Abstract: A centering of the fixed key is obtained by means of its support, a perfect locking of the support of the fixed key is obtained by a key wedge, a displacement of the mobile key is obtained by the assembly of the square shaped support, the mobile pin is fixed thereto and the fixed pin secured to the body and parallel to the mobile pin, a displacement is provided through three ball bearings, a first ball bearing being housed in the support and two ball bearings in the wall of the body, then two protecting caps are secured on the body for outerly protecting the two ends of the mobile pin.

Abstract: An apparatus for automatically engaging and measuring a spline of a workpiece with a gauge having first and second relatively rotatable sensing elements. The elements are rotatable to a first axially aligned position for insertion into grooves between adjacent teeth of the spline and to a second angularly displaced position to bear on opposed faces of adjacent teeth to clamp the spline in the gauge and measure the spline. The gauge elements are inserted in the grooves by moving the gauge and workpiece together with a lost motion to bear on each other adjacent an end of the spline and then rotating the gauge to align the elements with and start them into the grooves. Thereafter the elements are axially advanced fully into the grooves and then rotated to their second position.