GB690975A - Improvements in or relating to multiple speed gear mechanism - Google Patents

Abstract

690,975. Change-speed gearing; friction clutches. WESTINGHOUSE ELECTRIC INTERNATIONAL CO. June 6, 1951 [June 10, 1950], No. 13390/51. Class 80 (ii). Two-speed change-speed gearing, particularly for washing machines, comprises a driving shaft 21 selectively coupled through a worm 29 or spiral gear 28 to a driven shaft 14. The worm 29 is integral with the driving shaft 21 and meshes a worm wheel 35 on a countershaft 23 to which latter is secured a gear 36, meshing a gear 37 rotatable on a shaft 22 splined to the driven shaft 14. Gear 37 is coupled by a oneway helical coil clutch 41 to the hub of a spiral wheel 38 fast on shaft 22. The spiral gear 28 meshes spiral wheel 38 and is rotatable upon but selectively clutchable to the driving shaft 21 by a helical coil clutch 33 in series with a centrifugally operated friction clutch 34. The helical coil clutch 33 consists of a hub 44, fast on the driving shaft, surrounded by a helix 47 which also surrounds a hub 45 journaled on the driving shaft. The helix 47 has a projection 48 at its upper end which can be engaged by an electromagnetically controlled stop 49 to prevent it from frictionally coupling hubs 44, 45. Hub 45 is connected through a sleeve 59 to two weights 56 urged apart by springs, friction linings 57 being affixed to these weights. The friction linings can engage the inner surface of a cup-shaped member 54 connected by a sleeve 32 to the spiral gear 28. When the stop 49 is withdrawn, hubs 44, 45 are frictionally coupled by helix 47 and the weights 56 are rotated by the driving shaft 21 and coupled frictionally to the cup member 54. The initial gentle engagement of weights 56 with cup 54 is produced by the springs acting between them, increasingly fierce engagement resulting from the centrifugal force produced by their rotation. Thus spiral gear 28 rotates with driving shaft 21, and a high-speed drive is obtained' through train 28, 38, 22, 14, helical coil clutch 41 overrunning. When the stop 49 is engaged, a low speed drive is obtained through train 29, 35, 23, 36, 37, 41, 38, 22, 14, spiral gear 28 rotating freely on the driving shaft. Specification 527,540, [Group VIII], is referred to.