Treadmill

Abstract

A treadmill includes a frame, a primary transmission unit supported by the frame, a secondary transmission unit supported by the frame, and a caterpillar extending around the transmission units so that the primary and secondary transmission units keep the caterpillar in proper tension. The primary transmission unit includes a roller including an axle non-rotationally connected to the frame, a tube rotationally extending around the axle, and two bearings arranged between the axle and the tube to render the tube rotatable around the axle in one direction but no vice versa.

1 . A treadmill comprising a frame, a primary transmission unit supported by the frame, a secondary transmission unit supported by the frame, and a caterpillar extending around the transmission units so that the primary and secondary transmission units keep the caterpillar in proper tension, wherein the primary transmission unit comprises a roller comprising an axle non-rotationally connected to the frame, a tube rotationally extending around the axle, and two bearings arranged between the axle and the tube to render the tube rotatable around the axle in one direction but no vice versa. 
     
     
         2 . The treadmill according to  claim 1 , wherein one of the bearings is a one-way bearing. 
     
     
         3 . The treadmill according to  claim 1 , wherein the primary transmission unit further comprises two pulleys connected to the tube so that the pulleys are rotatable with the tube around the axle.