GB391823A - Improvements in and relating to chucks - Google Patents

Abstract

391,823. Chucks ; turning. SLOAN, H. E., 9, North Beacon Street, and HIGHBERG, G. A., 22, Fennbrook Road, West Hartford, both in Hartford, Connecticut, U.S.A. Sept. 3, 1931, No. 24750. [Class 83 (iii).] In a chuck wherein the jaws are moved radially by an axially sliding draw-spindle operated by a screw and nut which is actuated by a gear wheel, a pinion is provided for rotating the gear wheel and is moved into and out of operative position by a hand-lever. The pinion is driven by an electric motor and means are provided for holding one member of the screw and nut stationary whilst the other is rotated. In one form, the chuck-jaws 13, Fig. 8, are attached to bases 12 moved radially on the body 8 by means of levers 11 which are oscillated by a sliding ring 10 secured to a drawspindle 9 splined at 64 within the hollow chuckspindle 7. Axial movement of the spindle 9 is produced by a screw-thread 16 thereon and a rotatable nut 15 mounted in ball bearings in the spindle 7 and carrying a gear 20 adapted to be engaged by a pinion 46, Fig. 8, or 22, Fig. 2, splined on the shaft of a motor 21 attached to the machine frame. A hand-lever 26 or 62 provides for moving the pinion axially to engage the gear 20 of a chuck-spindle which has been brought by the turret 6 into the workchanging position and the gear 20 is connected to the nut 15 through a lost-motion device comprising dogs 18, 19 on the nut and gear respectively to allow the motor to deliver a blow to the nut to ensure opening of the chuck. Chuck-operating mechanism connected to brake on spindle; brakes, applications of.-To prevent rotation of the chuck during opening or closing a gear 63, Fig. 8, secured to the chuck-spindle 7 is adapted to be engaged by a braked pinion 57 moved into gear simultaneously with the motor pinion 46. In operation, when the lathe turret has brought the chuck into the work-changing position and a driving clutch for the spindle 7 has been thrown out by a cam, the hand-lever 62 is oscillated to move a gear-shifter 47 which is secured to the gear 46 in mesh with the motor pinion 45, the latter being elongated in this case. The gear is mounted on a sleeve 52 attached to a shaft 50 which is splined within brackets 48 on the machine frame, the first movement of the gear causing the shaft and pinion 57 to be moved to the left in Fig. 8 until the pinion is meshed with the gear 63 and a stop 61 on the shaft meets the bracket 48, whereupon further movement of the lever slides the gear-shifter 47 relatively to the sleeve 52 and causes a pin 59 to separate levers 55 and expand a brake-drum 56 into contact with the pinion 57, thereby preventing rotation of the chuck-spindle whilst the gear 20 is rotated by the motor 21. In an alternative construction a clutch 30, Fig. 2, for the drive of the chuck-spindle 7 is actuated by levers 31 rocked by a cone 33 splined to the spindle and moved axially by a cam-operated lever 35 which engages each cone 33 in turn as the spindle reaches the work-changing position. On opening of the clutch, a flange 38 on the cone is pressed against a face 39 on the spindle by the shoe 34 on the lever 35, thereby stopping rotation of the chuck. In another construction a toothed ring is secured to the chuck-spindle and is engaged by a solenoid-operated detent mounted on the machine frame.