Treadmill belt safety mechanism

Abstract

An improved lift apparatus for use in an exercise device having a support base and a moveable element is disclosed. The moveable element can be selectively raised and lowered relative to the support base by the user during operation of the exercise device. The improved lift apparatus includes: (i) a first lift motor; (ii) a second lift motor; and (iii) a synchronization mechanism for synchronizing the first and second lift motors. A belt safety mechanism for controlling unanticipated movement of the endless belt is also disclosed.

What is claimed and desired to be secured by United States Letters Patent is:  
     
         1 . An improved belt safety mechanism for use in an exercise device having a support frame, first and second rollers mounted on the support frame and an endless belt mounted on the first and second rollers wherein a drive system selectively moves the endless belt on the first and second rollers, the improved safety mechanism comprising: 
 a motion detector configured to detect movement of the endless belt; and    means for regulating movement of the endless belt when movement of the endless belt is unanticipated.    
     
     
         2 . The improved belt safety mechanism in  claim 1  wherein the means for regulating movement of the endless belt actuates the drive system when the movement of the endless belt is unanticipated.  
     
     
         3 . The improved belt safety mechanism in  claim 2  wherein the means for regulating movement of the endless belt actuates the drive system when movement of the endless belt results from a force independent from the drive system.  
     
     
         4 . An improved belt safety mechanism as recited in  claim 2  wherein the means for regulating movement of the endless belt comprises a logic circuit configured to determine whether movement of the endless belt is caused by the drive system.  
     
     
         5 . An improved belt safety mechanism as recited in  claim 4 , wherein the means for regulating movement of the endless belt further comprises means for actuating the drive system in the event that movement is caused by a force independent from the drive system.  
     
     
         6 . An improved belt safety mechanism as recited in  claim 2 , wherein the means for regulating movement of the endless belt further comprises means for allowing normal functioning of the drive system in the event that the movement is initially caused by the drive system.  
     
     
         7 . An improved belt safety mechanism as recited in  claim 2 , wherein the force independent from the drive system comprises a user ambulating on the belt without actuating the drive system.  
     
     
         8 . An improved belt safety mechanism as recited in  claim 2 , wherein the means for regulating movement of the endless belt actuates the drive system for a preset interval.  
     
     
         9 . An improved belt safety mechanism as recited in  claim 2 , wherein the means for regulating movement of the endless belt actuates the drive system at a predetermined slow speed.  
     
     
         10 . An improved belt safety mechanism as recited in  claim 2 , wherein the means for regulating movement of the endless belt comprises a belt movement regulator configured to engage the drive system for a preset interval in response to the unanticipated movement of the endless belt.  
     
     
         11 . An improved belt safety mechanism as recited in  claim 2 , wherein the motion detector comprises an optical sensor for detecting unanticipated movement of the endless belt.  
     
     
         12 . An improved belt safety mechanism as recited in  claim 2 , further comprising a safety circuit wherein the safety circuit recognizes operation of means for regulating movement of the endless belt and wherein safety circuit produces a message prompt upon actuating the drive system.  
     
     
         13 . An improved belt safety mechanism as recited in  claim 12 , wherein the message prompt comprises an audible message.  
     
     
         14 . An improved belt safety mechanism as recited in  claim 13 , wherein the message prompt comprises a visual message.  
     
     
         15 . An improved belt safety mechanism as recited in  claim 14 , wherein the means for regulating movement of the endless belt selectively disengages the drive system after a preset interval subject to user input overriding disengagement.  
     
     
         16 . An improved belt safety mechanism as recited in  claim 15 , where the means for regulating movement of the endless belt selectively reengages the drive system upon detecting motion of the endless belt after a preset interval of drive system disengagement.  
     
     
         17 . An improved belt safety mechanism for use in an exercise device having a support frame, first and second rollers mounted on the support frame and an endless belt mounted on the first and second rollers wherein the endless belt moves in response to one of: (i) a force exerted by the drive system; or (ii) a force independent of the drive system, the improved safety mechanism comprising: 
 a motion detector configured to detect movement of the endless belt; and    a means for regulating movement of the endless belt such that the drive system is actuated when movement of the endless belt results from a force independent from the drive system.    
     
     
         18 . An improved belt safety mechanism as recited in  claim 17  wherein the means for regulating movement of the endless belt comprises a logic circuit configured to determine whether movement of the endless belt is caused by the drive system.  
     
     
         19 . An improved belt safety mechanism as recited in  claim 18 , wherein the means for regulating movement of the endless belt further comprises means for actuating the drive system in the event that movement is caused by a force independent from the drive system.  
     
     
         20 . An improved belt safety mechanism as recited in  claim 17 , wherein the force independent from the drive system comprises a user ambulating on the belt without actuating the drive system.  
     
     
         21 . An improved belt safety mechanism for use in an exercise device having a support frame, first and second rollers mounted on the support frame and an endless belt mounted on the first and second rollers wherein the endless belt moves in response to one of: (i) a force exerted by the drive system; or (ii) a force independent of the drive system, the improved safety mechanism comprising: 
 a motion detector wherein the movement of the endless belt is detected; and    a belt movement regulator.    
     
     
         22 . The improved belt safety mechanism of  claim 21  wherein the belt movement regulator is configured to regulate movement of the endless belt by actuating the drive system when movement of the endless belt results from a force independent from the drive system.