Treadmill with improved adjusting mechanism

Claim 1

A treadmill having a base frame with a first and a second portion, an endless belt rotatably mounted on the base frame, a pair of upright posts each having an upper and a lower end, the upright posts being secured on the first portion of the base frame, an instrument mounted integrally between the upper ends of the posts, a handle portion secured to the instrument, a speed adjustable driving mechanism mounted within the first portion of said base frame for driving said endless belt at a variable speed, and a slope adjustable mechanism mounted below said base frame and being operative to vary the slope of the base frame, wherein said speed adjustable driving mechanism comprises: a driving motor having an output shaft; a driven shaft associated with said endless belt; a speed variable V-belt drive mechanism in connection with said output shaft and said driven shaft, said V-belt drive mechanism including a transmission shaft which is parallel to said output shaft and said driven shaft therebetween and which can be displaced laterally within a limited distance toward said output shaft or said driven shaft, two pairs of cone-shaped discs mounted coaxially on said transmission shaft, each of said pairs of said discs having a fixed disc and a slideable disc adjacent to said slideable disc of the other said pair of said discs, said slideable discs sliding mutually upon displacement of said transmission shaft, a first pulley mounted on said output shaft, a second pulley mounted on said driven shaft, a first V-belt passing over said first pulley and one of said pairs of cone-shaped discs, and a second V-belt passing over said second pulley and the other one of said pairs of said cone-shaped discs; and means for displacing said transmission shaft, including a crank shaft in parallel with said transmission shaft, a crank arm interconnecting said transmission shaft and said crank shaft, a first reversible motor for driving said crank shaft, and a gear transmission mechanism interengaging said crank shaft and said first reversible motor.