Machine tool

摘要

1,062,770. Lathes. INDEX-WERKE K. G. HAHN & TESSKY. Dec. 2, 1965 [Dec. 5, 1964], No. 51225/65. Heading B3T. [Also in Division F2] Cam surfaces (76a) (Figs. 1 and 3, not shown), mounted on a programming drum (34) act alternately with similar cam surfaces on a second drum (36) through followers (40, 42), a cranked lever (20) and rack-and-pinion means (26, 24) to feed successive tools (86) mounted on a lathe turret (84) to a workpiece (84b), each drum being arranged to rotate rapidly through a small angle at the end of a feed stroke to allow the cam follower to clear the cam surface quickly and thereby allow rapid return of the slide (28) and turret (84) under the action of a return spring (27). The cams consist of curved members (76) having elongated slots (82) by which they are adjustably bolted to a series of parallel T-section grooves in the drum walls. In a modification (Figs. 6 and 7, not shown) the two programming drums are replaced by two groups of three cam discs mounted on two coaxial shafts. Cams of one or the other group operate in alternation through followers (130) on cranked levers (128) which bear adjustably on a common pivoted carrier member (100) having a pinion (104) in mesh with the feed rack (106) of the turret slide. In both embodiments normal drive of the drum or cam-shafts is effected through coaxial worm gears in mesh with worms which are slidably mounted on their respective driveshafts. Rapid rotation of the drum or camshafts is brought about by imparting sliding movement to the worm on its drive shaft by means of a fluid pressure cylinder and piston acting at the appropriate point in the cycle (Figs. 5 and 8-10, not shown). In a modified drive arrangement (Figs. 11 and 12, not shown), the cam-shafts are driven through spur gears, one gear in the train having a circumferentially extended keyway to accommodate the superimposed rapid movement through a small angle. An annular gear mounted around the hub of one of the spur gears transmits drive thereto by a one-way drive clutch and is itself driven by a rack forming the end of a piston of a fluid-pressure cylinder.