Abstract:
An occupant-support base includes a stationary seat pan and a pad coupled to the seat pan. The pad is coupled to the seat pan and configured to provide comfort to an occupant resting on the occupant-support base and provide a pleasing aesthetic to the occupant.

Description:
PRIORITY CLAIM 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application Ser. No. 62/115,197, filed Feb. 12, 2015 and U.S. Provisional Application Ser. No. 62/113,712, filed Feb. 9, 2015, each of which is expressly incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to an occupant support, and particularly to an occupant support used in a vehicle. More particularly, the present disclosure relates to an occupant support having a variable dimension. 
       SUMMARY 
       [0003]    According to the present disclosure, an occupant-support base includes a stationary seat pan and a pad coupled to the seat pan. The pad is coupled to the seat pan and configured to provide comfort to an occupant resting on the occupant-support base and provide a pleasing aesthetic to the occupant. The pad includes a cushion cover arranged to cover the seat pan and a cushion located between the seat pan and the cushion cover. 
         [0004]    In illustrative embodiments, the occupant-support base further includes a pad-extension system. The pad-extension system is configured to provide means for moving a portion of the pad relative to the seat pan between a retracted configuration and an extended configuration so that support to an occupant is maximized while aesthetics are maximized. 
         [0005]    In illustrative embodiments, the pad-extension system includes a pan mount coupled to the seat pan in a fixed position, a movable pad support, and a pad-support mover. The movable pad support is coupled to the pan mount to move back and forth relative to the seat pan. The pad-support mover is arranged to extend between and interconnect the movable pad support and the pan mount to cause the movable pad support to move back and forth. 
         [0006]    In illustrative embodiments, the pad-support mover is an inflatable bladder arranged between the movable pad support and the pan mount. The inflatable bladder pushes the movable leg support away from the pan mount when inflated to cause the pad-extension system to assume the expanded configuration. Return springs are provided in the illustrative embodiment to pull the movable pad support back toward the pan mount when the inflatable bladder is deflated to cause the pad-extension system to assume the retracted configuration. 
         [0007]    In illustrative embodiments, the movable leg support rotates about an axis relative to the pan mount between the retracted and the expanded configurations. In illustrative embodiments, the movable leg support translates and slides relative to the pan mount between the retracted and expanded configurations. 
         [0008]    Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived. 
     
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         [0009]    The detailed description particularly refers to the accompanying figures in which: 
           [0010]      FIG. 1  is a side elevation view of a portion of a first embodiment of an occupant-support base in accordance with the present disclosure showing that the occupant-support base includes a seat pan and a pad-extension system coupled to the seat pan to change a size of a pad included in the occupant-support base by moving between a retracted configuration suggested here and in  FIG. 4  and an expanded configuration suggested here and in  FIG. 5  to change an overall length and height of the occupant-support base; 
           [0011]      FIG. 2  is an exploded assembly view of the pad-extension system of  FIG. 1  showing that the pad-extension system includes, from bottom to top, a pan mount, a shaft arranged to extend through first and second shaft-support receivers included in the pan mount, first and second rear guide pins, a pneumatic inflatable bladder, first and second bias units, and a movable pad support; 
           [0012]      FIG. 3  is perspective view of the pad-extension system of  FIGS. 1 and 2  in the retracted configuration showing the first and second bias units coupled to the pan mount and arranged to extend between and interconnect the movable pad support and the pan mount to cause the movable pad support to be biased toward the retracted configuration; 
           [0013]      FIG. 4  is a view similar to  FIG. 1  showing the pad-extension system in the retracted configuration with the shaft at a first distance from a mover-facing mount surface of the pan mount, an apex of the movable pad support at a first position, and the bias units providing a minimum amount of return force; 
           [0014]      FIG. 5  is a view similar to  FIG. 4  showing the pad-extension system in the expanded configuration with the shaft at a second distance from the mover-facing mount surface of the pan mount, the apex of the leg-support at a second position, and the bias units providing maximum amount of return force; 
           [0015]      FIG. 6  is a side elevation view of a second embodiment of an occupant-support base in accordance with the present disclosure showing that the occupant-support base includes a seat pan and a pad-extension system coupled to the seat pan to change a size of a pad included in the occupant-support base by moving between a retracted configuration suggested here and in  FIGS. 9A and 9B  and an expanded configuration suggested here and in  FIGS. 10A and 10B ; 
           [0016]      FIG. 7  is an exploded assembly view of the pad-extension system of  FIG. 6  showing that the pad-extension system includes, from bottom to top, a pan mount, a pair of return springs, a vertical pneumatic inflatable bladder, a movable pad support coupled to the pan mount to slide back and forth relative to the pan mount, a pair of mounting arms, and four mounting fasteners; 
           [0017]      FIG. 8  is a perspective view of the pad-extension system of  FIGS. 6 and 7 ; 
           [0018]      FIG. 9A  is a view similar to  FIG. 6  with the pneumatic inflatable bladder omitted showing the pad-extension system in the retracted configuration and the mounting arms at a first distance from a front side of the movable pad support; 
           [0019]      FIG. 9B  is a view similar to  FIG. 9A  showing the pad-extension system in the retracted configuration with the pneumatic inflatable bladder shown and the return springs providing a minimum return force; 
           [0020]      FIG. 10A  is a view similar to  FIGS. 9A and 9B  with the pneumatic inflatable bladder omitted showing the pad-extension system in the expanded configuration and the mounting arms are a relatively greater second distance from the front side of the movable pad support; and 
           [0021]      FIG. 10B  is a view similar to  FIG. 10A  showing the pad-extension system in the expanded configuration with the return springs providing maximum return force. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    A first embodiment of an occupant-support base  10  in accordance with the present disclosure is shown in  FIGS. 1-5 . A second embodiment of an occupant-support base  210  in accordance with the present disclosure is shown in  FIGS. 6-10B . Occupant-support bases in accordance with the present disclosure each include a seat pan, a pad coupled to the seat pan, and a pad-extension system. Each pad-extension system is configured to provide means for moving a portion of the pad relative to the seat pan between a retracted configuration and an extended configuration to cause the occupant-support base to be customized to an occupant so that comfort of the occupant supported by the occupant-support base is maximized. Occupant-support bases  10 ,  210  may be used as a seat bottom, a backrest, a head rest, a bolster included in a backrest or seat bottom, an armrest, or any combination thereof. 
         [0023]    Occupant-support base  10 , embodied as a seat bottom  10 , is adapted for use in a vehicle seat as suggested in  FIG. 1 . Occupant-support base  10  includes a seat pan  12 , a pad  13  coupled to seat pan  12 , and a pad-extension system  14  coupled to seat pan  12 . Pad-extension system  14  is configured to change a size and/or shape of pad  13  by moving between a retracted configuration as shown in  FIG. 4  and an expanded configuration as shown in  FIG. 5 . Pad-extension system  14  changes a height of a front portion of pad  13  between a first height H 1  associated with the retracted configuration and a relatively greater second height H 2  associated with the expanded configuration as suggested in  FIG. 1 . Pad-extension system  14  also changes a length of pad  13  between a first depth D 1  associated with the retracted configuration and a relatively greater second depth D 2  associated with the expanded configuration as suggested in  FIG. 1 . 
         [0024]    Pad-extension system  14  includes a pan mount  16 , a movable pad support  18 , and a pad-support mover  20  as shown, for example, in  FIG. 2 . Pan mount  16  is coupled to seat pan  12  of occupant-support base  10  in a fixed position relative to seat pan  12 . Movable pad support  18  is coupled to pan mount  16  to pivot and slide back and forth relative to pan mount  16  when pad-extension system  14  moves between the retracted configuration and the expanded configuration. Pad-support mover  20  is located between pan mount  16  and movable pad support  18  and is configured to move movable pad support  18  relative to pan mount  16 . Movable pad support  18 , also called structure carrier  18 , supports pad  13  that engage the legs of a user. 
         [0025]    Pad  13  includes a cushion  15  and a cushion cover  17  as suggested in  FIG. 4 . In the example where occupant-support base  10  is a seat bottom, cushion cover  17  and cushion  15  extend over pad-extension system  14  to support the legs of an occupant supported by occupant-support base  10  as pad-extension system  14  moves between the retracted configuration and the expanded configuration. In some examples, pad  13  may further include a slack compensator configured to control wrinkles in cushion cover  17  as pad-extension system  14  moves between the retracted configuration and the expanded configuration. In one example, cushion  15  is made from or any other suitable alternative or combination. In one example, cushion cover  17  may be made from cloth, leather, or any other suitable alternative or combinations. 
         [0026]    Pad-support mover  20  is, for example, a pneumatic inflatable bladder  24  configured to push movable pad support  18  away from pan mount  16  when pneumatic inflatable bladder  24  is inflated as suggested by an arrow  24 A shown in  FIGS. 1 and 5 . As shown in  FIG. 3 , a first bias unit  28 , also included in pad-extension system  14  is coupled to a first bias-unit mount  68  included in pan mount  16 . A second bias unit  29  included in pad-extension system  14  is coupled to a second bias-unit mount  69  also included in pan mount  16 . Bias units  28 ,  29  are arranged to interconnect pan mount  16  and movable pad support  18  to bias movable pad support  18  toward pan mount  16  when pneumatic inflatable bladder  24  is deflated. Bias units  28 ,  29  bias movable pad support  18  toward pan mount  16  to cause pad-extension system  14  to move from the expanded to the retracted configuration. 
         [0027]    A maximum change in height H 3  and a maximum change in depth D 3  traveled by movable pad support  18  between the fully retracted configuration and the fully expanded configuration may be modified for various embodiments in accordance with the present disclosure. In the illustrative embodiment, as suggested by  FIG. 1 , about 90% of the movement is a change in height, and about 10% of the movement is a change in depth. 
         [0028]    Pneumatic inflatable bladder  24  inflates in response to air entering pneumatic inflatable bladder  24  through a feed tube  26  as suggested by an arrow  26 A as shown in  FIG. 5 . Inflation of pneumatic inflatable bladder  24  pushes movable pad support  18  away from pan mount  16  causing pad-extension system  14  to expand. Air may be forced through feed tube  26  as suggested by arrow  26 A by a source of pressurized air. A pressure gradient across feed tube  26  is generated to cause pneumatic inflatable bladder  24  to inflate. 
         [0029]    Pad-extension system  14  further includes a shaft  80 , a first rear guide pin  83 , and a second rear guide pin  84 , as shown in  FIG. 2 . Shaft  80  and rear guide pins  83 ,  84  are arranged to interconnect pan mount  16  and movable pad support  18 . When pneumatic inflatable bladder  24  inflates, shaft  80  and rear guide pins  83 ,  84  cooperate to constrain and guide movement of movable pad support  18  as pneumatic inflatable bladder  24  pushes movable pad support  18  away from pan mount  16 . When pneumatic inflatable bladder  24  deflates, shaft  80  and rear guide pins  83 ,  84  cooperate to constrain and guide movement of movable pad support  18  as bias units  28 ,  29  bias movable pad support  18  toward pan mount  16 . 
         [0030]    Shaft  80  is coupled to pan mount  16  to move relative to pan mount  16  as movable pad support  18  moves relative to pan mount  16 . Movement of shaft  80  is constrained by first and second shaft-mount receivers  81 A,  82 A as shown in  FIG. 2 . First shaft-mount receiver  81 A is spaced apart laterally from second shaft-mount receiver  82 A as shown in  FIG. 2 . First shaft-mount receiver  81 A is formed to include a shaft-mount slot  81 B therein. Second shaft-mount receiver  82 A is formed to include a shaft-mount slot  82 B therein. Each shaft-mount slot  81 B,  82 B is arranged to extend along an angled axis  101 A,  101 B with both angled axes  101 A,  101 B arranged to lie in co-planar relation to one another. In an illustrative example, angled axis  101 A forms an angle  102 A between angled axis  101 A and a vertical reference line  103 A. In an illustrative example, angle  102 A is in a range of about 0 degrees and 30 degrees. 
         [0031]    Shaft  80  is arranged to extend through and move along both mount slots  81 B,  82 B. Shaft  80  is also arranged to extend through first and second shaft-support receivers  81 C,  82 C included in movable pad support  18 . First shaft-support receiver  81 C is formed to include a cylindrical shaft-support passageway  81 D therein. Second shaft-support receiver  82 C is formed to include a cylindrical shaft-support passageway  82 D therein. As shown in  FIG. 2 , both cylindrical shaft-support passageways  81 D,  82 D are arranged to lie in collinear relation with their respective center points aligned with a center point of shaft  80 . 
         [0032]    First rear guide pin  83  is coupled to pan mount  16  in rotative bearing engagement with pan mount  16  and movable pad support  18  to move relative to movable pad support  18 . Movement of first rear guide pin  83  is constrained by a first rear-mount guide-pin receiver  83 A included in pan mount  16  and a first rear-support guide-pin receiver  83 B included in movable pad support  18  as shown in  FIG. 2 . First rear-mount guide-pin receiver  83 A is formed to include a rear cylindrical passageway  83 C therein. First rear-support guide-pin receiver  83 B is formed to include a rear support slot  83 D therein. Rear support slot  83 D is arranged to extend along a rear angled axis  110 A. In an illustrative example, rear angled axis  110 A forms an angle  111 A between rear angled axis  110 A and a vertical reference line  112 A. In an illustrative example, angle  111 A is in a range of about 60 degrees to 90 degrees. 
         [0033]    Second rear guide pin  84  is coupled to pan mount  16  in rotative bearing engagement with pan mount  16  and movable pad support  18  to move relative to movable pad support  18 . Movement of second rear guide pin  84  is constrained by a second rear-mount guide-pin receiver  84 A included in pan mount  16  and a second rear-support guide-pin receiver  84 B included in movable pad support  18  as shown in  FIG. 2 . Second rear-mount guide-pin receiver  84 A is formed to include a rear cylindrical passageway  84 C therein. Second rear-support guide-pin receiver  84 B is formed to include a rear-support slot  84 D therein. Rear-support slot  84 D is arranged to extend along a rear angled axis  110 B. In an illustrated example, rear angled axis  110 B forms an angle  111 B between rear angled axis  110 B and a vertical reference line  112 B. In an illustrative example, angle  111 B is in a range of about 60 degrees to 90 degrees. The two vertical reference lines  112 A,  112 B associated rear support slots  83 D,  84 D are arranged to lie in coplanar relation to one another. 
         [0034]    As pad-extension system  14  moves from the expanded configuration to the retracted configuration, shaft  80  slides down and backward relative to pan mount  16  along angled axes  101 A,  101 B of spaced-apart shaft-mount slots  81 B,  82 B. Shaft  80  remains aligned with cylindrical shaft-support passageways  81 D,  82 D formed in movable pad support  18  as movable pad support  18  moves toward pan mount  16 . 
         [0035]    First rear guide pin  83  is coupled to pan mount  16  at first rear-mount guide-pin receiver  83 A and coupled to movable pad support  18  at first rear-support guide-pin receiver  83 B. As pad-extension system  14  moves between the retracted and expanded configurations, first rear guide pin  83  rotates in rear cylindrical passageway  83 C and slides up and forward relative to pan mount  16  along rear support slot  83 D formed in movable pad support  18 . First rear guide pin  83  remains aligned with rear cylindrical passageway  83 C of pan mount  16 . 
         [0036]    Second rear guide pin  84  is coupled to pan mount  16  at second rear-mount guide-pin receiver  84 A and coupled to movable pad support  18  at second rear-support guide-pin receiver  84 B. As pad-extension system  14  moves between the retracted and expanded configurations, second rear guide pin  84  rotates in rear cylindrical passageway  84 C and slides up and forward relative to pan mount  16  along rear support slot  84 D formed in movable pad support  18 . Second rear guide pin  84  remains aligned with rear cylindrical passageway  84 C of pan mount  16 . 
         [0037]    First bias unit  28  includes a first arm  28 A, a second arm  28 C, and a body  28 B connected therebetween, as shown in  FIG. 2 . As shown in  FIG. 3 , body  28 B is coupled to pan mount  16  at first bias-unit mount  68 . First arm  28 A is coupled to pan mount  16 , second arm  28 C is coupled to movable pad support  18 , and first bias unit  28  is arranged to bias movable pad support  18  toward pan mount  16  when pneumatic inflatable bladder  24  is deflated and pad-extension system  14  is moved from the expanded configuration to the retracted configuration. 
         [0038]    Second bias unit  29  includes a first arm  29 A, a second arm  29 C, and a body  29 B connected therebetween, as shown in  FIG. 2 . As shown in  FIG. 3 , body  29 B is coupled to pan mount  16  at second bias-unit mount  69 . First arm  29 A is coupled to pan mount  16 , second arm  29 C is coupled to movable pad support  18 , and second bias unit  29  is arranged to bias movable pad support  18  toward pan mount  16  when pneumatic inflatable bladder  24  is deflated and pad-extension system  14  is moved from the expanded configuration to the retracted configuration. 
         [0039]    In some embodiments, bias units  28 ,  29  may be tension springs or other biasing members arranged to cause movable pad support  18  to be biased to move toward pan mount  16  when pad-extension system  14  is not in the retracted configuration. When air exits pneumatic inflatable bladder  24  through feed tube  26 , or any other suitable alternative, as suggested by an arrow  26 B, shown in  FIG. 4 , pneumatic inflatable bladder  24  deflates. As pneumatic inflatable bladder  24  deflates, bias units  28 ,  29  apply a biasing force to movable pad support  18  to cause movable pad support  18  to move toward pan mount  16  causing pad-extension system  14  to retract. Air may be forced through feed tube  26  as suggested by arrow  26 B as a result of the biasing force supplied by bias units  28 ,  29 , or any other suitable alternative. 
         [0040]    Pan mount  16 , also called substrate  16 , is a monolithic component in illustrative embodiments. Pan mount  16  is formed to include a pan-mount panel  60  and a mount body  61  as shown in  FIG. 1 . Pan-mount panel  60  is substantially horizontal and is fixed to seat pan  12  as suggested in  FIG. 1 . Mount body  61  extends upwardly and downwardly from pan-mount panel  60  and provides a mover-facing mount surface  62  for pad-support mover  20  to engage and push against when moving movable pad support  18  relative to pan mount  16 . Pan-mount panel  60  includes first bias-unit mount  68  and second bias-unit mount  69 . 
         [0041]    Movable pad support  18  moves relative to seat pan  12  from a first position near mount body  61  when pad-extension system  14  is in the retracted configuration as suggested by  FIG. 4  to a second position further away from mount body  61  when pad-extension system  14  is in the expanded configuration as suggested by  FIG. 5 . Movable pad support  18  is illustratively a monolithic component formed to include a forward body  70 , a rearward body  72 , and an apex  71  located at the highest point of intersection between forward body  70  and rearward body  72 . Leg support apex  71  moves up by maximum height H 3  and forward by maximum depth D 3  when pad-extension system  14  moves from the fully retracted configuration to the fully expanded configuration. Forward body  70  includes first and second shaft receivers  81 A,  82 A as shown in  FIG. 2 . Forward body  70  provides a mover-facing leg-support surface  73  for pad-support mover  20  to engage and push against when moving movable pad support  18  relative to pan mount  16  as shown in  FIG. 1 . Rearward body  72  includes first and second rear-mount guide-pin receivers  83 A,  84 A as shown in  FIG. 2 . Rearward body  72  engages second arm  28 C of first bias unit  28  and engages second arm  29 C of second bias unit  29  as shown in  FIG. 3 . 
         [0042]    Other structures may provide the pivoting and sliding movement of a leg support relative to a mount as suggested in  FIGS. 4 and 5 . In an embodiment, a leg support includes a plurality of studs that are each coupled to one of a plurality of slots in a mount. The plurality of slots in the mount constrain and guide the leg support as movement of the leg support as a leg-support mover pushes the leg support away from the mount. The plurality of slots in the mount cooperate to constrain and guide movement of the leg support as a biasing mechanism biases the leg support toward the mount. 
         [0043]    In an illustrative embodiment, a mount includes a plurality of studs that are each coupled to one of a plurality of slots in a leg support. The plurality of slots in the leg support constrain and guide movement of the leg support as a leg-support mover pushes the leg support away from the mount. The plurality of slots in the leg support cooperate to constrain and guide movement of the leg support as a biasing mechanism biases the leg support to move toward the mount. 
         [0044]    In an embodiment, a front shaft and a rear shaft extend between and interconnect a leg support and a mount. A plurality of slots, passageways, or combinations thereof cooperate to constrain and guide movement of the leg support as the leg support pivots and slides relative to the mount. 
         [0045]    In an embodiment, a single shaft extends between and interconnects a leg support and a mount. A plurality of slots, passageways, or combinations thereof cooperate to constrain and guide movement of the leg support as the leg support pivots and slides relative to the mount. 
         [0046]    In an embodiment, a snap-in ball joint couples a leg support and a mount. The snap-in ball joint constrains and guides movement of the leg support as the leg support pivots and slides relative to the mount. 
         [0047]    Any other suitable mechanism may be used in accordance with the present disclosure to provide the pivoting and sliding movement of a leg support relative to a mount in accordance with the present disclosure as suggested in  FIGS. 4 and 5 . Any suitable combination of mechanisms as disclosed herein may also be used to constrain and guide movement of a leg support as the leg support to pivots and slides relative to a mount. 
         [0048]    An occupant-support base  210 , embodied as a seat bottom  210 , in accordance with the present disclosure is adapted for use in a vehicle seat as suggested in  FIG. 6 . Occupant-support base  210  includes a seat pan  212 , a pad  213  coupled to seat pan  212 , and a pad-extension system  214  coupled to seat pan  212 . Pad-extension system  214  is configured to change the size of occupant-support base  210  by moving between a retracted configuration as shown in  FIGS. 9A &amp; 9B  and an expanded configuration as shown in  FIGS. 10A &amp; 10B . Pad-extension system  214  changes the length of occupant-support base  210  between a first length L 1  associated with the retracted configuration and a relatively greater second length L 2  associated with the expanded configuration as suggested in  FIG. 6 . 
         [0049]    Pad-extension system  214  includes a pan mount  216 , a movable pad support  218 , and a pad support mover  220  as shown, for example, in  FIG. 7 . Pan mount  216  is coupled to seat pan  212  of occupant-support base  210  in a fixed position relative to seat pan  212 . Movable pad support  218  is coupled to pan mount  216  to slide back and forth relative to pan mount  216  when pad-extension system  214  moves between the retracted configuration and the expanded configuration. Pad support mover  220  is located between pan mount  216  and movable pad support  218  and is configured to move movable pad support  218  relative to pan mount  216 . 
         [0050]    Pad  213  includes a cushion  215  and a cushion cover  217  as suggested in  FIGS. 6 and 9B . In the example where occupant-support base  210  is a seat bottom, cushion cover  217  and cushion  215  extend over pad-extension system  214  to support the legs of an occupant supported by occupant-support base  210  as pad-extension system  214  moves between the retracted configuration and the expanded configuration. In some examples, pad  213  may further include a slack compensator configured to control wrinkles in cushion cover  217  as pad-extension system  214  moves between the retracted configuration and the expanded configuration. In one example cushion  215  is made from or any other suitable alternative or combination. In one example, cushion cover  217  may be made from cloth, leather, or any other suitable alternative or combinations. 
         [0051]    Pad support mover  220  is, for example, a pneumatic inflatable bladder  224  configured to push movable pad support  218  away from pan mount  216  when pneumatic inflatable bladder  224  is inflated as suggested by an arrow  224 A shown in  FIGS. 6 &amp; 10B . Return springs  228 ,  229  also included in pad-extension system  214  are located between and arranged to interconnect pan mount  216  and movable pad support  218  to bias movable pad support  218  toward pan mount  216  when pneumatic inflatable bladder  224  is deflated. Return springs  228 ,  229  bias movable pad support  218  toward pan mount  216  to cause pad-extension system  214  to move from the expanded to the retracted configuration. 
         [0052]    A maximum distance L 3  traveled by movable pad support  218  between the fully retracted configuration and the fully expanded configuration may be modified for various embodiments. In the illustrative embodiment, as suggested by  FIG. 6 , movable pad support  218  travels maximum distance L 3  of about 30 mm. 
         [0053]    Pneumatic inflatable bladder  224  inflates in response to air entering pneumatic inflatable bladder  224  through a feed tube  226  as suggested by an arrow  226 A as shown in  FIG. 10B . Inflation of pneumatic inflatable bladder  224  pushes movable pad support  218  away from pan mount  216  causing pad-extension system  214  to expand. Air may be forced through feed tube  226  as suggested by arrow  226 A by a source of pressurized air. A pressure gradient across feed tube  226  is generated to cause pneumatic inflatable bladder  224  to inflate. 
         [0054]    In some embodiments, return springs  228 ,  229  may be tension springs or other biasing members arranged to cause movable pad support  218  to be biased to move toward pan mount  216  when pad-extension system  214  is not in the retracted configuration. When air exits pneumatic inflatable bladder  224  through feed tube  226 , or any other suitable alternative, as suggested by an arrow  226 B, shown in  FIG. 9B , pneumatic inflatable bladder  224  deflates. As pneumatic inflatable bladder  224  deflates, return springs  228 ,  229  provide a bias force to movable pad support  218  to cause movable pad support  218  to move toward pan mount  216  causing pad-extension system  214  to retract. Air may be forced through feed tube  226  as suggested by arrow  226 B as a result of the bias force supplied by return springs  228 ,  229 , or any other suitable alternative. 
         [0055]    Pan mount  216 , also called substrate  216 , is a monolithic component formed to include a pan mount panel  260  and a face panel  262  as shown in  FIG. 7 . Pan mount panel  260  is substantially horizontal and is fixed to seat pan  212  as suggested in  FIG. 6 . Face panel  262  extends upwardly and downwardly from pan mount panel  260  and provides a surface for pad support mover  220  to engage and push against when moving movable pad support  218  relative to pan mount  216 . 
         [0056]    Movable pad support  218  moves relative to seat pan  212  from a first position near seat pan  212  when pad-extension system  214  is in the retracted configuration as suggested by  FIG. 9  to a second position further away from seat pan  212  when pad-extension system  214  is in the expanded configuration as suggested by  FIGS. 10A and 10B . Movable pad support  218  is illustratively a monolithic component formed to include a forward body  270  and an upper platform  272  as shown in  FIG. 7 . Forward body  270  defines a front side  232  of movable pad support  218  and is pushed away from pan mount  216  by pad support mover  220  as suggested in  FIG. 6 . Upper platform  272  extends rearwardly from forward body  270  to define a top side  233  of movable pad support  218 . In the illustrative embodiment, at least a portion of pan mount  216 , including face panel  262  of pan mount  216 , is received by movable pad support  218  between a bottom side  234  of movable pad support  218  and upper platform  272  as shown in  FIGS. 6-8 . In the retracted configuration, bottom side  234  of movable pad support  218  rests on face panel  262  of pan mount  216 . 
         [0057]    Pan mount  216 , movable pad support  218 , and a mounting arm  283  are coupled by a pair of mounting fasteners  283 A and  283 B. Pan mount  216 , movable pad support  218 , and a mounting arm  284  are coupled by a pair of mounting fasteners  284 A and  284 B. Mounting fasteners  283 A,  283 B,  284 A, and  284 B are coupled to pan mount  216  in a fixed position relative to pan mount  216 . Mounting fasteners  283 A,  283 B,  284 A, and  284 B are coupled to movable pad support  218  to allow movable pad support  218  to slide back and forth relative to mounting fasteners  283 A,  283 B,  284 A, and  284 B. When pad-extension system  214  is moved to the expanded configuration, front side  232  of movable pad support  218  moves away from pan mount  216  and mounting arms  283  and  284 . 
         [0058]    When pad-extension system  214  is moved to the retracted configuration, front side  232  of movable pad support  218  moves toward pan mount  216  and mounting arms  283  and  284 . Movable pad support  218  is formed to include four spaced-apart slots  285 A,  285 B,  286 A, and  286 B as shown in  FIG. 7 . Mounting fastener  283 A is arranged to extend through slot  285 A and mate with pan mount  216 . Mounting fastener  283 B is arranged to extend through slot  285 B and mate with pan mount  216 . Mounting fastener  284 A is arranged to extend through slot  286 A and mate with pan mount  216 . Mounting fastener  284 B is arranged to extend through slot  286 B and mate with pan mount  216  as shown in  FIG. 7 . Each slot  285 A,  285 B,  286 A, and  286 B includes a first end and a spaced-apart second end. 
         [0059]    When pad-extension system  214  is in the retracted position as shown in  FIG. 8 , mounting fasteners  283 A,  283 B,  284 A,  284 B are arranged to engage the first end of each associated slot. As pad-extension system  214  moves from the retracted configuration toward the expanded configuration, the spaced-apart second end of each slot  285 A,  285 B,  286 A,  286 B moves toward each associated mounting fastener  283 A,  283 B,  284 A,  284 B. In one example, each mounting fastener  283 A,  283 B,  284 A,  284 B engages the second end of each associated slot  285 A,  285 B,  286 A,  286 B when pad-extension system  214  is in the expanded position. In one example, slots  285 A,  285 B,  286 A,  286 B are arranged to lie in a generally horizontal plane. 
         [0060]    As shown for example in  FIG. 10A , movable pad support  218  is coupled to a support nose  219 . Support nose  219  engages pan mount  216  when pad-extension system  214  is in the expanded configuration, the retracted configuration, and moving between the configurations. When pad-extension system  214  is expanded fully, support nose  219  rests on pan mount  216  and supports movable pad support  218 . In one embodiment, pad support mover  220  is configured to fit around support nose  219 . In another embodiment, a support nose is movable and is moved into position when the extension system is expanded fully. Support nose  219  increases the maximum support load of movable pad support  218  when pad-extension system  214  is in the expanded configuration. In the illustrative embodiment, as suggested by  FIG. 10A , movable pad support  218  may support a load of about 890 N. 
         [0061]    In another embodiment, a support nose may be omitted from a leg support. In this example, a leg support mover may support the leg support when the extension system is fully expanded. In another embodiment without the support nose, when the extension system is expanded fully, a mount extends out and the leg support is supported by the mount.