Treadmill

Abstract

A treadmill includes a frame, two front wheels supported on the frame, two rear wheels supported on the frame, a caterpillar track wound on the front and rear wheels, and two rolling units each connected to a related one of two edges of the caterpillar track. Each of the front wheels includes a periphery and a plurality of recesses defined in the periphery. Each of the rolling units includes rollers each of which can be received in a related one of recesses.

1 . A treadmill including:
 a frame formed with a front end and a rear end;   two front wheels supported on the frame near the front end, wherein each of the front wheels includes a periphery and a plurality of recesses defined in the periphery;   two rear wheels supported on the frame near the rear end;   a caterpillar track wound on the front and rear wheels; and   two rolling units each connected to a related one of two edges of the caterpillar track, wherein each of the rolling units includes rollers each of which can be received in a related one of recesses.   
     
     
         2 . The treadmill according to  claim 1 , wherein each of the front wheels includes stops each located next to a related one of the recesses for preventing undesired lateral movement of a related one of the rollers. 
     
     
         3 . The treadmill according to  claim 2 , wherein each of the front wheels includes cutouts each defined in a related one of the stops for receiving a reduced extensive portion of each of the slabs. 
     
     
         4 . The treadmill according to  claim 1 , wherein each of the rear wheels includes a periphery and a stop extending along the periphery for preventing undesired lateral movement of a related one of the rollers. 
     
     
         5 . The treadmill according to  claim 1 , further including two guiding units each for guiding a related one of the rolling units. 
     
     
         6 . The treadmill according to  claim 5 , wherein each of the guiding units includes upper and lower rails each for guiding some of the rollers. 
     
     
         7 . The treadmill according to  claim 6 , wherein each of the guiding units includes upper and lower cushioning strips respectively attached to the upper and lower rails for cushioning the related rollers. 
     
     
         8 . The treadmill according to  claim 1 , wherein the frame includes a front axle for supporting the front wheels. 
     
     
         9 . The treadmill according to  claim 1 , wherein the caterpillar track includes:
 a plurality of slabs; and   two chains each including links each connected to a related one of two opposite ends of a related one of the slabs.   
     
     
         10 . The treadmill according to  claim 1 , wherein the frame includes a rear axle for supporting the rear wheels. 
     
     
         11 . The treadmill according to  claim 10 , further including two bearings for supporting the rear wheels on the rear axle.