GB720168A - Improvements in or relating to centrifugal clutches - Google Patents

Abstract

720,168. Friction clutches, breaking-pieces. EICKHOFF MASCHINENFABRIK UND EISENGIESSEREI GEB. May 16, 1951 [May 16, 1950; June 24, 1950], No. 11400/51. Classes 80 (2) and 80 (4). The weights or coupling blocks of a centrifugal clutch are connected to the driving rotor by natural or artificial rubber, or material incorporating rubber, and means may be provided to automatically disconnect the clutch on overheating. Provision may also be made for adjusting the mass of the coupling blocks. Friction-faced blocks 7, Fig. 1, are secured by straps 8 to a flanged rubber cup 4 bolted to the driving rotor 2, and engage a drum 10 detachably secured by screws 13 to a driven rotor. Cooling air enters at 15 and leaves through passages formed between the blocks, and cooling fins are provided on the drum 10. In a modification the rubber cup 4 is replaced by a rubber disc and the blocks are shaped to cooperate with a cylindrical drum surface. In a further modification, Fig. 6 (not shown), the blocks are secured by annular plates to pairs of rubber blocks bonded to the faces of a flexible corrugated steel disc carried by the driving shaft, and the friction face of the driven drum is spherically curved to allow relative angular displacement of driving and driven shafts. In the construction of Fig. 7 coupling blocks 30 having T-shaped projections 31 are interposed between ribs 28 on the driving rotor and are held by rubber blocks 32 which are retained by.flanged plates bolted to the ribs. Heat-insulating strips are inserted between the rubber blocks (which have a certain amount of free play) and the blocks 30. According to Fig. 10 a corrugated rubber body 53 secured to a driving rotor has a peripheral thickening to which are clamped blocks 54. The blocks have axial holes (not shown) in which may be inserted steel pins to increase the centrifugal mass, and a friction lining 57 is formed as a cap to retain the pins. A drum 59, whose inner surface is conically tapered to retain the blocks, is rotatably supported on the driven rotor by a bearing 60, and a pin 62 radially slidable in the drum normally engages a groove in the rotor to drive the latter. A plug 64 of a low-melting-point material, e.g., a bismuthtin-lead alloy fusing at approximately 100‹C., is interposed between the pin 62 and a screw 65 so that should the clutch slip and overheat the plug 64 melts and is discharged through a channel to allow the pin 62 to move outwardly and disconnect the drum 59 from the rotor. The channel may be dispensed with if the plug 64 is formed as a hollow cylinder. Alternatively, a bimetallic latch may replace the fusible plug. In a modification, Fig. 9 (not shown), fusible pins inserted in axial holes in abutting faces of a drum and a driven rotor normally interconnect the latter but shear on overheating. The bearing bush is preferably of a porous self-lubricating metal, but a grease chamber may be provided.