Abstract:
A foot mobility device includes a body, two pedals rotatable about an axis in opposition to each other and relative to the body, and a motor drive assembly. The feet of a user are placed on the pedals, and the motor drive assembly is powered to move the pedals even while the user is completely passive; i.e., without any active participation by the user. Moreover, the sensation received by the use, rather than being one of typical “exercise”, is massage-like and therapeutic, all while providing the same benefit of increased blood circulation due to contraction and relaxation of the calf muscle. The device may also be used in an active mode, pedaled by the user. Moreover, the foot mobility device may be moved between an open configuration adapted for use of the device and a collapsed configuration having a low profile and adapted for storage and portability.

Description:
[0001]    The application claims priority from U.S. Provisional Ser. No. 60/313,541, filed Aug. 20, 2001, which is hereby incorporated by reference herein in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates broadly to exercise devices. More particularly, this invention relates to exercise devices which promote circulation in the lower extremities by movement of the foot about a pivot.  
           [0004]    2. State of the Art  
           [0005]    Deep vein thrombosis (DVT) refers to the formation of a thrombus (blood clot) within a deep vein, commonly in the thigh or calf. The blood clot can travel to the lungs, resulting in pulmonary embolism, a potentially life-threatening condition.  
           [0006]    DVT occurs when the flow of blood is restricted in a vein, and can be caused by poor circulation because of problems such as heart disease, a recent heart attack or stroke, varicose veins, or from inactivity or prolonged bed rest. Recently, a lot of attention has been focused on DVT developed during long airplane flights and deaths resulting therefrom. In fact, DVT has been dubbed ‘economy class syndrome’ because the less expensive seats in a plane have less leg room, limited leg movement. However, DVT is not confined to economy class or to long haul flights.  
           [0007]    In view of current and impending lawsuits by passengers with respect to DVT, airlines have become proactive in trying to prevent the condition and are now directing passengers to get up and walk around the airplane cabin at least once an hour to increase blood circulation. However, flights are subject to meal service and turbulence which limit the amount of time available for passengers to exercise their legs. Moreover, flights are crowded and it is not feasible for all the passengers to walk through the narrow aisles in the cabin.  
           [0008]    As a response, a number of devices are being promoted to increase blood circulation while a passenger remains seated. For example, the LYMPHA-PRESS® SKY WALKER™ device by Mego Afek of Kibbutz Afek, Israel, is a portable, foldable exercise device operated from a seated position. The device includes two foot pedals which are not subject to any resistance other than minimal friction forces. When the user wants to increase circulation, the pedals can be easily moved by the feet of a user in a pedaling motion. The simple pedal movement of the user&#39;s feet effects contraction of the calf muscles which assists in moving venous blood back to the heart, augmenting arterial blood inflow and preventing thrombosis.  
           [0009]    However, this and similar devices have a common drawback when used for the purpose of preventing DVT on long airplane flights; they require too much effort. Even the SKY WALKER™ device, which offers substantially no resistance, requires the user to concentrate on the movement of the feet. That is, if the user concentrates on the in-flight movie or a magazine, it is easy to forget to continue to pedal and DVT can result.  
           [0010]    U.S. Pat. No. 6,217,488 to Bernardson discloses another lower leg exerciser which includes a base, foot pedals which rock along a pivot relative to the base, and a motor adapted to rock the pedals back and forth. When feet are placed on the pedals, the feet are rocked automatically and blood circulation in the legs is increased. However, the Bernardson device has several drawbacks. First, the rocking movement of the feet causes the knees to move up and down. This motion is not suited to airplane travel, as the room in front of a seat is limited, and once the user&#39;s feet are raised and placed on the device, the rocking motion may cause the user&#39;s knees to contact the back of the chair in front, may cause interference with a tray table, or may be annoying if, e.g., trying read a book held on the lap. A second drawback is that the Bernardson device cannot be reconfigured to a smaller size for increased portability. A third drawback is that should a power supply be unavailable for powering the device, i.e., no suitable power outlet or depleted batteries, the device does not provide anti-DVT exercising of the legs.  
         SUMMARY OF THE INVENTION  
         [0011]    It is therefore an object of the invention to provide a foot mobility device which moves the feet in a manner which limits knee movement.  
           [0012]    It is another object of the invention to provide a foot mobility device which requires no effort on the part of the user.  
           [0013]    It is an additional object of the invention to provide a foot mobility device which is portable.  
           [0014]    It is also an object of the invention to provide a foot mobility device which has a low profile.  
           [0015]    It is still another object of the invention to provide a foot mobility device which has a collapsed configuration.  
           [0016]    It is a further object of the invention to provide a foot mobility device which can be used as either a passive (powered) or active (non-powered) exercise device.  
           [0017]    In accord with these objects, which will be discussed in detail below, a foot mobility device is provided and includes a body, two pedals rotatable about a common axis preferably in opposition to each other and relative to the body, and a motor drive assembly coupled to the pedals. The feet of a user are placed on the pedals, and the motor drive assembly is powered to cause movement of the pedals even while the user is completely passive; i.e., without any active participation by the user. Moreover, the sensation received by the use, rather than being one of typical “exercise”, is massage-like and therapeutic, all while providing the same benefit of increased blood circulation due to contraction and relaxation of the calf muscle. Moreover, the foot mobility device may be moved between an open configuration adapted for use of the device and a collapsed configuration having a low profile and adapted for storage and portability.  
           [0018]    According to one embodiment of the invention, the foot mobility device includes a generally vertically oriented body, two foot pedals hingedly coupled on either side of the body to rotate substantially ninety degrees relative to the body between a closed position in which each foot pedal is substantially parallel to the body and an open position in which each foot pedal is substantially perpendicular to the body. In the open position, the pedals are adapted to cause feet placed thereon to rotate about the ankle joint.  
           [0019]    According to other embodiments of the invention, the foot mobility device includes a preferably flat base, two pedals rotatable about a heel pivot, and a motor mechanism which rotates the pedals. The motor mechanism is movable from a first position in which it lies against the base to an upright second position in which it is adapted to move the pedals. The pedals can be configured to lie flat against the base for storage and portability. In addition, the pedals can preferably be disengaged from the motor drive so that the device can be used as an active exercise device and also to facilitate moving the pedals for folding the device in a highly portable configuration.  
           [0020]    It will be appreciated that with the foot mobility device of the invention, a highly compact and therefore portable powered foot mobility device is provided.  
           [0021]    Additional objects and advantages of the invention will become apparent to those skilled in the art upon reference to the detailed description taken in conjunction with the provided figures.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    [0022]FIG. 1 is a perspective view of a first embodiment of a portable foot mobility device with the pedals in an open configuration;  
         [0023]    [0023]FIG. 2 is a perspective view similar to FIG. 1, but in which a left housing element has been removed such that the interior of the housing can be seen;  
         [0024]    [0024]FIG. 3 is a perspective view similar to FIG. 2, with the additional removal of the left pedal, left rocker, and left gearbox housing, and with front and rear legs in a closed position;  
         [0025]    [0025]FIG. 4 is a perspective view of the first embodiment of the portable foot mobility device with the legs in an open position;  
         [0026]    [0026]FIG. 5 is a perspective view of the foot mobility device in a closed configuration;  
         [0027]    FIGS.  6 ( a )- 6 ( f ) are perspective views similar to FIG. 4 illustrating the range of motion of the right pedal;  
         [0028]    [0028]FIG. 7 is a perspective view of a second embodiment of the foot mobility device of the invention in an open configuration;  
         [0029]    [0029]FIG. 8 is a side elevation view the second embodiment of the foot mobility device of the invention in an open configuration;  
         [0030]    [0030]FIG. 9 is a top view of the second embodiment of the foot mobility device of the invention in a closed configuration;  
         [0031]    [0031]FIG. 10 is a side elevation view of the second embodiment of the foot mobility device of the invention in an open configuration;  
         [0032]    FIGS.  11 - 13  are schematic views of the gear and switch assembly which operates reciprocable movement of the foot pedals in the second embodiment of the foot mobility device of the invention;  
         [0033]    [0033]FIGS. 14 and 15 are schematic views of the engagement and disengagement, respectively, of the gearbox from the drive gear, and also of the power switch operation in the second embodiment of the foot mobility device of the invention;  
         [0034]    FIGS.  16 ( a )- 16 ( d ) are schematic views of a third embodiment of a foot mobility device according to the invention, shown in several positions as being moved from an open configuration to a closed configuration;  
         [0035]    [0035]FIGS. 17 and 18 are schematic view of a first mechanism for automatically disengaging the drive train from the pedals in the second and third embodiments of the invention;  
         [0036]    [0036]FIG. 19 is a schematic view of a second mechanism for automatically disengaging the drive train from the pedals in the second and third embodiments of the invention;  
         [0037]    [0037]FIG. 20 is a perspective view of a fourth embodiment of the invention, in a collapsed configuration;  
         [0038]    [0038]FIG. 21 is a perspective view of the fourth embodiment of the invention, in an open configuration;  
         [0039]    [0039]FIG. 22 is a perspective view of the fourth embodiment of the invention, illustrating the maximum rise of one pedal relative to the other;  
         [0040]    [0040]FIG. 23 is a perspective view of the fourth embodiment of the invention with the left pedal removed to show the four-bar linkage support of the motor housing in the open configuration;  
         [0041]    [0041]FIG. 24 is a perspective view of the fourth embodiment of the invention, in an open configuration also showing the pedal at full travel (maximum rise);  
         [0042]    [0042]FIG. 25 is a perspective view of one side of the gear box of fourth embodiment;  
         [0043]    [0043]FIG. 26 is a perspective view of the other side of the gear box of fourth embodiment;  
         [0044]    [0044]FIG. 27 is a perspective view of the gear train, with the device in the ‘OFF’ position such that the idler gear of the gear train is not engaged;  
         [0045]    [0045]FIG. 28 is a perspective view of the gear train, with the device in the ‘ON’ position such that the idler gear of the gear train motor is engaged;  
         [0046]    [0046]FIG. 29 is a perspective view of the gear train, four bar linkage, and switching mechanism; and  
         [0047]    [0047]FIG. 30 is a schematic view of a passenger compartment of a vehicle having foot mobility device according to the invention integrated into or coupled to the floor thereof.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]    Turning now to FIG. 1, a first embodiment of a foot mobility device  10  is shown. The device generally includes an upstanding housing  12  (preferably defined by left and right housing members  14 ,  16 ), and left and right pedals  18 ,  20  rotatable relative to the housing. The left and right pedals  18 ,  20  function as foot rests when in the open position shown in FIG. 1 (oriented perpendicular to the housing), but are respectively rotatable by ninety degrees about hinges  22  into an upright position substantially parallel to the housing (FIG. 6), as discussed below. Front and rear legs  24 ,  26  respectively, described in more detail below, support the device on a surface away from the floor to allow clearance for pedal movement and provide stability for the housing  12 .  
         [0049]    Turning now to FIGS. 2 and 3, the pedals  18 ,  20  are coupled to a gearbox  30  having a housing  31  defined by left and right housing elements  32 ,  33 . More particularly, the pedal hinges  22  couple the pedals  18 ,  20  to left and right rockers  34 ,  36  which are, in turn, coupled to the gearbox  30  with left and right rocker links  38 ,  40  using left and right rocker bushings  42 ,  44 . Three preferably identical roller bearings  46  are mounted to the housing on roller bearing mounts  48 . The weight of the user&#39;s feet and legs tends to force the rockers  34 ,  36  toward each other, and the roller bearings  44  maintain separation between the two rockers  34 ,  36 . The diameter of each of the roller bearings  46  is equal to the desired distance between the left and right rockers.  
         [0050]    Referring particularly to FIG. 3, the gearbox housing  31  encases a motor  50 , powered by batteries  52  located inside the housing  12 . The motor  50  has an output shaft (not shown) which rotates in a preferably counter-clockwise direction, as viewed from the shaft end of the motor. The output shaft is provided with a motor pulley  54  which drives a worm pulley  56  by means of a belt  58  for purposes of isolating motor vibration and reducing noise. The worm pulley  56  is preferably a one-piece component with a pulley  60  at one end and a right-handed worm screw  62  coaxially located at the other end. The worm pulley  56  is rotatably mounted on a steel shaft (not shown) that is rigidly provided in gearbox housing  31 . The worm screw  62  engages a shaft-mounted compound worm gear  64 . The compound worm gear  64  has a spur gear  66  coaxially affixed to the worm gear, and the spur gear  66  engages a compound gear  68 . The compound gear  68  engages an idle gear  70  which, in turn, engages a cam gear  72 . Unlike the rest of the gears, the cam gear  72  preferably does not pivot on a shaft, but rather includes an annular projection  74  on each of its sides which is inserted into corresponding holes  76  in the left cam gear bearing  78  and right cam gear bearing (not shown).  
         [0051]    The cam gear  72  also has an additional annular projection  80  on each of its sides. The projections  80  are smaller in diameter than projection  74  and are parallel to, but not coaxial with, the axis of rotation of cam gear  72 . These projections, one on the left side and one on the right, are 180° out of phase with each other. The projections  80  provide a pivot joint for the attachment of the left and right rocker links  38 ,  40 . The rotation of cam gear  72  causes the gearbox ends of the rocker links to travel in circular paths. The other end of each of the rocker links is attached to a respective rocker  34 ,  36 . For example, right rocker link  40  is rotatably mounted to the right rocker  36  by means of rocker link bearing  44 . The rocker link bearing  44  is screwed to the right rocker  36  and has a flange  82  such that the right rocker link  40  is trapped between the flange  82  and the face  84  of the rocker  36 .  
         [0052]    The right rocker  36  is pivotably mounted on a rocker bearing  86  which is located and trapped between bosses  88  that project inward from both the left and right housing members  14 ,  16 .  
         [0053]    Referring to FIGS. 3 and 4, the front leg  24  is connected to the gearbox  30  with a gearbox link  89 . When the front leg  24  is in the closed (folded) position (FIG. 3), the gearbox  30  is spaced apart from the front wall  90  of the housing  12 . When the front leg  24  is pulled into the open position (FIG. 4), the gearbox link  90  is pulled, which in turn moves the gearbox  30  away from the rockers  34 ,  36  and toward the front wall  90  of the housing  12  (compare FIGS. 3 and 4). The movement of the gearbox  30  away from the rockers  34 ,  36  pulls the rocker links  38 ,  40 , which pulls the rockers  34 ,  36 . In the folded position of FIG. 3, the position of the gearbox  30  locates the rocker links  38 ,  40  and rockers  34 ,  36  at the midpoint of the pedal movement cycle, where each pedal  18 ,  20  is halfway between up and down and parallel to each other such that the pedals, when folded about hinges  22 , are aligned with the housing  12 , as shown in FIG. 5. When the front leg  24  is unfolded such that the gearbox  30  is moved toward the front wall  90  of the housing as shown in FIG. 4, the position of the gearbox  30 , rocker links, and rockers orients the pedals at an angle relative to a surface on which the foot mobility device rests (i.e., in the middle position of the pedal movement cycle), and ready for use. It is noted that the cam gear  72  is not at all moved by the folding the front leg  24  between the open and closed positions.  
         [0054]    Still referring to FIGS. 3 and 4, the rear leg  26  telescopes into and out of a rear portion  92  of the housing  12 . A resilient catch  94  automatically locks against the bottom  96  of the housing when the rear leg  26  is moved into an extended position, but may easily be released by finger pressure to collapse the rear leg back into the housing.  
         [0055]    Referring now to FIGS.  6 ( a )-( f ) the full range of motion for the right pedal  20  is shown, with an understanding that left pedal  18  (FIG. 1) undergoes a similar though opposite motion. FIG. 6( a ) depicts the lowest position for pedal  20 , FIG. 6( c ) depicts the middle, or folding, position for the pedal, FIG. 6( b ) depicts a position between FIGS.  6 ( a ) and  6 ( c ), FIG. 6( e ) depicts the maximum height position for pedal  20 , FIG. 6( d ) depicts a position between FIGS.  6 ( c ) and  6 ( e ), and FIG. 6( f ) depicts the pedal  20  on its way back toward the lowest position. The axis of rotation of the pedals  18 ,  20  is substantially about the location of the ankles of the feet placed on the pedals. This is facilitated by placing the foot pedals below the axis of rotation.  
         [0056]    Referring back to FIG. 5, it is appreciated that the folding of the pedals  18 ,  20  against the housing  12  provides a device  10  with a small profile which is highly suitable for storage and travel. In the folded position, the entirety of the device has a preferred length to thickness to height ratio of approximately 14 to approximately 3 to approximately 7. These relative dimensions provide a device suitable for carry-on luggage or even a briefcase.  
         [0057]    Turning now to FIGS. 7 and 8, a second embodiment of a portable foot mobility device  100  is shown. The foot mobility device  100  generally includes a base  112 , left and right foot pedals  118 ,  120  rotatable up and down relative to the base on a hinges  122  at heel portions of the pedals, and a motor housing  130  also movable relative to the base. The base  112  includes a battery compartment  132  which is electrically coupled to a motor  140 , discussed below, in the motor housing  130 . The motor housing  130  is coupled to a pair of movable trusses  134 ,  136  and the motor housing and trusses are movable between a closed configuration, in which both are substantially flush with the base (FIGS. 9 and 10), and an open configuration in which the trusses and a lower portion of the motor housing  130  assume a stable triangular configuration (FIGS. 7 and 8).  
         [0058]    Turning now to FIG. 11, the motor housing  130  includes a drive assembly. The drive assembly includes a motor  140  and a gearbox  180  (FIG. 14) provided with gears. The motor  140  has an output shaft  142  provided with a spur gear  144 . The spur gear  144  engages a first shaft-mounted compound gear  146  which engages a second shaft-mounted compound gear  148  to step down the rotational transmission of the motor  140 . A spur gear portion  150  of the second compound gear  148  engages a spur gear portion  152  of a drive gear  154 , which is located outside the gear box  180 . The drive gear  154  also includes a pulley portion  156 . Left and right pulleys  158 ,  160  are horizontally offset on either side of the pulley portion  156 , and the pulley portion of the drive gear  154  moves a rope  162 , or other flexible transmission line such as a cable, across the pulleys  158 ,  160 . The left and right pedals  118 ,  120  are each coupled to one end of the rope  162 , as shown with respect to the left pedal in FIG. 8.  
         [0059]    The motor drive  130  is also provided with a switch  170  having a contact arm  172  movable between two positions, with each position causing the motor  140  to rotate in an opposite rotational direction. The drive gear  154  includes a peg portion  174  on its face which extends sufficiently therefrom to interfere with the contact arm  172  at predetermined rotational positions so that the switch  170  may be activated.  
         [0060]    The-motor drive  130  operates the pedals  118 ,  120  in an up and down motion as follows. The contact arm  172  of the switch  170  is oriented in a position (e.g., to the left) causing counterclockwise rotation of the motor  140 . Rotation of the spur gear  144  at the end of the motor shaft  142  results in rotation of gears  146 ,  148 ,  150  and consequently clockwise rotation of the drive gear  152 , as indicated by the arrow in FIG. 11. The peg portion  174  on the drive gear  152  is thereby rotated to cause the peg portion  174  to contact the contact arm  172  (FIG. 12), and then to cause the contact arm to move into the second position which causes clockwise rotation of the motor and counterclockwise rotation of the drive gear  152  (FIG. 13). The drive gear  152  and peg  174  are then rotated counterclockwise until the peg  174  again contact and moves the contact arm  172  to reverse the direction of the motor  140 . Each time the drive gear  152  is rotated in an opposite direction, the rope is likewise pulled in an opposite direction, with the pedal at one end of the rope being raised, and the pedal at the other end of the rope being lowered.  
         [0061]    Turning now to FIG. 14, according to a preferred aspect of the invention, the gears in the gearbox  180  may be disengaged from the drive gear  152  to facilitate closing (collapsing) the foot mobility device such that both pedals are substantially flush with the base  112 . That is, when the gearbox is disengaged, the rope attached to the pedals may be moved without having to rotate all the gears in the gearbox against the resistance of the motor. According to a currently preferred disengagement (and engagement) mechanism, the gearbox  180  is provided with a cam  182  on its surface. The gearbox  180  is vertically movable within a slot defined by walls  184 ,  186 . A horizontally movable lever  188  is provided with a cam slot  190  in which the cam  182  rides. The lever  188  preferably includes left and right button portions  192 ,  194 . When the lever  188  is positioned to the left, as shown in FIG. 14, the cam  182  is forced into a portion of the slot  190  which causes the gearbox  180  to be in a vertical position which results in engagement of a gear in the gearbox with the drive gear  152 . When the lever is moved to the right, as shown in FIG. 15, the cam  182  is forced vertically downward in the cam slot  190 , and the gear box  180  is disengaged from the drive gear  152 . With the gearbox disengaged, the foot mobility device may be used as an active exercise device in which the user moves the pedals. This is particularly useful when the batteries are depleted, or when completely silent operation is desired.  
         [0062]    Moreover, the same mechanism can be, though not necessarily is, used to complete and disrupt a power switch to activate and deactivate (i.e., turn ON and OFF) the device  100 . Referring back to FIG. 14, contacts  196 ,  198  are required to be in electrical contact for the motor to receive power from the battery source. Contact  198  is resiliently biased away from contact  196 . When the gearbox  180  is in the engaged position, gearbox forces contact  198  against contact  196 , providing power from the battery source to the motor. However, when the gearbox is disengaged (FIG. 15), contact  198  moves away from contact  196  and power is removed.  
         [0063]    According to another preferred aspect of the invention, the lever is preferably actuatable by foot, with the left and right button portions  192 ,  194  extending outside the housing  12 , as shown in FIGS. 7 through 9. As such, once the device is in the open position, it may be easily turned ON by using a user&#39;s foot to move the lever  188  into the ON position and likewise turned OFF in the same manner; i.e., by moving the lever in the opposite direction with one&#39;s foot. The foot activation is very advantageous, especially when seated in a cramped airplane seat, where there is little room to bend to the floor and operate a device.  
         [0064]    Turning now to FIGS.  16 ( a )- 16 ( d ), a third embodiment of the foot mobility device  200 , substantially similar to the second embodiment, is shown. The foot mobility device  200  includes two pedals (only left pedal  218  shown in the figures) hinged to a base  212 , a motor drive (not shown) in a central foldable motor drive housing  230 , and a rope (or cable)  262  connecting the unhinged end of the pedals to the motor drive mechanism. When in the opened position of FIG. 16( a ) and powered, the motor drive causes the pedals to move up and down about their hinges  222 . When one pedal is down the other is up. The motor drive housing  230  is coupled to the base  212  by a four bar linkage (with the two left bars  234 ,  235  being shown, and similar right bars not shown) allowing the housing  230  to fold into intermediary positions shown in FIGS.  16 ( b ) and  16 ( c ), and finally into the flat position of FIG. 16( d ). Simultaneously with the folding, the tension on the rope  262  is released, such that the foot pedals  218 ,  220  are allowed to fold flat as well. To further allow for easy folding, the device  200  when folded automatically switches to OFF mode and disengages the motor from the gear train allowing the rope  262  to move freely so that if one pedal is all the way up the rope can easily adjust as the device is folded.  
         [0065]    Referring to FIG. 17, one mechanism for automatically disengaging the drive train from the pedals is shown. A cog  260  is slidably coupled to the gearbox  280 , and is biased by a first spring  262  toward the lever  288 . A cable  261  is coupled at one of its ends to the cog  260 , and at the other of its ends it is coupled to elsewhere on the device, as discussed below. The lever  288  includes a catch  264 , and the cog  260  includes a beveled end  266  engageable within the catch  264  when the lever  288  is positioned such that the device  200  is in an ON position. A second spring  268  is coupled to the lever  288  and tensioned to pull the lever  288  with sufficient force move the cam  282  relative to the cam slot  290  such that the gearbox  280  is moved into a disengaged position. When the drive mechanism housing  230  is upright, the cable  261  is slack allowing the cog  260  to move under the tension of the first spring  262  so that the beveled end  266  of the cog  260  enters the catch  264  and holds the lever  288  in the engaged position, locking the lever in place against the tension of the second spring  268 . Referring to FIG. 18, as soon as the housing ( 130  in the second embodiment, and  230  in the third embodiment) starts to move from the vertical position, either in its four bar linkage configuration (FIGS.  16 ( a )- 16 ( d )) or in its sliding configuration (FIGS. 7 and 8), the cable  261  is caused to go taught, pulling the cog  260  from the catch  264 , and allowing the lever  288  to spring, under the force of the second spring  268 , into the OFF position, removing power and disengaging the motor drive. For example, in the four bar linkage configuration of FIGS.  16 ( a )-( d ), either the pivoting action of the lower or upper bars  234 ,  235  can cause the cable  261  to go taught. In the sliding version of FIGS. 7 and 8, either the pivoting of bars  134 ,  136  or a rocker on the base  112  can be used to cause the link  261  to go taught when the housing  230  starts to move out of its upright position.  
         [0066]    Referring back to FIG. 17, it is appreciated that even when the cog  260  is engaged in the catch  264  and the cable  261  is slack, the lever  288  may be manually moved to disengage the drive mechanism such that the device  200  may be used as an active exerciser. Manual application of force to the lever  288  overcomes the frictional engagement of the beveled end  266  of the cog  262  in the catch, and the second spring  268  holds the lever  288  in the disengaged position (FIG. 18).  
         [0067]    Referring to FIG. 19, a second mechanism for automatically disengaging the drive train from the pedals is shown. A preferably L-shaped lever bar  360  having first and second arms  362 ,  364  is rotatably coupled to the lever  388 . The cable  361  is coupled to the first arm  362 . When the cable  361  is pulled (i.e., when the housing  230  is folded), the lever bar  360  is rotated until the second arm  364  contacts the wall  184 . Further rotational movement of the lever bar  360  causes the lever  388  to move to the right, thereby moving the cam  382  relative to the cam slot  390 , and thereby disengaging the motor drive from the pedals.  
         [0068]    Turning now to FIGS. 20 through 22, a fourth embodiment of a foot mobility device  400  is shown. In FIG. 20 the device is shown in a collapsed or folded configuration, with the pedals  418 ,  420  substantially flushly seated on a base  412  (FIG. 21), and a motor housing  430  also in a flush folded position. By pressing a latch release  450 , the housing  430  is released from an engagement further discussed below, and the device may be moved into the open configuration of FIG. 21. FIG. 22 shows the maximum travel or rise of a pedal  420  relative to the base  412 . The pedals rotate about axes through their heel portion  419 ,  421 .  
         [0069]    Referring to FIGS. 22 and 23, a compartment  452  is provided on the base  412  under the right pedal  420  to house the electronics which control the hereinafter described motor assembly  454  (FIGS. 25 and 26), and a battery compartment  456  is provided under the left pedal  418 . FIG. 23 also better illustrates the above mentioned latch release  450  and spring-biased latches  458  which are adapted to hold and then release catches  460  on the end of the motor housing  430 . Referring to FIG. 24, the pedals  418 ,  420  each also include a catch  462  which is caught under the motor housing  430  when the motor housing is in the closed position to hold the pedals in a closed position.  
         [0070]    Referring back to FIG. 23, the housing is coupled to the base with a four-bar linkage  464 . When in the fully upright position of FIG. 23, the housing  430  rests on the base  412 .  
         [0071]    Referring again to FIG. 24, the pedals  418 ,  420  have a rear depressed area  470 ,  472  which functions as a heel rest. In addition, the pedal is wider at the heel end. The user&#39;s feet can be placed laterally on the heel ends to position the feet in a relatively parallel orientation, or the feet can be placed medially on the heel ends to splay the feet. The foot position can be selected according to user comfort.  
         [0072]    Referring to FIGS. 24 and 25, the pedals  418 ,  420  are preferably coupled to the motor assembly  454  with ropes  474 ,  476 . The motor assembly  454  includes a gear train  480  coupled to a preferably vibrationally-isolated motor  482 . The gear train  480  includes a main pulley gear  484  and left and right idler pulleys  486 ,  488 . One rope  474  extends from the left pedal  418  clockwise about the left idler pulley  486  and then clockwise about the main pulley gear  484  to which it is then attached. The other rope  476  extends from the right pedal  420  counterclockwise about a right idler pulley  488  and then counterclockwise about the main pulley gear  484  to which it is also then attached. Reciprocal rotation of the main pulley gear  484  by the gear train  480  causes the pedals  418 ,  420  to move in an up and down motion about axes through the heel portions  419 ,  421  of the pedals.  
         [0073]    Referring to FIGS. 26 and 27, a switch  490  is coupled to a linkage  492  which is coupled to an idler gear  494 . The idler gear  494  is coupled to the motor  482  and can be brought into and out of engagement with a portion of the gear train mechanically coupled to the main pulley gear  484 . The linkage  492  is subject to the force of a spring  496  (FIG. 26) which stably holds the idler gear  494  in its current position until sufficient manual force is provided to the switch  490  to move the linkage  492  and thereby alter the position of the idler gear  494 . The switch  490  also operates to provide and remove power from the batteries (in the battery compartment  456 ) to the motor  482 ; i.e., to power ‘ON’ and ‘OFF’ the device.  
         [0074]    In FIG. 27, the switch  490  and linkage  492  are positioned to provide the device in the ‘OFF’ mode and to locate the idler gear  494  out of engagement with a gear  498  directly engaging the main pulley gear  484 . In this configuration, the device may be used in an active mode; i.e., with the user providing the power to rotate the pedals. In FIG. 28, the switch  490  and linkage  492  are positioned to provide the device in the ‘ON’ mode, and locate the idler gear  494  in engagement with gear  498 ; i.e., such that the motor assembly moves the pedals in a reciprocating motion. In addition, a clutch  500  is provided to prevent damaging force from being applied to a portion of the gear train and the motor, e.g., if a user were to apply foot pressure counter to the movement of the pedals by the motor assembly  454 .  
         [0075]    Turning to FIG. 29, a small L-shaped lever  502  is provided adjacent one of the supports  504  of the four bar linkage  464 . If the device  400  is folded while the motor is engaged, upon folding, the L-shaped lever  502  contacts a rocker  506  which operates to move the switch  490  to an OFF position, thereby disengaging the pedals from the motor.  
         [0076]    Referring to FIG. 30, a passenger compartment  510  of a vehicle, e.g., a car, a truck, a plane, or a train, is shown. A foot mobility device  400  according to the invention is coupled to or integrated into the floor  512  of the compartment  510 . As the embodiments of the devices can each be folded to assume a relatively low profile, when not in use the devices do not substantially encroach upon the leg room in the compartment.  
         [0077]    From the above, it is appreciated that several embodiments of the device can be used in either a passive (powered) mode or in an active (non-powered) mode. In the active mode the user simply pushes one foot down causing the device to raise the other foot, and thereby exercise the lower extremities.  
         [0078]    In the above described foot mobility devices, the pedals operate to reciprocably move the feet about either the heel or ankle, but do not cause the exaggerated leg movement which results from rocking the feet, moving the feet about the ball of the foot, or pedaling the feet in a bicycle pedal motion. As such, the foot mobility device is particularly suitable for use in areas which provide little leg room and/or where it is desired to maintain the knees relatively still during use of the foot mobility device.  
         [0079]    There have been described and illustrated herein embodiments of a powered foot mobility device. While particular embodiments of the invention have been described, it is not intended that the invention be limited thereto, as it is intended that the invention be as broad in scope as the art will allow and that the specification be read likewise. Thus, while particular gear assemblies have been disclosed, it will be appreciated that other gear assemblies using fewer or more gears, and/or different types of gears can be used as well. In addition, while preferred housing designs have been illustrated, it will be understood that other housing designs can be used. Also, while the device is preferably battery powered, for portability, it is recognized that the device may be powered by an AC power source instead of a DC battery source, or by an AC power source which either bypasses the battery power source or can be used to recharge a rechargeable battery source. Furthermore, while in the second embodiment a rope or other resilient element is used to move the pedals, it will be appreciated that other systems may be used to support and move the pedals. For example, gear-rotatable supports may be provided under the pedals. Also, while exemplar mechanisms for automatically disengaging the drive train for the pedals are described, it will be appreciated that other suitable mechanisms can be used. It will therefore be appreciated by those skilled in the art that yet other modifications could be made to the provided invention without deviating from its spirit and scope.