Patent GB-288094-A (GB)
Title: Improvements in and relating to clutches, ratchets and the like
IPC: F16D41/08
Filed: 1926-11-18
Abstract: 288,094. Joseph, F. A. Nov. 18, 1926. Addition to 261,486. Divided on 287,947. Clutches, free-wheel; facilitating changing speed; gearing for stopping and starting machinery. - Relates to a coupling-device comprising two oppositely-acting unidirectional clutches, one of which may be thrown out of action, and a control-member adapted to prevent restoration of bidirectional coupling except when the driving and driven parts are synchronized, and consists in various improvements chiefly directed to the application of the device between the gear box and road-wheels of a motor-vehicle, in order to facilitate speed-changing. A cylindrical driving-drum d, Figs. 1 (24922/27) and 3 (24922/27), carried by the driven shaft a of the gear-box, drives two sets of clutch rollers in cages h<1>, h<2>, one set coacting with a polygonal reverse-drive c<1> fast on the driven shaft e, and the other set with a ratchet-toothed forward-drive member c<2>, which is loose on the shaft e but has dogs f<2> co-operating with dogs f<1> on the part c<1> to limit its free motion. The forward rollers (not shown) are pressed into action by spring-plungers in the part c<2> and the reverse rollers i<1> by plungers j<1> in the cage h<1>, which carries pegs p coacting with slopes o on rods l, Fig. 1b (24922/27), carried by a collar k, so that the cage h' is displaced against a spring 22 to uncouple the reverse clutch when collar k is advanced, and, when shaft e overruns, the loose member c<2> which constitutes the above-mentioned " control-member," makes an angular movement to bring latches q on the dogs f<2> into notches r, thereby normally preventing withdrawal of collar k until the drum d overtakes the shaft e. The fork m operating the collar k is rocked by an arm n, Fig. 4 (24922/27), having a pin 14 held by a detent 13. Depression of a pedal P compresses a spring y and ultimately, by a lug 16 on a bellcrank lever 11, trips the detent 13 and allows spring y to shoot collar k forward against springs w. The lever 11 then tightens a brakeband 10, Fig. 1 (24922/27), on the drum d. A rod z connected to the gear-lever 17 prevents movement of the arm n when the reverse-gear is in action, and a lever x is provided for actuating a collar s, Fig. 1 (24922/27), carrying pointed rods u coacting with inclined recesses v in control-member c<2> to release latches q before synchronization, in order to allow the engine to be used as a brake or the car to be reversed after being stationary. A plate 21, secured to the cage h<1>, carries adjustable stops 20, Fig. 3 (24922/27), abutting on the rear of latches q, to prevent jamming due to simultaneous wedging of the two sets of rollers. In a modification, the brake-band 10 is anchored to a tension spring, so that, on tightening it, the drum d and part c<2> are turned forward sufficiently to unlatch the rods l when the car is stationary, so preparing for reverse drive. In a modification, the driving-drum 2, Fig. 1 (24923/27), on the gear-box shaft 1 coacts with forward and reverse rollers 10, 11, which are urged by spring-plungers 64 in the cages 8, 9 and co-operate respectively with polygonal driven members 5, 6. The member 6 and a toothed wheel 7 are rigidly splined to the driven shaft 4, while the " control-member " 5 has play on the splines, as shown in Fig. 5 (24923/27). Advance of rods 16, carried by a collar 18, causes slopes 19 to coact with adjustable pegs 20, Fig. 1" (24923/27), on cage 9 to uncouple the reverse clutch. When shaft 4 overruns, the drag of the drum 2 on flat springs 30 on cage 8 acts through adjustable stops 28, 29 to displace member 5 and bring latches 22 into notches 21, these parts being undercut to prevent accidental unlatching due to sudden deceleration. Depression of the engine-clutch pedal 59, Fig. 6 (24923/27) rotates a shaft 65 carrying a bell-crank lever 49, Fig. 7 (24923/27), so compressing a spring 53 acting on a trunnion 47 carried by an arm 46, and ultimately trips a bell-crank detent 54 to release the trunnion and arm 46. The collar 18 is then shot forward by a fork 31 on the shaft 32 of the arm 46. Further depression of the pedal applies a brake-band 50 and main-clutch stop (not shown). Further return of pedal 59 after release of the brakes is prevented, while the rods 16 are latched, by engagement of an extension 63 of bell-crank lever 49 with a ledge 62 on a link 56, but, due to slotted engagement of this link with the trunnion 47, the main-clutch spring-pressure is applied through arm 57, shaft 39, and fork 38, Fig. 1 (24923/27), to an auxiliary cone clutch 36, 37, which brings in a train of gears 7, 34, 33, 35, effecting a speed-up of drum 2 and permitting complete return of all the parts. Spring-plungers (not shown) on cage 9 act on stops 27 on wheel 7 to restore activity of the reverse clutch. Adjustable stops 24 on a plate 23 secured to cage 9 coact with flats on member 5 or stops on cage 8 to prevent jamming, as before. A cam 70, Fig. 7 (24923/27), loose on shaft 39, is turned by linkage 71, 72, Fig. 6 (24923/27), when reverse gear is engaged, to act on a button 73 and move arm 46 to the '' bidirectional " position and hold it. If, due to forward motion of the car, the rods 16 are latched, reverse gear cannot be engaged. Unlatching is effected when the car is stationary by slightly engaging the engine clutch as the slidable gear-wheel 66 meshes with the first-speed pinion 67 before passing to the reverse idler 69. Synchronizing-clutch 36, 37 may be held out of action by an arm 74 and slotted link 75 operated by the hand-brake lever when displaced beyond the normal " off " position. In another form, the cage 9, Fig. 10 (Comp), of the reverse clutch is provided with adjustable stops 24 abutting on projections 25 on the loose forward-clutch driven member to prevent jamming; with spring plunges 26 abutting on portions 27 of the driven shaft; and with adjustable pegs 20 coacting with slopes 19 in the slidable control-rods 16. The forward cage 8, Fig. 12, (Comp) in which the clutch rollers (not shown) are somewhat loose, carries the dragsprings 30 and has adjustable stops 28 bearing against notches 29 in a flange 91 on the loose control-member 5, which is urged to its latching- position by laminated springs 82. The fork operating the sliding collar 18, Fig. 8c (Comp.), carrying the rods 16, is actuated by an arm 46, Fig. 13, (Comp), provided with a trunnion 47 located between collars 79, 52, which are pressed by initially-stressed springs 77, 53 and bear on shoulders on a rod 48 connected to bellcrank lever 49. Depression of the main-clutch pedal (not shown) further compresses spring 53, until adjustable stop 96 trips the detent 54 and releases the trunnion 47. - The collar 18 is then retracted to the extreme position shown in Fig. 8c (Comp.), and the reverse clutch uncoupled, while a brake 50 is applied to the driving-drum 2 through a weak spring 95 and a further band brake (not shown) is applied to the driving end of the gear-box through a powerful spring, these brakes being adjustable as to strength and timing. Further release of the clutch pedal after taking off the brakes merely compresses spring 77, as further return of the arm 46 is prevented by engagement of the ledges 22 on control-member 5 with notches 21 in the rods 16 until the engine is sufficiently accelerated. A short, stiff spring 78 may be provided to oppose full engagement of the engine clutch until all backlash has been taken up. To engage reverse gear when the car is stationary, the clutch pedal is fully depressed, the slopes 89, 90 acting to throw control-member 5 out of action, and the cam 70 is rotated by moving the gear-lever to reverse, this cam acting on a pin 73 to restore and hold the arm 46. Should, however, the car be in forward motion, ledges 22 will again lock rods 16 and so prevent full and effective movement of the gear-lever. Supplementary notches 22a allow motion of the member 5 when strain on the reverse clutch is communicated thereto by the stops 24, 25. The driven shaft may be directly gear-driven in reverse, without passing torque through the unidirectional clutches. A lever-actuated catch may be provided for preventing return of arm 46 when the car is to "freewheel ' for a length of time, the spring 78 being then omitted. The second Provisional Specification describes also a modification of the arrangement shown in Fig. 7 filed therewith, wherein the auxiliaryclutch control is omitted, the arrangement being substantially an inversion of that shown in Fig. 13 of the complete Specification; it also describes a form in which the rods 16 are moved outwards to uncouple the reverse clutch. The fourth Provisional Specification describes the use of a resilient liner between the clutch rollers and driving-drum.