Patent ID: 8882640

Claim:
An improved structure of treadmill, which comprising: a pedestal, set transversely in an elongated pattern, including: a holding portion and mounting surface; an arm stand, set vertically onto the mounting surface of the pedestal; a drag wheel pivoted axially onto the pedestal through a vertical framework; a mandrel is set transversely onto a center of the drag wheel; two swinging rods and two pedals; of which two swinging rods include a pivotal end, a swinging end and a middle portion located between the pivotal end and swinging end; the pivotal end is pivoted onto the pedestal and located at a spacing on two sides of the drag wheel; moreover, a pivoting location of the pivotal end corresponds to the lower position of the mandrel at center of the drag wheel; two pedals are separately set onto the swinging ends of two swinging rods; moreover, a floorstand is set on said pedestal between two swinging rods; a stride regulating mechanism, set onto the floorstand, comprising of a free wheel, a double-end pull rope, a lifting base and a regulating member; of which the double-end pull rope is hung onto the free wheel in U shape, and two ends of the double-end pull rope are separately attached to the middle portion of two swinging rods; the free wheel is pivoted onto the lifting base in a rotary state; and the lifting base is suspended onto the floorstand through the regulating member; two elbow-type drive connecting rods, linked separately to the mandrel and two swinging rods of the drag wheel; said drive connecting rod comprises of a front and a rear elbow; the front and rear elbows are coupled via a pivoted portion; moreover, a one-way bearing sleeving portion is set at front end of the front elbow for sleeving onto the mandrel of the drag wheel; the rear end of the rear elbow is provided with a rear pivoted portion linked to the middle portion of the swinging rod; when two swinging rods swing vertically, the front and rear elbows of the drive connecting rod are driven for inching movement with varying included angle; furthermore, the drag wheel is rotated under one-way drive of the one-way bearing sleeving portion for the mandrel; when the swinging rod swings upwards to a preset biggest swinging angle so that a minimal included angle is formed between the front and rear elbows of the drive connecting rod, the swinging angle of the front elbow is of a back rake angle without exceeding vertical angle, so as to avoid dead point for driving.