Patent Publication Number: US-6217486-B1

Title: Elliptical step exercise apparatus

Description:
FIELD OF THE INVENTION 
     This invention relates generally to exercise equipment and more particularly to exercise equipment which can be used to provide a user with an elliptical step exercise. 
     BACKGROUND OF THE INVENTION 
     There are a number of different types of exercise apparatuses that exercise a user&#39;s lower body by providing a circuitous stepping motion. These elliptical stepping apparatuses provide advantages over other types of exercise apparatuses. For example, the elliptical stepping motion generally reduces shock on the user&#39;s knees as can occur when a treadmill is used. In addition, elliptical stepping apparatuses exercise the user&#39;s lower body to a greater extent than, for example, cycling-type exercise apparatuses. Examples of elliptical stepping apparatuses include U.S. Pat. Nos. 3,316,898; 5,242,343; 5,383,829; 5,499,956; 5,685,804; 5,759,136; 5,762,588; 5,779,599; 5,792,026; 5,899,833 and German Patent No. DE 2 919 494. 
     However, known elliptical stepping exercise apparatuses suffer from various drawbacks. For example, some apparatuses are limited to exercising the user&#39;s lower body and do not provide exercise for the user&#39;s upper body. In addition, the elliptical stepping motion of some apparatuses does not produce an optimum foot motion including heel to toe flexure. Moreover, due to their mechanical arrangement, some previous stepping exercise apparatuses can be difficult for the user to mount. Also, for those exercisers that include arm handles for upper body exercise, the range of motion of the arm handle in many instances does not provide for a comfortable upper body exercise. A need therefore exists for an improved elliptical stepping exercise apparatus. One such improved elliptical stepping exercise apparatus can be found in a commonly owned application entitled “Cross Training Exercise Apparatus”, Ser. No. 08/814,487 (hereinafter “the &#39;487 application”). The entire disclosure of the &#39;487 application is incorporated herein by reference. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the invention to provide an elliptical stepping exercise apparatus that exercises the user&#39;s lower and upper body in an easy to use and comfortable manner. 
     Another object of the invention is to provide a stepping exercise apparatus that simulates a natural foot motion thereby promoting exercise efficiency. 
     Another object of the invention is to provide an elliptical stepping exercise apparatus that has a bent pedal lever thereby making it easier for the user to mount. 
     Another object of the invention is to provide an elliptical stepping apparatus that provides for upper body exercise utilizing arm handles connected to rockers which in turn are connected to the pedal levers where the arm handles are approximately the same length as the rockers. 
     In addition, unlike some examples of elliptical stepping apparatuses such as the machine shown in U.S. Pat. No. 5,383,829, the preferred embodiment of the invention does not utilize a coupling member to pivotally couple the pedal levers to the pivot axis. By contrast, the present invention uses a stroke link which is pivotally connected between a crank arm and a lower section of the pedal lever. Additionally, the pedal lever is not pivotally connected to the crank but instead rides on a roller and is bent to provide easier user access to the machine. As a result of the action of the stroke link and the roller, the end of the bent pedal lever travels in an elliptical path. A significantly different and unique foot motion will result due to the elliptical path taken by the end of the pedal lever. 
     These and other objectives and advantages are provided by the present invention which is directed to an exercise apparatus that can be employed by a user to exercise the user&#39;s upper and lower body. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings which illustrate the best modes presently contemplated for carrying out the invention: 
     FIG. 1 is a partially cut-away side perspective view of the preferred embodiment of an exercise apparatus according to the invention; 
     FIG. 2 is a partially cut-away top perspective view of the exercise apparatus in FIG. 1 showing the pulley, flywheel, alternator and transmission; 
     FIG. 3 is a partial cut-away top perspective view of the exercise apparatus in FIG. 1; 
     FIG. 4 is a partial cut-away top view of the exercise apparatus in FIG. 1; 
     FIG. 5 is a partial simplified side perspective view of the stroke link, roller, pedal lever and double offset crank assembly of the exercise apparatus in FIG. 1; 
     FIGS. 6A-6H are simplified functional schematic representations of the reciprocating movement of the second end of the pedal lever and illustrations of the elliptical pathway traced by the pedal as the second end of the pedal lever completes its elliptical reciprocating path of travel; 
     FIG. 7 is a partial simplified side perspective view of a second embodiment of an exercise apparatus according to the invention; 
     FIG. 8 is a partial simplified side view of a third embodiment of an exercise apparatus according to the invention; 
     FIG. 9 is a partial simplified side perspective view of the exercise apparatus in FIG. 8; 
     FIG. 10 is a partial simplified perspective view of a fourth embodiment of an exercise apparatus according to the invention; 
     FIG. 11 is a partial simplified side perspective view of a fifth embodiment of an exercise apparatus according to the invention; 
     FIG. 12 is a partial simplified rear perspective view of the exercise apparatus in FIG. 11; 
     FIG. 13 is a partial simplified side perspective view of a sixth embodiment of an exercise apparatus according to the invention; and 
     FIG. 14 is a partial simplified side perspective view of a seventh embodiment of an exercise apparatus according to the invention. 
    
    
     DETAILED DESCRIPTION 
     I. Overview of Mechanical Aspects of the Invention 
     A primary objective of the present invention is to provide a mechanically simple elliptical stepping exercise apparatus in which the pedal follows a substantially elliptical pathway in such a manner so as to simulate the natural foot weight distribution, and optimal foot motion and flexure associated with a natural walking or running gait while at the same time providing a synchronized mechanism for upper body exercise. The present invention implements numerous different pedal actuation assemblies for providing this more natural foot motion. In addition, each of these pedal actuation assemblies can be connected to an arm handle assembly to provide an upper body workout. 
     This invention is thus directed to numerous general embodiments of an exercise apparatus in which the foot pedal follows a substantially elliptical pathway and moves in a manner that simulates a natural weight distribution, and a natural foot motion and flexure of a foot associated with the normal human walking or running gait. It should be understood, however, that the mechanisms as described can be modified within the scope of the invention to produce other types of foot motion. The first general embodiment, which is the preferred embodiment of the invention, is discussed with reference to FIGS. 1-6. The second general embodiment is discussed with reference to FIG.  7 . The third general embodiment is discussed with reference to FIGS. 8 and 9. The fourth general embodiment is discussed with reference to FIG.  10 . The fifth general embodiment is discussed with reference to FIGS. 11 and 12. The sixth general embodiment is discussed with reference to FIG.  13 . The seventh general embodiment is discussed with reference to FIG.  14 . 
     Through all of the various embodiments and Figures, like reference numbers denote like components. In addition, the pedaling mechanism of the invention is symmetrical and includes a left portion and a right portion. The following detailed description of all of the various embodiments is directed to the components of the left portion although it is to be understood that the right portion includes like components that operate in a like fashion. 
     II. Detailed Description of the First General Embodiment 
     Referring now to the drawings in which like reference numerals designate like or corresponding parts throughout the several views, there is shown in FIGS. 1-6 the first general embodiment, which is the preferred embodiment of an exercise apparatus incorporating the unique features in accordance with the present invention which is designated generally by the reference numeral  10 . 
     The exercise apparatus  10 , as well as all of the various embodiments further described herein, include motion controlling components which operate in conjunction with the various pedal actuation assemblies and motion generating components to provide a pleasurable exercise experience for the user. 
     As illustrated in FIGS. 1-4, the exercise apparatus  10  includes a frame, shown generally at  12 . The frame  12  includes vertical support members  14 ,  16 A and  16 B which are secured to a longitudinal support member  18 . The frame  12  further includes cross members  20  and  22  which are also secured to and bisect the longitudinal support member  18 . The cross members  20  and  22  are configured for placement on a floor  24 . A pair of levelers  26  are secured to cross member  22  so that if the floor  24  is uneven, the cross member  22  can be raised or lowered such that the cross member  22 , and the longitudinal support member  18  are substantially level. Additionally, a pair of wheels  28  are secured to the longitudinal support member  18  of the frame  12  at the rear of the exercise apparatus  10  so that the exercise apparatus  10  is easily moveable. 
     The exercise apparatus  10  further includes a rocker  30 , a pedal  32 , a pedal actuation assembly  34  and a motion controlling assembly  36 . As more fully illustrated in FIG. 2, the motion controlling assembly  36  includes a pulley  38  supported by vertical support members  16 A and  16 B around a pivot axle  40 . The motion controlling assembly  36  also includes resistive force and control components, including an alternator  42  and a speed increasing transmission  44  that includes the pulley  38 . The alternator  42  provides a resistive torque that is transmitted to the pedal  32  and to the rocker  30  through the speed increasing transmission  44 . The alternator  42  thus acts as a brake to apply a controllable resistive force to the movement of the pedal  32  and the movement of the rocker  30 . Alternatively, a resistive force can be provided by any suitable component, for example, by an eddy current brake, a friction brake, a band brake or a hydraulic braking system. Specifically, as best seen in FIG. 2, the speed increasing transmission  44  includes the pulley  38  which is coupled by a first belt  46  to a second double pulley  48 . A second belt  50  connects the second double pulley  48  to a third pulley  52  that in turn is attached to a flywheel  54  of the alternator  42 . The speed increasing transmission  44  thereby transmits the resistive force provided by the alternator  42  to the pedal  32  and the rocker  30  via the pulley  38 . Since the speed increasing transmission  44  causes the alternator  42  to rotate at a greater rate than the pivot axle  40 , the alternator  42  can provide a more controlled resistance force. Preferably the speed increasing transmission should increase the rate of rotation of the alternator  42  by a factor of 20 to 60 times the rate of rotation of the pivot axle  40  and in the preferred embodiment the pulleys  38  and  48  are sized to provide a multiplication in speed by a factor of  40 . Also, size of the transmission  44  is reduced by providing a two stage transmission using pulleys  38  and  48  is used. 
     As illustrated in FIGS. 1 and 5, the pedal actuation assembly  34  includes a pedal lever  56 , a stroke link  58 , an extension arm  60 , a roller  62  and a crank  64 . The pedal lever  56  is bent and includes a first portion  66 , a second portion  68  and a third portion  70 . The first portion  66  of the pedal lever  56  has a forward end  72 . The first portion  66  of the pedal lever  56  is approximately 11 inches in length and upwardly extends from the second portion  68  at an angle of approximately 25°. The second portion  68  of the pedal lever  56  has a top surface  71  and a rearward end  74 . The second portion  68  of the pedal lever  56  is approximately 26 inches in length. The pedal  32  is secured to the top surface  71  of the second portion  68  of the pedal lever  56  by any suitable securing means. In the preferred embodiment, the pedal  32  is secured such that the pedal  32  is substantially parallel to the second portion of the pedal lever  68 . A bracket  76  is located at the rearward end  74  of the second portion  68  approximately 6¾ inches from the pedal  32 . The third portion  70  of the pedal lever  56  has a rearward end  78 . The third portion  70  of the pedal lever  56  is approximately 19½ inches in length and upwardly extends from the second portion  68  at an angle of approximately 9°. The bent pedal lever  56  allows a user to more easily mount the exercise apparatus  10 . 
     Continuing, as illustrated in FIGS. 1 and 5, the crank  64  includes a forward end  80  and a rearward end  82 . The rearward end  82  of the crank  64  is connected to and rotates about the pivot axle  40 . A roller axle  84  is secured to the forward end  80  of the crank  64  to rotatably mount the roller  62  so that it can rotate about the roller axle  84 . The extension arm  60  includes a forward end  88  and a rearward end  90 . The rearward end  90  of the extension arm  60  is secured to and rotates about an outer surface  92  of the roller  62  about the roller axle  84 . The stroke link  58  includes a forward end  94  and a rearward end  96 . The rearward end  96  of the stroke link  58  is pivotally connected to the forward end  88  of the extension arm  60  at a pivot point  98  by any suitable connecting means. Moreover, the forward end  94  of the stroke link  58  is pivotally connected to the bracket  76  by any suitable connecting means. 
     The pedal  32  of the exercise apparatus  10  includes a toe portion  100  and a heel portion  102  so that the heel portion  102  is intermediate the toe portion  100  and the pivot axle  40 . The pedal  32  of the exercise apparatus  10  also includes a top surface  103 . As explained in more detail below, in reference to FIG. 6, the pedal  32  is secured to the top surface  71  of the pedal lever  56  in a manner so that the desired foot weight distribution and flexure are achieved when the pedal  32  travels in a substantially elliptical pathway  104  (shown in FIG. 6) as the rearward end  78  of the third portion  70  of the pedal lever  56  rolls on top of the roller  62 , travelling in a rotationally arcuate pathway with respect to the pivot axle  40  and in the preferred embodiment moves in an elliptical pathway  106  (shown in FIG. 6) around the pivot axle  40 . Since the rearward end  78  of the pedal lever  56  is not maintained at a predetermined distance from the pivot axis  40  but instead follows the elliptical pathway  106 , a more refined foot motion is achieved. In the preferred embodiment, the rearward end  78  of the third portion  70  of the pedal lever  56  can move in two ways in the elliptical pathway  106  around the pivot axle  40 . First, the rearward end  78  of the third portion  70  of the pedal lever  56  can move counterclockwise in the elliptical pathway  106 , as seen from the user&#39;s left side. When the rearward end  78  of the third portion  70  of the pedal lever  56  travels counterclockwise in the elliptical pathway  106 , the pedal  32  travels in a direction along the elliptical pathway  104  that simulates a forward-stepping motion. In the forward-stepping mode, as the pedal  32  moves in the elliptical pathway  104 , the heel portion  102  is lowered below the toe portion  100  when the forward end  72  of the first portion  66  of the pedal lever  56  moves in a reciprocating arcuate pathway  108  in a direction towards the pivot axle  40 . Second, the rearward end  78  of the third portion  70  of the pedal lever  56  can move clockwise in the elliptical pathway  106 , as seen from the user&#39;s left side. When the rearward end  78  of the third portion  70  of the pedal lever  56  travels clockwise in the elliptical pathway  106 , the pedal  32  travels in a direction along the elliptical pathway  104  that simulates a backward-stepping motion. In the backward-stepping mode, as the pedal  32  moves in the elliptical pathway  104 , the heel portion  102  of the pedal  32  is raised above the toe portion  100  of the pedal  32  when the forward end  72  of the first portion  66  of the pedal lever  56  moves in the reciprocating arcuate pathway  108  in a direction towards the pivot axle  40 . 
     In the preferred embodiment, the exercise apparatus  10  also includes an upper handle  110  as shown in FIGS. 6A-6H. The upper handle  110  is rigidly attached to an upper portion  112  of the rocker  30 . The upper portion  112  of the rocker  30  is pivotally attached to an axle  114  at a pivot point or hub  116 . The axle  114  bisects and is connected to the vertical support member  14  of the frame  12 . A lower portion  118  of the rocker  30  is pivotally connected to the forward end  72  of the first portion  66  of the pedal lever  56  at a pivot point  120 . 
     During operation, the rocker  30  swings forward and aft, causing the forward end  72  of the first portion  66  of the pedal lever  56  to travel forward and aft along the reciprocating pathway  108 . As the upper handle  110  moves, as indicated by a line  121 , toward the rearward end  78  of the third portion  70  of the pedal lever  56 , the rearward end  78  of the third portion  70  of the pedal lever  56  moves in the elliptical pathway  106  towards the pivot axle  40 . In the reverse direction, as the rearward end  78  of the third portion  70  of the pedal lever  56  moves away from the pivot axle  40 , the upper handle  110  moves towards the pivot axle  40 . In the preferred embodiment, the upper handle includes a hand grip  122  portion that extends from the upper handle  110  at a predetermined angle which is selected to promote ergonomic efficiency. It has also been found that the arm motion feels best when the rocker  30  and the upper handle  110  are approximately the same length. More particularly, the most desirable feel to the user results when the range of motion of the rocker  30  at pivot point  120  is approximately equal to the range of motion of the portion of the arm handle  110  having the hand grip  122 . By using the pedal lever  56  having a bent first portion  66 , it is possible to size the rocker  30  so as to provide optimum upper arm movement. For example, if the pedal lever  56  were straight, without changing the length of the rocker  30  or the upper handle  110 , the user would tend to grasp the upper handle  110  at a point higher up which would result in a range of arm motion that would be too great. Similarly, if the pedal lever  56  were straight, and the length of the rocker  30  were to be increased, the user could grasp the upper handle  110  at the same point  122  as the apparatus  10  shown in FIGS. 1-6, but this would result in an undesirable decrease in the range of arm motion. It will also be appreciated that the stroke link  58  primarily controls the horizontal movement of the pedal lever  56 . The geometry of the pedal actuation assembly  34  is such that the horizontal movement of the pedal lever  56  is greater than the vertical movement and preferably, the rocker  56  and upper handle are approximately equal so as to provide the optimum foot and arm motion. 
     The contributions of the components of the pedal actuation assembly  34  to the desired elliptical motion are now explained generally with reference to FIG.  6 . As the pulley  38  rotates about the pivot axle  40 , the rearward end  78  of the third portion  70  of the pedal lever  56  moves in the generally elliptical pathway  106  due to the coupling between the pivot axle  40 , the crank  64 , the roller  62  and the rearward end  78  of the third portion  70  of the pedal lever  56 . The forward end  72  of the first portion  66  of the pedal lever  56 , however, is constrained to move in the arcuate pathway  108 , due to the pivotal connection between the forward end  72  of the first portion  66  of the pedal lever  56  and the rocker  30 . Consequently, as the rearward end  78  of the third portion  70  of the pedal lever  56  moves in the elliptical pathway  106 , the forward end  72  of the first portion  66  of the pedal lever  56  moves in the reciprocating arcuate pathway  108 . The translation from the elliptical motion of the rearward end  78  of the third portion  70  of the pedal lever  56  to the reciprocating arcuate motion of the forward end  72  of the first portion  66  of the pedal lever  56  provides a substantially elliptical motion intermediate the rearward end  78  of the third portion  70  of the pedal lever  56  and the forward end  72  of the first portion  66  of the pedal lever  56 . Consequently, the pedal  32 , which is coupled to the top surface  71  of the pedal lever  56  intermediate the rearward end  78  of the third portion  70  of the pedal lever  56  and the forward end  72  of the first portion  66  of the pedal lever  56  moves in the substantially elliptical pathway  104  as shown in FIG.  6 . The horizontal dimension of the elliptical pathway  104  is determined by the major diameter of the elliptical pathway  106 . The vertical dimension of the elliptical pathway  104  is determined by the exact location of the pedal  32  on the pedal lever  56 , and the minor diameter of the elliptical pathway  106 . Specifically, the motion of the pedal  32  approaches a more elliptical motion the closer the pedal  32  is to the third portion  70  of the pedal lever  56  and the motion of the pedal  32  approaches a more arcuate motion the closer the pedal  32  is to the first portion  66  of the pedal lever  56 . Consequently, the height of the elliptical pathway  104  can be changed by changing the location of the pedal  32  along the top surface  71  of the pedal lever  56 . 
     The movement of the pedal  32 , which is determined by the components of the pedal actuation assembly  34 , is now discussed in detail with reference to the simplified functional schematic drawings labeled as FIGS. 6A-6H. FIGS. 6A-6H trace the motion of the pedal  32  as the pedal  32  completes one forward-stepping revolution along the elliptical pathway  104 , beginning at the rearmost position of the reciprocating arcuate pathway  108  of the first portion  66  of the pedal lever  56 . As previously stated, the exercise apparatus  10  can be operated both in a forward-stepping mode and in a backward-stepping mode. When the exercise apparatus  10  is operated in the forward-stepping mode, the pedal  32  travels in a counterclockwise sequence as illustrated in FIGS. 6A-6H. Alternatively, when the exercise apparatus  10  is operated in the backward-stepping mode, the sequence of the pedal  32  is reversed so that the pedal  32  moves from the starting point, shown in FIG. 6A, in a clockwise direction to the position shown in FIG.  6 H. 
     Beginning at FIG. 6A, the forward end  72  of the first portion  66  of the pedal lever  56  is at the rearmost position on the arcuate pathway  108 . As noted previously, the rearward end  78  of the third portion  70  of the pedal lever  56  moves in the reciprocating elliptical pathway  106  as the forward end  72  of the first portion  66  of the pedal lever  56  moves in the reciprocating arcuate pathway  108 . Consequently, the movement of the rearward portion  78  of the third portion  70  of the pedal lever  56  generates a varying angular displacement  124  between the pedal lever  56  and a fixed, horizontal reference plane  126 . When the forward end  72  of the first portion  66  of the pedal lever  56  is at the rearmost position on the reciprocating arcuate pathway  108 , the angular displacement  124  between the pedal lever  56  and the reference plane  126  is 5.7°. In addition, an angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  is 5.7° while an angle  130  between the top surface  103  of the pedal  32  and the top surface  71  of the pedal lever  56  is 0°. Moreover, a linear displacement  132  between a point  134  on the top surface  103  of the pedal  32  and the horizontal reference plane  126  is about 9.8 inches. 
     As the pedal  32  is moved by the user in the forward-stepping mode, rotation of the pulley  38  on the pivot axle  40  by about 45° moves the pedal  32  to the position shown in FIG.  6 B. The forward end  72  of the first portion  66  of the pedal lever  56  has advanced about one-fourth of the distance along the reciprocating arcuate pathway  108  away from the pivot axle  40 . At this point, the varying angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  is about 11.0° while the angle  130  between the top surface  103  of the pedal  32  and the top surface  71  of the pedal lever  56  remains 0°. In addition, the linear displacement  132  between the point  134  and the horizontal reference plane  126  has increased to about 11.5 inches while the angular displacement  124  between the pedal lever  56  and the horizontal reference plane  126  has increased to about 11.0°. This change in the angular displacement  128  also corresponds to a flexure of the foot in which the toe portion  100  of the pedal  32  is being raised above the heel portion  102  of the pedal  32 . The weight distribution and flexure thus provided by the pedal actuation assembly  34  corresponds to that of the normal human gait. 
     Forward rotation of the pulley  38  on the pivot axle  40  by about another 45° brings the pedal  32  to the position shown in FIG. 6C, at which point the forward end  72  of the first portion  66  of the pedal lever  56  has traveled about half-way along the reciprocating arcuate pathway  108  away from the pivot axle  40 . At this point, the varying angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane is about 12.3° while the angle  130  between the top surface  103  of the pedal  32  and the top surface  71  of the pedal lever  56  remains 0°. In addition, the linear displacement  132  between the point  134  and the horizontal reference plane  126  has increased to about 12.4 inches while the angular displacement  124  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has increased to about 12.3°. This change in the angular displacement  128  also corresponds to the flexure in which the toe portion  100  of the pedal  32  is being raised even higher than the heel portion  102  of the pedal  32  as would occur in a normal non-assisted forward-stepping gait. 
     Forward rotation of the pulley  38  on the pivot axle  40  by about another 45° brings the pedal  32  to the position shown in FIG. 6D, at which point the forward end  72  of the first portion  66  of the pedal lever  56  has traveled about three-fourths the distance along the reciprocating arcuate pathway  108  away from the pivot axle  40 . At this point, the varying angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  is about 7.1° while the angle  130  between the top surface  103  of the pedal  32  and the top surface  71  of the pedal lever  56  remains 0°. In addition, the linear displacement  132  between the point  134  and the horizontal reference plane  126  has increased to about 13.0 inches while the angular displacement  124  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has decreased to about 7.1°. 
     Continued rotation of the pulley  38  on the pivot axle  40  by about another 45° brings the pedal  32  to the position shown in FIG. 6E, where the forward end  72  of the first portion  66  of the pedal lever  56  has traveled the entire distance along the reciprocating arcuate pathway  108 . The varying angular displacement  128  has now changed to about 0.4°, while the angle  130  remains 0°. The linear displacement  132  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  has decreased to about 12.2 inches and the angular displacement  128  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has decreased to about 0.4°. 
     Forward rotation of the pulley  38  on the pivot axle  40  by about another 45° moves the forward end  72  of the first portion  66  of the pedal lever  56  backwards by about one-fourth of the distance along the reciprocating arcuate pathway  108 , toward the pivot axle  40 , and brings the pedal  32  to the position shown in FIG.  6 F. Although the angle  130  between the top surface  103  of the pedal  32  and top surface  71  of the pedal lever  56  remains 0°, the angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  has decreased to about −2.7°. The linear displacement  132  between the point  134  and the horizontal reference plane  126  has decreased to about 9.3 inches and the angular displacement  124  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has decreased to about −2.7°. The pedal  32  is now in the lower portion of the elliptical pathway  104  which corresponds to the second half of the forward-stepping motion. 
     Continued rotation of the pulley  38  on the pivot axle  40  by about another 45° 0  brings the pedal  32  to the position shown in FIG. 6G, at which point the forward end  72  of the first portion  66  of the pedal lever  56  has traveled backwards about half-way along the reciprocating arcuate pathway  108  towards the pivot axle  40 . The angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  has increased to about −2.3° although the angle  130  remains 0°. The linear displacement  132  between the point  134  and the horizontal reference plane  126  has decreased even further, to about 7.3 inches, and the angular displacement  124  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has increased to about −2.3°. 
     Forward rotation of the pulley  38  on the pivot axle  40  by about another 45° moves the forward end  72  of the first portion  66  of the pedal lever  56  backwards to a position that is about three-fourths of the distance along the reciprocating arcuate pathway  108 , towards the pivot axle  40 , and brings the pedal  32  to the position shown in FIG.  6 H. Even though the angle  130  between the top surface  103  of the pedal  32  and the top surface  71  of the pedal lever  56  remains 0°, the angular displacement  128  between the top surface  103  of the pedal  32  and the horizontal reference plane  126  has increased to about 0.5°. In addition, the linear displacement  132  between the point  134  on the top surface  103  of the pedal  32  and the horizontal reference plane  126  has increased to about 7.8 inches and the angular displacement  124  between the top surface  71  of the pedal lever  56  and the horizontal reference plane  126  has increased to about 0.5°. Continued rotation of the pulley  38  on the pivot axle  40  by about another 45° completes the forward-stepping motion along the elliptical pathway  104  and brings the forward end  72  of the first portion  66  of the pedal lever  56  back to the rearmost position along the reciprocating arcuate pathway  105  and the pedal  32  back to the position shown in FIG.  6 A. 
     The foregoing examples of displacements and angles represent a preferred motion of the pedal  32 . It should be understood, however, that these motions can be changed by varying various parameters of the pedal actuation assembly  34  such as the lengths of the crank  64  and the length of the extension arm  60  as well as changing the relative height of the pivot axle  40 . 
     As a result of the bent pedal lever  56 , the exercise apparatus  10  is easy for the user to mount. When the user then operates the pedal  32  in the previously described manner, the pedal  32  moves along the elliptical pathway  104  in a manner that stimulates a natural heel to toe flexure that minimizes or eliminates stresses due to the unnatural foot flexures. If the user employees the moving upper handle  110 , the exercise apparatus  10  exercises the user&#39;s upper body concurrently with the user&#39;s lower body thereby providing a total cross-training workout. The exercise apparatus  10  thus provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     III. Detailed Description of the Second General Embodiment 
     FIG. 7 shows a second general embodiment of an exercise apparatus  200  according to the invention. As noted previously, the second embodiment of the exercise apparatus  200  of the invention includes a second type of pedal actuation assembly and therefore implements the desired elliptical pedal motion in a similar fashion as the exercise apparatus  10 . As with the exercise apparatus  10 , the exercise apparatus  200  includes, but is not limited to, the frame  12 , the pedal  32 , the pulley  38  and associated pivot axle  40 , the pedal lever  56 , the upper handle  110 , and the various motion controlling components, such as the alternator  42  and the transmission  44 . The exercise apparatus  200  differs primarily from the exercise apparatus  10 , along with the various embodiments that follow, in the nature and construction of the pedal actuation assembly. As noted earlier, the pedal actuation assembly refers to those components which cooperate to (1) provide an elliptical path and (2) provide the desired foot flexure and weight distribution on the pedal  32 . 
     The pedal actuation assembly  202  of the exercise apparatus  200  includes the stroke link  58 , the extension arm  60 , the crank  64  and a rise link  204 . Similar to the pedal actuation assembly  34 , in the pedal actuation assembly  202 , the rearward end  82  of the crank  64  is pivotally attached to and rotates about the pivot axle  40 . Additionally, the forward end  94  of the stroke link  58  is pivotally attached to the pedal lever  56  by any suitable securing means. The rearward end  96  of the stroke link  58  is pivotally attached to and rotates about the forward end  88  of the extension arm  60  at the pivot point  98 . 
     The rise link  204  of the pedal actuation assembly  202  includes an upper portion  206  and a lower portion  208 . The upper portion  206  of the rise link  204  is pivotally connected to the rearward end  78  of the third portion  70  of the pedal lever  56  at a pivot point  210 . The forward end  80  of the crank  64  is pivotally connected to and rotates about the lower portion  208  of the rise link  204  on an inner portion  212  of the rise link  204  at a pivot point or shaft  214 . The rearward end  90  of the extension arm  60  similarly pivots about and is connected to the lower portion  208  of the rise link  204  on an outer portion  216  of the rise link  204  at the pivot point or shaft  214 . Thus, the significant difference between the pedal actuation assembly  202  of the exercise apparatus  200  and the pedal actuation assembly  34  of the exercise apparatus  10  is that the pedal lever  56  of the exercise apparatus  10  rests on the roller  62  while the pedal lever  56  of the exercise apparatus  200  is pivotally attached to the rise link  204 . 
     During operation, the rise link  204  of the pedal actuation assembly  202  of the exercise apparatus  200  controls the vertical movement of the third portion  70  of the pedal lever  56 . Similarly to the exercise apparatus  10 , in the exercise apparatus  200 , the stroke link  58  primarily controls the horizontal movement of the pedal lever  56 . The geometry of the pedal actuation assembly  202  of the exercise apparatus  200  is such that the horizontal movement of the pedal lever  56  is greater than the vertical movement. 
     When the user operates the exercise apparatus  200  as described, the pedal  32  moves along the elliptical pathway  104  in a manner that simulates a natural heel to toe flexure that minimizes or eliminates stresses due to unnatural foot flexure. The exercise apparatus  200  thus also provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     IV. Detailed Description of the Third Embodiment 
     FIGS. 8-9 show a third general embodiment of an exercise apparatus  250  according to the invention. As noted previously, the third embodiment of the exercise apparatus  250  of the invention includes a third type of pedal actuation assembly and therefore implements the desired elliptical pedal motion in a similar fashion as the exercise apparatuses  10  and  200 . As with the previous embodiments of the exercise apparatuses  10  and  200 , the exercise apparatus  250  includes, but is not limited to, the frame  12 , the pedal  32 , the pulley  38  and associated pivot axle  40 , the pedal lever  56 , and the various motion controlling components, such as the alternator  42  and the transmission  44 . The exercise apparatus  250  differs primarily from the exercise apparatus  10  and  200  along with the various embodiments that follow, in the nature and construction of the pedal actuation assembly. 
     Specifically, a pedal actuation assembly  252  of the exercise apparatus  250  is identical to the pedal actuation assembly  202  of the exercise apparatus  200  except that the crank  64  has been displaced at an angle relative to the extension arm  60  to modify the motion of the pedal lever  56 . As shown in FIGS. 8 and 9, the extension arm  60  is displaced approximately 60° relative to the crank  64 . Thus, as the crank  64  rotates counterclockwise, the crank  64  will be time phased ahead of the extension arm  60 . Changing the fixed angle between the crank  64  and the extension arm  60  offers a method for tuning the motion of the pedal  32 . 
     Thus, when the user operates the exercise apparatus  250  as described above, the pedal  32  moves along the elliptical pathway  104  in a manner that simulates a natural heel to toe flexure that minimizes or eliminates stresses due to unnatural foot flexures. The exercise apparatus  250  thus also provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     IV. Detailed Description of the Fourth General Embodiment 
     FIG. 10 shows a fourth embodiment of an exercise apparatus  300  according to the invention. As noted previously, the fourth embodiment of the exercise apparatus  300  of the invention include a fourth type of pedal actuation assembly and therefore implements the desired elliptical pedal motion in a similar fashion as the exercise apparatuses  10 ,  200  and  250 . As with the previous exercise apparatuses  10 ,  200  and  250 , the exercise apparatus  300  includes, but is not limited to, the frame  12 , the pedal  32 , the pulley  38  and associated pivot axle  40 ′ (which corresponds generally in function to the pivot axle  40  described in the previous embodiments), and the various motion controlling components, such as the alternator  42  and the transmission  44 . 
     As shown in FIG. 10, the exercise apparatus  300  differs primarily from the previous exercise apparatuses  10 ,  200  and  250 , along with the various embodiments that follow, in that the crank is positioned in front of the user. The exercise apparatus  300  includes a pedal lever  302  having a forward end  304  and a rearward end  306 . Attached to the rearward end  306  of the pedal lever  302  is a roller  308  which rides in a track  310 . The track  310  is attached to the frame  12 . The exercise apparatus  300  further includes a pedal mount link  312  having a forward end  314 , a rearward end  316  and an upper surface  317 . A cam follower  318  is rotatably attached to the forward end  314  of the pedal mount link  312 . The rearward end  316  of the pedal mount link  312  is pivotally connected to the pedal lever  302  at a pivot point  320 . The pedal  32  is rigidly attached to the upper surface  317  of the pedal mount link  312 . The exercise apparatus  300  further includes a crank  322  having a lower end  324 . Bolted to the crank  322  is a cam  326 . The lower end  324  of the crank  322  and the cam  326  are pivotally attached to the forward end  304  of the pedal lever  302  at a pivot point  328 . Moreover, the cam  326  contacts the cam follower  318  on the pedal mount link  312 . 
     As the crank  322  rotates, the pedal lever  302  is caused to reciprocate. Moreover, as the crank  322  rotates, the cam  326  and the cam follower  318  cause the pedal mount link  312  and the pedal lever  302  to articulate relative to one another. The exercise apparatus  300  offers the advantage of having a crank connected directly to the pedal lever. This direct connection better stabilizes the pedal lever, which allows using one roller instead of two. The purpose for introducing the pedal mount link  312  and the cam  326  is to provide a means for tuning the motion of the pedal  32 . Similarly, when the user operates the pedal  32  in the above-described manner, the pedal  32  moves along the elliptical pathway  104  in a manner that simulates a natural heel to toe flexure that minimizes or eliminates stresses due to unnatural foot flexures. The exercise apparatus  300  thus provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     V. Detailed Description of the Fifth General Embodiment 
     FIGS. 11 and 12 show a fifth general embodiment of an exercise apparatus  350  according to the invention. As noted previously, the fifth embodiment of the exercise apparatus  350  of the invention includes a fifth type of pedal actuation assembly and therefore implements the desired elliptical pedal motion in a similar fashion as the exercise apparatuses  10 ,  200 ,  250  and  300 . As with the previous exercise apparatuses  10 ,  200 ,  250  and  300 , the exercise apparatus  350  includes, but is not limited to, the frame  12 , the pedal  32 , the pulley  38  and associated pivot axle  40 , and the various motion controlling components, such as the alternator  42  and the transmission  44 . The exercise apparatus  350  is also similar to the exercise apparatus  300  including, but not limited to, the pedal lever  302 , the pedal mount link  312 , the cam follower  318 , the crank  322  and the cam  326 . The major difference between the exercise apparatus  300  and the exercise apparatus  350  are that the above described components are behind the user in the exercise apparatus  350  instead of in front of the user in the exercise apparatus  300 . As illustrated, the exercise apparatus  350  also replaces the roller  308  and the track  310  of the exercise apparatus  300  with the rocker  30 . As previously discussed, the rocker  30  is pivotally attached to the frame  12 . 
     In the exercise apparatus  350 , the cam  326  aids in fine tuning the motion of the pedal  32 , particularly the heel to toe flexure relationship. When the user operates the pedal  32  in the previously described manner, the pedal  32  moves along the elliptical pathway  104  in a manner that simulates a natural heel to toe flexure that minimizes or eliminates stresses due to the unnatural foot flexures. Thus, the exercise apparatus  350  similarly provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     VI. Detailed Description of the Sixth General Embodiment 
     FIG. 13 shows a sixth general embodiment of an exercise apparatus  400  according to the invention. As noted previously, the exercise apparatus  400  of the invention includes a sixth type of pedal actuation assembly and therefore implements the desired the elliptical pedal motion in a similar fashion as the exercise apparatuses  10 ,  200 ,  250 ,  300  and  350 . As with the previous exercise apparatuses  10 ,  200 ,  250 ,  300  and  350 , the exercise apparatus  400  includes, but is not limited to, the frame  12 , the pedal  32 , the pulley  38  and associated pivot axle  40 , and the various motion controlling components, such as the alternator  42  and the transmission  44 . The exercise apparatus  400  differs primarily from the previous exercise apparatuses  10 ,  200 ,  250 ,  300  and  350 , along with the embodiment that follows, in the nature and construction of the pedal actuation assembly. As noted earlier, the pedal actuation assembly refers to those components which cooperate to (1) provide an elliptical path and (2) provide the desired foot flexure and weight distribution of the pedal  32 . 
     A pedal actuation assembly  402  of the exercise apparatus  400  includes a pedal lever  404  having a forward end  406  and a rearward end  408 , a pedal mount link  410  having a forward end  412 , a rearward end  414  and a top surface  415 , and a pickle link  416  having an upper portion  418  and a lower portion  420 . The pedal actuation assembly  402  of the exercise apparatus  400  further includes the rocker  30 , the pedal  32 , the extension arm  60 , and the crank  64 . The forward end  406  of the pedal lever  404  is pivotally connected to the rocker  30 . As previously set forth above, the rocker  30  is then pivotally attached to the frame  12 . The pedal  32  is rigidly attached to the top surface  415  of the pedal mount link  410 . The forward end  412  of the pedal mount link  410  is pivotally attached to the pedal lever  404  at a pivot point  422 . 
     As explained in more detail above, the rearward end  82  of the crank  64  is pivotally connected to the pivot axle  40 . The forward end  80  of the crank  64  is pivotally connected to the rearward end  408  of the pedal lever  404  at a pivot point  424 . The rearward end  90  of the extension arm  60  is similarly pivotally connected to the rearward end  408  of the pedal lever  404  at the pivot point  424 . The forward end  88  of the extension arm  60  is pivotally connected to the lower portion  420  of the pickle link  416  at a pivot point  426 . The upper portion  418  of the pickle link  416  is pivotally connected to the rearward end  414  of the pedal mount link  410  by any suitable connecting means. 
     The exercise apparatus  400  produces a similar motion as the exercise apparatuses  300  and  350  having the cam  326 . As the crank  64  rotates, the pickle link  416  and the extension arm  60  cause the pedal mount link  410  and the pedal lever  404  to articulate relative to one another. The longer the extension arm  60 , the more the pedal mount link  410  will articulate relative to the pedal lever  404 . Thus, the pedal actuation assembly  402  of the exercise apparatus  400  provides a means for tuning the motion of the pedal  32 . 
     In this regard, when the user operates the pedal  32  in the previously described manner, the pedal  32  moves along the elliptical pathway  104  in a manner that stimulates a natural heel to toe flexure that minimizes or eliminates stresses due to unnatural foot flexure. Similarly, the exercise apparatus  400  thus provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience. 
     VII. Detailed Description of the Seventh General Embodiment 
     FIG. 14 shows a seventh general embodiment of an exercise apparatus  450  according to the invention. As noted previously, the exercise apparatus  450  of the invention includes a seventh type of pedal actuation assembly and therefore implements the desired elliptical pedal motion in a similar fashion as the exercise apparatuses  10 ,  200 ,  250 ,  300 ,  350  and  400 . As with the previous exercise apparatuses  10 ,  200 ,  250 ,  300 ,  350  and  400 , the exercise apparatus  450  includes, but is not limited to, the frame  12 , the rocker  30 , the pedal  32 , the pulley  38  and associated pivot axle  40 , and the various motion controlling components, such as the alternator  42  and the transmission  44 . The exercise apparatus  450  differs primarily from the exercise apparatus  400 , along with the various embodiments described above, in the nature and construction of the pedal actuation assembly. As noted earlier, the pedal actuation assembly refers to those components which cooperate to (1) provide an elliptical path and (2) provide the desired foot flexure and weight distribution on the pedal  32 . 
     A pedal actuation assembly  452  of the exercise apparatus  450  includes the pedal lever  404 , the pedal mount link  410 , the pedal  32 , the crank  64  and the extension arm  60 . The exercise apparatus  450  differs from the exercise apparatus  400  in that the pickle link  416  attached to the rearward end  414  of the pedal mount link  410  is replaced by a roller  454 . As explained in more detail above, the forward end  412  of the pedal mount link  410  of the exercise apparatus  450  is pivotally connected to the pedal lever  404  at the pivot point  422 . The forward end  80  of the crank  64  is pivotally connected to the rearward end  408  of the pedal lever  404  at the pivot point  424  while the rearward end  90  of the extension arm  60  is pivotally connected to the rearward end  408  of the pedal lever  404  at the pivot point  424 . The roller  454  is pivotally connected to and rotates about the forward end  88  of the extension arm  60  on a shaft  456 . Additionally, a track  458  is attached to the rearward end  414  of the pedal mount link  410  by any suitable attachment means. The roller  454  contacts and rolls along the track  458 . 
     As the crank  64  rotates, the roller  454  and the extension arm  60  cause the pedal mount link  410  and the pedal lever  404  to articulate relative to one another. This provides a means for tuning the motion of the pedal  32 . Thus, when the user operates the pedal  32  in the previously described manner, the pedal  32  moves along the elliptical pathway  104  in a manner that simulates a natural heel to toe flexure that minimizes or eliminates stresses due to unnatural foot flexures. Similarly, the exercise apparatus  450  thus provides a wide variety of exercise programs that can be tailored to the specific needs and desires of individual users, and consequently, enhances exercise efficiency and promotes a pleasurable exercise experience.