Control system and method for exercise machine

Abstract

An exercise machine for simulating running has a frame having a forward portion and a rear portion. A shoulder harness is connected to the forward portion of the frame for supporting the torso of the user and preventing the forward movement of the user's body. Two levers are pivotally connected to the rear portion of the frame, and a pedal assembly is connected to each lever, for receiving the foot of the user. In one embodiment, a passive means for generating a counter force is connected between the lever and the rear frame, such as an elastic band, spring, torsion bar or hydraulic cylinder. In another embodiment a hydraulic or pneumatic actuator is connected between each lever and the frame, and an active control system is operatively connected to each actuator; the active control system being configured to generate a counter force to the user according to a preselected program.

1 . An exercise machine for simulating running, comprising: 
 a frame, the frame having a center portion and a rear portion,    two levers pivotally connected to the rear portion of the frame,    a pedal assembly connected to each lever arm, for receiving the foot of the user,    an extension arm connected to each lever at the pivotal connection of the levers to the rear portion of the frame; and,    a passive means for generating a counter force; the passive means connected between each extension arm and the rear frame.    
   
   
       2 . The exercise machine of  claim 1  where the means for generating a counter force is at least one elastic band connected between each extension arm and the rear frame.  
   
   
       3 . The exercise machine of  claim 2  where the attachment points of the elastic band to the extension arm and the rear frame are selectively variable.  
   
   
       4 . The exercise machine of  claim 1  where the means for generating a counter force is at least one elastic band connected between each extension arm and the rear frame and further comprising: 
 a circular sheave connected to the lever arm concentric with the pivot of the lever arm; and,    the elastic band configured to seat in the groove of the circular sheave as the circular sheave rotates.    
   
   
       5 . The exercise machine of  claim 1  where the means for generating a counter force is at least one elastic band connected between each extension arm and the rear frame and further comprising: 
 an eliptical sheave connected to the lever arm concentric with the pivot of the lever arm; and,    the elastic band configured to seat in the groove of the eliptical sheave as the eliptical sheave rotates.    
   
   
       6 . The exercise machine of  claim 1  where the means for generating a counter force is at least one spring connected between each extension arm and the rear frame.  
   
   
       7 . An exercise machine for simulating running, comprising: 
 a frame, the frame having a center portion and a rear portion,    two levers pivotally connected to the rear portion of the frame,    a pedal assembly connected to each lever arm, for receiving the foot of the user,    a passive means for generating a counter force; the passive means connected between the levers and the rear frame.    
   
   
       8 . The exercise machine of  claim 7  where the passive means for generating a counter force is a torsion bar.  
   
   
       9 . The exercise machine of  claim 7  where the passive means for generating a counter force is a flat spring.  
   
   
       10 . An exercise machine for simulating running, comprising: 
 a frame, the frame having a center portion and a rear portion,    two levers pivotally connected to the rear portion of the frame,    a pedal assembly connected to each lever arm, for receiving the foot of the user,    a first eliptical wheel connected coaxially with the pivot of the lever;    a second eliptical wheel connected rotabably to the rear frame;    the first and second eliptical wheels rotatably connected by a belt;    the first and second eliptical wheels postitioned so the their long axes are perpendicular;    a passive means for generating a counter force; the passive means connected between the first eliptical wheel and the rear frame.    
   
   
       11 . The exercise machine of  claim 10  where the a passive means for generating a counter force is a torsion bar.  
   
   
       12 . The exercise machine of  claim 10  where the passive means for generating a counter force is a flat spring.  
   
   
       13 . The exercise machine of  claim 1  where the passive means for generating a counter force is a pneumatic cylinder.  
   
   
       14 . An exercise machine for simulating running, comprising: 
 a frame, the frame having a center portion and a rear portion,    two levers pivotally connected to the rear portion of the frame,    a pedal assembly connected to each lever arm, for receiving the foot of the user,    an extension arm connected to each lever at the pivotal connection of the levers to the rear portion of the frame; and,    an active means for generating a counter force; the active means connected between each extension arm and the rear frame.    
   
   
       15 . The exercise machine of  claim 14  where the active means for generating a counter force further comprises: 
 a pneumatic cylinder;    a pressure sensor connected to the pneumatic cylinder;    a pressure control valve connected to the pneumatic cylinder;    a displacement sensor connected to the pneumatic cylinder;    the pressure sensor, the pressure control valve and the displacement sensor connected to a computer;    the computer executing a stored program for: 
 measuring and displaying on the computer the displacement of the cylinder;  
 measuring and displaying on the computer the pressure in the pneumatic cylinder; and,  
 according to the stored program, computing and displaying on the computer the counter force generated when the exercise machine is operated.  
   
   
   
       16 . The exercise machine of  claim 15 , further comprising: 
 a pressure amplifier connected between a source of pressure and the pressure control valve.    
   
   
       17 . The exercise machine of  claim 15 , further comprising: 
 a position-limit valve connected between a source of pressure and the control valve.