GB567676A - Improvements in or relating to clutch mechanism - Google Patents

Abstract

567,676. Friction clutches. WOLFF, O. E. Sept. 19, 1942, No. 13252. Convention date, Jan. 13, 1942. [Class 80 (ii)] [Also in Group XXXIV] In a friction clutch the driving and driven members are held in unlubricated static frictional contact whenever there is no relative motion thereof, or whenever the torque transmitted is less than a predetermined torque, and are sub-- stantially completely disengaged with continuous films of lubricant between their normally contacting surfaces whenever there -is relative motion, or whenever the torque reaches a predetermined value. As shown a plate 38, Fig. 1, on a driving shaft 32 is spring- urged towards a plate 60 on a driven shaft 36 and has friction pads 44 pivoted thereto. The housing 52 is partially filled with lubricant. When driving takes place there is no lubricant between the pads 44 and the plate 60, Fig. 4, but should relative motion or slip occur the pads 44 tilt and an oil film 68, Fig. 3, is built up and the clutch is disengaged. Re-engagement is obtained by bringing the plates 38, 60 to the same speed. In a modification the pads 85, Fig. 5, are supported by centrifugal weights 75 carried by arms 74 on the driving shaft 70, and bear on a drum 90 fixed to the driven shaft. Springs 80 also urge the weights radially outwardly. Thus the torque that can be transmitted is increased with the speed of rotation. The pads may be integral with the weights and may be chamfered at the leading edges. In another modification three sets of centrifugal weights 312, 314, Figs. 24, 25, are pivoted to arms 310 on the driving shaft 300, the pads 320 being carried by springs 318 on the weights. Movement of the weights under centrifugal force is limited by abutments 324, 325, some of the weights being permitted more movement than the others. The pads 320 engage a drum carried by the driven shaft 302. In another modification in which the clutch disengages when the speed exceeds a predetermined value, the pads 210, Fig. 19, engage the outside of a drum 204 on the driven shaft and are carried. by stems 206 radially slidable in a drum 198 on the driving shaft. Springs 216 urge the pads towards the drum 204. In another modification the pads 236, Fig. 20, are integral with centrifugal weights 232 slidingly carried by arms 230 on a casing 228 fixed to the driving shaft. Pins 237 in the casing carry gears 238 which mesh with a gear 225 on the driven shaft. Thus when relative motion occurs between the driving and driven shafts the gears act as oil pumps and oil passes through pipings 240 and ducts 244 to the engaging surfaces.