GB1223381A - Improvements in mechanisms on lathes for the automatic insertion and withdrawal of chasers in thread cutting operations - Google Patents

Abstract

1,223,381. Screw cutting lathes. SCHAUBLIN S.A. 26 Feb., 1969 [19 April, 1968], No. 10152/69. Heading B3T. Apparatus on a lathe for automatic feed and withdrawal of a chaser in thread-cutting operations comprises a transverse slide 5 guided on a member 4 on the lathe carriage, a chasing tool 25, 23, a tool support member 14 mounted on the slide 5 for displacement parallel to the direction of traverse of the lathe carriage, and means operable by the feed and return traverse of the carriage to withdraw the chaser and effect subsequent incremental feed thereof, respectively. In operation, a stop-rod 29 connected to the tool support 14 effects a restraining action on the tool support immediately before the end of a feed traverse by engagement between a stop 30 on the rod and a stop 50 on a member 49 fixed to the machine, displacement of the support occurs relative to the slide 5 and a plunger 32 engages in a recess 36 in the support side 14a thereby effecting retraction of the slide 5 by springs 8 to an extent equal to the depth of the recess 36. This retraction of the slide 5 effects movement of a disc member 39 by co-operation between stop portion 40 and stops 41, 42. The movement of the disc member 39 effects incremental displacement of a cam 35 through a oneway coupling, the movement of the cam controlling the position of the plunger 32 relative to the slide 5 which is consequently displaced incrementally towards the workpiece ready for the next traverse of the saddle. Immediately prior to the end of the return traverse of the carriage stops 47, 51 on a rod 46 and the fixed member 49, respectively, co-operate effecting pivoting of a bell-crank lever 44 on the member 4 which by engagement with pin 45 in-feeds the slide 5 with the chaser 25. Dial means is secured to the cam member 35 whereby rotation of the cam is indicated denoting the incremental feed of the slide and chaser. Increments of feed may also be effected manually by rotation of the dial.