GB563917A - Improvements in work locating devices for use with the rotatable work holders of machine tools - Google Patents

Abstract

563,917. Indexing. FRYE, J. May 7, 1943, No. 7268. [Class 83 (iii)] Work-holders.-In an indexing work-holder, the holder, such as a three-jaw chuck A, is attached to two or more notched index plates C, D, rotatably mounted in a body B. An index bolt E is eccentrically mounted in a bush F on the body, which is rotatable to register the bolt with any one of the index discs, locking of the bush being effected by a split clamp K and a screw. The bolt, which is splined in the bush F, is raised against the pressure of its spring by a handoperated rack and pinion G and is held in the raised position by a spring trigger I. A graduated ring M having two scales M<1>, M<2> corresponding to the index plates and a scale M<3> marked in degrees is rotatable on the body and is capable of being locked to the chuck by a screw N, a stop O on the ring being brought into contact with a stop P on the body after the ring has been secured at the required setting to the chuck. The chuck may be locked to the body by screws R and the body has flat faces B<1>, B<2>, for mounting the work vertically or horizontally, each face having keys B<3> for engaging slots in' a machine table. In operation, to divide the work into aliquot parts of a circle, the scale indication representing the required number of parts, e.g. 28, is brought opposite the stop P, the index bolt E is engaged with the corresponding notch in the appropriate plate C or D and the scale and work are rotated to bring the stop O, which is now spaced from the stop P by one twenty-eighth of a revolution, into contact with stop P. The bolt E is then released from its index plate, the scale rotated to bring the 28 indication again into register with the stop P, and the operation repeated until the twenty-eight divisions have been made.