GB612816A - Improvements in crankshaft turning lathes - Google Patents

Abstract

612,816. Lathes. BUGATTI, E. I. A. April 18, 1945, No. 9716. Convention date, March 1, 1944. [Class 83 (iii)] A crank-shaft turning-lathe of the stationary work type with a number of flat annular tool carriers spaced apart and encircling the work adapted to operate simultaneously on different portions thereof, is characterised in that each flat annular tool carrier has an annular rotary cam controlling a tool rest guided in a radial recess of the carrier. A number of drums 7, Fig. 5, according to the number of crank-pins to be turned are mounted in a bed 56. Supporting segments 29 bolted to the drums carry clamping means 33, 65, 66 for clamping the ends or webs of a crank-shaft which is held stationary during machining. The tools. 40, Fig. 6, which cut the full width of the crankpin as the feeding movement develops (see below), are carried in radial slides 36 with V- shape guide edges which move in ways 38 in rotatable carriers 13, 16, Figs. 2 and 3. A cam plate 17 rotatably mounted in an annular recess formed by the two parts of the carrier, feeds the tools inwardly against the tension of springs 48 carried in the drum. The tool carrier disc and the cam disc have toothed peripheries, the number of teeth differing slightly so that when rotated by the pinions 23 and 25 from self-contained electric motors, Fig. 10, a slow feed movement is imparted to the tool carriers. Four tools are used in each annular carrier with differently shaped cutting edges so that the crank-pin and webs are cut progressively as the tools feed inwardly.