Patent GB-326468-A (GB)
Title: Improvements in or relating to clutch mechanism
IPC: F16D41/00
Filed: 1928-12-06
Abstract: 326,468. Midland Railway Carriage & Wagon Co., Ltd., and Champeney, C. C. Dec. 6, 1928. Locking by frictional detents; blocks acting on axles, drums, and hubs; energy-absorbing elements.-Relates to clutch or brake mechanism of the kind in which there are interposed between a rotary eccentric 3, Figs. 1 and 2, and a rotatable or fixed encircling-member 4, a uniform floating ring 6 and an eccentric locking-member 7 in contact with the floating ring and encircling- member, which parts have a torque-transmitting connection allowing orbital motion of the floating ring, so that relative angular displacement of the members under torque produces a locking-effect which is released when the two eccentric elements 3, 7 are constrained to occupy a certain critical position, and consists in providing multiple-pin torque-transmitting means between the orbital ring 6 and encircling-member 4. As applied to a clutch, Figs. 1 and 2, pairs of flattened pins 11, 13 project respectively from the parts 4, 6 to engage perpendicular pairs of slots 9 in a loose ring 8, the whole constituting a form of Oldham coupling. The parts 3, 4 are released when a lug 17 on a disc or arm 14, slidable on the shaft 1 of the eccentric 3, is engaged in a recess 18 in the ring 7. If the recess 18 is widened in one direction and the lug 17 fixed in engagement therewith, the device functions as a free-wheel clutch. In a modification, Figs. 9 and 10, the drum 4 is connected to a flange 5b on the shaft 2 and is coupled to the uniform ring 6 of four cranks 19. The eccentric 3 is integral with a disc 20, which is connected to the locking-ring 7 by a pin 21 having a pointed end 22 engaging a recess in the ring 7 and an inclined end 23 coacting with an inclined face on an arm 24 rigid with the shaft 1. When the shaft 1 drives in the direction of the arrow, Fig. 10, the arm 24 leaves the pin 21 free to be thrust out and the parts jam, while, on overrunning, the arm 24 forces the pin 21 inwards to turn the ring 7 into its " free " position, axial thrust on the arm 24 being taken by a plate 25. By sliding a flanged bush 82, carrying a ring 31, a wedge 27, slidable on an arm 26 and connected by links 29 to the ring 31, is thrust between lugs 28 on the disc 20 and prevents the arm 24 from acting on the pin 21, so that the clutch drives bidirectionally. The device may run in an oil-filled casing 39. As there is little movement between the parts 3, 7, the controlling parts 17, 18, Figs. 1 and 27, 28, Figs. 9 and 10, may be tapered and, if not fully withdrawn, are always ready for re-engagement. To avoid lost motion in picking up the drive after free-wheeling, a spring plunger 38, Fig. 8, may be used, through which the torque is transmitted from the arm 14 to the ring 7 during free-wheeling. This construction is particularly applicable to friction ratchet gearing. In order that the pressures on the ring 7 may be exerted on the more favourable parts thereof and to facilitate lubrication, the more tapered parts C of the ring, Fig. 13, may be relieved at the outer or inner surfaces 42, 43, or both.