Patent Publication Number: US-6709367-B1

Title: Leg exercise machine comprising two footrests capable of horizontal and vertical motions at the same time

Description:
RELATED U.S. APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable. 
     FIELD OF THE INVENTION 
     The present invention relates generally to a leg exercise machine, and more particularly to a swivel mechanism enabling the footrests of the leg exercise machine to swivel horizontally and vertically at the same time. 
     BACKGROUND OF THE INVENTION 
     The conventional leg exercise machine comprises two footrests capable of moving up and down. In operation, the feet of an exerciser are supported on the footrests. As one of the two footrests is forced to move downwards, other one of the two footrests is caused to move upwards. Such a mechanism of the conventional leg exercise machine is similar in nature to that of a seesaw. However, the footrests of the conventional leg exercise machine are limited in design in that they are incapable of moving vertically and horizontally at the same time. 
     BRIEF SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a leg exercise machine with a mechanism enabling two footrests of the leg exercise machine to swivel vertically and horizontally at the same time. 
     The leg exercise machine of the present invention comprises a base and a swivel mechanism by which two footrests are mounted on the base. The swivel mechanism comprises a horizontal support tube, a horizontal shaft, a first universal joint, a second universal joint, and a link rod. The two footrests are oppositely mounted on the horizontal support tube which is fitted rotatably over the horizontal shaft. The horizontal support tube is connected at one end with one end of the link rod by the first universal joint. The link rod is connected at other end with the base by the second universal joint. As one of the two footrests is forced to move down, other one of the two footrests moves up. In the meantime, the horizontal support tube is caused to swivel horizontally, thereby causing the footrests to swivel likewise. 
    
    
     The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 shows a perspective view of a first preferred embodiment of the present invention. 
     FIG. 2 shows an exploded perspective view of the first preferred embodiment of the present invention. 
     FIG. 3 shows a top plan view of the first preferred embodiment of the present invention. 
     FIG. 4 shows a side view of the first preferred embodiment of the present invention. 
     FIG. 5 shows a first side schematic view of the first preferred embodiment of the present invention in action. 
     FIG. 6 shows a first top schematic view of the first preferred embodiment of the present invention in action. 
     FIG. 7 shows a second side schematic view of the first preferred embodiment of the present invention in action. 
     FIG. 8 shows a second top schematic view of the first preferred embodiment of the present invention in action. 
     FIG. 9 shows a perspective view of a second preferred embodiment of the present invention. 
     FIG. 10 shows a perspective view of a third preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIGS. 1-4, a leg exercise machine embodied in the present invention comprises a base  10  on which a first footrest  11  and a second footrest  12  are oppositely mounted by two tilted arms  13  in conjunction with a swivel mechanism. 
     The swivel mechanism comprises a horizontal support tube  14 , an upright post  16 , a horizontal shaft  161 , a first universal joint  21 , a second universal joint  22 , and a link rod  30 . The upright post  16  is rotatably mounted at a bottom end on the base  10 . The horizontal shaft  161  is pivotally fastened at one end with a top end of the upright post  16  such that the horizontal shaft  161  and the upright post  16  form a right angle. The horizontal support tube  14  is rotatably fitted over the horizontal shaft  161 . The two tilted arms  13  are fastened oppositely at a lower end with the horizontal support tube  14 , with the upper ends of the two tilted arms  13  supporting respectively the first footrest  11  and the second footrest  12 . As a result, when the two footrests  11  and  12  are caused to move up and down, the horizontal support tube  14  turns on the horizontal shaft  161 . The horizontal support tube  14  is provided at an outer end  141  with a connection bar  17  extending therefrom such that the connection bar  17  is perpendicular to the longitudinal axis of the horizontal support tube  14 . The outer end  141  of the horizontal support tube  14  is connected by the connection bar  17  to one end of the link rod  30  in conjunction with the first universal joint  21 . The link rod  30  is fastened at other end with a fastening piece  18  of the base  10  in conjunction with the second universal joint  22 . It must be noted here that the two footrests  11  and  12  are supported by the horizontal support tube  14  in conjunction with the two tilted arms  13  and two damping devices  15  by which the exercise effect of the machine is enhanced. 
     As illustrated in FIGS. 5 and 6, the first footrest  11  is exerted on by an external force to move downward, the horizontal support tube  14  is thus actuated to turn on the horizontal shaft  161 , thereby causing the second footrest  12  to move upward. In the meantime, the reaction force of the link rod  30  causes the horizontal support tube  14  and the horizontal shaft  161  to swivel clockwise. Similarly, when the second footrest  12  is exerted on by an external force to move downward, as shown in FIG. 7, the horizontal support tube  14  is actuated to turn on the horizontal shaft  161 , thereby causing the first footrest  11  to move upward. In the meantime, the horizontal support tube  14  and the horizontal shaft  161  are caused to swivel counterclockwise, as shown in FIG.  8 . In light of the horizontal support tube  14  being fitted over the horizontal shaft  161  which is pivotally fastened at one end thereof with a top end of the upright post  16 , the horizontal support tube  14  and the horizontal shaft  161  can swivel together. 
     It must be noted here that the link rod  30  and the horizontal support tube  14  are preferably arranged in such a manner that the longitudinal axes of the link rod  30  and the horizontal support tube  14  form an angle of 90 degrees. 
     As shown in FIG. 2, the upright post  16  is provided at the bottom end with a threaded hole  163 . The base  10  is provided in an upper side with a mounting seat  101  in which a bearing  102  is located. The upright post  16  is mounted uprightly on the base  10  such that a lower segment  162  of the upright post  16  is inserted into the bearing  102 , and that a bolt  103  is engaged with the threaded hole  163  of the bottom end of the upright post  16 . The bolt  103  is fastened into the bottom end of the upright post  16  from the underside of the mounting seat  101  in conjunction with a washer  104 . 
     As shown in FIG. 2, the horizontal shaft  161  is provided with a support structure comprising a support frame  60  and a reinforcing member  70 . The horizontal shaft  161  is disposed between the support frame  60  and the reinforcing member  70 . In addition, the support frame  60  is provided with a through hole  61 , while the reinforcing member  70  is provided with a through hole  71  corresponding in location to the through hole  61  of the support frame  60 . The support frame  60  and the reinforcing member  70  are fastened with one end of one of the two damping devices  15  by a fastening bolt  62  which is put through the through holes  61  and  71 . 
     The machine of the present invention further comprises a handle  50  which is mounted on the swivel mechanism, as shown in FIG. 9, or a handle  501  which is mounted on the base  10 , as shown in FIG.  10 . 
     The embodiments of the present invention described above are to be regarded in all respects as being illustrative and nonrestrictive. Accordingly, the present invention may be embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scope of the following claims.