The compliant structure in an intermediate joining region 108 between the seat and back portions 109, 107 may also enable recline of the back portion 107 relative to the seat portion 109.
As the back portion 107 is reclined relative to the seat portion 109, the joining region 108 deforms. For example, the joining region may contract and/or expand in the first direction V and/or in the second orthogonal direction H. The joining region may contract and/or expand in both the first direction V and in the second orthogonal direction H. The joining region 108 of the shell may exhibit the auxetic characteristics described above.
The seat shell 105 has a solid perimeter 53 that extends along the top and down the sides of the back portion 107, and along the front edge and along the sides of the seat portion 109. The perimeter comprises a section of the compliant surface where the Y-shaped voids are ‘filled in’. Alternatively, the perimeter may be a solid, unpatterned strip.
The perimeter 53 is substantially non-compressible and substantially non-extendible in the plane of the structure, such that the length of the perimeter along the sides of the back portion 107 is unchanged as the back portion 107 reclines or flexes relative to the seat portion 109, and such that the length of the perimeter along the sides of the seat portion 109 is substantially unchanged as the seat portion 109 flexes. That assists with lifting of the seat portion 109 as the back portion 107 of the shell is reclined.
In the embodiment shown, the solid perimeter 53 extends around the entire edge of the seat shell 105. However, alternatively the solid perimeter 53 may extend along only a portion of the shell edge, or the seat shell 105 may not have a solid perimeter.
In addition, the seat shell 105 comprises a number of solid, substantially non-compressible attachment regions 55 for attachment to a chair support structure; e.g., to a transom or seat support for example. The solid attachment regions 55 may be regions where the Y-shaped voids are ‘filled in’ or, alternatively, each attachment region may comprise a solid, unpatterned region. The attachment regions 55 provide additional strength and a suitable surface for attaching a support, for example, for bolting to a back support 35, 135, a seat support 15,115, or transom 11, 111. Additionally, the attachment regions 55 provide suitable load transfer paths and can act as flow leaders during injection moulding of the seat shell 5, 105.
The solid perimeter 53 and attachment regions 55 limit the compression or extension of the compliant structure 45. That can help control the amount of inward lateral movement of the sides of the intermediate region 108 of the shell 105 which is forced to stretch and compress vertically and horizontally in a forward/rearward direction of the chair as the back portion 107 is reclined. Excessive inward lateral movement could be considered by some occupants to be undesirable.
The centres of the Y-shaped voids 51 may be braced or fused where less compliance is desirable.
Additionally or alternatively, the shell 105 may comprise structural regions for other purpose(s). For example, the structural regions may comprise solid regions or relatively stiff regions, to provide reduced compliance in the structural regions. The structural regions may be solid and/or may be relatively thick.
Different regions of the compliant structure 45 may comprise resilient connectors 49 of differing thicknesses, the thicknesses being selected to provide regions of greater and lesser compliance within the compliant structure. For example thicker resilient members 49 may be provided where less compliance is desirable, and thinner resilient members 49 may be provided where more compliance is desirable.
In addition or alternatively, different regions of the compliant structure 45 may comprise resilient connectors 49 of differing lengths, the lengths being selected to provide regions of greater and lesser compliance in the compliant structure. For example shorter resilient members 49 may be provided where less compliance is desirable, and longer resilient members 49 may be provided where more compliance is desirable.
Referring to
The support shell 105 is an integral single layer one piece injection moulded plastic component, but alternatively could be otherwise constructed, or may comprise an alternative material with some resilience, such as a metal or wood based material. The seat and back portions 7, 107, 9, 109 are preferably integrally formed.
The occupant-facing surface of the support shell 105, or both the occupant-facing and opposite surface of the support shell 105 may be upholstered and may comprise cushioning between the shell and the upholstery. In one form, the upholstery may extend across a front of the back portion and top of the seat portion, and have short sections that are received behind the shell, while leaving a large part of the shell open to the rear. In another form, the upholstery may fully surround the shell to cover the front and the back of the shell. Alternatively, the upholstery may be in the form of a pad, and may be provided only for the seat portion or only for the back portion for example.
Preferred embodiments of the invention have been described by way of example only and modifications may be made thereto without departing from the scope of the invention.
For example, the chair may comprise only one back support arm 35, 135, or two or more than two back support arms. In the embodiment of
Rather than slots or notches, the increased flexibility in the flex regions of the back support members 35 may be otherwise provided. For example, the back support member 35 may have a corrugated region, a necked region, a varied cross-section, or may comprise a more flexible material.
The back support arm 35 and resilient front support members 39 are shown as being bolted to the back and seat portions 7, 9 of the shell 5. However, alternatively the back supports 35 and/or the resilient members 39 may be integral with the seat shell 5, 105, for example by being integrally moulded with the seat shell 5, 105. Additionally or alternatively the lower rock surfaces 21 and/or the curved racks 25 may be integral with the base 3. Similarly the upper rock surfaces 18 and/or the spur gears 23 may be integral with the transom 11 or with the seat shell 5. The described pattern of the compliant structure in the seat shell 105 is just one possible configuration. The members or cells 47 could have any suitable shapes and/or sizes, with the voids 51 having related shapes and/or sizes. For example, rather than being triangular in plan view, the cells 47 could be circular, square, pentagonal, hexagonal, or any suitable shape. The shapes of the voids will be complementary to the shapes of the cells. The seat shell 105 could have cells of differing shapes in different regions of the seat shell 105. The cells 47 could have a different number of associated resilient connectors 49. For example, the cells could have two, three, four, five, six, or more associated resilient connectors 49. Different cells in different regions of the seat shell could have differing numbers of associated resilient connectors, particularly if the cells have differing shapes in those regions.
The rocking mechanism, recline mechanism, and seat shell are shown on a base having four legs. That configuration is particularly suited to an application where a traditional rigid chair would normally be used, for example, a dining chair. However, alternatively the rocking mechanism, recline mechanism, and/or seat shell may be provided on a pedestal type height adjustable base, for example in a task chair, and/or on a swivel base that enables rotation of the rocking mechanism and support shell about a vertical axis. The features described herein could be used in any suitable seating application, including but not limited to dining chairs, multipurpose chairs, cafeteria chairs, restaurant chairs, breakout space chairs, and meeting environment chairs.
While the preferred form chair will advantageously have all of the features described herein, the various features described herein may be provided alone or in combination. For example, the rocking mechanism could be used in a chair that does not have a recline mechanism (e.g., a tub chair that has a back portion and seat portion in a fixed relationship), or in a chair that has a different type of recline mechanism. As another example, the recline mechanism could be used in a chair that does not have a rocking mechanism or that has a different type of rocking mechanism from that described. As yet another example, the recline mechanism may be used in combination with a chair shell that has some flexibility, but that has a different compliant structure. The recline mechanism could be used in a chair that doesn't have a rocking mechanism.
Other example modifications are outlined in the Summary of the Invention section.
| Number | Date | Country | Kind |
|---|---|---|---|
| 716713 | Feb 2016 | NZ | national |
This application is a continuation of U.S. application Ser. No. 17/405,143, filed Aug. 18, 2021, which is a continuation of U.S. application Ser. No. 16/074,355, filed Jul. 31, 2018, which is a nationalization of PCT Application No. PCT/NZ2017/050009, filed Feb. 3, 2017, which claims priority to New Zealand Application No. 716713, filed Feb. 5, 2016, which are incorporated herein by specific reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 17405143 | Aug 2021 | US |
| Child | 18523623 | US | |
| Parent | 16074355 | Jul 2018 | US |
| Child | 17405143 | US |
