| 摘要 |
880,190. Automatic lathes ; drilling. BECHLER, A. Dec. 22, 1959 [March 26, 1959], No. 43459/59. Class 83 (3). An automatic lathe has means for slowing down and stopping the spindle which is subsequently turned through an angle of less than 360 degrees. The cam control shaft 5, Fig. 3, carries a cam-drum 10 with a cam-piece 9 having a control part 9b and a short rise 9a. The latter moves the double cone clutch to engage a brake surface 12 to stop the work-spindle 3. The clutch is then held in the neutral position throughout rotation of the cam part 9b. During this time a further cam 13, Fig. 2, on the control shaft engages the end of a spring-returned sliding bar 14 which moves a rack 16 engaging a pinion 21. A train of gears 21-26 conveys this motion to a disc loose on the end of the spindle which carries a pawl 28 adapted to engage a ratchet-wheel secured to the spindles. The pawl is disengaged by a stop 32a in the extreme position of the supporting disc, but, with the spindle drive inoperative and the first step 13a of cam 13 moving bar 14 the ratchet is turned through a predetermined angle. A further step 13c moves the spindle through a second angle. Drilling, milling. During the spindle dwell periods, represented by cam portions 13b and 13d, the work 34, Fig. 1, may be cross-drilled by a drill 33 carried by a spindle 36 and movable by a slide for axial feed. Alternatively, a tool may be used to cut a groove in the work either circumferentially during a small rise on the cam 13 or longitudinally in the work by the normal headstock movements. |
