GB897036A - Device for the braking and indexing of the working spindle of automatic lathes - Google Patents

Abstract

897,036. Lathes. HAHN, E. Sept. 8, 1958 [Oct. 21, 1957], No. 28788/58. Class 83 (3). An automatic lathe has an electric motor 88 for rotating the spindle 19 and means 81 for stopping the spindle in selected positions. The lathe also has a turret 12 carrying a cutter 13 to mill faces 21 on a workpiece 20. Two sprocket wheels 32, 33 are rotated at different speeds or in opposite directions and are connected selectively to the spindle 19 by clutches 26, 27 engaged by a cam 38 engaging a lever 36. The cam 38 is rotated from a continuouslyrotating shaft 43 by engagement of a clutch 42. Projections 53, 54 on the cam 38 control levers 55, 56 which lock together by projections 61, 62 whenever the cam rotates 120 degrees in either direction from its neutral point. A link 70 connects the lever 55 with a lever 77 and carries a dog 74 to actuate a switch 75. The dog 81 on the lever 77 engages one of a series of notches 83 in a disc 82 on the spindle 19. The disc 82 may be rotated through gears 86, 85 by the motor 88 driving through an electric clutch 87. The lever 77 is actuated by a cam 96 on a shaft 97 rotated from the shaft 43. In operation, when a pawl 90 on the lever 77 runs off a portion 100 of the cam 96, the lever is moved by a spring 80 causing the switch 75 to be operated. The clutch 87 is then energized and the shaft 19 is braked and stopped, the dog 81 subsequently engaging a notch 83. After a working operation has been performed by the cutter 13, a dog 99 on the cam 96 operates the lever 77 to release the dog 81. The cam 96 and the disc 82 then rotate until the dog 81 drops into the next notch 83 and a further operation is performed. The workpiece shown is milled on two faces and cross-drilled at points determined by the dogs 99. Alternatively, a series of holes may be drilled and threaded in a disc. In a modification, only one clutch 27 is provided.