GB844305A - Improvements in or relating to machine tools having a reciprocable element controlled by a tracer control unit - Google Patents

Abstract

844,305. Copying-lathes. SUNDSTRAND CORPORATION, [formerly SUNDSTRAND MACHINE TOOL CO.]. Jan. 23, 1957 [Jan. 27, 1956], No. 2426/57. Class 83 (3). A lathe &c. has a transversely - controlled copying-slide which carries an adjustable tracer control unit having biasing- means urging it in one direction, and a number of individually-operable control-devices for limiting the adjustment in opposition, the biasing-means, the controldevices being movable to a retracted inoperative position to disengage the control unit. An obliquely-arranged tool-carrying slide 22, Fig. 1, is supplied by a T-shaped guide 23, Fig. 4, on a longitudinal lathe-carriage 16. The slide 22, Fig. 1, is moved by an hydraulic piston-andcylinder 27, the piston-rod 30 of which is anchored to a bracket 31 secured to the carriage. The slide is retracted against an adjustable-stop 38. A bracket 60 is secured to the slide 22, and carries a dove-tailed slide 63 adjustable by a screw-and-nut 64, 65. An L-shaped extension is formed on the slide 63, comprising a horizontal leg 70 and a vertical leg 71 which is provided with pivots 75, 76, for a tracer control unit 40. The latter is biased by a spring 86, Fig. 1, in a clockwise direction, Fig. 2, away from a template 42, and towards a set of stops 97. These stops form part of piston-and-cylinder units 90, Fig. 4, which are adjustable by screws 94 along guideways in the leg 70. The stops 97 are set to project at different distances by a gauging-device 112, Fig. 2. The tracer control unit may thus be adjusted automatically at the end of each traverse to give a deeper cut, the control unit finally engaging a fixed stop 100 when all the stops 97 have been utilized and retracted. Tracer mechanism.-The control unit 40 has a stylus 41, Fig. 2, which engages an exchangeable templet 42 clamped to a bracket 44 secured to the lathe-bed. Fluid-pressure is supplied to the unit 40 from a pump driven by an electric motor. The unit includes a slide-valve which is normally biased by a spring to a position establishing fluid-flow to the cylinder 27 to move the tool T away from the work. A solenoid, on energization, disables the spring and enables a weaker spring to move the valve to a position where pressure-fluid is delivered to move the tool towards the work. The stylus is thus brought against the template, and on contact, reverses the movement of the toolslide. Reference has been directed by the Comptroller to Specification 803,522.