GB168984A - Ratchet coupling - Google Patents

Abstract

168,984. Schurmann, C. June 10, 1920. Clutches, ratchet.-In friction ratchet mechanism for use in power transmission, switchlevers, &c., an expanding-coil clutch 5 is used, provided with means so acting on the ends of the coil as to make all the turns effective for driving, without introducing excessive friction during overrunning &c. In one form, suitable for low powers, such as ratchets, switches, &c., the ends of the coil are made to project slightly to engage frictionally the casing-parts 2, 3, either by flattening the last half-convolutions or by hingeing them to the rest of the coil, which need not be initially larger than the casing. As shown in Fig. 5, each end of the coil may be attached by a pin 10 to one of a pair of shoes 6, 7 adjustably spring-pressed against the casing, or, when axial space is restricted, against the inside of the coil itself. In the form shown in Fig. 7, split - collars 6, 7 are caused to grip the shafts 1, 4, preferably by springs housed around their connecting-bolts 60, 70, and the coil ends are coupled thereto by inclined links 11. which press them against the casing-parts 2, 3 when the driving- shaft turns in the. engaging-direction. Fig. 9 .shows means for coupling a gear-wheel 12 to a. shaft 1. One end 14 of the coil 5 is inserted in a gripping-collar of the type shown in Fig. 7, and the other end 15 is wound tightly round a boss 16 of the wheel 12. In all the forms, one end of the clutch coil may be directly secured to the driving or driven member. Reference has been directed by the Comptroller to Specification 3527/82.