Patent Publication Number: US-2007099762-A1

Title: Elliptical trainer

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates generally to exercise equipment and more particularly, to exercise equipment that facilitates the foot movement of a user through a generally elliptical path.  
      2. Description of the Related Art  
      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 and climber machines allow a person to climb in place; bicycle machines allow a person to pedal in place; and still other machines allow a person to skate and/or stride in place. Yet another type of exercise equipment facilitates relatively more complicated exercise motions and/or better simulates real life activity. Such equipment typically links a relatively simple motion, such as circular motion, to a relatively more complex motion, such as elliptical motion.  
      Elliptical exercisers permit a user to stand on pedal mechanisms and drive the pedals in a manner similar to driving the pedals of a stationary bicycle or a stair climbing machine. However, as opposed to stationary bicycles and stair climbing machines, the pedals of an elliptical pedal exerciser do not traverse a circular path of motion or an oscillating up-and-down path of motion. Instead, the pedals of an elliptical pedal exerciser are coupled to a pedal movement mechanism that causes the pedals to follow generally elliptical paths of motion, simulating the striding foot movements of a person while running or walking.  
      The terms “elliptical” and “generally elliptical” are used 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. There are many examples of elliptical trainers disclosed in the prior art, representative examples being found, for example, in U.S. Pat. Nos. 6,196,948; 6,063,008; 6,045,487; 6,544,146; 6,340,3406; 5,897,463 and 5,957,814.  
      Users of exercise equipment favor those devices that take up a minimum amount of space and are easily stored. While many different types of elliptical exercise apparatus have been proposed and many have been commercialized, the need exists for improvements in construction and design that result in an exercise machine of reduced size that is of relatively simple construction, has a minimum of moving parts and that provides smooth, repeatable movement as well as a robust mechanism that can withstand prolonged and repeated use.  
     SUMMARY OF THE INVENTION  
      The present invention provides exercise machines for facilitating a foot movement of a user to follow a generally elliptical path. Particular embodiments of the exercise machine include a static disk that is fixed in place and a dynamic disk that both rotates about its axis and revolves about the static disk. The static disk and the dynamic disk are mechanically coupled in a manner that provides a constant angular relationship between the rotation of the dynamic disk about its axis and the revolution of that axis about the axis of the static disk.  
      In a particular embodiment of the present invention, the exercise machine includes a static disk and a static pivot axis. The static pivot axis supports a rotating member that is attached to the static pivot axis. The exercise machine further includes a crank axle that is substantially parallel to the static pivot axis and is distally mounted to the rotating member such that the rotating member imposes a fixed distance between the crank axle and the static pivot axis. This fixed distance is the effective length of the rotating member. The crank axle is mounted to the rotating member in such a manner that the crank axle is free to turn about its axis. The exercise machine further includes a crank fixed to the crank axle so that rotation of the crank causes the crank axle to rotate.  
      The exercise machine may further include a dynamic disk fixed to the crank axle so that when the crank rotates the crank axle, the crank axle rotates the dynamic disk. The dynamic disk is further mechanically coupled to the static disk to impose a constant angular relationship between the rotation of the crank about the crank axle and the revolution of the crank axle about the static pivot axis. The exercise machine further includes a foot pedal member pivotally supported at a distal end of the crank so that rotation of the crank causes the foot pedal to follow a generally elliptical path.  
      Particular embodiments of the present invention may further include a frame that indirectly supports the static disk, the static pivot axis or combinations thereof. Alternatively, the frame may directly support the static disk, the static pivot axis or combinations thereof. In particular embodiments of the present invention, both the static disk and the dynamic disk may be disposed between the frame and the rotating member and further, the static pivot axis may be substantially perpendicular to static disk and may be substantially aligned with a center of the static disk, but the invention is not so limited.  
      Any arrangement of the static and dynamic disks is suitable that provides for them to be mechanically coupled in a manner that imposes the constant angular relationship between rotation of the crank about the crank axle and revolution of the crank axle about the static pivot axis. To facilitate the movement of the foot pedal in a generally elliptical path, the constant angular relationship provides that the crank rotates about the crank axle once in one direction for each revolution of the crank axle around the static pivot axis in an opposite direction. Typically, this preferred constant angular relationship may be achieved by setting the ratio of the diameter of the static disk to the diameter of the dynamic disk to be 2:1.  
      In particular embodiments of the present invention, the crank has a crank length that is less than a distance between the crank axle and the static pivot axis. Preferably, the crank length is between about 2 inches and about 10 inches.  
      The dynamic disk and the static disk may be selected from a pulley, a sprocket, a gear, a roller or combinations thereof. Furthermore, the dynamic disk may be mechanically coupled to the static disk by one or more belts, chains, gears, rollers or combinations thereof. In a particular embodiment of the present invention, the rotating disk and the static disk are substantially parallel to each other and/or may have a substantially coplanar alignment.  
      The rotating member may be selected from a disk, a bar, a rod, a sheet, a plate or combinations thereof.  
      The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawing wherein like reference numbers represent like parts of the invention.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  describes an ellipse.  
       FIG. 2  is a front view of an exemplary drive mechanism for one side of an elliptical trainer in accordance with the present invention.  
       FIG. 3  is a side view of the exemplary drive of  FIG. 2 .  
       FIGS. 4A-4B  describe the elliptical paths followed by a foot pedal during one revolution of the crank axle around the static pivot axis.  
       FIG. 5  is a perspective view of an exemplary elliptical trainer in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      The present invention provides an exercise machine that facilitates the foot movement of a user to follow a generally elliptical path during use of the exercise machine.  FIG. 1  describes an ellipse. The ellipse  11  is defined by its major axis  12  and its minor axis  13 . Generally, without limiting the invention, it is preferred that elliptical exercise trainers provide a foot movement having a generally elliptical path that has a major axis  12  of between about 16 inches and about 24 inches, more preferably about 20 inches, and a minor axis  13  of between about 2 inches and about 8 inches, more preferably about 4 inches.  
       FIG. 2  is a front view of an exemplary drive mechanism for one side of an elliptical trainer in accordance with the present invention and  FIG. 3  is a side view of the exemplary drive of  FIG. 2 . The description of the drive mechanism that follows is of only one pedal driven drive mechanism. However, as known to those having ordinary skill in the art, elliptical trainers have two pedals that operate 180 degrees out of phase, so that, for example, when the left foot pedal is at its lowest point, the right foot pedal is at its highest point. Therefore,  FIG. 2  provides a front view of both drive mechanisms of the elliptical trainer and it should be recognized that both sides operate in identical fashion. The reference numbers shown on  FIG. 3  differ between opposing sides only by the addition of a prime to the reference numbers of one side.  
      The exemplary drive mechanism is mounted to a frame  21  that is designed to sit on a floor. Both a static disk  22  and a static pivot axis  28  are supported by the frame  21 , either directly (with the static disk  22  and/or static pivot point  28  fixed directly to the frame  21 ) or indirectly (with the static disk  22  and/or the static pivot point  28  fixed to other parts that are attached directly and/or indirectly to the frame  21 ). For example, in the illustrated exemplary embodiment of the present invention, a static disk support  32  is fixed to both the frame  21  and the static disk  22  so that the frame  21  directly supports the static disk  22 . The static pivot axis  28  is then fixed to the static disk  22  so that the static pivot axis  28  is indirectly supported by the frame  21 .  
      The static pivot axis  28  supports a rotating member  27  that is attached to the static pivot axis  28  in a manner that allows the rotating member  27  to rotate about the static pivot axis  28 . A crank axle  24  is distally mounted to the rotating member  27 ; i.e., the crank axle  24  is mounted to the rotating member  27  at a location away from the point at which the rotating member  27  attaches to the static pivot axis  28 . The crank axle  24  is mounted to the rotating member  27  in a manner that allows the crank axle  24  to rotate about its axis. A crank  31  is fixed to the crank axle  24  so that the crank axle  24  rotates about its axis when the crank  31  is rotated.  
      The rotating member  27  is selected so that it imposes a fixed distance between the crank axle  24  and the static pivot axis  28  and may be, therefore, any suitable shape, including, for example, a bar, a rod, a disk, a plate, a sheet or combinations thereof.  
      A dynamic disk  23  is also fixed to the crank axle  24  so that the dynamic disk  23  is rotated by the rotation of the crank  31 . The dynamic disk  23  is mechanically coupled to the static disk  22  to impose a constant angular relationship between the rotation of the crank  31  about the crank axle  24  and the revolution of the crank axle  24  about the static pivot axis  28 . To facilitate a generally elliptical movement of the foot pedal  25  that is pivotally supported by the crank  31 , the mechanical coupling of the static and dynamic disks  22 ,  23  is selected to provide a constant angular relationship that imposes the crank  31  to rotate about the crank axle  24  once in one direction for each revolution of the crank axle  24  about the static pivot axis  28  in an opposite direction. For example, if the rotating member  27  rotates in a clockwise direction, then the crank  31  rotates counterclockwise. Alternatively, if the rotating member  27  rotates in a counterclockwise direction, then the crank  31  rotates clockwise.  
      In the illustrated exemplary embodiment, the static disk  22  is a sprocket that is mechanically coupled by a chain  29  to a sprocket that is the dynamic disk  23 . However, other suitable mechanical couplings of the static and dynamic disks  22 ,  23  may be useful as known to those having ordinary skill in the art. For example, the static and dynamic disks  22 ,  23  may take the form of sprockets, pulleys, rollers and/or gears and may be mechanically coupled by one or more belts, chains, gears, rollers or combinations thereof. The static and dynamic disks  22 ,  23  may be mechanically coupled through friction using, for example, one or more rollers. It should be noted that, for example, if interlocking gears couple the static and dynamic disks or if rollers couple the disks through friction, then an intermediate gear or roller would be required to cause the rotating member  27  and the crank  31  to rotate in opposite directions. Any mechanical coupling of the static and dynamic disks  22 ,  23  is acceptable as long as the mechanical coupling imposes the desired constant angular relationship between the rotation of the crank  31  once about the crank axle  24  in one direction, e.g., clockwise, for each revolution of the crank axle  24  about the static pivot axis  28  in an opposite direction, e.g., counterclockwise.  
      A foot pedal member  25  is pivotally supported at the distal end of the crank  31  by a foot peddle pivot axis  26 . The foot of a user drives the foot pedal member  25  so that the crank  31  is rotated. The crank  31  rotation causes the dynamic disk  23  to rotate and, because the dynamic dick  23  is mechanically coupled to the static disk  22 , the rotating member  27  is caused to rotate about the static pivot axis  28 , thereby causing the crank axle  24  to revolve around the static pivot axis  28 , and thereby facilitating the foot pedal  25  to move in a generally elliptical path.  
       FIGS. 4A-4B  describe the elliptical path followed by a foot pedal during one revolution of the crank axle around the static pivot axis. In  FIG. 4A , at position a, the rotating member  27  is positioned so that the crank axle  24  is at the lowest position. The crank  31  is positioned so that the foot pedal pivot axis  26  is aligned between the static pivot point  28  and the crank axle  24 . This position of the foot pedal pivot axis  26  places the foot pedal  25  (See,  FIG. 3 ) at its lowest position in the elliptical path  32 .  
      At position b, the rotating member  27  has rotated a quarter of a turn around the static pivot axis  28  and the crank  31  has rotated one-quarter turn in the opposite direction around the crank axle  24 . In position b, the rotating member  27  and the crank  31  are positioned so that the foot pedal pivot axis  26  is at a far right position along the elliptical path  31 . As can be seen, in position b, the foot pedal pivot axis  26  is no longer aligned between the static pivot axis  28  and the crank axle  24  but instead, has rotated to place the foot pedal pivot axis  26  at the far right position along the elliptical path  32 .  
      At position c, the rotating member  27  has rotated one-half turn from position a and the crank  31  has also rotated one-half turn, thereby again placing the foot pedal pivot axis  26  in alignment between the static pivot point  28  and the crank axle  24 . At position c, the foot pedal  25  is at its highest point in the elliptical path  32 .  
      At position d, the rotating member  27  has rotated three-quarters of a rotation from position a about the static pivot axis  28  and the crank  31  has also rotated three-quarters of a turn about the crank axle  24 . In position d, the foot pedal pivot axis  26  is no longer aligned between the static pivot axis  28  and the crank axle  24  but instead, has rotated to place the foot pedal pivot axis  26  at a far left position along the elliptical path  32 . The movement of the rotating member  27  then facilitates the completion of the elliptical path of the foot pedal by returning to position a.  
       FIG. 4B  illustrates the effect of the length of the crank  31  on the shape of the generally elliptical path  32  that foot pedal  25  (See,  FIG. 3 ) will follow. Even though the distance between the static pivot axis  28  and the crank axle  24  is the same in both  FIG. 4A  and  FIG. 4B , the generally elliptical path  32  traced in  FIG. 4B  is longer and narrower than that of  FIG. 4A  because the effective length of the crank  31  is longer.  
      The major axis and the minor axis (See,  FIG. 1 ) of the generally elliptical path  32  traced by the foot pedal  25  may be set by the effective length of the crank  31  and the effective length of the rotating member  27 . As shown in  FIG. 4A , the effective length  11  of the rotating member  27  may be defined as the distance between the static pivot axis  28  and the crank axle  24 . The effective length  12  of the crank  32  may be defined as the distance between the crank axle  24  and the foot pedal pivot axis  26 . The length of the minor axis of the generally elliptical path  32  can be described, therefore, as 2(l 1  −l 2 ) and the length of the major axis of the generally elliptical path  32  can be described as 2(l 1 +l   2 ). Therefore, by changing the effective length l 2  of the crank  31  or by changing the effective length l 1  of the rotating member  27 , the shape of the generally elliptical path  32  may be changed to make the path longer/shorter and thinner/fatter.  
      In particular embodiments of the present invention, the effective length l 1  of the rotating member  27  and the effective length of the l 2  of the crank  31  may be changed by the user. For example, holes may be provided at different locations  33  along the rotating member to allow the user to move the foot pedal pivot axis  26  from its shown location to a second location  33 . Alternatively, the rotating member and/or the crank may be placed on a threaded rod so that rotation of the threaded rod will change the effective length of the rotating member  27  or the crank  31 .  
      In particular embodiments of the present invention, the effective length of the crank is less than the effective length of the rotating member. The closer the effective length of the crank is to the effective length of the rotating member, the shorter will be the minor axis of the generally elliptical path followed by the foot pedal. Although not limiting the invention, the effective length of the rotating member preferably ranges between about 4 and about 10 inches, more preferably between about 6 and about 8 inches. Preferably, though not meant to limit the invention, the effective crank length may range between about 3 and about 9 inches, more preferably between about 4 and about 8 inches. Advantageously, because the crank adds length to the generally elliptical path followed by the foot pedal, the rotating member can be made smaller, thereby providing a smaller and lighter exercise machine.  
       FIG. 5  is a perspective view of an exemplary elliptical trainer in accordance with the present invention. The exemplary elliptical trainer  50  further includes a handle  53  useful for exercising muscles of the upper body. The handle  53  is supported by a column  55  through the handle pivot axis  52 . The foot pedal member  25  is further pivotally supported at a distal end of the handle  53  at a distal foot pedal pivot axis  51 .  
      The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The term “consisting essentially of,” as used in the claims and specification herein, shall be considered as indicating a partially open group that may include other elements not specified, so long as those other elements do not materially alter the basic and novel characteristics of the claimed invention. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. For example, the phrase “a solution comprising a phosphorus-containing compound” should be read to describe a solution having one or more phosphorus-containing compound. The terms “at least one” and “one or more” are used interchangeably. The term “one” or “single” shall be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” are used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.  
      It should be understood from the foregoing description that various modifications and changes may be made in the preferred embodiments of the present invention without departing from its true spirit. The foregoing description is provided for the purpose of illustration only and should not be construed in a limiting sense. Only the language of the following claims should limit the scope of this invention.