Patent GB-416127-A (GB)
Title: Improvements in chucking mechanism
IPC: B23B9/10
Filed: 1933-04-21
Abstract: 416,127. Lathes ; chucks. CONE, F. L., 129, State Street, Windsor, Vermont, U.S.A. April 21, 1933, No. 11722. Convention date, May 19, 1932. [Class 83 (iii).] In chuck-actuating mechanism for a lathe or like machine means are provided for disconnecting the spindle drive, stopping the rotation of the spindle, connecting the chuck-operating means to the opening and closing mechanism and setting into motion means for actuating the chuck-operating means. As applied to a multiple-spindle work-turret lathe, the turret 1 carries a number of parallel work-spindles 10, each provided with a chuck 12 comprising jaws 50, Fig. 7, on carriers 51 moved radially by bevelled ribs 52 thereon engaging similar grooves 53 on a head 54 attached to a draw spindle 57 splined at 58 within the chuck sleeve 15. The rear end of the draw-spindle is screwed at 60, Fig. 8, for engagement with a rotatable but axially fixed nut 61 provided with clutch teeth 68. Each chuck sleeve 15 is rotated through a multiple-plate clutch 23, Fig. 7, and gear 21 engaging a central pinion 20 on the shaft 2, Fig. 1, on which the turret rotates, the clutch being controlled by levers 30, Fig. 3, and a slidable cone 35 connected by a yoke to a rod 38 slidable through a part 17 of the turret and carrying a roller 39. In operation, on indexing of the turret by means of an arm 6 on a cam-shaft 5, the spindle which stops at the work-changing station has its clutch-control roller 39 placed within a slot 111; Fig. 3, on an arm 101 attached to a hand lever 110. On raising the hand lever from the full line position of Fig. 1 to the dotted line position the rod 38 is moved to the right, thereby releasing the clutch 23. Simultaneously, a lug 115, Fig. 3, on the lever 110 acts through a compression spring 117, link 116, and lever 78 to slide a sleeve 70, Fig. 8, splined at 710 within a part 71 of the machine frame. Clutch teeth 72 on the sleeve 70 engage similar teeth 18 on the chuck sleeve 15 to stop rotation thereof when the clutch 23 is released. A shaft 73 which is rotatably mounted in the sleeve 70 is movable axially therewith and carries clutch teeth 74 engageable with the teeth 68 on the nut 61. A sprocket wheel 86 is secured to a collar 82 splined on the shaft 73 and is driven by a chain from an electric motor 93 to rotate the nut 61 in the chuck opening or closing direction whilst the sleeve 15 is held stationary by the sleeve 70. Considerable circumferential clearance is left between the teeth of both the inner and outer clutches to allow relative rotation before engagement and thus impart a blow to the nut 61 to ensure disengagement of the chuck jaws from the work. Two push buttons 145, 146, Fig. 1, are provided for starting the motor 93 in either direction after the hand lever 110 has been raised and variable transformers are inserted in the motor circuit to adjust the voltage supplied to the motor in the chuckclosing direction and thus vary the pressure of the jaws on the work when the motor stalls. A spring detent 130 on the lever 110, actuated by a trigger 132, coacts with a quadrant 131 to determine the two positions of the lever. Beds and framings.-The turret 1 is rotatably mounted on a shaft 2 between upper and lower frame members 3, 4 which are tied together by vertical members 71, 104. Headstock spindle-mountings.-The spindles 15 are mounted in roller bearings 40, 41, Fig. 7, of the turret members 16, 17 respectively.