Abstract:
Described is an exercise apparatus for providing elliptical foot motion that utilizes a pair of rocking links suspended from an upper portion of the apparatus frame permitting at least limited arcuate motion of the lower portions of the links. Foot pedal assemblies are connected to rotating shafts or members located on the lower portion of the links such that the foot pedals will describe a generally elliptical path in response to user foot motion on the pedals.

Description:
FIELD OF THE DESCRIBED APPARATUS 
       [0001]    The described apparatus 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 DESCRIBED APPARATUS 
       [0002]    There are a number of different types of exercise apparatuses that exercise a user&#39;s lower body by providing a generally elliptical stepping motion. 
         [0003]    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 tend to produce a more natural foot motion than certain other types of exercise equipment. 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, 6,099,439, 6176,814, 6,217,486 and 6,846,272 along with U.S. Patent Application Publication No. 20050164837. 
         [0004]    However, known elliptical stepping exercise apparatuses suffer from various drawbacks. As an example, most elliptical machines use at least one crank rotating about an axel fixed to the machine&#39;s frame, as exemplified by the various apparatus described in the above identified documents. As a result, either the elliptical machines do not closely correspond to a natural walking or running foot motion or elaborate mechanisms are used to compensate for the constraints of a fixed axel crank arrangement. 
       SUMMARY OF THE DESCRIPTION 
       [0005]    It is therefore one object of the described mechanism to provide an elliptical stepping exercise apparatus having pedals that can more closely simulate natural foot motion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a side view of the left hand portion of an elliptical step apparatus mechanism illustrating a first embodiment of the described mechanism; 
           [0007]      FIG. 2  provides an expanded and partially sectioned, rear perspective view of the mechanism of  FIG. 1 ; 
           [0008]      FIGS. 3A ,  3 B,  3 C and  3 D are schematic views illustrating the operation of the mechanism of  FIG. 1 ; 
           [0009]      FIG. 4  is a left perspective view illustrating a second embodiment of the described mechanism; and 
           [0010]      FIGS. 5A ,  5 B,  5 C and  5 D are schematic views illustrating the operation of the mechanism of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0011]      FIG. 1  is an example of an elliptical step apparatus  10 , which provides an illustrative environment for describing a first and preferred embodiment, indicated generally at  12 , of a rocker mechanism for generating an elliptical foot motion. In this case, the elliptical step apparatus  10  includes a frame  14  having a forward vertical support member  16  and a rear vertical support member  17 . A pair of pedals  18  and  20  are fixed to and supported by a pair of pedal levers  22  and  24  that are in turn pivotally attached to a pair of arm handle rocker members  26  and  28  in this particular embodiment of the apparatus  10 . Here, the arm handle rockers  26  and  28  are also attached to a pivot point indicated at  30  on the vertical support member  16  and as a result provide support for the forward ends of the pedal levers  22  and  24  and allow for a generally horizontal, reciprocating motion of the forward ends of the pedal levers  22  and  24 . It will be appreciated, however that other methods can be used to support the forward ends of the pedal levers  22  and  24  for substantially horizontal movement including using rollers engaged with tracks mounted on the frame  14 . The arrangement of  FIG. 1  has the advantage that a pair of arm handles  32  and  34  can be attached to the rockers  26  and  28  at the pivot point  30  such that the handles  32  and  34  move with the pedals  18  and  20 . 
         [0012]    As shown in  FIG. 1  and in more detail and in perspective in  FIG. 2 , the embodiment of the mechanism  12  includes a pair of rocking links  36  and  38  that are rotatably attached at their upper ends to an upper shaft  40  by a set of bearing mounts indicated at  42  and  44 . In this embodiment, the upper shaft  40  is mounted on the vertical support structure or member  17  such that the lower ends of the rocking links  36  and  38  can have at least a limited arcuate motion. In the preferred embodiment, the shaft  40  is mounted, for example by a set of bearings, on the member  17  such that it can also rotate. Also included in the mechanism  12 , are a pair of rocking link shafts  46  and  48  that are secured in the lower ends of the rocking links  36  and  38  by another set of bearing mounts indicated at  50  and  52 . The bearing mounts  50  and  52  permit the rocking link shafts to rotate on the lower ends of the rocking links. Each of the rocking link shafts  46  and  48  has attached to it for rotation an outer crank arm  54  and  56  respectively. The ends of the outer cranks  54  and  56  are then pivotally connected at a hub  58  and  60  to the pedal links  22  and  24  thereby serving as a connection assembly of the pedal levers  22  and  24  to the rotating rocking link shafts  46  and  48 . Also attached for rotation to the rocking link shafts  46  and  48  are a pair of inner crank arms  62  and  64 . In this embodiment, the ends of the inner cranks  62  and  64  are pivotally attached to one end of a pair of rocker members  66  and  68  via a pair of hubs  70  and  72 . The rocker members  66  and  68  are then pivotally attached to the frame  14  by a pair of bearings, as generally indicated at  74 , that in turn are secured to the frame  14  by a pair of mounting plates, generally indicated at  76 . 
         [0013]      FIGS. 3A-3D  illustrate the operation of the rocker mechanism  12 . These figures depict in schematic form the basic elements of left hand portion of the mechanism  12 . First, the combination of rotation of the inner crank  62  with the rocker  66  will result in the rocking link  36  rotating about the upper shaft  40  producing a limited arcuate motion of the rocking link shaft  46  located on the lower end of the rocking link  36 . When the inner crank  62  is in the 360 degree position, as shown in  FIG. 3A , the rocking link  36  will be substantially, vertical; when the inner crank  62  is in the 270 degree position as shown in  FIG. 3B , the rocking link  36  will be rotated to almost its rear most position; when the inner crank  62  is in the 180 degree position as shown in  FIG. 3C , the rocking link  36  will be again be substantially vertical; and when the inner crank  62  is in the 90 degree position as shown in  FIG. 3D , the rocking link  36  will be rotated to almost its forward most position. This action will cause the rearward end of the pedal lever  22  at hub  58  to reciprocate in an essentially horizontal direction. At the same time, as shown in  FIGS. 3A-3D , rotation of the outer crank arm  58  which connected to the hub  58  will cause the reward end of the pedal lever  22  to essentially reciprocate vertically. As a result of these combinations of movements, the reward end of the pedal lever  22  at the hub  58  will trace an essentially elliptical path as the rocking link shaft  46  rotates and consequentially in the pedal  18  will also move in an essentially elliptical path indicated by a dashed line  77 . It will be appreciated, that the dimensions of the various elements shown in  FIGS. 3A-D  can be varied to adjust the shape as well as the horizontal and vertical extent of the ellipse traced by the pedal  22 . Additionally, the angular relation between the inner crank  62  and the pedal crank  54 , which in the preferred embodiment is 180 degrees, can be varied to further modify the path of the foot pedal  18 . 
         [0014]      FIGS. 1 and 2  also illustrate the preferred embodiment of a resistance mechanism  78  for use with the apparatus  10 . In this embodiment the resistance mechanism  78  preferably includes a flywheel generator assembly. However, other types of resistance devices can be used such as an alternator, eddy current brakes or various mechanical and hydraulic devices. Also, in the preferred embodiment, the resistance mechanism  78  is connected to the rocking link shafts  46  and  48  by a belt  80  that serves to connect a pulley  82  mounted on the shaft of the flywheel generator assembly  78  to another pulley  84  secured for rotation on the upper shaft  40 . Then, the shaft  40  is connected for rotation with the rocking link shafts  46  and  48  by a pair of belts  86  and  88  that serve to connect a pair of pulleys  90  and  92  mounted for rotation with the upper shaft  40  with a pair of pulleys  94  and  96  that are mounted for rotation with rocking link shafts  46  and  48 . Under some circumstances it might be desirable to provide aid in maintaining engagement of the belt  86  with the pulleys  90  and  94 . For example, a pair of idler pulleys  97  and  98  can be rotatably attached to a tensioner bracket  100  that in turn is secured to the rocking link  36 . Similarly, to aid in maintaining engagement of the belt  88  with the pulleys  92  and  96 , another pair of idler pulleys  102  and  104  can be rotatably attached to a tensioner bracket  106  secured to the rocking link  38 . Thus, in this embodiment, the resistive force generated by the resistance device  78  can be transmitted to the pedals  18  and  20 . It should also be noted that in this embodiment, the belts  86  and  88  in combination with the shaft  40  serve to effectively couple the left pedal  18  for operation with the right pedal  22 . 
         [0015]      FIG. 4  depicts another example of an elliptical step apparatus  200 , which includes a second embodiment, indicated generally at  202 , of a rocker mechanism for generating an elliptical foot motion. For simplicity of description, those elements of the apparatus  200  that generally correspond to the elements of the apparatus  10  are identified by the same reference numerals. The apparatus  200  differs from the apparatus  10  of  FIGS. 1 and 2  in a number of respects. First, the pedals  18  and  20  are shown as secured to a pair of U-shaped pedal support members  204  and  206  that are configured to permit the members  204  and  206  to move longitudinally along a pair of pedal lever  208  and  210  respectively. Various mechanical methods including roller assemblies can be used to support the pedals  18  and  22  on the pedal levers  208  and  210  while allowing them to move along the pedal levers  18  and  22 . A pair of stroke links  212  and  214  are pivotally connected between the pedal support members  204  and  206  and the outer crank arms  54  and  56 . Similarly, a pair of links  218  and  220  is pivotally connected between the pedal support members  204  and  206  and the rocker members  26  and  28 . The pedal levers  208  and  210  are pivotally connected to the inner crank arms  62  and  64  at a pair of pivot points  222  and  224  at one end and are preferably secured at the other end, indicated generally at  226  and  228 , within a receptacle  230 . To permit limited angular rotation of the pedal levers  208  and  210 , the receptacle  230  itself can be pivotally secured to the frame  14  as represented by a pivot  232 . As a result the receptacle  230  will permit angular motion of the pedal levers  208  and  210  about the pivot point  232 . In this embodiment, the pedal levers  208  and  210  will also have the effect of causing the angular rotation of the rocking links  36  and  38  as the inner crank arms  62  and  64  rotate on the shafts  46  and  48 . As with the apparatus  10 , a resistance device such as the flywheel generator assembly  78  can be connected to the shafts  46  and  48  using a mechanical arrangement represented by the belts  80 ,  86 , and  88  and the pulleys  84 ,  90 ,  92 ,  94  and  96 . In this case, a pair of idler pulleys, represented by  234 , which are pivotally mounted on a pair of support members  236  and  238 , can function as belt tensioners. 
         [0016]      FIGS. 5A-5D  illustrate in schematic form the operation of the rocker mechanism  202  using the basic elements of left hand portion of the rocker mechanism  202 . Here, the rotation of the inner crank  62  will result in the end of the pedal lever  208  at pivot point  222  to rotate about the shaft  46 . At the same time, movement of users foot on pedal  18  transmitted on the stroke link  214  and the outer crank  54  will cause the shaft  46  to rotate. The combination of the motion of both the pedal  18  along the pedal lever  208  and the substantially vertical reciprocating motion of the end of the pedal lever  208  at pivot point  222  will result in the limited arcuate motion of the shaft  46  located on the lower end of the rocking link  36 . When the inner crank  62  is in the 90 degree position, as shown in  FIG. 5A , the rocking link  36  will be rotated to almost its forward most position; when the inner crank  62  is in the 360 degree position as shown in  FIG. 5B , the rocking link  36  will be rotated to a substantially vertical position; when the inner crank  62  is in the 180 degree position as shown in  FIG. 3C , the rocking link  36  will be again be rotated to almost its forward most position; and when the inner crank  62  is in the 180 degree position as shown in  FIG. 3D , the rocking link  36  will again be substantially vertical. This will result in the in the reward end of the pedal lever at pivot point  222  tracing an essentially elliptical path as the rocking link shaft  46  rotates and as a result the pedal  18  will also move in an essentially elliptical path. It will be appreciated, that the dimensions of the various elements shown in  FIGS. 5A-D  can be varied to adjust the shape as well as the horizontal and vertical extent of the ellipse traced by the pedal  18 . Additionally and as with the apparatus  10 , the angular relation between the inner crank  62  and the pedal crank  54 , which is shown at 180 degrees, can be varied to further modify the path of the foot pedal  18 . 
         [0017]    It will be appreciated that the above description and depictions of the apparatus  10  and  200  represent the preferred embodiments of two different approaches to a mechanism for generating elliptical foot motion utilizing a rocking link of the type  36  and  38 . For example, other assemblies for connecting a rocking link type member to foot pedals or foot pedal assemblies can be used that would for example use a rotating cam arrangement instead of the crank arms  54 ,  56 ,  62  and  64 . As another example, the preferred embodiments have the elliptical generating portion of the mechanism at the rear of the apparatus as shown in the figures. However, there can be instances where it would be desirable to place this portion of the mechanism at the front of the apparatus. Moreover, it should be appreciated that certain terms such as “rocking link”, “pedal lever”, “crank arms” and stroke link” have been used to facilitate understanding of the construction and operation of the described embodiments and are not intended to limit the components described to any particular mechanical element or mechanism.