DEVICE FOR TIGHTENING AN ENDLESS ELEMENT TRAINED OVER DRIVING MEMBERS

摘要

A drive transmission and tightening device for an endless drive element of the drive transmission with said endless driving element lying substantially in one plane and being trained over a primary rotary driving member and at least one rotary driven member which with the endless driving element are disposed in a drive transmission housing including side walls on either side of the plane in which the endless driving element lies and said housing having a width slightly greater than the width of said endless driving element; said tightening device comprising: a curved or bow-shaped tightener element disposed in the housing adjacent to and extending in the general direction of one run of the endless driving element and pivoted at the upstream end thereof with respect to the normal direction of movement of said run of the endless driving element to be engageable on its outer curved surface with the endless driving element; tightener-sustaining means supported on the inside of one said side wall of the housing and disposed on the side of the bow-shaped tightener element remote from said endless driving element to contact the tightener element and to be displaceable relative to the tightener element; urging means provided outwardly of and extending along said one side wall of the housing as biassing means for urging the tightener element, via said tightener-sustaining means, toward the endless driving element; adjusting means also provided outwardly of said one side of the housing for adjusting the power of said urging means.