Easy folding device for treadmills

Abstract

A treadmill includes a base having two side rails and each side rail has a passage defined therethrough. A frame having two sides are connected between the two side rails and a running belt reeves around two ends of the frame. Two collars are respectively movably received in the two passages and each collar has two first spiral ramps located on different surfaces. Two pins movably respectively extend through the two collars and are fixed to the two sides of the frame. Two springs are mounted to the two pins and biased between the two side tails of the base and the two sides of the frame. Each pin has two second spiral ramps located on different surfaces of a head of each pin. The first spiral ramps are movably engaged with the second spiral ramps.

What is claimed is:  
     
         1 . A treadmill comprising: 
 a base having two side rails and each side rail having a passage defined therethrough;    a frame having two sides and a running belt reeving around two ends of the frame;    two collars respectively movably received in the two passages in the two side rails and two first spiral ramps located on different surfaces on one side of each collar, and    two pins movably respectively extending through the two collars and fixed to the two sides of the frame, two springs mounted to the two pins and biased between the two sidle rails of the base and the two sides of the frame, each pin having a head with two second spill ramps located on the same side but different surfaces, the first spiral ramps movably engaged with the second spiral ramps.    
     
     
         2 . The treadmill as claimed in  claim 1 , wherein each of the passages has three grooves defined in an inner periphery thereof and each collar has three ridges which are movably engaged with the grooves.