Telescopic guide, especially for transmittance of torque

Claim 1

A telescoping device for transmitting torque in opposite directions of rotation, of the type comprising a telescopic shaft having at least three axially extending guide grooves therein that are spaced apart circumferentially, a telescopic sleeve axially slidably surrounding said telescopic shaft along at least a part of its length and having inwardly opening axially extending counter grooves, one for each guide groove, said counter grooves being so spaced circumferentially that each is opposite its guide groove, and a plurality of torque transmitting round elements, each being of circular cross-section and being received in part in one of said guide grooves and in part in its opposite counter groove, characterized in that: A. certain of the round elements, received in one of said guide grooves and in its opposite counter groove, are of resiliently elastic material and are under resiliently deformed compression between said telescopic shaft and said telescopic sleeve; and B. all of the round elements that are received in two other guide grooves and in the respective counter grooves opposite those guide grooves (1) are of substantially harder and less resilient material than said certain round elements, (2) cooperate with surfaces of the grooves in which they are received to maintain said certain round elements under said compression, and (3) are themselves maintained in torque transmitting engagement with said surfaces by the reaction force due to said compression.