GB1013878A - Mechanism for imparting intermittent rotation to tables - Google Patents

Abstract

1,013,878. Grinding. W. CANNING & CO. Ltd. Sept. 28, 1964 [May 7, 1964; Sept. 27, 1963], Nos. 38126/63 and 18990/64. Heading B3D. An apparatus having a rotatable table 11 carrying a plurality of spindles 12 rotatable relative to the table and spaced angularly about the axis of rotation of the table includes a mechanism for intermittently rotating the table comprising a common driving member 15 for the spindles, and clutch or brake means operable to cause or permit rotation of the table by the driving member to cause the spindles to move orbitally relatively to the axis of rotation of the table. The table is rotatably supported on a spindle 21 upstanding from a base 10 and carries a plurality of work spindles 12 which are rotatably supported by the table and alternate with a plurality of clutch spindles 13. A plurality of tool supports, not shown, are mounted on respective bases around the table, each support having a separate motor driving a mop, brush or grinding wheel. Each work spindle and clutch spindle carries a sprocket 14 engaged by a chain 15 which is driven by a motor 16 through a gear-box 18 and sprocket 17, the chain also running over a guide sprocket 19 and tensioning sprocket 20. The chain is continuously driven to rotate the work spindles and to intermittently rotate the table so that the work spindles are presented to the tool supports and an unloading and loading station adjacent the driving sprocket 17, at which station the sprocket on the work spindle at that station is disengaged from the chain. The intermittent rotation of the table is effected by successive actuation of the clutches on the spindles 13. Each clutch consists of a lower ring 22b which is fixed to a sprocket 14 and has teeth interengageable with teeth on an upper ring 22a axially movable on the spindle 13. The ring 22a is urged by a spring 23 towards the ring 22b and has a pin 26 engaging a slot in a lever at one end mounted on a pivot 25 and at the other end carrying a roller 27 for engaging a track 28 on the stand. The track normally maintains the levers and rings 22a in an upper position wherein the clutch is disengaged, but a portion 29 of the track can be lowered by a pneumatic device 30 so that a spring 23 can engage a clutch so that the associated sprocket is prevented from rotating on its spindle and the chain 15 thereby rotates the table. When all the clutches are disengaged, the table is prevented from rotating by a rod 31 which can be moved by a pneumatic device 32 to selectively engage one of a plurality of recesses on the underside of the table. The table is slowed down during its rotation prior to engagement by the rod 31 with one of the recesses by a brake 34 which is actuated by a pneumatic device 38 to engage a cylindrical surface 35 on the table. The operation of the pneumatic devices 30, 32 and 38 controlling clutch engagement, locking and braking is effected by an electro-pneumatic circuit having a timer, the circuit being actuated by microswitches 40, 40 operated by an arm 41 on the table. In other embodiments, the chain is replaced by a belt, brakes perform the functions of the clutches, and the work and clutch spindles are combined. The devices may be operated by solenoids and clutches be electromagnetic.