Patent GB-1160416-A (GB)
Title: Improvements in or relating to Overload Clutches.
Inventor: GOLD DEREK LAWRENCE
IPC: F16D43/206
Filed: 1965-12-02
Abstract: 1,160,416. Overload release clutches. FISHOLOW PRODUCTS Ltd. 24 Nov., 1966 [2 Dec., 1965; 11 Jan., 19661, Nos. 51123/65 and 1207/66. Heading F2C. In an overload release clutch for a conveyer wherein torque transmitting balls 18 carried by cam slots 20 in a freely rotatable disc 19 normally engage recesses 16, 17 in driving and driven clutch discs 10, 11 urged together by springs 15, oppositely directed pawls 21, 22 normally connect the carrier disc 19 to the driving or driven disc 10 or 11 so that on overload the balls ride out of the recesses 16, 17 and are guided by the slots 20 to a position radially spaced from the recesses to permit free relative rotation between the driving and driven discs 10, 11. When the balls 18 reacn the ends of their sots 20 they release the appropriate pawls to permit the carrier disc 19 to rotate relative to both the driving and driven discs 10, 11 whereupon the relative rotation between the driving and driven discs 10, 11 is accompanied by rolling of the balls 18. To reset the clutch the driving or driven disc 10 (or 11) is rotated relative to the other disc 11 (or 10) in a direction opposite to that during clutch disengagement and the accompanying rotation of the carrier disc 19 causes the non-released pawls to reconnect the disc 19 with the driving or driven disc 10 or 11 when the recesses 16 or 17 are at the mid-points of the slots 20 whereafter further relative rotation of the driving and driven discs causes the balls 18 to ride into the recesses 16, 17. As shown the pawls 21, 22 are pivoted at 25 to the carrier disc 19 and are urged by springs 26 into engagement with stops 24 on a ring 23 fast with the driving disc 10. On overload with the driving disc 10 rotating in the direction of the arrow A, the balls 18 ride out of the recesses 16, 17 and move to the position shown at the ends of the slots 20 where they pivot the pawls 22 out of engagement with the stops 24 and permit the driving disc 10 to overrun the carrier disc 19 with the pawls 21 ratchetting over the stops 24. To reset the clutch the driving disc 10 is rotated in the direction B or the driven disc 11 is rotated in the direction A to cause the carrier disc 19 to rotate clockwise relative to the driving disc 10 until the pawls 21 engage the stops 24 whereupon the recesses 16 are at the mid-points of the slots 20. On further rotation of the driving or driven members the balls are guided along the slots 20 until they engage the recesses 16 whereafter addition they engage the recesses 16 whereafter additional rotation brings the recess 17 into engagement with the balls 18. If the driving member 10 is initially rotating in the direction B the balls roll to the other end of the slots 20 on overload to release the pawls 21 and the pawls 22 are operative during resetting. In Figs. 5-8 (not shown) the pawls (21, 22) are carried by plungers radially slidable in the carrier disc (19). Springs (26) bias the plungers radially inward so that arms on the pawls engage stop surfaces (24b, 24c) at the ends of recesses (31) in the driven member 11. On overload the balls ride out of the recesses 16, 17 and move to one end of the slots and lift the appropriate plunger and pawl to permit the carrier disc to overrun the driven members. Resetting is similar to that described above.