Abstract:
An exercise apparatus links rotation of left and right cranks to elliptical movement of left and right foot supporting members. The foot supporting members include left and right foot platforms that travel through space defined between the left and right cranks. Rollers on the cranks allow the foot supporting members to translate relative to the cranks, and amplified drawbar/rocket link arrangements determine the extent of the translation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Disclosed herein is subject matter that is entitled to the filing date of U.S. Provisional Application No. 60/760,578, filed Jan. 21, 2006. 
    
    
     FIELD OF THE INVENTION 
     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 
     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 exercise equipment has been designed to facilitate relatively more complicated exercise motions 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. Despite various advances in elliptical motion exercise machines, room for improvement still exists. 
     SUMMARY OF THE INVENTION 
     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. More specifically, left and right cranks are rotatably mounted on respective sides of a frame to provide rotating left and right connection points which define a space therebetween. Left and right foot supporting linkages are movably interconnected between the frame and respective connection points in such a manner that rotation of the cranks is linked to generally elliptical movement of adjacent left and right foot platforms. The linkages include foot supporting members that are connected, but not coupled, to respective connection points for purposes of determining vertical movement of a person&#39;s feet (as a function of the crank diameter traversed by the cranks). The linkages also include drawbar/rocker link arrangements that determine horizontal movement of the person&#39;s feet (independent of the crank diameter). These “decoupled” foot platforms or dual drive assemblies facilitate increases in stride length and/or decreases in machine length. 
     The foot supporting members are preferably configured and arranged to accommodate movement of a person&#39;s feet into the space defined between the cranks. This arrangement allows for shorter machines without sacrificing stride length. 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. 
     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. As the foot supports move through their generally elliptical paths, the handlebras 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. 
     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 cranks (as a function of the crank diameter), and forward and backward by respective drawbar/rocker link arrangements (independent of the crank diameter). The fore and aft movement may be varied through a range between zero and several times the crank diameter, ether 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 DRAWINGS 
       With reference to the Figures of the Drawing, wherein like numerals represent like parts and assemblies throughout the several views, 
         FIG. 1  is a perspective view of an exercise apparatus constructed according to the principles of the present invention; 
         FIG. 2  is a different perspective view of the exercise apparatus of  FIG. 1 ; 
         FIG. 3  is another perspective view of the exercise apparatus of  FIG. 1 , showing a rearward section of the apparatus partially pivoted toward a folded position relative to a forward motion of the apparatus; and 
         FIG. 4  is yet another perspective view of the exercise apparatus of  FIG. 1 , showing the rearward section pivoted entirely into a folded position relative to the forward section. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides elliptical motion exercise machines which link rotation of left and right cranks 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 cranks 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. As a result of this feature, a person&#39;s feet may pass through a space between the cranks while nonetheless traveling through a generally elliptical path having a desirable aspect ratio, and the machines that embody this technology may be made relatively more compact, as well. 
     The embodiments shown and/or described herein are generally symmetrical about a vertical plane extending lengthwise through a floor-engaging base (perpendicular to the transverse ends thereof), the noteworthy exceptions being the provision of a resistance mechanism on only one side of the machine, and the relative orientation of certain parts of the linkage assembly on opposite sides of the plane of symmetry. In general, the “right-hand” components are one hundred and eighty degrees out of phase relative to the “left-hand” components. However, 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. 
     With the foregoing in mind, the present invention will now be descried with reference to a preferred embodiment exercise apparatus designated as  100  in  FIGS. 1-4 . The machine  100  includes a frame that is designed to rest upon a floor surface. The frame includes a forward section  99 , and a rearward section  199 . The rearward section  199  is pivotally connected to the forward section  99  at pivot axis T. The forward section  99  includes a floor engaging base and a forward stanchion that extends upward from a forward end of the base. A display and/or interface device (not shown) may be mounted on the forward stanchion (on the exposed portion of bar  35 , 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. 
     Left and right cranks  8  are rotatably mounted on respective sides of the rearward frame section  199  at respective journals  12 . An intermediate Z-shaped bar or crank connector  10  is interconnected between the cranks  8 , and constrains the crank  8  to rotate together as a unit about a common crank axis designated as P. Left and right rollers  24  are rotatably mounted on respective cranks  8  for orbital movement about the crank axis P and rotation relative to respective cranks  8 . Both cranks  8  are shown in the form of discs, but crank arms may be used in the alternative. As shown on the depicted machine  100 , an advantage of using a crank disc is that it may be more readily connected to any of various known inertia altering devices, including, for example, a motor, a “stepped up” flywheel, an adjustable braking mechanism, or various combinations thereof. For example, the machine  100  is shown with a stepped-up flywheel  55  connected to the left side crank  8  via a belt  45 . 
     Left and right pivot members are pivotally mounted on respective sides of the frame at pivot axis T. Each pivot member includes a triangular plate or first member  20  having a respective pivot connection point at each of its three corners. One of the pivot connection points axially aligns with the pivot axis T. Left and right drawbar links  14  are pivotally interconnected between respective cranks  8  and respective pivot members (at corresponding second pivot connection points on the triangular plates  20 ). The drawbar links  14  link rotation of respective cranks  8  to pivoting of respective pivot members. 
     Each pivot member also includes an extension or second member  5  that is pivotally connected to the triangular plate  20  (at the remaining one of the pivot connection points on a respective triangular plate  20 ). Each pivot member also includes an adjustable length or third member  22 , which may be a linear actuator or a manually lead screw, for example. Each adjustable length member  22  is operatively interconnected between a respective triangular plate  20  and a respective extension  5  for purposes of selectively reorienting the extension  5  relative to the pivot axis T, as further explained below. 
     Left and right rocker links are pivotally mounted on respective sides of the forward stanchion for pivoting about a common pivot axis Q. Each rocker link includes a respective first segment  30  that extends generally downward from the support bar  35  on the forward stanchion; a respective second segment  42  that extends generally rearward from the bar  35 ; and a respective third segment  33  that extends generally upward from the bar  35 . Each third segment  33  is sized and configured for grasping and may be described as a handlebar. Each second segment  42  cooperates with a respective first segment  30  to define an inverted, generally L-shaped configuration. 
     Left and right connector links  28  are pivotally interconnected between respective second segments  42  and respective extensions  5 , thereby linking rotation of respective cranks  8  to pivoting of respective rocker links (via pivoting of respective pivot members). Left and right foot supports  25  have forward ends that are pivotally connected to lower portions of respective first segments  30 , and relatively rearward portions hat are supported on respective rollers  24 . The resulting linkage arrangement constrains at least part of each foot support  25 , including a respective foot pad  26 , to move through a generally elliptical path as the cranks  8  rotate. 
     The foot platforms  26  move through generally elliptical paths that are disposed between the left and right cranks  8 . Generally speaking, the vertical displacement of the foot platforms  26  is a function of the crank swing or diameter defined by rotation of the cranks  8 . On the other hand, the horizontal displacement of the foot platforms  26  is not similarly limited. In this regard, the extensions  5  may be adjusted relative to respective triangular plates  20  to provide horizontal displacement ranging from essentially zero to several (at least three) times the crank diameter defined by the cranks  8 . As the extensions  5  are pivoted closer to alignment with the pivot axis T, the horizontal displacement decreases, and alternatively, as the extensions  5  are pivoted farther from alignment with the pivot axis T, the horizontal displacement increases. 
       FIGS. 3 and 4  show how the machine  100  may be folded into a more compact configuration, with the rearward frame section  199  pivoted into a generally parallel orientation relative to the forward stanchion on the forward frame section  99 . The extensions  5  are preferably moved into alignment with the axis T prior to folding the machine  100  into the configuration shown in  FIG. 4 . In a manner known in the art, a bolt may be inserted through aligned holes in the two frame sections  99  and  199  to secure the frame in the configuration shown in  FIGS. 1-2  and/or the configuration shown in  FIG. 4 . Also, a spring assist mechanism may be interconnected between the two frame sections  99  and  199  to facilitate folding and unfolding of the rearward section  199  relative to the forward section  99 . 
     The present invention has been described with reference to a preferred embodiment  100  with the understanding that persons skilled in the art will recognize additional embodiments and/or applications. With the foregoing in mind, the scope of the present invention is to be limited only to the extent of the claims which follow.