Patent Publication Number: US-2004058784-A1

Title: Stationary type of exercise apparatus that enables movement of the user&#39;s feet in a reciprocating motion

Description:
[0001] The present application is a continuation-in-part of pending U.S. patent application Ser. No. 09/674,322, with filing date of Jul. 7, 2001, and entitled “A Stationary Type of Exercise Apparatus That Enables Movement of the User&#39;s Feet in a Reciprocating Motion,” which is a National Stage filing of PCT International Application PCT/US99/30935, having the same title and the international filing date of Dec. 22, 1999. Each of the above applications is incorporated by reference for all purposes and made a part of the present disclosure. 
    
    
     
       BACKGROUND OF THE INVENTION  
       [0002] The present invention relates generally to an exercise apparatus and, more particularly, to an exercise apparatus that enables the user to move his feet or legs in a reciprocating motion while remaining stationary.  
       [0003] Running, walking, skiing and other activities wherein the feet or legs are moved in a reciprocating motion are considered effective forms of exercise. These activities help to load the cardiovascular system as well as build muscle mass. Accordingly, exercise apparatus exist which attempt to simulate these activities. A typical prior art apparatus is designed to enable the user to exercise within an enclosed structure while obtaining most of the benefits of these simulate activities. The apparatus disclosed in U.S. Pat. No. 3,941,377 (hereby incorporated by reference) allows for variable resistance to be employed when foot carriages are moved rearwardly, but allows for generally un-resisted movement of the foot carriage in the forwardly direction. U.S. Pat. No. 4,684,121 (hereby incorporated by reference) discloses, on the other hand, an apparatus that may be used to simulate a skiing motion or a rowing motion. Adapted for a skiing exercise, the foot carriages disclosed can be moved along rails and against a variable resistance. The resistance is constant regardless of the direction of the movement of the foot carriages.  
       [0004] Operation of most, if not all, of the exercise apparatus in the prior art fails to accurately represent or simulate the actual physical activity. Many of these exercise apparatus require the user to exert some force other than force required in the normal exercise activity to operate the system. For example, the user may be required to exert additional force to accelerate a pedal or foot block back to a system speed. Application of such force during the simulated activity is unnatural and is not representative of the actual activity. Furthermore, the application of such force usually creates undesirable resistant forces which impact the user.  
       SUMMARY OF THE INVENTION  
       [0005] It is one of several objects of the present invention to provide a stationary type of exercise apparatus that is operable to simulate activity wherein the feet or legs are moved in a reciprocating motion, such as running, walking and skiing activities. Another object of the invention is to provide an apparatus for simulating such exercise activities in a manner that more closely represents the actual physical activity and/or causes relatively low impact to the user. A further object of the invention is to provide at least one embodiment, the operation of which involves utilization of inertia in the moving components of the apparatus to accelerate foot travelers or foot carriage assemblies. Preferably, the exercise apparatus is operable without requiring the user to exert additional force to operate the moving components of the apparatus.  
       [0006] In one aspect of the invention, an exercise apparatus is provided for enabling reciprocating motion of the user&#39;s legs or feet while the user remains generally stationary. The inventive apparatus includes a stationary frame, a first longitudinal rail supported, at least partially, by the frame, and a second longitudinal rail also supported, at least partially, by the frame and in generally parallel relation with the first rail. The apparatus further includes a first foot carriage assembly (or foot traveler) that is movably engageable along the first rail, a second foot carriage (or foot traveler) that is movably engageable along the second rail, and an inertia drive assembly disposed proximate the first and second rails. The inertia drive assembly includes a first transmission device (preferably a continuous belt) that is engageable with the first carriage assembly such that movable operation of the first carriage assembly drives the inertia drive assembly, and a second transmission device (preferably a continuous belt) engageable with the second carriage such that movable operation of the second carriage also drives the inertia drive assembly. Moreover, the first and second carriage assemblies are interconnected such that the inertia drive assembly can accelerate each carriage assembly (e.g., as each of the first and second carriage assemblies initially advances rearwardly or forwardly along one of the rails) by way of one of the first and second transmission devices.  
       [0007] The inertia drive assembly and the first or second carriage assemblies may be interconnected such that as the first or second carriage initially advances from a point of change in direction (rearwardly or forwardly), the inertia drive assembly can accelerate the carriage assembly up to a predetermined velocity without the user having to exert additional force to accelerate the carriage assembly. In one embodiment, each of the first and second carriage assemblies is frictionally engageable with one of the first and second belts (i.e., first and second transmission devices) to drive the belt in a first direction when the first or second carriage is moved in the first direction. Further, the first or second carriage is disengageable from a substantially frictionally engaged relation (attached and/or movable therewith) with the belt to move in a second direction opposite the first direction. Further yet, the first and second carriage assemblies may be interconnected (i.e., by a common continuous belt) such that each carriage assembly may be accelerated in the second direction by the inertia drive assembly. More particularly, the first carriage assembly may be accelerated in the second direction through rotation of the second belt by the inertia drive assembly (and transmission of this rotation through the common continuous belt) and the second carriage assembly may be accelerated through rotation of the first belt by the inertia drive assembly (and transmission of this rotation through the common continuous belt).  
       [0008] In another aspect of the invention, an exercise apparatus is provided that has a stationary frame, first and second longitudinal rails each supported, at least partially, by the frame and in generally parallel relation. The apparatus also has a first foot carriage assembly movably engageable along the first rail, a second foot carriage movably engageable along the second rail, and an inertia drive assembly that includes a first energy device. The inertia drive assembly is disposed proximate the first and second rails and is engageable with the first and second carriages such that, as the first or second carriage initially advances rearwardly or forwardly along one of the rails, the first energy device is usable to accelerate the carriage assembly. The apparatus also has a second energy device (i.e., distinct from the first energy device) that is engageable with the inertia drive assembly and adapted to transmit energy thereto. Preferably, the first energy device is a flywheel rotatably mounted on an inertia drive shaft of the drive assembly and the second energy device is a motor that is engageable with the inertia drive assembly (e.g., operably connected or coupled with the inertia drive shaft).  
       [0009] In one embodiment, the motor is operable to continuously transmit power to the inertia drive assembly during operation of the exercise apparatus by the user. In this way, the motor is used to compensate for frictional losses, inertia directional losses, and other energy losses inherent in the operation of the apparatus. The motor may also be used (in conjunction with or in lieu of the first energy device) to accelerate each of the foot carriage assemblies to a predetermined speed upon a change in direction.  
       [0010] In yet another aspect of the invention, an exercise apparatus is provided that includes a stationary frame, first and second longitudinal rails supported, at least partially, by the frame and in generally parallel relation. The apparatus also includes a first foot carriage assembly movably engageable along the first rail, a second foot carriage assembly movably engageable along the second rail and a drive assembly (e.g., an inertia drive assembly) disposed proximate the first and second rails and drivable upon movable operation of the first or second carriage assembly. The drive assembly includes first and second continuous belts, each of which is engageable with a first or second carriage assembly. Further, each of the first and second belts is rotatably supported by a suspension system that includes a resilient support assembly responsive to deflection of the belt upon frictional engagement between the belt and a carriage assembly.  
       [0011] The resilient support assembly is preferably interconnected with the first or second belt so as to further tension the belt upon frictional engagement with the carriage assembly. The support assembly may include a spring device interconnected with the belt which acts to resist deflection of the belt. The support assembly may also include a movable pulley interconnected with the spring device and rotatably supporting the belt. The movable pulley is preferably supported so as to be shiftable upon deflection of the belt.  
       [0012] In further embodiments of the invention, the movable or shiftable pulley is supported on a pivotable arm and is arcuately or rotatably movable about its pivot point upon loading of the belt by one of the carriage assemblies. A spring or tensioning device is preferably attached to the pivot arm so as to be responsive to deflection of the first or second belt. In this way, the spring device provides resilient resistance (and bias) against loading of the belt by one of the carriage assemblies. One advantageous result of this is that impact experienced by the user (e.g., when the user steps down on the carriage assembly to change its direction or to transfer weight) is minimized.  
       [0013] In yet another aspect of the invention, an exercise apparatus employs a unique, advantageous resilient support system. The apparatus includes a stationary frame, first and second longitudinal rails supported, at least partially, by the frame, and in mutual generally parallel relation, first and second foot carriage assemblies movably engageable along the first or second rail and pivotally fixed such that the first or second foot carriage assembly deflects angularly downward through an angular path from an inactive position upon application of pressure thereon by a user. The exercise apparatus also includes an inertia device disposed proximate the first and second rails and drivable upon movable operation of at least one of the first and second carriage assemblies. Furthermore, the exercise apparatus employs a first resilient support assembly positioned relative to the first carriage assembly so as to be responsive to angular deflection of the first carriage assembly by imparting a resistant force on the first carriage assembly and against pressure applied thereon, and a second resilient support assembly positioned relative to the second carriage assembly so as to be responsive to angular deflection of the second carriage assembly by imparting a resistant force on the second carriage assembly and against pressure applied thereon. Each resilient support assembly is configured such that the resistant force increases at a varying rate (e.g., at a non-linear rate) as the first or second carriage assembly deflects through the angular path.  
       [0014] The resilient support assembly may include an elastic device (e.g., a spring or elastic band) and an intermediate deflection element (e.g., a cam surface, belts and pulleys, or linkage assembly) operatively positioned intermediate the elastic device and the first or second carriage assembly. In this way, the intermediate deflection element is directly engageable with the first or second carriage assembly and movably responsive to angular deflection of the first or second carriage assembly. Further, the elastic device is directly engageable with the intermediate element such that movement of the intermediate deflection element in response to angular deflection of the first or second carriage assembly causes the elastic device to stretch and impart a resistant force thereon.  
       [0015] Other and further objects, features, and advantages of the present invention will be apparent from the following description of a presently preferred embodiment (s) of the invention, given for the purpose of disclosure, and taken in conjunction with the accompanying drawing. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0016] A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiment is considered in conjunction with the following Figures, in which:  
     [0017]FIG. 1 is a plan view of an exercise apparatus embodying the present invention;  
     [0018]FIG. 2 is an elevation view of the exercise apparatus in FIG. 1 showing a foot carriage assembly in a forward moving mode;  
     [0019]FIG. 3 is an elevation view of the exercise apparatus in FIG. 1 showing the foot carriage assembly in a rearward moving mode;  
     [0020]FIG. 4 is a view of certain movable portions of the exercise apparatus in FIG. 1;  
     [0021]FIG. 5 is an elevation view of an alternate foot carriage assembly for the exercise apparatus shown in the forward moving mode;  
     [0022]FIG. 6 is an elevation view of the foot carriage assembly of FIG. 5 shown in the rearward moving mode;  
     [0023]FIG. 7 is an elevation view of a second alternate foot carriage assembly for the exercise apparatus shown in the forward moving mode;  
     [0024]FIG. 8 is an elevation view of the foot carriage assembly of FIG. 7 shown in the rearward moving mode;  
     [0025]FIG. 9 is an elevation view of a third alternate foot carriage assembly for the exercise apparatus shown in the forward moving mode;  
     [0026]FIG. 10 is an elevation view of the foot carriage assembly of FIG. 9 shown in the rearward moving mode;  
     [0027]FIG. 11 is an elevation view of an exercise apparatus incorporating an alternative resilient support system according to the present invention;  
     [0028]FIG. 12 is a graphical illustration of the resistant force response of the resilient support system to pedal deflection, according to the present invention; and  
     [0029]FIGS. 13A and 13B are elevation views of an alternative resilient support system, according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
     [0030] FIGS.  1 - 4  depict an exercise apparatus  20  embodying the invention. The exercise apparatus  20  is of a stationary type that enables a user to reciprocate motion of his/her feet or legs so as to simulate running, walking and similar physical activity, while the user remains generally stationary. It should be noted that the structural configuration of exercise apparatus  20  and its particular operation are exemplary and are described herein to facilitate description of multiple aspects of the invention which are applicable and adaptable to other types of exercise apparatus. Upon reading the description and/or viewing the Figures, such applications, adaptations and extensions of the invention shall become apparent to one skilled in the relevant mechanical or structural art.  
     [0031] With reference to FIGS.  1 - 4 , exercise apparatus  20  includes a rear frame  300 , a front frame  301  and two pairs of longitudinal rails  382  which connect frames  300 ,  301  and extends therebetween. In the embodiment of FIG. 1, front frame  301  and rear frame  300  are supported on the floor and remain stationary during operation of exercise apparatus  20 , as do longitudinal rails  382 . Exercise apparatus  20  may also be equipped with a stand that is connected to front frame  301 . Such a stand is used to house panels, gauges or displays which may indicate, for example, exercise time and energy expended. Accessories such as handles and armrests may also be supported on this stand. Front frame  301  may be further equipped with an elevation adjustment arm that is pivotally attached to front frame  301 . Such an elevation adjustment arm will typically be supported near the front end of stationary exercise apparatus  20  and manually operable to adjust the elevation of the front end of stationary exercise apparatus  20 . Accordingly, exercise apparatus  20  may be placed in an inclined position such that the front end is elevated above the rear end thereby increasing the difficulty of the exercise.  
     [0032] As shown in FIG. 1, the pairs of rails  382  are disposed in generally parallel relation and are spaced apart to approximate the width of the user&#39;s stance. Referring to FIGS. 2 and 3, foot carriage assemblies or travelers  380  are movably attached to rails  382  and include a foot attachment carriage or foot base portion  380   a  and wheels  381  attached to the foot base portion  380   a . The wheels  381 , as will be shown below, are designed to rollably engage and ride along rails  382 . For engaging a user&#39;s foot, traveler  380  is equipped with a foot pedal  383  disposed on a top surface of foot base portion  380   a  and above rails  382 , and a foot toe piece  380   c  integrated or attached thereto. Traveler  380  also includes a generally downwardly extending pressure arm  380   b.    
     [0033] As will be further described below, when foot base portion  380   b  is forced into a substantially horizontal attitude, which occurs when the user is exerting force onto or through foot pedal  383 , traveler  380  is advanced into an active position and then moved rearward from the front end of exercise apparatus  20  to the rear end of the exercise apparatus  20  (see mode illustrated in FIG. 3 as illustrated by the direction of arrow  350 ). This travel segment may be referred to as a rearward or power stroke in that the user is exerting force onto the exercise apparatus  20 . In other words, the user pushes the foot pedal  383  which moves the traveler  380  rearwardly toward rear frame  300 . When the user removes weight from the foot base portion  380   b , traveler  380  returns automatically to an inclined or inactive position and is then moved from the rear end of exercise apparatus  20  to the front end of exercise apparatus  20  where it is prepared for another power stroke (see mode illustrated in FIG. 2 as illustrated by the direction of arrow  351 ). This travel segment may be referred to as the forward or return stroke. In one aspect of the invention further described below, operation of apparatus  20  does not require for the user to exert additional force to change the moving direction of traveler  382  (e.g. to change from the rearward moving direction to the forward moving direction).  
     [0034] Other aspects of the invention are embodied in an improved inertia transfer portion of the exercise apparatus  20 . Most of the components which may be described as of the inertia transfer assembly or inertia drive assembly are located generally adjacent rear frame  300 , but may be located, in further embodiments, elsewhere around the structure of the exercise apparatus  20 . Referring to FIGS.  1 - 4 , the inertia transfer assembly may be described as an assembly including a pair of vertically disposed front drive pulleys  310 , an inertia drive shaft  318  extending perpendicularly through the two drive pulleys  310 , and a first energy source or front flywheel/brake  306  rotatable with inertia drive shaft  318  and drive pulleys  310 . Flywheel  306  may include a brake system to increase or decrease resistance, well known to those skilled in the art. Such a brake may include a mechanical band brake system or an electromagnetic brake system, or an air-fan brake system. Referring to FIG. 4, which better illustrates certain of the movable components of the exercise apparatus  20 , front drive pulleys  310  are fixedly attached to and rotatable with inertia drive shaft  318  which is also fixedly attached with flywheel/brake  306 . The inertia transfer assembly may also be described as further including a pair of vertically oriented continuous inertia belts  323  which are disposed in rotational relation about the pair of drive pulleys  310  on the rear end and about a pair of idler pulleys  311  on the front end. As discussed below, inertia belt  323 , inertia drive shaft  318  and the components mounted to inertia drive shaft  318  are rotatable in the clockwise direction (for purposes of the present description) as indicated by arrows ZZ in FIG. 4.  
     [0035] It should be noted that shaft  318 , pulleys  310 ,  311  and belts  323  which are integrated in exercise apparatus  20  are conventional energy transmission devices. Upon reading the description and viewing the drawings, it shall be apparent to one skilled in the mechanical art to adapt the inventive exercise apparatus  20  so as to integrate alternate transmission devices and achieve many of the advantages and attributes associated with the embodiment described herein.  
     [0036] In one aspect of the invention, exercise apparatus  20 , or more particularly, the inertia transfer portion, does not employ clutch pulleys, clutch belts and other transmission devices which have been employed in the prior art. One result is that exercise apparatus  20  employs a simpler, more efficient design, which can be operated with greater ease and reduced energy losses. In one respect, exercise apparatus  20  can eliminate the use of clutch belts or pulleys because a common continuos belt  314  is provided to interlink or interconnect travelers  380  (and thus belts  323 ) without engaging inertia drive shaft  318  or pulleys  310 . Moreover, common belt  314  does not directly drive inertia transfer assembly (i.e., inertia drive shaft  318 ) to energize flywheel/brake  306 . Instead, the user drives the inertia transfer assembly by utilizing travelers  380  to drivingly engage inertia belts  323 , which drives inertia drive shaft  318 .  
     [0037] Referring to FIG. 4, common belt  314  is rotatably engaged about an idler pulley  309  and an idler pulley  308 . Travelers  380  are permanently coupled to the common belt  314  on opposite side of the belt at locations which divide the belt into two equidistant segments. Accordingly, when belt  314  is moved in a reciprocal manner (shown by arrow YY) by user action on the travelers  380 , common belt  314  assures that travelers  380  are moving in generally opposite directions.  
     [0038] Referring now to the side elevation views of FIGS. 2 and 3, inertia belts  323  is supported by a resilient suspension system which includes pulleys  310  and  311 . At any given time during operation of the exercise apparatus  20 , belt  323  may be described as having an upper portion  323   a  and a lower portion  323   b . In yet another inventive aspect of apparatus  20 , the belt system is configured such that rail  382  does not directly engage or directly support inertia belt  323  and inertia belt  323 . This configuration provides more flexibility to inertia belt  323  and allows inertia belt  323  to frictionally engage traveler  380  independent of the track  382 . Moreover, belt  323  can be used as part of a shock absorber system of the exercise apparatus which, when engaged by travelers  380 , biases travelers  380  toward the inclined or inactive position.  
     [0039] As described above, foot base portion  380   a  includes wheels  381  for rollingly engaging the inside track of rail  382 . Pressure arm  380   b  is equipped with a support roller  390  that is fixed at an intermediate location on the arm  380   a  and a coupling member  391  fixed at the end. The coupling member  391  has an extended engagement surface  391   a  that is particularly adapted to frictionally engaging the lower portion  323   b  of belt  323 . The support roller  390  is configured to frictionally engage the upper portion  323   a  of belt  323 , as shown in FIGS. 2 and 3. In a forward moving mode of the foot traveler  380 , as shown in FIG. 2, traveler  380  is supported by wheels  381  which engage rail  382  and is confined therein and by support roller  390  which rollingly engages upper portion  323   a  of belt  323 . In this forward moving mode, tension or spring forces of belt  323  acting through engagement of upper portion  323   a  and roller  390  causes traveler  380  to be slightly rotated in the clockwise direction (see reciprocating rotational path XX) and pivot about wheels  381 . Pressure arm  380   b  is, therefore, moved upwardly such that coupling member  391  disengages lower portion  323   b  of belt  323 .  
     [0040] As best shown in FIG. 3, belt  323  is rotatably supported about drive pulley  310  and idler pulley  311 . FIG. 3 also depicts the suspension system as including a link assembly or link  385  including a suspension arm  385   a  and a pulley support arm  385   b . The support arm  385   b  supports idler pulley  311  while suspension arm  385   a  is resiliently attached with a spring/shock absorber assembly or tensioner  386 . The link  385  is pivotally supported about a pivot  384  that is fixed to front frame  301  or other rigid support. Tensioner  386  is pivotally attached at one end to suspension arm  385  while fixedly supported to frame  301  on an opposite end. The tensioner  386  may be one of several conventional types which are commercially available and generally known in the industry including, but not limited to, standard springs, coils and/or spring-shocks. A primary function of tensioner  386  is to provide tension or resiliency to belt  323  via link  385 . During operation of apparatus  20 , link  385  rotates about pivot  384  (i.e., in the clockwise direction when referring to FIG. 3) upon force being exerted by support roller  390  and/or coupling member  391  to belt  323 . The combination of belt  323  and tensioner  386  also provides a shock or impact absorber for the apparatus  20 , particularly when the user transfers weight or steps onto pedal  383 . The combination of pulley  311 , link  385  and tensioner  386  may be referred to as a resilient support assembly for purposes of the present description.  
     [0041]FIG. 3 depicts traveler  380  in the rearward moving mode (moving from right to left in this view in the direction of arrow  350 ). In the rearward moving mode, the user steps down and exerts some body weight on foot pedal  383  and thus on traveler  380 , thereby causing his foot to move rearwardly (right to left). As a result of pressure applied onto foot pedal  383 , traveler  380  is rotated counterclockwise and coupling member  391  is moved downwardly to frictionally engage lower portion  323   b  of belt  323 . Further, link  385  rotates in the clockwise direction due to the downward flection in belt  323  which causes tensioner  386  to extend longitudinally outward. This extension of tensioner  386  provides a resisting force and damping to the system. As mentioned above, one advantageous result is a further reduction of the impact load experienced as the user applies force to exercise apparatus  20 .  
     [0042] By frictionally engaging coupling member  391  with belt  323 , the inertia transfer portion is coupled with one foot traveler  380 . The inertia transfer portion is also indirectly coupled to the other traveler  380  through common belt  314  which is connected to both travelers  380 . Thus, when coupling member  391  frictionally engages lower portion  323   b  of belt  323  (i.e., in the rearward moving mode depicted in FIG. 3), the inertia of the system is used to accelerate both travelers  380 . It should be noted that the force applied to the belt  323  through foot pedal  383  and pressure arm  380   b  is applied at two places—through coupling member  391  frictionally engaging lower portion  323   b  and through support roller  390  rollingly engaging upper portion  323   b . In this way, the tension applied on the belt  323  is reduced by approximately one-half of what it would be if the force was applied only through coupling member  391 , for any given angular deflection of foot traveler  380 .  
     [0043] Now turning to FIG. 11, an exercise apparatus  1120  is depicted having an alternative resilient support system according to the invention. An exercise apparatus of the type shown in FIG. 11 (minus the resilient support system and the foot/pedal system) is described in U.S. Pat. No. 5,690,589 (hereby incorporated by reference for all purposes and made a part of the present disclosure). The focus of the present description will be on the inventive resilient support system rather than the basic structural elements of the exercise apparatus  1120 . As will become apparent to one skilled in the art, the inventive resilient support system is equally applicable to other types and variations of the exercise apparatus. The exercise apparatus  1120  of FIG. 11 is described herein for exemplary purposes.  
     [0044] Briefly, the exercise apparatus  1120  includes a frame  1110 , a top or upright portion  1116 , and a support platform  1116   a  connected thereto for user support. The exercise apparatus  1120  further includes a pair of left and right reciprocating members  1140 . Each reciprocating member  1140  has a first end with a roller  1136  fixed thereto and adapted for travel along a predetermined path defined by left or right rail  1126 . Each reciprocating member  1140  also has a second, upper end rotatably attached to inertia device  1150  by way of crank  1142 . The inertia device  1150  comprises a coupling system fixed to the frame  1110  and may include a pulley, crank members, resistant brake, belts and other components as is generally known in the art.  
     [0045] In one aspect of the invention, the exercise apparatus  1120  according to this embodiment also includes a pair of left and right travelers  1180  (i.e., carriage assemblies) having a foot pedal  1182 . Each traveler or carriage assembly  1180  is fixedly joined to a reciprocating member  1140 , and thus, is operable to move reciprocating members  1140  and inertia device  1150 .  
     [0046] The resilient support assembly includes a linkage assembly  1184  having a first link  1184   a  and a second link  1184   b , and a linearly extending spring  1186 . The first link  1184   a  has one end pivotally attached to the traveler  1180  and an opposite end pivotally attached to the second link  1184   a . The second link  1184   b  is also pivotally attached to the reciprocating member  1140 . Further, the intersection or pivotal connection between links  1184   a  and  1184   b  is joined with one end of the spring  1186 , which is attached on an opposite end to reciprocating member  1140 . As illustrated in FIG. 11, movement of traveler  1180  causes movement of reciprocating member  1140  and inertia device  1150 . Movement of traveler  1180  is initiated by the user applying pressure on the pedal  1182  causing to deflect angularly downward, which, in turn, directly causes pivotal movement of links  1184   a ,  1184   b . Movement of links  1184   a ,  1184   b  further causes linear extension (although disproportionately) of spring  1186 , as will be further described below.  
     [0047] One feature of the resilient support assembly (or pedal suspension system) is that it is attached to the reciprocating member  1140  (as opposed to the frame; see FIGS. 2 and 3) and thus travels with the reciprocating member  1140 . As foot pedal  1182  rotates or deflects angularly downward under application of user weight, links  1184   a  and  1184   b  causes linear extension of the spring  1186 . The configuration or geometry of the links  1184   a ,  1184   b  is such that, while the links  1184  are directly movably responsive to angular deflection of the traveler  1180  (through linear and angular movement, angular deflection of traveler  1180  does translate, at least initially, directly to spring  1186  and to linear spring extension. Accordingly, angular deflection of the traveler  1180  does not always cause a directly corresponding linear extension of spring  1186  (whereas, it may cause a directly corresponding movement of link  1184   a ,  1184   b ). Instead, as the traveler  1180  angularly deflects downward from the inactive position to a generally horizontal, fully engaged position, the spring  1186  becomes more directly responsive. That is, as the traveler  1180  approaches the generally horizontal position, the response of the spring  1186  (i.e., linear extension) increases, and thus, the apparent stiffness (or apparent spring constant) of the resilient support system increases dramatically. This response is similar to the response of the resilient support system in FIGS. 2 and 3.  
     [0048] In other words, angular deflection of foot pedals  1182  causes linear extension of the spring  1186 ; however, the rate of linear extension (as a response) increases with further deflection. As a result, the increase in resistance of the spring  1186  (due to spring extension) is highly concentrated or pronounced at a small window corresponding to a particular phase or arc of the angular deflection of foot pedal  1182 . This window corresponds to angular deflection of the foot pedal  1182  as the foot pedal  1182  approaches the generally horizontal position (as shown for the right pedal in FIG. 1100). Within this window, the rate of spring extension increases substantially as does the resultant resistant force.  
     [0049] When designing a pivoting pedal suspension system as in FIGS.  1 - 11  (and FIG. 12), the total range of user body weights must be considered. Such a pedal suspension system must typically accommodate weight ranges between about 80-300 lbs. The typical spring or spring system with linear or approximate linear behavior may not accommodate such a range of body weights. A spring appropriate for the 80 lb. user will bottom out for the 300 lb. user, whereas a spring appropriate for the 300 lb. user will be barely deflected by the 80 lb. user. Therefore, a highly non-linear resilient support system is required to provide a workable suspension in a pivoting footplate system. Such a highly non-linear system is also shown in FIGS. 2 and 3. As the user steps on pedal  383 , it pivots downward, forcing deflection of belt  323 . Belt  323  in turn applies force to pulley  311 . Pulley  311  which is mounted on element  385 , rotates upwardly about pivot  385  causing linear extension of spring  386 . As the pedal  383  is pivoted further downward and pulley  311  further rotates upward, the stiffness (or apparent spring constant) of the pedal system increases dramatically due to increased rate of extension of spring  1186 .  
     [0050] In these designs, the resilient support systems may be said to have a non-linear spring constant, because the resistant force generated due to spring extension is non-linear. In fact, the additional resistant force generated per a given spring extension increases substantially as the foot pedal or carriage assembly approaches the generally horizontal position.  
     [0051]FIG. 12 illustrates the deflection range of the pedal, versus the user weight and resistant force generated by the resilient support system. The deflection range of the pedal represented by the intersection of the vertical lines on the horizontal axis is similar for a wide range of body weights. For a given small window  1210  of pedal deflection, the exercise apparatus, particularly the resilient support system, can accommodate a range of body weights corresponding to the range between a light user and a heavy user, as is desired. FIG. 12 also shows that through the first phase of pedal angular deflection—before the small window  1210 —the response of the resilient support system (in the form of a resistant force generated primarily by an elastic device as described herein) increases at a very slow rate. Then, at the small window  1120 , the response increases substantially.  
     [0052]FIGS. 13A and 13B depict yet another embodiment of the resilient support system according to the invention. In this embodiment, an elastomeric system is employed in the form of an elastomeric support band  1330 . The band  1330  provides support to foot pedals  1382  (i.e., carriage assemblies). Each foot pedal  1382  includes an integrated cam or cam surface  1386  having a unique shape. The cam  1386  engages elastomeric band  1330  as shown in FIG. 13A. As the pedal  1382  deflects angularly downward, the stretch induced in elastomeric band  1330  substantially increases because of the shape of the cam surface. The point or area of contact of the band  1330  on the cam  1386  moves rearward as the pedal  1383  rotates downward, thereby further increasing the apparent stiffness of the resilient support system. In this embodiment, the resilient support system is provided by the combination of the elastomeric band  1130  and the cam  1386 .  
     [0053] In each of the embodiments of FIGS.  1 - 11 , FIG. 12, and FIG. 13, the resilient support system may be referred to as having an elastic device and an intermediate deflection element operatively positioned between the traveler and pedal, and the elastic device. The elastic device is primarily responsible for generating the resistant force (against the pressure applied to the pedal by the user) in a non-linearly responsive manner. The intermediate deflection element is positioned to directly engage and be directly movably responsive to the pedal and to pedal deflection. In FIGS. 2 and 3, the intermediate deflection element is provided in the form of continuous belts  323  and pulleys  310 ,  311 , and the elastic device is in the form of spring  386 . In FIG. 12, the intermediate deflection element is provided in the form of links  1184   a ,  1184   b , and the elastic device is spring  1186 . Finally, in the embodiment of FIGS. 13A and 13B, the intermediate deflection element is provided in the form of cam surface  1386 , and the elastic device is elastic band  1330 .  
     [0054] It should again be noted that flywheel  306  provides an energy source for performing the function of accelerating the system as the foot travelers  380  changes direction. This energy, which is stored by flywheel  306  is supplied by the user. In this respect, flywheel  306  performs instantaneously and continuously.  
     [0055] In yet another aspect of the invention, the inertia transfer assembly may include, or may be operable with, a second energy source such as a motor  399  (see FIGS. 2 and 3). Such a second energy source may be provided for continuously adding energy to the system and to compensate for energy losses due to friction and inertial direction changes. The utilization of two energy sources in this way further facilitates operation of exercise apparatus  20  and makes such operation almost transparent to the user. The user of the present inventive apparatus  20  needs only to support his weight while performing a running motion; the user does not need to apply any other force to the pedals  380  to keep the system in continuous motion.  
     [0056] In FIGS. 2 and 3, an electric motor  399  is shown as the second energy source. The motor  399  includes a pulley  399   a  which is rotatably coupled, via a belt  399   b , with another pulley  399   c  that is disposed about, and rotatable with, inertia shaft  318 . In the Figures, motor  399  is shown supported just below inertia shaft  318  with second pulley  399   b  disposed adjacent flywheel/brake  306 . Unlike flywheel/brake  306 , motor  399  is preferably energized by a source external to the inertia transfer assembly (e.g. a/c or d/c power), i.e., not by the user. Motor  399  is, however, operable to drive inertia shaft  318  and the rest of the inertia transfer portion.  
     [0057] In alternative embodiments, exercise apparatus  20  may employ a combination of a motor and inertia device such as a flywheel. In further alternative embodiments, an energy source in the form of a motor may serve dual functions as both the motor and inertia device. In such a case, a flywheel may be added to and become an integral part of the motor, or the armature of the motor may be designed to function as a flywheel. Control of a motor in any of these embodiments may be performed in one of several ways which are familiar to those skilled in the art. For example, a conventional torque controller may be used to power the motor and so as to overcome drag present in the system. Alternately, a velocity controller may be integrated and employed to power the motor so as to maintain a specified system velocity.  
     [0058] The present inventive exercise apparatus  20  enhances the workout of the user and provides for a more natural motion by essentially eliminating the need for the user to exert force to initiate movement of each traveler from zero velocity. The user of the inventive apparatus does not have to accelerate the traveler from zero velocity at the beginning of each active stroke to the velocity of a normal gait or system speed. Acceleration is instead achieved through utilization of the inertia drive system and/or another energy device such as a motor. Accordingly, the present invention can more accurately simulate normal constant speed activity, such as running.  
     [0059] In the alternative embodiment depicted in FIGS. 5 and 6, exercise apparatus  20  employs an alternate foot traveler  480  according to the invention. FIG. 5 depicts traveler  480  in the forward moving mode while FIG. 6 depicts traveler  480  in the rearward moving mode. The foot traveler  480  is equipped with a second support roller  492  in addition to support roller  490 , each of which is connected onto pressure arm  480   a . Traveler  480  also has a coupling member  491  that extends outward from pressure arm  480   a  and has an engagement surface  491   a  for frictionally engaging lower portion  423   b  of belt  423 . The second support roller  492  works in conjunction with first support roller  490  and coupling member  491  by engaging belt  423  as the traveler rotates counterclockwise but before engagement surface  491   a  engages lower portion  423   b  of belt  423 . The second support roller  492  allows lower portion  423   b  of belt  423  to share, with first support roller  490 , the load with upper portion  423   b  during intermediate angles of traveler rotation (i.e., during directional changes).  
     [0060] In the alternative embodiment depicted in FIGS. 7 and 8, exercise apparatus  20  employs yet another foot traveler  580  according to the invention. FIG. 7 depicts traveler  580  in the forward moving mode while FIG. 8 depicts traveler  580  in the rearward moving mode. The foot traveler  580  is equipped with a second support roller  592  in addition to support roller  590 , each of which is attached to pressure arm  580   a . Traveler  580  also has a coupling member  591  that extends outward from pressure arm  580   a  and has an engagement surface  591   a . Unlike foot traveler  480  and other foot travelers, however, engagement surface  591   a  of traveler  580  is designed to frictionally engage upper portion  523   a  of belt  523  rather than lower portion  523   b . The engagement surface  591   a  is an inclined surface that faces upward and is frictionally engageable with the bottom side of upper portion  523   a  when traveler  580  is rotated in the clockwise direction. Accordingly, traveler  523  is movable with upper portion  523   b  in the forward moving mode of traveler  523 .  
     [0061]FIGS. 9 and 10 depict yet another embodiment of the exercise apparatus  20  according to the invention. The exercise apparatus  20  employs a traveler  680  that is equipped with a foot pedal  683  that is pivotable relative to the traveler  680 . Through the foot pedal  683 , traveler  680  extends the rotational range of motion of the user or more particularly, the user&#39;s foot. Among other attributes, this feature improves the user&#39;s comfort and flexibility. In further embodiments, a spring may be provided on traveler  680  to bias the engagement with foot pedal  683 .  
     [0062] It should be noted that the travelers depicted and described with respect to FIGS.  2 - 10  may be used in combination with any other structural features of the inventive exercise apparatus  20 . The selection of, and performance of, any necessary modification will be apparent to one skilled in the art, upon reading the above description, and the invention adapted to suit particular applications.  
     [0063] The foregoing description of the various aspects of the present invention has been presented for purposes of illustration and description. It is to be noted that the description is not intended to limit the invention to the exercise apparatus, its components and the method of operation disclosed herein. For example, various aspects of the invention may be applicable to other exercise apparatus or apparatus requiring reciprocal motion or simulating actual physical activity on a stationary frame, any of which will become apparent to one skilled in the relevant mechanical art who is provided with the present disclosure. Consequently, variations and modifications commensurate with the above teachings, and the skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments of the inventive exercise apparatus described are further intended to explain best modes for practicing the invention, and enable others skilled in the art to utilize the invention in other embodiments and with various modifications required by the particular applications or uses of the present invention.