GB283380A - Centrifugal friction couplings - Google Patents

Abstract

283,380. Stewart, J. F., (Allgemeine Elektricitõts-Ges.). April 31, 1927. Clutches, friction. - In centrifugal friction clutches, particularly for facilitating the starting of short-circuited armature electromotors, the centrifugal masses which effect. clutching between the driving and driven members are, on starting, coupled to the driving-member solely by an auxiliary centrifugal or other friction device, which subsequently does not assist in transmitting torque. The torque transmissible from the main driving-surface, preferably exceeds that transmissible to the driven surface. A driving- member b, Fig. 1, carries auxiliary centrifugal clutch shoes e, coacting with a loose intermediate, member d, which carries on radial guide pins the main centrifugal shoes, a connected together by circumferential retracting-springs (not shown). When the member d has attained a predetermined speed, the shoes a contact by friction casings m, n with conical surfaces on the driveing-member b and driven pulley c, the conicity or radial distance from the shaft axis of these surfaces being preferably different. The masses e may be omitted, and the member d driven by direct friction with the hub of the part b. The surfaces n of the shoes a may, as shown in Fig. 3, coact with a loose coned ring f, provided with a flat friction face p to clutch the pulley c. The ring f may, however, be disposed between the surfaces m and the driving-member b, but the coefficients of friction or radial distances of the driving and driven surfaces should then be chosen to ensure greater transmissible torque from the driving- member. In a modification, the wedging-action between the surfaces m and member b moves the part d axially to clutch a flat surface thereon to the pulley c. In another form, the shoes a, Fig. 8, coact with inclined faces on axially-movable discs f<1>, f<2>, splined to the driving-member b and adapted to grip the pulley c by their faces p', p<2>. The shoe-carrier d may be driven by auxiliary masses e or by direct friction with the bosses of the discs f<1>, f<2>. There may be two or more concentric intermediate members d, d1, Fig. 7, driving one another by friction, the innermost member d being driven by friction with the discs f<1>, f<2> or by auxiliary centrifugal shoes. The action of the shoes a may be further delayed by the drag of spring-pressed pads w, Fig. 8, rubbing on the pulley c. The same effect may be obtained by shoes m, Fig. 11, pressed on the rim d2 of a wheel-like member d by springs r and adjusting- screws s carried by the pulley c, or by loose spherically-faced weights w, Fig. 12, normally housed in recesses in the main weights a and slidable on extensions of the guide-pins l to contact frictionally with the pulley c as soon as the part d rotates. The effect can be adjusted by changing the weights w.