Abstract:
A semi-recumbent cycling apparatus constrains left and right foot supports to move through substantially elliptical paths of motion relative to a frame, while supporting a person&#39;s back in an inclined position relative to an underlying floor surface. The paths of the foot supports have major axes which extend generally perpendicular to the floor surface.

Description:
FIELD OF THE INVENTION 
     The present invention relates to exercise methods and apparatus and more particularly, to a semi-recumbent cycling machine which facilitates foot movement through an elliptical path. 
     BACKGROUND OF THE INVENTION 
     Cycling machines are known in the art. In general, a person sits on a seat and faces toward handle bars with legs extending downward. With the feet on respective pedals, the person is able to move his or her legs through a continuous motion. However, shortcomings associated with this type of exercise include a relatively limited range of motion and lack of back support during exercise. The art is also replete with recumbent cycling machines, which provide requisite back support but provide the same limited range of motion. An object of the present invention is to provide an exercise apparatus which provides comfortable back support while facilitating exercise through a continuous path of motion having an extended range. 
     SUMMARY OF THE INVENTION 
     In one respect, the present invention may be seen to provide a novel linkage assembly and corresponding exercise apparatus suitable for linking circular motion to relatively more complex, generally elliptical motion. In particular, an intermediate portion of a connector link is rotatably connected to a crank; a first end of the connector link is sized and configured to support a person&#39;s foot; and a second, opposite end of the connector link is constrained to move through a fixed path. The arrangement links rotation of the flywheel to movement of the foot support through a generally elliptical path. 
     In another respect, the present invention may be seen to provide a novel exercise apparatus which supports a person in an inclined and supine position relative to a horizontal floor surface while facilitating movement of the person&#39;s feet through generally elliptical paths having major axes which are generally perpendicular to the floor surface. In this regard, the linkage assembly components are configured and arranged to facilitate exercise which is safe, comfortable, and effective. 
     In yet another respect, the present invention may be seen to provide a novel exercise apparatus which facilitates foot travel through any of several fixed elliptical paths. In this regard, the constraint imposed on the second end of the connector link is moved relative to the crank axis to adjust the exercise stroke. Many of the features and advantages of the present invention may become more apparent from the detailed description that follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     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 another perspective view of the exercise apparatus of FIG. 1; 
     FIG. 3 is a side view of the exercise apparatus of FIG. 1; 
     FIG. 4 is an opposite side view of the exercise apparatus of FIG. 1, the apparatus having been adjusted to generate a relatively shorter exercise stroke; 
     FIG. 5 is a front view of the exercise apparatus of FIG. 1; 
     FIG. 6 is a top view of the exercise apparatus of FIG. 1; 
     FIG. 7 is a perspective view of another exercise apparatus constructed according to the principles of the present invention; and 
     FIG. 8 is another perspective view of the exercise apparatus of FIG. 7, the apparatus having been adjusted to generate a relatively shorter exercise stroke. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a leg exercise assembly which moves relative to a frame in a manner that links rotation of left and right cranks to generally elliptical motion of respective left and right foot supporting members. The term “elliptical motion” is intended in a broad sense to describe a closed curved path of motion having a relatively longer first axis or major axis and a relatively shorter second axis or minor axis. 
     A first exercise apparatus constructed according to the principles of the present invention is designated as  100  in FIGS. 1-6. The apparatus  100  includes a leg exercise assembly which moves relative to a frame  110  in a manner that links rotation of right and left cranks  130  and  132  to generally elliptical motion of respective right and left foot supporting members  141 . 
     The frame  110  includes a base  112  which is designed to rest upon a generally horizontal floor surface. The apparatus  100  is generally symmetrical about a vertical plane extending lengthwise through the base  112 . The linkage assembly has like parts on each side of the plane of symmetry, but the parts are one hundred and eighty degrees out of phase with one another. Nonetheless, like reference numerals are used to designate both the “right-hand” and “left-hand” components of the linkage assembly, and when reference is made to linkage assembly parts on only one side of the apparatus  100 , it is to be understood that similar parts are disposed on the opposite side of the apparatus  100 . 
     The base  112  includes a forward end which coincides with a transversely extending support  113 ; a rearward end which coincides with a transversely extending support  114 ; an intermediate frame portion  115  extending upward from the base  112 ; and a rear frame portion  116  extending upward from the base  112 . An inclined body support  120  is mounted on top of both frame portions  115  and  116  and is oriented at an angle of approximately one hundred and thirty-five degrees relative to the base  112  and the underlying floor surface. The body support  120  is sized and configured to support a person&#39;s head, back, and posterior. The body support  120  is rigidly mounted on the frame  110 , but provisions could be made for adjusting the position of the former relative to the latter to accommodate people of different sizes and/or having different needs. 
     Right and left cranks  130  and  132  are rotatably mounted to the frame portion  115  by means known in the art. The right crank  130  is depicted as a crank arm, and the left crank  132  is depicted as a relatively large diameter pulley. As shown in FIG. 4, the cranks  130  and  132  rotate about a common crank axis X 4  relative to the frame  110 . A flywheel  135  is rotatably mounted to the frame portion  115  by means known in the art. A belt  134  is formed into a closed loop about the pulley  132  and a relative small diameter pulley  133  which is secured to the flywheel  135  and/or the flywheel shaft. As a result of this arrangement, the flywheel  135  is “stepped up” relative to the cranks  130  and  132  and rotates relatively faster than the cranks  130  and  132 . Those skilled in the art will recognize that other known types of inertia altering mechanisms (including, for example, a drag strap resistance device) may be added to or substituted for the stepped up flywheel arrangement. 
     Right and left connector links  140  have intermediate portions  143  which are rotatably connected to distal ends of respective cranks  130  and  132 . As shown in FIG. 4, each connector link  140  is thereby constrained to pivot about a respective axis Y 4  relative to a respective crank  130  or  132 . A forward end of each link  140  supports a respective foot platform  141  which is sized and configured to support a person&#39;s foot. Each foot support  141  defines an angle of approximately one hundred and forty-five degrees relative to the longitudinal axis of a respective connector link  140 . 
     The connector links  140  have rearward ends  145  which are movably connected to the frame  110 . In particular, right and left constraints  150  are rotatably mounted on opposite sides of a block  156 , and each constraint  150  is provided with a pair of opposing bearing members  154 . As shown in FIG. 4, the constraints  150  rotate about a common “guide” axis Z 4  relative to the block  156 . The rearward ends  145  of the connector links  140  are constrained to rotate about the axis Z 4  (together with respective constraints  150 ) but are free to move in a radial direction relative to both the axis Z 4  and the constraints  150 . As a result, rotation of the cranks  130  and  132  is linked to rotation of the connector link ends  145  together with the constraints  150  and translation of the connector link ends  145  relative to the constraints  150  and to generally elliptical movement of the foot supports  141  relative to the frame  110 . The relative sizes and spacial relationships of the parts shown in FIGS. 1-6 result in a very desirable exercise stroke. 
     The magnitude of the exercise stroke (the path traveled by the foot supports  141 ) may be adjusted by moving the block  156  (and the guide axis Z 4 ) relative to the crank axis X 4 . On the embodiment  100 , the adjustment means  160  includes a motor  165  which selectively rotates a worm gear  166 . The block  156  is operatively connected to the worm gear  166  and constrained to move along a rail  117  on the frame portion  115  in response to rotation of the worm gear  166 . Rotation of the worm gear  166  in a first direction causes the block  156  to move forward toward the relatively long stroke position shown in FIG.  3 . Rotation of the worm gear  166  in a second, opposite direction causes the block  156  to move rearward toward the relatively short stroke position shown in FIG.  4 . 
     Those skilled in the art will recognize that each of the components of the linkage assembly is necessarily long enough to facilitate the depicted interconnections but need not terminate immediately beyond the points of connection. Furthermore, for ease of reference in both this detailed description and the claims set forth below, the components are sometimes described with reference to “ends” being connected to other parts. However, a term such as “rear end” should be interpreted broadly, in a manner that could include “rearward portion” and/or “behind an intermediate portion”, for example. Those skilled in the art will further recognize that the components of the linkage assembly may be arranged and/or interconnected in a variety of ways without departing from the scope of the present invention, and that the spatial relationships, including the radius and/or angular displacement of the crank axes, may vary for different sizes, configurations, and/or arrangements of the components of the linkage assembly. 
     One such modification of the present invention is the alternative embodiment exercise apparatus which is designated as  200  in FIGS. 7-8. As suggested by the common reference numerals, this second embodiment  200  is similar in some respects to the first embodiment  100 . A similar body support  120  and a similar crank arrangement, including cranks  130  and  132 , are mounted on a similar frame  110 . 
     Right and left connector links  240  have intermediate portions  243  which are rotatably connected to distal ends of respective cranks  130  and  132 . As a result, each connector link  240  is constrained to pivot about a respective axis relative to a respective crank  130  or  132 . A forward end of each link  240  supports a respective foot platform  241  which is sized and configured to support a person&#39;s foot. Each foot support  241  defines an angle of approximately one hundred and forty-five degrees relative to the longitudinal axis of a respective connector link  240 . 
     The connector links  240  have rearward ends  245  which are movably connected to the frame  110 . In particular, right and left constraints  250  are rotatably mounted on opposite sides of the block  156 . As shown in FIG. 8, the constraints  250  pivot about a common “guide” axis Z 8  relative to the block  156 . The constraints  250  may be described as rocker links which are connected in telescoping fashion to “tubular” portions of respective connector links  240 . The rearward ends  245  of the connector links  240  are constrained to pivot about the axis Z 9  (together with respective constraints  250 ) but are free to move in a radial direction relative to both the axis Z 8  and the constraints  250 . As a result, rotation of the cranks  130  and  132  is linked to rotation of the connector link ends  245  together with the constraints  250 , and translation of the connector link ends  245  relative to the constraints  250 , and also, to generally elliptical movement of the foot supports  241  relative to the frame  110 . 
     The same adjustment assembly  160  is provided to adjust the exercise motion generated by the second embodiment  200 . The motor  165  selectively rotates the worm gear  166 , which in turn, moves the block  156  along the rail  117 . The motor  165  may operate in response to an input signal from a person or in response to a control signal from another source. 
     Although the present invention has been described with reference to specific embodiments and particular applications, those skilled in the art will recognize additional embodiments, modifications, and/or applications which fall within the scope of the present invention. Accordingly, the scope of the present invention is to be limited only to the extent of the claims which follow.