Patent ID: 7303186

Claim:
An aligning drive mechanism, comprising: a guide hole ( 10 ) as a reference surface for aligning is formed in a housing ( 6 ), an output member ( 13 ) is inserted into the guide hole ( 10 ) axially movably, the output member ( 13 ) is provided with a plurality of guided portions ( 21 , 22 ) axially at intervals, an annular aligning space ( 31 , 32 ), which narrows in either one axial direction, is formed between at least one of the guided portions ( 21 , 22 ) and the guide hole ( 10 ), a shuttle member ( 41 , 42 ), which is diametrically expandable and contractible, is inserted into the aligning space ( 31 , 32 ), the shuttle member ( 41 , 42 ) is supported on either one of the guide hole ( 10 ) or the guided portion ( 21 , 22 ) axially movably, and configured to make a tapering engagement with the other of the guided portion or the guide hole ( 21 , 22 or 10 ), the shuttle member ( 41 , 42 ) is urged by an urging means ( 51 , 52 ) in such a direction as to tighten the tapering engagement, the output member ( 13 ) is configured to be axially reciprocatable by a driving means (D).