Patent GB-303435-A (GB)
Title: Improvements in, or relating to, free-wheel clutches
IPC: F16D41/08
Filed: 1927-10-03
Abstract: 303,435. Joseph, F. A. Oct. 3, 1927. C l u tc he s , ratchet; facilitating changing speed, combinations of clutches with brakes.-In free-wheel clutches comprising driving and driven members coupled by one or more main wedging-members, one or more auxiliary unidirectional wedging-members are provided to assist throwing the main member or members into action, as by coacting with a cage supporting the main wedging - members. The wedging-angle for the auxiliary members may be more acute than that or the main members, and means may be provided for relieving overload on the auxiliary clutch. As applied to an isolating-clutch for facilitating speed-changing on motor vehicles, main rollers 6. Figs. 1 (Comp.) and 4 (Comp), coact with the cylindrical surface 3 of a drum 2 on the driving- shaft 1 and with a bi-directional cam-member 5 integral with the driven shaft 4. the auxiliary rollers 11 coacting with a drum 12 riveted to the main oage 7 and with a unidirectional cam-member 8 frictionally held by a spring 10 against the drum 2. The rollers 6 are carried into contact with the forward slopes 5a of cam 5 by the auxiliary clutch and with the reverse slopes 5b by spring plungers 14 on cage 7 gearing on stops 15 on the cam. Coned and stepped members 30 on the cage are adapted to coact with adjustable pegs 28 on a collar 21 slidable on shaft 4 and actuated by a fork 24. Fork 24 is rigid with an arm 31, Fig. 5, (Comp.), and a shouldered rod 33, jointed to an arm 34 pivoted at 39, slides through a trunnion 32 on arm 31 and carries a spring 37 bearing on a nut 35 and sleeve 36a contacting with shoulder 36. Arm 34 is coupled to the engine-clutch pedal (not shown) by an external arm 38a and link 38b, Fig. 1 (Comp.). A bell-crank trip lever 43, loose on pivot 39, coacts with a lug 45 on arm 34 by an adjustable stop 44 and with the cross-bar of aT-shaped piece 41 carried by arms 31. Axial travel of sleeve 21 is limited by contact of T.piece 41 with a hook 49 on a cam 47 pivoted on a pin 46, which carries also a lever 48 having a lug 53. Lug 53 is swung into the path of T-piece 41 by a spring 54 and removed by a cam 55 connected by linkage 57, 58, &c. to the handbrake lever (not shown). The parts 43, 47, 31 are biassed by springs 43a, 47a, 31a. A slidable rod 51, carrying the reverse-gear selector-fork (not shown), coacts with an arm 50 on cam 47. In changing gear, depression of the clutch pedal actuates arm 34 and compresses spring 37. Through stop 44 and trip 43, member 41 is released and arm 31 and sleeve 21 are shot forward. Pegs 28 then coact with coned members 30 to throw cage 7 and rollers 6 into neutral, so that the isol ating- clutch becomes unidirectional. Final depression of the engineclutch pedal tightens a brake-band (not shown), on a drum on the engine-clutch driven shaft, whereafter a gear can be freely engaged and the pedal released. During overrunning, pegs 28 are held behind the first step 30a of members 30, until, on accelerating, the auxiliary clutch turns cage 7, when spring 31a returns sleeve 21 and bi-directional coupling is restored without shock. Movement of the hand-brake lever beyond its normal "off" position displaces cam 55 and allows spring 54 to bring lug 53 into the path of member 41, whereby return of sleeve 21 is prevented and the device acts continuously as a freewheel. The first part of the movement to engage reverse gear actuates arm 50 and removes hook 49 from member 41, so allowing sleeve 21 to make its full travel and carry pegs 28 beyond the second step 30b of members 30, whereby cage 7 is freed and the device is bidirectional. To prevent cage 7 from being accidentally unlatched from sleeve 21 by jolting, the sleeve is loosely splined to shaft 4 and is pressed by spring plungers 23, whereby it can follow up inertial movements of the cage. The drum (not shown), on which tho clutch-stop band acts is similarly connected to its shaft, in order to relieve engaged gear wheels from strain and facilitate unmeshing thereof when the vehicle is stationary and braked and the clutch-stop in action. Specification 261,486 is referred to. The first Provisional Specification describes a form in which the auxiliary clutch rollers 15, Fig. 3 (26100/27), jam between the driving- drum 2 and laminated springs 17 secured in slots 16 in the main roller-clutch cage 6. The springs 17 may be replaced by rigid slopes if the rollers 15 are hollow or if the drum 2 is of reduced thickness in their plane. The adjustable pegs 9 on the slidable sleeve 5 coact with coned members 8 having a single step 20, Fig. 5 (26100/27), and a further coned part acting to facilitate engagement of reverse gear when the vehicle is at rest, as described in Specification 288,094. The sleeve 5 may be operated conjointly with the engine-clutch pedal or by an independent lever, and the spring plungers 13 urging the main rollers into reverse-drive position may be replaced by a second set of auxiliary rollers. The second Provisional Specification describes a further form in which the bidirectional driven cam-member 3, Fig. 1 (6131/28), is external to the cylindrical driving- member 2, in order to avoid delay in " take-up " after free-wheeling, due to spinning of the main rollers 7. The auxiliary-clutch cam-member 16 is spring-pressed against member 2, and the cage 6 carries double-stepped conical members 8, acting as set forth in the complete Specification, the device being operated as described in Specification 287,947 and 288,094. Massive rollers 24, Fig. 3 (6131/28), guided between stops 19, 26 on the cage, coact with convex pieces 25 on the cam-members 3, in order to compensate for the tendency of the rollers 7 to ride centrifugally to the middle of the concave cam-surfaces on the part 3. A hand-lever may be provided for holding the actuating-sleeve 5 in the free-wheel position. The third Provisional Specification describes the use of the hand-brake lever io control continuous free-wheeling in tha clutch arrangements described in Specifications 261,486 and 288,094.