UEBERLASTKUPPLUNG

1501232 Overload release clutches F JOS LAMB CO and J H BREMS 18 March 1975 [6 May 1974] 11136/75 Heading F2C An overload release clutch for connecting driving and driven elements in a single angular driving relationship comprises a single torque transmitting roller 28 carried by a slot 26 in a driving sleeve 16 and urged into engagement with a single axial groove 30 in a driven element 18 by a circumferentially continuous elastic element 44 which is cylindrical in its unstressed state, the element 44 reacts against a roller or rollers 38, 40 diametrically opposite the roller 28 and carried by a slot or slots 34, 36 in the sleeve 16. On overload the torque transmitting roller 28 is cammed out of the groove 30 and during subsequent relative rotation between the driving sleeve 16 and the driven gear 18 the reaction roller or rollers 38, 40 are prevented from torque transmitting engagement with the groove 30 by, as shown, one of the rollers preventing the elastic element 44 from urging the other of the rollers into the groove 30 as it passes the latter. In Figs. 7 and 8 (not shown) a single reaction roller has a length which exceeds that of the groove in the driven element and thus is prevented from entering the groove. The resilient element 44 may, as shown, be provided within the sleeve 16 and urge the torque transmitting roller into a groove 30 in the inner periphery of a surrounding driven gear-wheel 18, or may, Figs. 5-8 (not shown), surround the driving sleeve and urge the torque transmitting roller radially inward into a groove in the external surface of a driven shaft. Additional rollers 46, 48 may be provided to prevent the elastic element from frictional engagement with the driving sleeve. To increase the torque transmitted a pair of cylindrical elastic elements, one within the other, may be provided. The inclined surfaces 32 of the groove 30 are parabolic in section to compensate for the increasing force applied to the rollers by the elastic element 44 during clutch disengagement. Disengagement of the clutch on overload may stop the driving motor.