Patent GB-331239-A (GB)
Title: Improvements in or relating to coupling devices
IPC: F16D45/00
Filed: 1929-03-26
Abstract: 331,239. Joseph, F. A. March 26, 1929. Clutches, friction and ratchet; facilitating changing speed.-In clutch mechanism, particularly an isolating-clutch disposed behind a motorvehicle gear-box, comprising disengagable caged wedging-members between the driving and driven members, an engageable and disengageable friction clutch, preferably of a quick-acting or " fierce type, is provided to synchronize the members prior to re-engagement, one friction clutch member being rigid with the cage. The wedging-members are held out of action by a locking-member adapted to be released by a control-member, rigid with one friction-clutch member, when the friction-clutch torque drops to a predetermined value. Springs are provided to overcome residual frictional torque and ensure release of the locking-member on synchronism. The bidirectional clutch, Fig. 1, comprises an external " cam" member 4 on the propellershaft 18, rollers 6, a cage 5, and an internal smooth drum 2 secured on the gear-box tail-shaft 1, as described in Specification 303,435. Spring- plungers 11, having limited outward travel, are carried by an extension 7 of the cage 5 and coact with pegs 12 on the part 4 to bring the rollers into, but not beyond, the " neutral " or non- driving position. Splined respectively to the extension 7 and member 2 are the double-cone clutch elements 8, 9, 10, pressed into engagement by springs 22 and disengaged by pins 28 and a collar 26 actuated by a fork 27. The cage 5 also carries a slotted control-ring 13 engageable by dogs 16 on a locking-collar 17, which is slidden forward on the shaft 18 by springs 23 and withdrawn by a fork 19. The external controls, Fig. 2, comprise a. three-armed lever 31, 33, 36, which is coupled by a link 34 to the engineclutch pedal 35 and, by an adjustable link 37 and lost-motion slot 40, to a pin 38 on an arm 39 secured to the fork 27. The fork 19 carries on an arm 29 an adjustable stop 30 coacting with the end of the arm 31, which has a " heel " 31<a>. On opening the engine clutch by the pedal 35 while the shaft 18 is tending to overrun the shaft 1, the plungers 11 move the rollers 6 into neutral and bring the slots 15 of the ring 13 into line' with the dogs 16, which are shot forward into engagement therewith as soon as the stop 30 is free of the arm 31, the shaft 1 being still driven through the cone clutch. Further depression of pedal 35 disengages also the cone clutch to isolate the gear-box for speed-changing. On release of pedal 35, the cone clutch first re-engages to speed up the shaft 1, but the friction between the parts 15, 16 due to torque prevents the heel 31<a> from lifting the arm 29 to withdraw the locking-collar 17, any play between the parts 15. 16 causing slight compression of the spring-plungers 11. The cage 13 is therefore not released until the shafts 1, 18 are synchronized. In a modification, Figs. 3 to 6 (not shown), the cone-member 9 is fixed, the member 10 being acted on directly by the fork 27 and a spring-pressed collar; the pegs 12 are pressed on both sides by pairs of spring- plungers 11, which are carried in a housing secured to the member 4; the slots 15 are replaced by dogs engageable between pairs of dogs 16 on the collar 17, the spring for which is connected to the external arm 29; and the controls for the fork 27 are modified to suit its reversed direction of motion. Extreme depression of the pedal 35 may engage a clutch-stop to slow down the gear-box parts. The Provisional Specification states that the invention is applicable also to a dog clutch or a unidirectional clutch combined with a dog clutch; that means, preferably controlled by the hand-brake, as shown in Fig. 8 of Specification 303,435, may be provided to retain the collar 26 in the disengaging-position to allow the roller clutch to function unidirectionally ; that an auxiliary unidirectional clutch may be provided between the cage 5 and drum 2, as shown in Specification 303,435, Fig. 1 (second Provisional Specification); and that the dogs 16 may latch into the slots 15.