GB321637A - Improvements in or relating to friction clutches for the transmission of power - Google Patents

Abstract

321,637. Gillett, E. H. J. C. Aug. 3, 1928. Controlling different functions by same lever; guarding against wrong movements and the like; relay or power apparatus.-Comprises a transmission system in which a clutch is operatively connected to the engine accelerator pedal or other speed-controlling member and to a servomechanism deriving energy from the engine in such a manner that movement of the pedal to accelerate the engine engages the clutch lightly which thereupon brings the servo-mechanism into .action to effect and maintain tight engagement of the said clutch until the driven shaft at any time overruns the driving shaft, whereupon the .clutch is automatically disengaged. The invention is shown applied to a clutch mounted at the rear of the change-speed gear. A clutch disc 2 is slidably-keyed on the driving shaft 1 and is adapted to be engaged by friction annuli 5, 6 carried by a casing 4 freely mounted on the driven shaft 17. The clutch is normally disengaged by springs 10 and is engaged by means of .a sliding plate 12 which is freely mounted on the driven shaft and is operated by the accelerator pedal 28 through a cam 25, arm 24, a sliding collar 21 and pins 18. When the pedal is depressed, the clutch is lightly engaged so that the disc 2 drives the casing 4 and plate 12. Inclined dog teeth 14 on the plate 12 then engage and drive similar teeth 15 on a collar 16 fixed to the shaft 17, so that (1) the drive is transmitted through the dogs to the shaft 17 and (2) the resistance of the shaft 17 exerts a wedging action on the inclined teeth and slides the plate 12 to effect tighter engagement of the clutch until the drive is fully taken up. When the accelerator pedal is released, the plate 12 is brought back to its original position by springs 29 so that the clutch is disengaged. A dash-pot 31 connected to the arm 24 comes into action after the clutch is first engaged and ensures smooth engagement. The dogs 14, 15 are inclined on both faces so that the clutch acts similarly for both directions of rotation. In order to prevent engagement of the clutch in the reverse direction except when the driven shaft is stationary, a pawl (not shown) is pivoted to the plate 12 and is adapted to engage a, notch in the collar 16. Normally, the pawl is held out of action by means of a spring but when the plate 12 rotates at more than a very low speed, a weighted end of the pawl moves under centrifugal force and causes tue pawl to engage the collar 16, so that the inclined dogs 14, 15 are prevented from coming into contact and the drive is not transmitted. According to the Provisional Specification, the brake lever or pedal may be connected to the clutch so that when the brake is applied, the clutch is disengaged. Specification 310,783, [Class 80 (ii), Gearing, Variable-speed &c.], is referred to in the Provisional Specification.