Abstract:
An exercise apparatus includes a frame; left and right first cranks rotatably mounted on the frame; left and right second cranks rotatably mounted on the frame; left and right rails rotatably interconnected between respective first cranks and respective second cranks; left and right foot supports movably mounted on respective rails; left and right rocker links pivotally mounted on the frame and operatively connected to respective foot supports; and left and right drawbar links movably interconnected between respective cranks and respective rocker links. The resulting assembly constrains the rails to move through respective circular paths relative to the frame, and constrains the foot supports to move back and forth relative to the rails.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to exercise methods and apparatus and more particularly, to exercise equipment which facilitates movement of a person&#39;s feet through generally elliptical paths.  
         BACKGROUND OF THE INVENTION  
         [0002]    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 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 uses a linkage assembly to convert a relatively simple motion, such as circular, into a relatively more complex motion, such as elliptical. For example, see U.S. Pat. No. 4,185,622 to Swenson; U.S. Pat. No. 5,279,529 to Eschenbach; 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. 6,080,086 to Maresh et al.  
         SUMMARY OF THE INVENTION  
         [0003]    Generally speaking, the present invention provides a novel linkage assembly and corresponding exercise apparatus suitable for linking circular motion to relatively more complex, generally elliptical motion. On a preferred embodiment, left and right first cranks are rotatably mounted on a rearward portion of a frame, and left and right second cranks are rotatably mounted on an opposite, forward portion of the frame. Left and right rails are rotatably interconnected between respective first cranks and respective second cranks, and left and right foot supports are movably mounted on respective rails. Left and right rocker links are pivotally mounted on the frame, and operatively connected to respective foot supports. Left and right drawbar links are movably interconnected between respective cranks and respective rocker links. The resulting assembly constrains the rails to move through respective circular paths relative to the frame, while also constraining the foot supports to move back and forth relative to respective rails. Among other things, the present invention may be considered advantageous to the extent that the foot supports remain in a single, desirable orientation during exercise activity. Additional features and/or advantages of the present invention will become apparent from the more detailed description that follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]    With reference to the Figures of the Drawing, wherein like numerals represent like parts and assemblies throughout the several views,  
         [0005]    [0005]FIG. 1 is a perspective view of an exercise apparatus constructed according to the principles of the present invention;  
         [0006]    [0006]FIG. 2 is another perspective view of the exercise apparatus of FIG. 1;  
         [0007]    [0007]FIG. 3 is a side view of the exercise apparatus of FIG. 1;  
         [0008]    [0008]FIG. 4 is a perspective view of another exercise apparatus constructed according to the principles of the present invention; and  
         [0009]    [0009]FIG. 5 is another perspective view of the exercise apparatus of FIG. 4. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0010]    The present invention provides elliptical motion exercise machines and methods that link rotation of left and right cranks to generally elliptical motion of left and right foot supports.  
         [0011]    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 (which extends perpendicular to the major 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 the minor axis, and displacement of crank driven members to move the foot supports in a direction coincidental with the major axis As a result, the crank diameter determines the length of the minor axis, but only indirectly affects the length of the major axis.  
         [0012]    The embodiments disclosed herein are generally symmetrical about a vertical plane extending lengthwise through a floor-engaging base. Linkage assembly components on the left side of the machines are preferably one hundred and eighty degrees out of  5  phase relative to their opposite side counterparts. Also, to the extent that reference is made to forward or rearward portions of a machine, it is to be understood that a person can typically exercise while facing in either direction relative to the disclosed linkage assembly.  
         [0013]    One embodiment of the present invention is designated as  100  in FIGS.  1 - 3 . The machine  100  generally includes a frame  110 ; left and right linkage assemblies movably mounted on the frame  110 ; and a user interface  190  mounted on the frame  110 . The interface  190  may be designed to perform a variety of 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 orientation of the exercise motion, and/or (f) immediately stop the exercise motion.  
         [0014]    The frame  110  includes a floor engaging base  112 ; a forward stanchion  114  that extends upward from opposite sides of the base  112 , proximate the front end of the frame  110 ; and rearward supports  116  that extend upward from respective sides of the base  112 , proximate the rear end of the frame  110 . The forward stanchion  114  may be described as an inverted U-shaped member having a middle portion or console portion  119  that supports the user interface  190 , and generally vertical leg portions that define a gap therebetween. The console portion  119  may be configured to support additional items, including a water bottle, for example.  
         [0015]    Each linkage assembly includes a rearward crank  120  or  121  rotatably mounted to a respective support  116  and rotatable about a common crank axis. Left and right support shafts  123  are rigidly secured to radially displaced portions of respective cranks  120  and  121 , and define respective, diametrically opposed axes. A central crank disc  122  is rigidly interconnected between the inward ends of the diametrically opposed support shafts  123 , thereby constraining the left and right linkage assemblies to remain one hundred and eighty degrees out of phase with one another.  
         [0016]    A similar crank arrangement is provided at the forward end of the machine  100 . In other words, each linkage assembly also includes a forward crank  220  and  221  rotatably mounted to a respective side of the stanchion  114  and rotatable about a common crank axis. Left and right support shafts  223  are rigidly secured to radially displaced portions of respective cranks  220  and  221 , and define respective, diametrically opposed axes. A central crank disc  222  is rigidly interconnected between the inward ends of the diametrically opposed support shafts  223 , thereby constraining the left and right linkage assemblies to remain one hundred and eighty degrees out of phase with one another.  
         [0017]    Each linkage assembly also includes a rail  130  or  131  having a rearward end that is rotatably mounted on a respective rearward support shaft  123 , and an opposite, forward end that is rotatably mounted on a respective forward support shaft  223 . As a result of this arrangement, the rails  130  and  131  are constrained to move through respective circular paths in response to rotation of the cranks  120  and  121  and  220  and  221 .  
         [0018]    Each linkage assembly also includes a foot support or skate  140  or  141  movably mounted on a respective rail  130  or  131 . Rollers or bearings are preferably disposed between the foot supports  140  and  141  and respective rails  130  and  131  to facilitate a smooth gliding interface therebetween. In any event, the foot supports  140  and  141  are constrained to move vertically together with respective rails  130  and  131 , but remain free to move horizontally relative to respective rails  130  and  131 . In this regard, the “skate” arrangement effectively “decouples” the foot supports  140  and  141  from the horizontal displacement of the cranks  120  and  121  and  220  and  221 .  
         [0019]    Each linkage assembly also includes a rocker link  150  or  151  pivotally mounted on a respective side of the stanchion  114  and pivotal about a common pivot axis. On the embodiment  100 , each rocker link  150  and  151  is pivotally connected to a common support shaft  115  that spans the stanchion  114 . Each rocker link  150  and  151  has an upper distal portion  155  that is sized and configured for grasping. Each rocker link  150  and  151  has an opposite, generally L-shaped lower portion that extends downward and then rearward. Forward ends of respective intermediate links  160  are rotatably connected to lower distal ends of respective rocker links  150  and  151 , and opposite, rearward ends of respective intermediate links  160  are rotatably connected to respective foot supports  140  and  141 .  
         [0020]    Each linkage assembly also includes a drawbar link  170  or  171  having a rear end pivotally coupled to a respective crank  120  or  121  (or rail), and a forward end pivotally coupled to a respective rocker link  150  or  151 . Each drawbar link  170  or  171  links rotation of a respective crank  120  or  121  to reciprocal pivoting of a respective rocker link  150  or  151 . The “pivot arm” or radius associated with the drawbar links  170  and  171  is shorter than the “pivot arm” or radius associated with the intermediate links  160  and  161 , and thus, the foot supports  140  and  141  are constrained to move fore and aft to a greater extent than the drawbar links  170  and  171 . This “amplification effect” may be adjusted by securing the drawbar links  170  and  171  in alternative locations along respective rocker links  150  and  151 .  
         [0021]    On the machine  100 , each drawbar link  170  or  171  is pivotally connected to a respective bracket  175 , which in turn, is movably mounted on a respective rocker link  150  or  151 . Low friction material is preferably disposed between the brackets  175  and respective rocker links  150  and  151  to facilitate a smooth gliding interface therebetween. Actuators or stepper motors  180  and  181  are mounted on respective rocker links  150  and  151 , and are connected to respective brackets  175  via respective lead screws  185 . The actuators  180  and  181  may be connected to the interface  190  (or another suitable controller) in various known ways, including wires routed through respective rocker links  150  and  151  and then through the support shaft  115 . The lead screws  185  are threaded through respective brackets  175 , and the actuators  180  and  181  are operable to rotate respective lead screws  185  and thereby move respective brackets  175  along respective rocker links  150  and  151 . As the brackets  175  are moved closer to the pivot axis of the rocker links  150  and  151 , the amplification effect is increased, and the foot supports  140  and  141  are constrained to move through relatively longer paths.  
         [0022]    The machine  100  is shown with a bar  232  rotatably interconnected between forward and rearward crank arms  231 , which are keyed to respective cranks  121  and  221 . The bar  232  is ninety degrees out of phase with the rails  130  and  131 , and it cooperates with the rails  130  and  131  to maintain reliable synchronization between the rearward cranks  120  and  121  and the forward cranks  220  and  221 .  
         [0023]    The machine  100  is also shown with a flywheel  202  rotatably mounted on the right side of the stanchion  114 . As shown in FIG. 2, a belt  201  is looped about the crank  221  and a relatively smaller diameter pulley, which in turn, is keyed to the flywheel  202 . As a result, the flywheel  202  is constrained to rotate at a relatively faster speed than the crank  221 . The flywheel  202  adds inertia to the linkage assemblies, and various types of known devices (such as a drag strap or an eddy current brake) may be operatively connected to the flywheel  202  to provide adjustable resistance, as well.  
         [0024]    An advantage of the machine  100  is that essentially the entire length of the machine  100  is available for accommodating movement of a person&#39;s feet through desirable elliptical paths. As a result, both the footprint or planform of the machine  100  and the space needed for its operation are relatively small in comparison to the available stride length. The machine  100  may also be considered advantageous to the extent that the stride length may be adjusted during exercise activity, and/or the stride length is not limited by the diameter or stroke of any of the cranks.  
         [0025]    Another desirable feature of the machine  100  is that the foot platforms  140  and  141  are positioned in close proximity to one another, thereby accommodating foot motion which may be considered a better approximation of real life activity. In this regard, the opposite side cranks  120  and  121  and  220  and  221  and the central support cranks  122  and  222  eliminate the need for a frame supported bearing assembly between the foot platforms  140  and  141 . In the absence of a central bearing assembly, one or more shields or guards may be disposed between the opposite side foot supports  140  and  141  in order to eliminate pinch points.  
         [0026]    Another embodiment of the present invention is designated as  400  in FIGS.  4 - 5 . The exercise machine  400  includes a frame  410  having a floor engaging base  412 ; a forward stanchion  414  that extends upward from the base  412 ; and a rearward stanchion  416  that extends upward from the base  412 .  
         [0027]    Rearward cranks  420  and  421  are rotatably mounted on the rearward stanchion  416 . The cranks  420  and  421  are keyed to a common shaft and rotatable about a common axis. Left and right support shafts  427  are rigidly secured to radially displaced portions of respective cranks  420  and  421 , thereby defining respective, diametrically opposed axes that rotate about the rearward crank axis. Similarly, forward cranks  520  and  521  are rotatably mounted on the forward stanchion  414 , keyed to a common shaft, and rotatable about a common crank axis. Left and right support shafts  528  are rigidly secured to radially displaced portions of respective cranks  520  and  521 , and define respective, diametrically opposed axes that rotate about the forward crank axis.  
         [0028]    A left rail  430  has a rearward end that is rotatably mounted on the left rearward support shaft  427 , and an opposite, forward end that is rotatably mounted on the left forward support shaft  528 . Similarly, a right rail  431  has a rearward end that is rotatably mounted on the right rearward support shaft  427 , and an opposite, forward end that is rotatably mounted on the right forward support shaft  528 . As a result, the rails  430  and  431  are constrained to move through circular paths in response to rotation of the cranks  420  and  421  and  520  and  521 , and to remain one hundred eighty degrees out of phase relative to one another.  
         [0029]    A left foot support or skate  440  is movably mounted on the left rail  430 , and a right foot support or skate  441  is movably mounted on the right rail  431 . Rollers or bearings are preferably disposed between the foot supports  440  and  441  and respective rails  430  and  431  to facilitate a smooth gliding interface therebetween. In any event, the foot supports  440  and  441  are constrained to move vertically together with respective rails  430  and  431 , but remain free to move horizontally relative to respective rails  430  and  431 . In this regard, the “skate” arrangement effectively “de-couples” the foot supports  440  and  441  from the horizontal displacement of respective rails  430  and  431  and the associated cranks  420  and  421  and  520  and  521 .  
         [0030]    Rocker links  450  and  451  are pivotally mounted on opposite sides of the forward stanchion  414  and pivotal about a common pivot axis. Each rocker link  450  and  451  has an upper distal portion  455  that is sized and configured for grasping. Each rocker link  450  and  451  has an opposite, generally L-shaped lower portion that extends downward and then rearward. Forward ends of respective intermediate links  460  are rotatably connected to lower distal ends of respective rocker links  450  and  451 , and opposite, rearward ends of respective intermediate links  460  are rotatably connected to respective foot supports  440  and  441 .  
         [0031]    A left drawbar link  470  has a rear end pivotally coupled to the left rearward support shaft  427 , and a forward end pivotally coupled to an intermediate portion of the left rocker link  450 . Similarly, a right drawbar link  471  has a rear end pivotally coupled to the right rearward support shaft  427 , and a forward end pivotally coupled to an intermediate portion of the right rocker link  451 . Each drawbar link  470  or  471  links rotation of a respective crank  420  or  421  to reciprocal pivoting of a respective rocker link  450  or  451 . The “pivot arm” or radius associated with the drawbar links  470  and  471  is shorter than the “pivot arm” or radius associated with the intermediate links  460  and  461 , and thus, the foot supports  440  and  441  are constrained to move fore and aft to a greater extent than the drawbar links  470  and  471 . The extent of this “amplification effect” may be adjusted by securing the drawbar links  470  and  471  in alternative locations along respective rocker links  450  and  451 .  
         [0032]    On the machine  400 , each drawbar link  470  or  471  is pivotally connected to a respective bracket  475 , which in turn, is movably mounted on a respective rocker link  450  or  451 . Low friction material is preferably disposed between the brackets  475  and respective rocker links  450  and  451  to provide a smooth interface therebetween. Pins  487  are mounted on respective brackets  475 , and are connected to respective rocker links  450  and  451  via respective holes  457 . Spring latching arrangements or other known means may be provided to bias the pins  487  to remain in selected holes  457 . As the brackets  475  are moved closer to the pivot axis of the rocker links  450  and  451 , the amplification effect is increased, and the foot supports  440  and  441  are constrained to move through relatively longer paths.  
         [0033]    The machine  400  is shown with a timing belt  432  looped about the left cranks  420  and  520 . The timing belt  432  ensures reliable synchronization between the rearward cranks  420  and  421  and the forward cranks  520  and  521 . The machine  400  is also shown with a flywheel  502  and a relatively small diameter pulley  504  rotatably mounted on opposite sides of the forward stanchion  414 . The flywheel  502  and the pulley  504  are keyed to a common shaft, and a belt  501  is looped about the pulley  504  and the relatively larger diameter crank  521 . As a result, the flywheel  502  is constrained to rotate at a relatively faster speed than the crank  521 . The flywheel  502  adds inertia to the linkage assemblies, and various types of known devices (such as a drag strap or an eddy current brake) may be operatively connected to the flywheel  502  to provide adjustable resistance, as well.  
         [0034]    The present invention is disclosed with reference to particular embodiments and specific applications, and this disclosure will enable persons skilled in the art to derive additional embodiments, improvements, and/or applications. Therefore, the scope of the present invention should be limited only to the extent of the following claims.