Abstract:
An exercise apparatus links rotation of left and right crank members to elliptical movement of left and right foot supporting members. Rollers on the cranks allow the foot supporting members to translate relative to the cranks, and crank driven linkage arrangements determine the extent of the translation.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    Disclosed herein is subject matter that is entitled to the filing date of U.S. Provisional Application No. 60/799,419, filed May 9, 2006. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to exercise methods and apparatus and more particularly, to exercise equipment that guides a person&#39;s feet through generally elliptical paths of motion. 
       BACKGROUND OF THE INVENTION 
       [0003]    Exercise equipment has been designed to facilitate a variety of exercise motions. For example, treadmills allow a person to walk or run in place; stepper machines allow a person to climb in place; bicycle machines allow a person to pedal in place; and various other machines allow a person to skate and/or stride in place. Yet another type of machine has been designed to facilitate relatively more complicated exercise motion and/or to better simulate real life activity. Such equipment typically converts a relatively simple motion, such as circular, into a relatively more complex motion, such as elliptical. Examples of such equipment are disclosed in U.S. Pat. No. 4,185,622 to Swenson; U.S. Pat. No. 5,383,829 to Miller; U.S. Pat. No. 5,540,637 to Rodgers, Jr.; U.S. Pat. No. 5,882,281 to Stearns et al.; and U.S. Pat. No. 5,993,359 to Eschenbach. Despite many advances in elliptical motion exercise machines, room for improvement still exists. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention may be described in terms of linkage assemblies and corresponding exercise apparatus which link circular motion to relatively more complex, generally elliptical motion. On a preferred embodiment, left and right crank members are rotatably mounted on a frame at diametrically opposed locations relative to a common crank axis, and left and right linkages are movably interconnected between the frame and respective crank members. The linkages include foot supporting links that are supported on, but not coupled to, respective crank members for purposes of determining vertical movement or stride height of a person&#39;s feet (as a function of the crank diameter defined by the crank members). The linkages also include crank amplifying arrangements that determine horizontal movement or stride length of the person&#39;s feet (independent of the crank diameter). Each crank amplifying arrangement includes a crank link movably interconnected between a respective crank member and at least one guide on the frame; an intermediate link having a lower end rotatably connected to a respective crank link, proximate the at least one guide; and a rocker link having an upper portion rotatably mounted on the frame, an offset arm rotatably connected to the upper end of a respective intermediate link. A lower portion of each rocker link is rotatably connected to a forward end of a respective foot supporting link, and an opposite, rearward end of each foot supporting link defines a foot platform. 
         [0005]    On the preferred embodiment, the left and right crank members are rotatably mounted on respective sides of the frame in a manner that defines a space therebetween, and the foot platforms are preferably configured and arranged to accommodate movement of a person&#39;s feet into the space defined between the crank members. This arrangement allows for shorter machines without sacrificing stride length. If desired, at least one guard or shield may be provided between the foot platforms to eliminate pinch points and/or reduce the likelihood of the user&#39;s feet or ankles striking one another during exercise. 
         [0006]    In another respect, the present invention may be described in terms of linkage assemblies and corresponding exercise apparatus which link reciprocal motion to relatively more complex, generally elliptical motion. For example, left and right handlebar links may be pivotally mounted on the frame and linked to at least one link in the elliptical motion linkage assembly. On the preferred embodiment, left and right handles are mounted on upper distal ends of respective rocker links. As the foot supports move through their generally elliptical paths, the handles pivot back and forth relative to the frame. In order to accommodate the proximity of the foot platforms on the preferred embodiment, the frame may be provided with opposite side posts for supporting respective handlebar links at outboard locations relative to the foot supporting linkages. 
         [0007]    In yet another respect, the present invention may be described in terms of linkage assemblies and corresponding exercise apparatus which independently generate the horizontal and vertical components of generally elliptical exercise motion. In this regard, the foot platforms are driven up and down by respective crank members (as a function of the crank diameter), and forward and backward by respective crank amplifying arrangements (independent of the crank diameter). The fore and aft movement may be varied through a range between a fraction of the crank diameter and several times the crank diameter, either as a matter of design choice or via an adjustment feature incorporated into the machine. Additional features and/or advantages of the present invention may become apparent from the more detailed description that follows. 
     
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0008]    With reference to the Figures of the Drawing, wherein like numerals represent like parts throughout the several views, 
           [0009]      FIG. 1  is a perspective view of a preferred embodiment exercise apparatus constructed according to the principles of the present invention; 
           [0010]      FIG. 2  is a different perspective view of the exercise apparatus of  FIG. 1 ; 
           [0011]      FIG. 3  is a top view of the exercise apparatus of  FIG. 1 ; 
           [0012]      FIG. 4  is a side view of the exercise apparatus of  FIG. 1 , with the apparatus configured for a relatively short stride length; and 
           [0013]      FIG. 5  is a side view of the exercise apparatus of  FIG. 1 , with the apparatus configured for a relatively long stride length. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    The present invention provides elliptical motion exercise machines which link rotation of left and right crank members to generally elliptical motion of respective left and right foot supports. The term “elliptical motion” is intended in a broad sense to describe a closed path of motion having a relatively longer major axis and a relatively shorter minor axis. In general, the present invention may be said to use displacement of the crank members to move the foot supports in a direction coincidental with one axis of the elliptical path, and displacement of crank driven members to move the foot supports in a direction coincidental with the other axis. A general characteristic of the present invention is that the crank diameter determines the length of the one axis, but does not determine the length of the other axis. Also, the crank members are preferably configured and arranged to accommodate a person&#39;s feet within a space defined therebetween, while nonetheless traveling through generally elliptical paths having a desirable aspect ratio. As a result, the machines that embody this technology may be made relatively more compact, as well. 
         [0015]    The preferred embodiment shown and described herein is generally symmetrical about a vertical plane extending lengthwise through a floor-engaging base (perpendicular to the transverse ends thereof). However, the components of the “right-hand” linkage assembly are generally one hundred and eighty degrees out of phase relative to the components of the “left-hand” linkage assembly. In any event, like reference numerals are used to designate both the “right-hand” and “left-hand” parts, and when reference is made to one or more parts on only one side of an apparatus, it is to be understood that corresponding part(s) are disposed on the opposite side of the apparatus. Also, to the extent that reference is made to forward or rearward portions of an apparatus, it is to be understood that a person can typically exercise on such apparatus while facing in either direction relative to the linkage assembly. 
         [0016]    With the foregoing in mind, the present invention will now be described with reference to a preferred embodiment exercise apparatus designated as  100  in  FIGS. 1-5 . The machine  100  includes a frame  110  that is designed to rest upon a floor surface and to support left and right linkage assemblies. The frame  110  includes a floor engaging base  112  and a forward stanchion  114  that extends upward from a forward end of the base  112 . A user interface and/or display device (not shown) may be mounted on the forward stanchion  114  (on the exposed portion of bar  116 , for example) to perform various functions, including (1) displaying information to the user regarding items such as (a) exercise parameters and/or programs, (b) the current parameters and/or a currently selected program, (c) the current time, (d) the elapsed exercise time, (e) the current speed of exercise, (f) the average speed of exercise, (g) the number of calories burned during exercise, (h) the simulated distance traveled during exercise, and/or (i) internet data; and (2) allowing the user to (a) select or change the information being viewed, (b) select or change an exercise program, (c) adjust the speed of exercise, (d) adjust the resistance to exercise, (e) adjust the path of the exercise motion, and/or (f) immediately stop the exercise motion. 
         [0017]    Left and right crank discs  120  are rotatably mounted on respective sides of the frame  110  at respective journals  118 . An intermediate Z-shaped bar or crank connector  122  is interconnected between the crank discs  120 , and constrains the crank discs  120  to rotate together as a unit about a common crank axis. As shown in  FIG. 2 , left and right crank rollers  124  are rotatably mounted on respective ends of the bar  122 , or respective crank members, for rotation relative thereto, and for orbital movement about the crank axis. Each roller  124  is configured and arranged to underlie a rearward portion of a respective foot supporting link  130 , as further described below. Also, left and right crank links  140  have rearward ends that are also rotatably mounted on respective ends of the bar  122 , or respective crank members, for rotation relative thereto, and for orbital movement about the crank axis. Left and right guide rollers  144  are rotatably mounted on opposite, forward ends of the crank links  140  for reasons described below. 
         [0018]    At least one of the crank discs  120  is preferably connected to a conventional inertia altering device (not shown), including, for example, a motor, a “stepped up” flywheel, an adjustable braking mechanism, or some combination thereof. For example, a belt is preferably looped about the cylindrical wall of one disc  120  and also about a relatively smaller diameter pulley spaced radially apart from the rotational axis of the disc  120 . The pulley is constrained to rotate together with a relatively larger diameter flywheel, subject to resistance imparted on the flywheel by a conventional eddy current brake. Persons skilled in the art will also recognize that at least one of the crank discs  120  may be replaced by a crank arm on an alternative embodiment. 
         [0019]    Left and right rocker links  150  are rotatably mounted on respective sides of the forward stanchion  114  for pivoting about a common pivot axis. More specifically, each rocker link  150  includes a base member or tube that is mounted coaxially on a respective portion of the bar  116 . Each rocker link  150  also includes an upper portion that extends generally upward from the base member, and the upper distal end of each upper portion may be described as a handle  155  that is sized and configured for grasping. Each rocker link  150  also includes an offset arm  156  that extends generally forward from the base member, proximate the pivot axis. Each rocker link  150  also includes a lower portion that extends generally downward from the base member, and the lower distal end of each lower portion is rotatably connected to the forward end of a respective foot supporting link  130 . As suggested in a previous paragraph, and perhaps best seen in  FIG. 3 , the foot supporting links  130  are positioned “inboard” relative to the handles  155 . 
         [0020]    Left and right intermediate links  160  have upper ends that are rotatably connected to the distal ends of respective offset arms  156 , and lower ends that are rotatably connected to the forward ends of respective crank links  140 . On the preferred embodiment  100 , the respective intermediate links, crank links  140 , and guide rollers  144  are all rotatably connected to one another at a common axis. However, persons skilled in the art will recognize that the present invention is not limited to such an arrangement. In other words, each guide roller  144  could be rotatably mounted to one forward portion of a respective crank link  140 , and each intermediate link  160  could be rotatably connected to a discrete forward portion of a respective crank link  140 . Alternatively, each guide roller  144  could be rotatably mounted to one lower portion of a respective intermediate link  160 , and each crank link  140  could be rotatably connected to a discrete lower portion of a respective intermediate link  160 . 
         [0021]    Each guide roller  144  is configured and arranged to travel along a respective track or guide  111  that is pivotally mounted on a respective side of the forward stanchion  114 , proximate the base  112 . The guides  111  are preferably rigidly interconnected to one another by welding each to a common rod  113 , and may alternatively be described as at least one guide having first and second tracks. One end of an adjustable length member  190  is rotatably connected to a central section of the rod  113 , and an opposite end of the adjustable length member  190  is rotatably connected to the frame  110  (at rod  119 ). As seen by comparing  FIGS. 4 and 5 , when the adjustable length member  190  assumes a relatively short configuration (see  FIG. 4 ), the guides  111  are relatively less inclined relative to the underlying floor surface (and the foot supporting links  130  travel a relatively shorter distance measured perpendicular to the crank axis and parallel to the floor surface), and when the adjustable length member  190  assumes a relatively long configuration (see  FIG. 5 ), the guides  111  are relatively more inclined relative to the underlying floor surface (and the foot supporting links  130  travel a relatively greater distance measured perpendicular to the crank axis and parallel to the floor surface). 
         [0022]    On the preferred embodiment  100 , the adjustable length member  190  is a linear actuator that is preferably linked to the user interface (described above but not shown). Under such circumstances, the adjustable length member  190  changes length in response to a control signal. On an alternative embodiment, a spring and dampener piston is substituted for the linear actuator to accommodate changes in stride length as a function of user imparted force against the handles  155  and/or the foot supporting links  130 . 
         [0023]    Each foot supporting link  130  has a rearward portion that defines an upwardly facing platform sized and configured to support a person&#39;s foot. The left and right foot platforms  133  move through adjacent, generally elliptical paths that are disposed between the left and right crank discs  120 . Generally speaking, the vertical displacement of the foot platforms  133  is a function of the crank swing or diameter defined by rotation of the crank members, namely, the radially displaced and diametrically opposed left and right portions of the crank bar  122 . On the other hand, the horizontal displacement of the foot platforms  133  is not similarly limited. In this regard, the guides  111  may be adjusted relative to the frame  110 , as described above, to provide horizontal displacement ranging from a fraction of the crank diameter to several (at least three) times the crank diameter. 
         [0024]    The present invention has been described with reference to specific embodiments with the understanding that persons skilled in the art will recognize various advantages thereof, as well as numerous alternative embodiments thereof. With the foregoing in mind, the scope of the present invention is to be limited only to the extent of the claims which follow.