Patent Publication Number: US-6342042-B1

Title: Adjustable amplitude exerciser with foot cradle

Description:
BACKGROUND OF THE INVENTION 
     This invention deals generally with exercise devices and more specifically with a footstool type device which subjects the user&#39;s feet and ankles to a swinging motion. 
     There is significant interest developing in swinging exercise devices that are virtually unknown in mainstream culture. The devices look very much like footstools except that they typically have two depressions in their top surface, and the depressions are shaped like half cylinders. The devices are actually swinger devices, and they are used to swing the user&#39;s feet and ankles. The footrest of the device is set on top of a swinger enclosure; the footrest cushion is typically a soft material covered by vinyl; and the two half cylinder depressions are used to support the user&#39;s feet or ankles. The devices are used by resting on a flat surface and placing the feet or ankles on the support depressions on the footrest cushion while supplying electrical power to a swinging assembly within the enclosure which supports the footrest cushion. 
     Several patents have been granted on such devices. U.S. Pat. Nos. 5,468,215 to Park, 5,411,469 to Wang, and 5,328,433 to Lee all show parallelogram structures which are used to move the footrest back and forth. However, all of these prior art devices lack one feature. None of the prior art patents suggest any means for varying the amplitude of the vibration to which the user is subjected although such an adjustment would be very desirable. The ability to adjust the vibration amplitude would be very helpful for users such as those who are arthritic or have limited mobility for other reasons, and to whom the fixed amplitudes now available are excessive. With a means to adjust the amplitude of the vibration, such users can initially use a smaller amplitude vibration, and, as their range of mobility increases they can adjust the swinger to have a greater amplitude. 
     SUMMARY OF THE INVENTION 
     The present invention provides a foot and ankle swinging device with the capability of changing the amplitude of oscillation. The foot swinger is built upon a horizontal support base which acts as the bottom of the swinger enclosure and the support structure for all the other components. The mechanism which produces the oscillatory motion for the footrest cushion is supported from the upper portion of a vertical support plate extending from side to side in the swinger. The actual motion produced within the swinger is also side to side, that is, in a direction parallel to the diameters of the two half cylinder depressions in the padded footrest of the swinger and across the direction of the legs of the user. Thus the motion imparted to the user&#39;s ankles is a motion transverse to the normal walking motion of the legs. 
     The swinger structure is based upon a swing-like parallelogram structure hung from the vertical support structure located approximately midway between the front and back of the swinger. In the preferred embodiment, the vertical support structure is a plate which has two bearings attached near the top of the vertical plate with the two bearings separated by a substantial portion of the width of the swinger. A swinging arm is hung from each of these bearings. The arms are of equal length, their bottom ends approach the bottom support base plate of the entire unit, and a pivot point is attached near the bottom of each arm with the pivot points at equal distances from the bearings. A bridge structure spans the distance between the swinging arms and is attached to the arms at their pivot points. Thus, the arms and bridge structure form a parallelogram and can swing back and forth together and move the bridge structure back and forth in a path parallel to the vertical support structure and side to side of the swinger. 
     Motion is imparted to the parallelogram through a speed reducing gearbox by an electric motor. In the preferred embodiment, the motor is located on the opposite side of the vertical support structure from the parallelogram structure, and the drive shaft protrudes through the vertical support structure. The drive shaft has a rotating cam attached, and a drive link is attached between the rotating cam and one of the swinging arms of the parallelogram structure. The attachment point of the drive link to the rotating cam is offset from the rotating shaft by a short distance. Thus, as the drive shaft and cam rotate, the point at which the drive link is connected to the swinging arm moves back and forth a distance which is twice the offset between the drive shaft and the point at which the drive rod is connected to the cam. The entire parallelogram structure then moves back and forth a distance determined by the point at which the drive link is attached to the swinging arm. In the preferred embodiment of the invention the motion of the parallelogram and the foot cushion is variable between 1⅛ and 1⅝ inches. 
     It is this variability of the oscillation amplitude which is not available in the prior art devices. The adjustment of the oscillation amplitude is accomplished quite simply by either of two mechanisms. In one, the cam simply has several connection points, such as holes, at different distances from its connection point to the drive shaft, and the adjustment is accomplished by moving the drive link connection from one hole to another. As the connection point is changed the oscillatory motion changes by twice the distance between the two connection holes. Thus, all that is required to change the amplitude of the oscillation is to open the case of the swinger assembly, remove the nut on the screw holding the drive link to the cam, and change the hole in the cam at winch the drive link is connected. 
     The second method of changing the amplitude of oscillation is also very simple. It only involves moving the connection point between the drive link and the swinging arm closer to or farther away from the point at which the swinging arm is connected to its top bearing at the vertical support plate. This is facilitated by several holes formed along the length of the swing arm so that the bolt connecting the drive link can be moved from one hole to another to change the amplitude of oscillation. 
     These simple changes can easily be accomplished by the average user of the foot swinger, and since it is not a frequently required change, the several steps to accomplish it are not a hardship. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The FIGURE is a partial cross section front view of the interior of the preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The FIGURE is a partial cross section front view of the preferred embodiment of foot swinger  10  in which cushion  12  atop foot swinger  10  is moved back and forth in the direction indicated by arrow A by swinger assembly  14 . Swinger assembly  14  is mounted within enclosure  16  upon horizontal base  18  to which a vertical support structure such as vertical plate  20  is attached. Vertical plate  20  has two bearings  22  and  24  mounted near its top, located at equal distances above base  18 , and separated by a substantial distance. 
     Swinging arms  26  and  28  are hung from bearings  22  and  24  respectively, and bridge  30  is attached near the bottoms of swinging arms  26  and  28  at pivot points  32  and  34  to interconnect swinging arms  26  and  28 . Pivot points  32  and  34  are located at equal distances from the bearings on their respective swinging arms. The top of vertical support  20 , swinging arms  26  and  28 , and bridge  30  thereby form a hanging parallelogram structure which, although shown in the vertical position in the FIGURE, can be moved to the right or left. A position to the left is shown in dashed lines by alternate swinging arm positions  26 A and  28 A. 
     As the parallelogram structure moves to the right and left in the FIGURE, bridge  30  follows the same movement, and cushion  12 , which is attached to bridge  30 , moves along with bridge  30 . Cushion  12  can be attached to bridge  30  by any conventional means, but is shown in the FIGURE with block  36  fitted into cushion  12  and bolts  38  attaching block  36  to bridge  30 . Cushion  12  is held onto block  36  by a screw (not shown) which penetrates the side of cushion  12  and enters hole  40  in block  36 . Block  36  moves right and left in slot  42  in the top of enclosure  16 . 
     The swinging motion is imparted to the parallelogram structure by drive shaft  44  which is driven by gearbox  46  located behind vertical plate  20 . Gearbox  46  is itself driven by an electric motor (not shown) which is also typically on the far side of vertical plate  20 . The rotation of drive shaft  44  is converted into linear motion by rotating cam  48  and drive link  50 . Cam  48  includes at least two rotating connection points such as holes  50 ,  52 , and  54 , and cam  48  is attached to drive shaft  44  and rotates with it. As cam  48  rotates, holes  50 ,  52 , and  54 , each at different distances from drive shaft  44 , rotate around the center of drive shaft  44  on circles with different diameters. Drive link  56  is always connected to cam  48  at one of the holes  50 ,  52 , and  54 . In the FIGURE the rotating connection point is shown at hole  50 . 
     The other end of drive link  56  is connected to swinging arm  26  at one of at least two pivoting connection points such as holes  58 ,  60 , and  62  which are spaced along the length of swinging arm  26 . In the FIGURE the pivoting connection point is shown at hole  60 . As can easily be appreciated from the FIGURE, as cam  48  rotates in the direction of arrow B shown, drive link  56  will move to the right and cause swinging arm  26  and, in fact the entire parallelogram structure and cushion  12  to also move to the right. 
     Thus, the several holes on cam  48  and the several holes on swinging arm  26  are the means for adjusting the amplitude of oscillation of cushion  12 . As the connection point of drive link  56  at cam  48  is moved from, for example hole  50  to hole  54 , the motion of drive link  56  is increased because the circle upon which the connection point moves has a greater diameter, and this greater motion is transmitted to cushion  12 . 
     The adjustment of the amplitude of oscillation at swinging arm  26  is a bit more subtle than at cam  48 . At swinging arm  26 , moving the connection point of drive link  56  from hole  60  to, for example, hole  58  will increase the amplitude of oscillation of cushion  12  because the ratio of the radii between the motion of drive link  56  and that of bridge  30 , which is attached at the far end of swinging arm  26 , changes. 
     It should be appreciated that the actual means for connecting drive link  56  to cam  48  and to swinging arm  26  are not pictured in the FIGURE, both because they would interfere with the view of the connection points and because they can be any of many conventional devices. Perhaps the most common is a simple screw and nut, but other connection devices such as cotter pins or spring clips could also be used. Regardless of the specific connection means used, all that is required to adjust the amplitude of the oscillation of cushion  12  is to open enclosure  16  of the swinger assembly and to move one end or the other of drive link  56  to another connection point. The invention thereby provides a foot swinger which can be adjusted for the capabilities of the user. 
     It is to be understood that the form of this invention as shown is merely a preferred embodiment. Various changes may be made in the function and arrangement of parts; equivalent means may be substituted for those illustrated and described; and certain features may be used independently from others without departing from the spirit and scope of the invention as defined in the following claims. 
     For example, cushion  12  could be connected to bridge  30  by many conventional devices such as brackets or threaded connections molded directly into cushion  12 .