GB1280093A - Automatic band polishing machine - Google Patents

Abstract

1280093 Grinding OVISCONTI 14 Aug 1970 [16 Sept 1969] 39354/70 Heading B3D A machine for automatic polishing of ring- shaped workpieces 40, such as the bows of scissors, comprises two spaced supporting means 2, 30 for an endless abrasive band 1 and between which a workpiece is intended to be placed, band tensioning means 6 associated with the supporting means 2 to support the band in an idle position free of the supporting means 30 whereby the workpiece can be placed in the free space between the band and the supporting means 30, means 13 for extending the band from its idle position through the ring-shaped workpiece 40 towards the supporting means 30, means 31a, 31b for receiving the extended portion of the band and placing it around the supporting means 30, and means 3 for driving the band extending between the two supporting means. The supporting means 2 consists of a pulley mounted on the shaft of a motor 3 carried by a slide 4 urged to the left along guides 5 in a frame 7 by a spring 6. The frame 7 is secured to a disc 15 supported in idlers wheels 16 and can be rotated by gearing 17, 18 from a motor 20. The band runs over the pulley 2, tensioning pulleys 10 on the end of spring-loaded arms 11, and a pusher 13 which can be extended by a pneumatic cylinder 14. The workpieces 40 are fed from a magazine 35 operated step-by-step singly to jaws 37 carried by a cylinder 38, and a cylinder 39 is operable to move the workpiece to an inclined position. The supporting means 30 consists of a pulley mounted on a bracket 27 which can be moved vertically on a slide 23 by a pneumatic cylinder 29 the slide being movable along guides 24 on a gear wheel 21. A further bracket 26<SP>1</SP> carries a plate 27<SP>1</SP> on which is a pair of linkages 32a, 32b carrying fingers 31a, 31b, a cylinder 33 acting on the linkages. The gear wheel 21 meshes with a gear 22 on a rod 19 connected to the gear 18. A motor is operated by a timer and rotates a cam disc controlling the operation of the machine. In operation, the mechanism 35 and cylinder 38 are operated to feed a new workpiece into the jaws 37. Cylinder 14 is then actuated to advance the pusher 13, which passes the abrasive band through the workpiece, and cylinder 29<SP>1</SP> operated to raise the fingers 31a, 31b into the loop of the band, one each side of the pusher. Thereafter cylinder 33 spreads the fingers and cylinder 29 moves pulley 30 downwardly into the widened out loop, cylinder 33 returning the fingers to thus initial position so that the band is around pulley 30. The pusher 13 is then retracted and the fingers lowered. The slide 23 is moved by cylinder 25 away from the axis of the machine and cylinder 39 tilts the workpiece. Polishing is then effected under the control of a timer by operation of motor 3 driving the band and motor 20 rotating gears 17, 21, and hence the supporting pulleys 2, 30 about the longitudinal axis of the machine.