Patent Application
20170130455
The present invention generally relates to ceiling systems, and more particularly to suspended ceiling systems which create a seamless appearance.
One of the biggest challenges for acoustic ceilings is the balance between acoustic performance and visual appearance. On one extreme, acoustic ceilings which are integrally formed with the top surface of a space sacrifice significant acoustic performance in favor of a very uniform and seamless visual appearance. On the other extreme, acoustic ceilings formed of acoustic ceiling panels installed within a grid system are able to significantly increase the acoustic performance of the acoustic ceiling, but only at the sacrifice of a seamless visual appearance. Acoustic ceilings have therefore been introduced which hide the grid system, by concealing it within the edges of the supported acoustic ceiling panels, in order to present a more visually appealing appearance to the ceiling. However, it is inescapable that a grid of acoustic ceiling panels, even with a hidden grid system, can still appear as a grid of acoustic ceiling panels. Therefore, an improved ceiling system is desirable, particularly one which is better able to decouple visual appearance from acoustic performance.
The present invention provides a ceiling system which includes a ceiling structure suspended from an overhead structure, such that the ceiling structure provides a seamless visual appearance and offers the ability to fine tune the acoustic properties of the ceiling system without altering or affecting the overall visual appearance. The seamless visual appearance is achieved by stretching a single sheet of fabric across an entire ceiling structure, which may be formed of a frame, may include a grid of acoustic ceiling panels, and may be suspended from an overhead structure within a space free from direct attachment to walls or other similar ceiling structures.
According to one embodiment, a ceiling system includes a ceiling structure suspended in an interior space. The ceiling structure includes: a perimeter frame defining a central opening, the perimeter frame comprising a fabric gripping member; a support grid comprising a plurality of intersecting struts defining a plurality of grid openings, the support grid disposed within the central opening and coupled to the perimeter frame; a plurality of acoustic ceiling panels, each of the acoustic ceiling panels mounted to the support grid and disposed in one of the grid openings; and a tensioned fabric sheet having a perimeter portion that is engaged by the fabric gripping member of the perimeter frame, the tensioned fabric sheet located below the acoustic ceiling panels and covering the central opening.
According to another embodiment, a ceiling system including a ceiling structure suspended in an interior space. The ceiling structure includes: a perimeter frame defining a central opening, the perimeter frame including: a first fabric gripping member; and a second fabric gripping member; a first tensioned fabric sheet having a perimeter portion that is engaged by the first fabric gripping member of the perimeter frame, the first tensioned fabric sheet covering the central opening; and. a second tensioned fabric sheet having a perimeter portion that is engaged by the second fabric gripping member of the perimeter frame, the second tensioned fabric overlying the first tensioned fabric.
According to yet another embodiment, a ceiling system including a ceiling structure suspended in an interior space. The ceiling structure includes a perimeter frame defining a central opening, the perimeter frame including: a fabric gripping member; a track comprising a first retaining element configured to couple the fabric gripping member to the track and a second retaining element configured to couple the fabric gripping member to the track; and the fabric gripping member coupled to a selected one of the first or second retaining elements; and a tensioned fabric sheet having a perimeter portion that is engaged by the fabric gripping member of the perimeter frame, the tensioned fabric covering the central opening.
According to yet another embodiment, a fabric gripping apparatus includes: an anchor plate; a gripping portion including: a first wall extending outward from a first surface of the anchor plate; a second wall extending outward from the first surface of the anchor plate and extending substantially orthogonal to the anchor plate along a first reference plane, the second wall comprising a base section and a first gripping section having a plurality of first teeth; a fabric collection cavity formed between the first wall and the base section of the second wall; a gripping plate connected to a distal end of the first wall, the gripping plate comprising a lever section and a second gripping section having a plurality of second teeth; and the gripping plate positioned so that the second teeth oppose the first teeth to form an access slot into the fabric collection cavity, the gripping plate oriented so that the lever section of the gripping plate diverges from the first reference plane with distance from the anchor plate.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.
In the description of embodiments disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation. Terms such as “attached,” “coupled,” “affixed,” “connected,” “interconnected,” and the like refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise.
Being suspended in a free-hanging manner, however, is not a requirement for all embodiments. Thus, in certain embodiments, one or more of the ceiling structures 13 may be suspended within the interior space 15 so as to be partially or entirely spaced from all walls 21 of the interior space 15. Additionally, in embodiments having one or more ceiling structures 13, any one or more of the ceiling structures 13 may be directly coupled to one or more of the walls or one of the other ceiling structures 13. When the ceiling structure 13 is coupled to a wall or other ceiling structure 13, such coupling is not necessary to provide structural support to any of the ceiling structures 13. Rather, directly coupling any one or more of the ceiling structures 13 to one or more of the walls or to one or more of the other ceiling structures 13 may be done to create differences in the overall visual appearance of the interior space 15.
In still other embodiments, only one ceiling structure 13 may be included in an interior space, such that the one ceiling structure 13 spans from wall to wall of the interior space, thereby enabling uniform acoustic performance across the interior space, while at the same time allowing the presentation of a desired seamless visual appearance that is decoupled from the acoustic performance of the ceiling structure 13.
In still other embodiments, the ceiling system 11 may include one or more ceiling structures 13 installed in a space which includes an overhead structure 17 and is not bounded by walls. Such an embodiment is possible because walls are not required to provide structural support to the ceiling structures 13 that form the ceiling system 11.
Turning to
A top perspective view of the ceiling structure 13 is shown in
Because the tensioned fabric sheet 35 spans across the entire central opening 41 of the perimeter frame 31, the appearance of the acoustic ceiling panels 49 may be entirely irrelevant because they are blocked from view by the tensioned fabric sheet 35. Therefore the acoustic performance of the acoustic ceiling panels 49, in certain embodiments, may be improved because there is no need for the acoustic ceiling panels 49 to strike a balance between acoustic performance and aesthetic appearance.
The support grid 43, in addition to supporting the acoustic ceiling panels 49, also serves as a support assembly for the ceiling structure 13. The suspension members 19 have a first end 51 coupled to the support grid 43 and a second end 53 that is configured to couple to the overhead structure 17 of the interior space 15. Thus, when the ceiling structure 13 is suspended, it is suspended entirely by the support grid 43 functioning as a support assembly. In certain embodiments, the acoustic ceiling panels 49 may be omitted, such that the support grid 43 may have a structure that need not be configured to support the acoustic ceiling panels 49. In still other embodiments, the support grid 43, as a support assembly, need not be a grid at all, but rather configured purely as a support assembly for the ceiling structure 13.
In the exploded view of the ceiling structure 13 shown in
The support grid 43 is formed from the plurality of intersecting struts 45, which include longitudinal strut members 71 (e.g. main beams) and lateral strut members 73 (e.g. cross tees). The longitudinal strut members 71 may be referred to as main beams because in certain embodiments the suspension members 19 may couple to these strut members alone to providing suspension support for the entire ceiling structure 13. The lateral strut members 73 may be referred to as cross tees because these strut members are generally, but not necessarily, supported only by the longitudinal strut members 71 without having suspension members 19 securing them to the overhead structure.
The longitudinal and lateral strut members 71, 73 are elongated in shape having a length greater than their respective width (e.g. at least twice), and in various embodiments lengths substantially greater than their widths (e.g. 3 times or more). The longitudinal strut members 71 may have a substantially greater length than the lateral strut members 73, such that the longitudinal strut members 71 form “runners” or “rails” which are maintained in a substantially parallel spaced apart relationship by the lateral strut members 73. The lateral strut members 73 may be permanently or detachably coupled to and between adjacent (but spaced apart) longitudinal strut members 71 at appropriate intervals. The manner in which the lateral strut members 73 are coupled to the longitudinal strut members 71 is a matter of design choice, and is not to be limiting of the invention. The support grid 43 also includes support members 75 which couple to multiple ones of adjacent (but spaced apart) longitudinal strut members 71, and the first end 51 of the suspension members 19 may be coupled to the support members 75. The support members 75 may also be coupled to adjacent lateral strut members 73 to provide greater stability in the lateral direction. By having the support members 75 coupled to multiple ones of adjacent longitudinal strut members 71, every longitudinal strut member 71 need not be directly coupled to one of the suspension members 19. The combination of the interconnected longitudinal and lateral strut members 71, 73 and the support members 75 helps provide strength and stability to the ceiling structure 13.
The longitudinal and lateral strut members 71, 73 intersect to form an array of grid openings 47 which receive and are closed by ceiling panels 49 when positioned within the grid openings 47. In some embodiments, the longitudinal and lateral strut members 71, 73 may be arranged in an orthogonal pattern to intersect, respectively, at right angles (i.e., perpendicular) to form grid openings 47 which are rectilinear, such as squares or rectangles (in top plan view).
The terminal ends 81 of the lateral strut members 73 that couple to the longitudinal strut members 71 have end connections configured for permanent or detachable connection to the longitudinal strut members 71 at right angles as part of forming the rectilinear grid pattern. The lateral strut members 73 may be coupled to the longitudinal strut members 71 through use of a permanent connection such as, without limitation, welding, soldering, and the like, or through use of a detachable connection such as, without limitation, clips, brackets, threaded fasteners, interlocking tabs/slots, and the like. Accordingly, the present invention is not limited by the manner of attachment or coupling used between the lateral strut members 73 and the longitudinal strut members 71 unless otherwise so limited by the claims.
Similarly, the terminal ends 83 of the lateral strut members 73 that couple to the elongated frame members 61 have end connections configured for permanent or detachable connection to the elongated frame members 61 at right angles as part of forming the rectilinear grid pattern. The lateral strut members 73 may be coupled to the elongated frame members 61 through the use of a support bracket 85. In certain embodiments, the lateral strut members 73 may be coupled to the elongated frame members 61 through the use of any detachable connection such as, without limitation, clips, brackets, threaded fasteners, interlocking tabs/slots, and the like. Accordingly, the present invention is not limited by the manner of attachment or coupling used between the lateral strut members 73 and the elongated frame members 61 unless otherwise so limited by the claims.
The terminal ends 87 of the longitudinal strut members 71 have end connections configured for permanent or detachable end-to-end connection to the elongated frame members 61 to form the continuous spans of the main beams. The longitudinal strut members 71 may likewise be coupled to the elongated frame members 61 through the use of the support bracket 85. In certain embodiments, the longitudinal strut members 71 may be coupled to the elongated frame members 61 through the use of any detachable connection such as, without limitation, clips, brackets, threaded fasteners, interlocking tabs/slots, and the like. Accordingly, the present invention is not limited by the manner of attachment or coupling used between the longitudinal strut members 71 and the elongated frame members 61 unless otherwise so limited by the claims.
The configuration and orientation of the parts forming the support grid 43 may vary widely while still remaining within the scope of the claims. By way of example, some lateral strut members 73 may be run the same direction between and parallel to main beam longitudinal strut members 71, the longitudinal strut members 71 and the lateral strut members 73 may intersect at non-perpendicular angles, any part or all of the support grid 43 may be positioned in a horizontal or other orientation. Any combination of such alternative design characteristics may be incorporated into the ceiling structure 13.
The acoustic ceiling panels 49 may be of any appropriate design to provide the ceiling structure 13 desired acoustical properties. For example, an exemplary acoustic ceiling panel 49 may include at least a core layer (not shown) (not shown) formed from one or more sub-layers. In such an exemplary and non-limiting embodiment, the acoustic ceiling panel 49 has a generally rectangular shape. In other embodiments, the acoustic ceiling panel 49 may be square, have more or fewer peripheral sides, or be irregularly shaped. The core layer of such an exemplary acoustic ceiling panel 49 may be constructed of any suitable material or combinations of different materials, which in certain embodiments preferably have acoustical properties. Some non-limiting examples of core layer materials that may be used include, without limitation, mineral fiber board, fiberglass, metals, polymers, metal, wood, composites, combinations thereof, or other. Embodiments of the core layer may be constructed so that the acoustic ceiling panel 49 has a sufficiently high noise reduction coefficient (NRC) and ceiling attenuation class (CAC) rating to be characterized as an acoustical substrate in contrast to gypsum-based drywall having substantially lower NRCs (e.g. 0.05) characteristic of sound reflecting, not absorbing materials. NRC is a measure of sound energy absorption of a material. An NRC rating of 0 is a perfect sound reflection material. An NRC rating of 1 is a perfect sound absorption material. CAC is a measure for rating the performance of a ceiling material as a barrier to block airborne sound transmission through the material to/from the upper interior space above the suspended ceiling panels and into an adjacent room. This property is measured in decibels (dB).
In some embodiments, the core layer may impart to the acoustic ceiling panel 49 an NRC of at least 0.50 and/or CAC of at least 30 dB depending on the desired acoustical characteristics of the ceiling system. In a certain embodiment, the NRC rating may be at least 0.70. In certain other embodiments, additional acoustic layers and/or features may be included as part of the acoustic ceiling panel 49, along with the core layer, to achieve desired acoustic properties for the acoustic ceiling panel 49.
The track 67 includes an upstanding wall 91 which has an outer surface 93 and an inner surface 95. The inner surface 95 includes a lower support element 97 and an upper support element 99. Each of the lower and upper support elements 97, 99 are configured to couple the support brackets 85 to the perimeter frame 31. The support brackets 85 are discussed in greater detail below. Each of the lower and upper support elements 97, 99 also permit the support brackets 85 to be coupled to the perimeter frame 41 at a first height (the lower support element 97) or at a second height (the upper support element 99), respectively.
A lower retaining element 101 protrudes from the inner surface 95 of the upstanding wall 91 at a bottom portion of the upstanding wall 91, and an upper retaining element 103 protrudes from the inner surface 95 of the upstanding wall 91 at a top portion of the upstanding wall 91. As with the track 67, each of the retaining elements 101, 103 circumscribes the central opening 41 of the perimeter frame 31. In certain embodiments, either one or both of the retaining elements 101, 103 may not circumscribe the central opening 41. In certain embodiments, one or the other of the retaining elements 101, 103 may be omitted.
In the exemplary embodiment depicted, both retaining elements 101, 103 have identical configurations but different orientations, and as such the ensuing description applies to the configurations of both. Therefore, the description of the retaining element 101 applies equally to the retaining element 103, except for where otherwise noted. In certain embodiments, however, the retaining elements 101, 103 may have different configurations. The retaining element 101 includes a retaining channel 105 and an access slot 107 forming a passageway into the retaining channel 105. The access slot 107 of the lower retaining element 101 faces downward, and the access slot 107 of the upper retaining element 103 faces upward. The retaining element 101 also includes a floor 109, a first wall 111, and a second wall 113 that collectively define the retaining channel 105 and access slot 107, and at least one of the walls 111, 113 of the retaining element 101 includes an overhang portion 115. With the retaining element 101 configured in this manner, one of the elongated grip bars 63 may be placed in sliding relationship with the retaining element 101. In certain embodiments, as described in more detail below, the fabric gripping member may be coupled to one or the other of the retaining elements 101, 103. With elongated grip bars 63 coupled to the retaining members 101 of each frame member 61, the fabric gripping member 69 circumscribes the central opening 41. In this configuration, the elongated grip bar 63 protrudes from the inner surface 95 of the upstanding wall 91, from a location at a bottom portion of the upstanding wall 91, so that the outer surface 93 of the upstanding wall 91 remains exposed when the tensioned fabric sheet 35 is coupled to the fabric gripping member 69. In addition, the bottom portion of the upstanding wall 91 circumscribes the tensioned fabric sheet 35. In an alternate configuration, when the fabric gripping member 69 is coupled to the retaining member 103 and the tensioned fabric sheet 35 is coupled to the fabric gripping member 69, the elongated grip bar 63 protrudes from the inner surface 95 of the upstanding wall 91, from a location at a top portion of the upstanding wall 91, so that the tensioned fabric sheet 35 wraps around and at least partially conceals the outer surface 93 of the upstanding wall 91.
As can be seen in
A detailed cross-sectional view of one of the elongated grip bars 63 coupled to the one of the retaining members 101 is shown in
The elongated grip bar 63 is configured with a fabric collection cavity 121, a first gripping jaw 123, and a second gripping jaw 125. The first and second gripping jaws 123, 125 oppose one another to form an access slot 127, which forms a passageway into into the fabric collection cavity 121. More particularly, the fabric gripping member 69 includes an anchor plate 131 and a gripping portion 133 in the form of the first and second gripping jaws 123, 125. The gripping portion 133 includes a first wall 135 and a second wall 137, both extending outward from a first surface 139 of the anchor plate 131. A gripping plate 141, which includes a lever section 143 and a second gripping section 145 having a plurality of first teeth 147, is connected to the distal end of the first wall 135. In certain embodiments, the first wall 135 may be a curved wall. The second wall 137 extends substantially orthogonal from the anchor plate 131 along a reference plane RP and includes a base section 151 and a gripper section 153 having a plurality of second teeth 155. The gripping plate 141 of the second wall 137 is positioned so that the plurality of first teeth 147 on the gripping plate 141 oppose the plurality of second teeth 155 of the gripper section 153. With this configuration, the first and second gripping jaws 123, 125 and the access slot 127 are formed, and the fabric collection cavity 121 is formed between the first wall 135 and the base section 151 of the second wall 153. The gripping plate 141 of the second wall 137 is oriented so that the lever section 143 diverges from the first reference plane RP the further the lever section 143 extends from the anchor plate 131. In addition, at least one of the first wall 135 or the second wall 137 is resilient, with the first and second teeth 147, 155 are biased into contact with one another. Having such a configuration, the first and second teeth 147, 155 may be drawn apart when an appropriate force is applied to the lever section 143 of the gripping plate 141.
The perimeter portion of the tensioned fabric sheet 35 may be inserted into the fabric collection cavity 121 of the elongated grip bar 63 so that the first and second teeth 147, 155 of the first and second gripping jaws 123, 125 engage the perimeter portion of the tensioned fabric sheet 35 to hold the tensioned fabric sheet 35 in place. The tensioned fabric sheet 35 is therefore prevented from being withdrawn from the fabric collection cavity 121 by the first and second teeth 147, 155, which are biased toward each other.
In the exemplary embodiment depicted, both lower and upper support elements 97, 99 have identical configurations, and as such the ensuing description applies to the configurations of both. Therefore, the description of the upper support element 99 applies equally to the lower support element 97, except for where otherwise noted. In certain embodiments, the lower and upper support elements 97, 99 may have different configurations. The upper support element 99 includes a first channel 161, a second channel 163, and a back wall 165, with the first channel 161 and the second channel 163 facing one another and the back wall 165 separating the first and second channels 161, 163. The back wall 165 includes a surface texturing 167, which may be a plurality of ridges, as depicted, or any other type of texturing that provides a fine-scale non-planar surface for the back wall 165. For each frame member 31 to be adjoined, a first corner bracket 65 is inserted into the upper support element 99 with upper and lower edges of the corner bracket 65 seated, respectively, within the first channel 161 and the second channel 163 of the upper support element 99. Similarly, a second corner bracket 65 is inserted into the lower support element 97 with upper and lower edges of the corner bracket 65 seated, respectively, within the first channel 161 and the second channel 163 of the lower support element 97. Each corner bracket 65 includes a threaded hole (not shown) into which a threaded fastener 169 is inserted, and each threaded fastener 169 engages the threaded hole so that an end of the threaded fastener 169 presses into the texturing 167 of the back wall 165. The surface texturing 167 of the back wall 165 serves to help maintain the threaded fastener 169 in place without slipping. In addition, the pressure of the threaded fastener 169 against the back wall 165 causes the upper and lower edges of the corner bracket 65 to press against the walls of the respective first and second channels 161, 163. The combination of the pressure of the threaded fastener 169 against the back wall 165 and the pressure of the corner bracket 65 against the walls of the first and second channels 161, 163 serves to hold the corner bracket 65 in position with respect to the frame member 31, which in turn serves to secure and hold adjacent frame members 31 together.
One intersection 181 of the intersecting struts 45 is shown in
The coupling of a longitudinal strut member 71 to a frame member 61 is shown in
The support bracket 85, which is shown in
The clamp member 213 includes a middle planar portion 231 with a threaded hole 233 for engaging the threaded fastener 203. A first side of the middle planar portion 231 faces the “L” bracket member 211 when the two are secured together. One end of the middle planar portion 231 includes a stabilizing tab 235 extending from the first side of the clamp member 213, and the stabilizing tab 235 serves to help prevent the clamp member 213 and the “L” bracket member 211 from rotating with respect to each other when coupled together by the threaded fastener 203. The bottom portion 237 of the clamp member 213 extends at an acute angle from the second side of the clamp member 213 in the opposite direction of the stabilizing tab 235. The bottom portion 237 also includes an engagement leg 239, which is substantially parallel to the middle planar portion 231 and positioned to engage the one of the first and second channels 161, 163 of one of the lower and upper support elements 97, 99.
The support bracket 85 secures to one of the lower and upper support elements 97, 99 with the engagement leg 229 of the “L” bracket member 211 positioned in one of the first and second channels 161, 163 and the engagement leg 239 of the clamp member 213 positioned in the other of the first and second channels 161, 163. The bottom portion 225 of the “L” bracket member 211 is located outside of the one of the first and second channels 161, 163 in which the engagement leg 239 of the clamp member 213 is positioned. When the threaded fastener 203 engages the threaded hole 233 of the clamp member 213, the clamp member 213 is drawn toward the “L” bracket member 211, and the threaded fastener 203 presses into the texturing 167 of the back wall 165 of the respective lower and upper support element 97, 99. The texturing 167 of the back wall 165 serves to help maintain the threaded fastener 203 in place without slipping. In addition, the pressure of the threaded fastener 203 against the back wall 165 causes the engagement leg 229 of the “L” bracket member 211 and the engagement leg 239 of the clamp member 213 to press against the walls of the respective first and second channels 161, 163. Also, the a wall of one of the first and second channels 161, 163 is clamped between the bottom portion 225 of the “L” bracket member 211 and the engagement leg 239 of the clamp member 213. Thus, with the threaded fastener 203 coupling the support bracket 85 to one of the lower and upper support elements 97, 99, the support bracket 85 serves to securely couple a longitudinal strut member 71 (or a lateral strut member 73) to the track 67. By using the support bracket 85 to couple the longitudinal and lateral struts 71, 73 to the track 67, the outer surface of the upstanding wall 91 may be formed without any through holes.
The end of a frame member 61, including the elongated grip bar 63, is shown in
The track 315 includes an upstanding wall 321 which has an outer surface 323 and an inner surface 325. The inner surface 325 includes a lower support element 327 and an upper support element 329. Each of the lower and upper support elements 327, 329 are configured to couple the support brackets 331 to the perimeter frame 307. Each of the lower and upper support elements 327, 329 also permit the support brackets 331 to be coupled to the perimeter frame 307 at a first height (the lower support element 327) or at a second height (the upper support element 329), respectively. The support brackets 331 have the same configuration as the support bracket 85 shown in
A lower retaining element 335 protrudes from the inner surface 325 of the upstanding wall 321 at a bottom portion of the upstanding wall 321, and an upper retaining element 337 protrudes from the inner surface 325 of the upstanding wall 321 at a top portion of the upstanding wall 321. As with the track 315, each of the retaining elements 335, 337 circumscribes the central opening of the perimeter frame 307. In certain embodiments, either one or both of the retaining elements 335, 337 may not circumscribed the central opening. In certain embodiments, the lower retaining element 101 may be omitted.
One of the elongated grip bars 341 is placed in sliding relationship with the retaining element 337, and with elongated grip bars 341 so placed with each frame member 311, a fabric gripping member is formed that circumscribes the central opening of the perimeter frame 307. The elongated grip bar 341 of this embodiment may be formed the same as the elongated grip bar 63 shown in
The track 415 includes an upstanding wall 421 which has an outer surface 423 and an inner surface 425. The inner surface 425 includes a lower support element 427 and an upper support element 429. Each of the lower and upper support elements 427, 429 are configured to couple the support brackets 431 to the perimeter frame 407. Each of the lower and upper support elements 427, 429 also permit the support brackets 431 to be coupled to the perimeter frame 407 at a first height (the lower support element 427) or at a second height (the upper support element 429), respectively. The support brackets 431 have the same configuration as the support bracket 85 shown in
A lower retaining element 435 protrudes from the inner surface 425 of the upstanding wall 421 at a bottom portion of the upstanding wall 421, and an upper retaining element 437 protrudes from the inner surface 425 of the upstanding wall 421 at a top portion of the upstanding wall 421. As with the track 415, each of the retaining elements 435, 437 circumscribes the central opening of the perimeter frame 407.
One of the elongated grip bars 441 is placed in sliding relationship with the retaining element 435, and another of the elongated grip bars 443 is placed in sliding relationship with the retaining element 437. Each elongated grip bar 441, 435 of this may be formed the same as the elongated grip bar 63 shown in
With this configuration, the across the central opening of the perimeter frame 407, the upper surface of the second tensioned fabric 405 is adjacent the lower surface of the first tensioned fabric 403. In certain embodiments, the first tensioned fabric sheet 403 may be a first color and the second tensioned fabric sheet 405 may be a second color that is different than the first color. In certain embodiments, the first tensioned fabric sheet 403 may include a loose weaving or even larger holes which allow more of the second tensioned fabric sheet 405 to be seen underneath the first tensioned fabric sheet 403.
