| 摘要 |
504,269. Chucks. FAIRWEATHER, H.. G. C. (National Acme Co.) July 21, 1937, No. 20180. [Class 83 (iii)] In an electrically-operated chuck the jaws are actuated by a drawspindle moved by a rotatable nut threaded thereon and an annular spring is provided in the abutment of the nut in order to urge the nut and draw-spindle axially in 'the closing direction so as to preserve the grip of the jaws on the work if they should tend to bite in after the closing means have ceased to operate. The jaws, (not shown), are moved radially by levers rocked by a draw-spindle 15 prevented from rotating relatively to the lathe spindle 12 by splines 16 and having a screw thread 17 engaged by a nut 19. Dogs 41 on the nut are adapted to be engaged by dogs 40 on a motordriven'shaft 30 which is moved axially at the work-changing station of the lathe turret, as described in Specifications 453,332 and 495,205. A flange 42 on the nut is engaged by thrust bearings 20, 43 held axially by screwed sleeves 22, 23 attached to the spindle 12 and locked by a key 24. The bearings have slight axial play within the sleeves and a corrugated annular spring 44 is placed against the bearing 20 so as to form a resilient abutment therefor which is compressed when the nut is rotated to close the jaws on the work. Should the jaws tend to bite further into the work after the shaft 30 has been disengaged, the spring 44 will expand to move the nut and spindle 15 axially to preserve the grip on the work. The spindle 12 is driven through a clutch 13 and stopped by a brake B, as described in the Specifications above referred to. |
