Patent ID: 7310891

Claim:
A head for the linear dimension checking of mechanical pieces, comprising: a casing, a movable arm with a first portion partly located inside the casing and a second portion entirely located at the exterior of the casing, a position transducer inside the casing and associated with said first portion, a feeler coupled with said second portion for contacting the piece to be checked, a zero-setting mechanism for adapting the head, by adjusting the relative arrangement between the first portion and the second portion of the movable arm, to check pieces with different nominal dimensions, the zero-setting mechanism including a movable mechanical reference between the movable arm and the casing, arranged at the exterior of the casing, the movable mechanical reference being adapted to have at least two positions, to hold said first portion of the movable arm in a preset position with respect to the casing and to release the first portion, respectively, wherein the zero-setting mechanism includes a quick locking/unlocking device between said first portion and said second portion of the movable arm.