GB785516A - Improvements in or relating to template switching arrangements for copying lathes and like machines - Google Patents

Abstract

785,516. Copy-turning. FISCHER AKT.- GES., G. Dec. 7, 1955 [Dec. 7, 1954], No. 35195/55. Class 83 (3). A templet-changing arrangement for a copying-lathe &c. to perform two different turning or like operations in accordance with a pair of templets successively on the same workpiece, the latter being repositioned in the machine between operations, comprises changing means for moving each templet in turn into the operative position and sensing means for actuating the changing means in dependence upon the position of a part of the work, e.g. a collar, in the machine. The work 10, Figs. 1 and 2, is carried by a chuck 9 and tailstock 8 and has a flange 46 which, for the first turning operation I (heavy lines) is nearer the tailstock. A tool 12 is mounted on a copying-slide 11 controlled by hydraulic or electric means (not described), and having a follower 14 which co-operates with one or other of a pair of templets 15, 25, Fig. 3. The latter are mounted on a rockable support 17 which is moved automatically to bring the second templet 25 into co-operation with the follower for the second operation II, Fig. 2. The work is repositioned for the latter operation with the flange nearer the headstock. When brought into this position the flange 46 on the work contacts a switch-roller 39, Fig. 3, carried by a switch-box 37, Fig. 1, adjustable on a top beam 3 of the machine. The roller 39, Fig. 3, is thus raised and a tapered collar on the stem supporting the roller moves a switch 40 to the right. An electric circuit is thus completed from a power line to the coil 24 of an electromagnet and closed switches 42, 43. A slide valve 22 is moved to the right by the electromagnet and fluid allowed to pass from cylinder 30 to reservoir 19 so that piston 32 is relieved from fluid pressure and is moved to the right by a spring 31. A linkage 33-36, connected between the piston and templet carrier, rocks the latter to the position where templet 25 is operative for the cutting cycle II. Rocking the templet carrier moves a switch 42 to the left-hand position for conditioning an electromagnetic 23 for the next operation, where templet 15 is required. When the tool 12 moves forward to start the cut of cycle II a cam 47 moves off a switch arm and the circuit to a relay 43a is broken so that switch 43 is opened. This breaks the circuit to prevent inadvertent operation of the templets until the tool is retracted again for the next operation. A modified arrangement is described using electrical means only and the safety switch 47 may be embodied in the tailstock spindle instead of the tool.