Folding device for treadmills

Abstract

A treadmill includes a base with two side rails and two posts with two handles are connected to the two side rails. Two guide members are connected to the two side rails and each guide member has two curve grooves which are located symmetrically about a diameter of the guide member corresponding thereto and share a common center. A frame with an endless belt is pivotably connected between the two side rails and two pin sets are respectively connected to each of two sides of a first end of the frame and movably engaged with the two curve grooves of respective one of the two guide members. Each pin set includes a bearing movably received in the curve groove so that the frame is easily pivoted by moving the pin sets in the curve grooves.

1 . A treadmill comprising: 
 a base with two side rails and a handle connected to the base, two guide members connected to the two side rails and each guide member having two curve grooves defined therein, the two curve grooves located symmetrically about a diameter of the guide member corresponding thereto and sharing a common center, and    a frame having an endless belt reeving two ends thereof, two pin sets respectively connected to each of two sides of a first end of the frame and movably engaged with the two curve grooves of respective one of the two guide members.    
   
   
       2 . The treadmill as claimed in  claim 1 , wherein each of the pin sets includes a pin and a bearing connected to an end of the pin, the bearings together with the two respective ends of the pins being movably received in one of the two curve grooves.  
   
   
       3 . The treadmill as claimed in  claim 1 , wherein a roller is connected to each of two sides of a second end of the frame.  
   
   
       4 . The treadmill as claimed in  claim 1 , wherein a pneumatic cylinder is connected between an underside of the frame and a transverse bar between two side rails of the base.  
   
   
       5 . The treadmill as claimed in  claim 1 , wherein the two guide members are connected at two respective ends of the side rails.  
   
   
       6 . A treadmill comprising: 
 a base with two side rails and a handle connected to the base;    a frame having an endless belt reeving two ends thereof and two guide members connected to two sides of a front end of the frame, each guide member having two curve grooves defined therein, the two curve grooves located symmetrically about a diameter of the guide member corresponding thereto and sharing a common center, and    two pin sets respectively extending through each of the two side rails and connected to two bearings movably received in the two curve grooves.    
   
   
       7 . The treadmill as claimed in  claim 6 , wherein a roller is connected to each of two sides of a second end of the frame.  
   
   
       8 . The treadmill as claimed in  claim 6 , wherein a pneumatic cylinder is connected between an underside of the frame and a transverse bar between two side rails of the base.  
   
   
       9 . A treadmill comprising: 
 a base with two side rails and a handle connected to the base;    a frame having an endless belt reeving two ends thereof and two guide members connected to two sides of a front end of the frame, each guide member having two curve grooves defined therein, the two curve grooves located symmetrically about a diameter of the guide member corresponding thereto and sharing a common center;    two pin sets respectively extending through each of the two side rails and connected to two bearings movably received in the two curve grooves, and    two protrusions extending from the two side rails and each protrusion including an upright through hole, the two guide members movably received in the upright through holes in the two protrusions.