GB480563A - Improvements in and relating to thread copying devices for automatic lathes - Google Patents

Abstract

480,563. Lathes. SKODA WORKS, PLZEN. May 6, 1937, No. 12995. Convention date, June 8, 1936. [Class 83 (iii)] A thread-copying device for automatic lathes comprises two thread templets 7, 9, Fig. 1, which are arranged parallel and rotate in opposite directions, and threaded guide members 10, 11, Fig. 4, which are mounted on a slidable control bar 13 and adapted to engage alternately the thread templets, the control bar directly effecting the longitudinal movement of the cutter and indirectly its transverse movement. Cams 17, 18, Fig. 1, carried by the driven templet shafts alternately engage the guide members 10, 11, mounted on a lever 12, with the threaded templets for forward and return movement respectively. The control bar 13 is moved by the thread controls and directly effects the longitudinal movement of the slide member 8, Figs. 1 and 3. The partial rotation of the control bar during the alternate nut engagements acts through a cam-piece 15 on the end of the bar to raise a lever 19 fixed to a cross-shaft 20 mounted in the slide 8 ; the end of this shaft carries a cam-piece 21 which bears on the outside or inside of a stud 22, fixed to the tool-carrying cross-slide' 23, according to whether external or internal threads are to be cut. The stud is maintained in engagement with the cam-piece by a spring and the tool is thus fed into or relieved from the work by rotation of the shaft 13.