Patent GB-392267-A (GB)
Title: Improvements in or relating to the drive of self-propelled vehicles
IPC: B60K23/02
Filed: 1931-12-24
Abstract: 392,267. Controlling motor-vehicle clutches. RENAULT, L., 8, Avenue Emile Zola, Billancourt, Seine, France. Dec. 24, 1931, No. 35712. Convention date, Feb. 14. [Class 79 (v).] The clutch is disengaged by means of a servomotor controlled by the accelerator pedal, the servomotor being energized to disengage the clutch when the pedal is released, and means are provided responsive to the difference in speed between the two clutch members adapted to keep the servomotor energized until the speeds of the clutch members are substantially equal. The servomotor may comprise a vacuum cylinder, an electric motor, a solenoid, or a shaft driven by the vehicle engine, and may be put out of action if desired, the vehicle being then controlled by the usual separate clutch and accelerator pedals. In the construction shown in Figs. 1, 3, 5, and 6 the accelerator pedal 1, when in the released position shown, allows a slidable contact piece 7 to bridge two contacts 11, 12 and complete the circuit of an electric motor 33 which disengages the clutch by means of worm gear 35, a slipping clutch 38 and an arm 41 on a shaft 37. When the clutch is disengaged the motor 33 continues to rotate, slipping taking place at 38. The arm 41 is connected to the shaft 37 by a spring-controlled device 39 which allows the arm to be operated by the usual clutch pedal without affecting the servomotor gear. The driving and driven members of the clutch each drive one of the sun pinions of a differential gear having a planet carrier 18 engaged by a friction ring 20 which can have a rotary movement limited by stops 22, 22<1>. Thus, when the clutch members rotate at the same speed the differential planet carrier is stationary and the ring 20 is held in a central position by springs 23, but when the clutch members rotate at different speeds the ring is rotated in one direction or the other until it bears against one of the stops ; this movement rocks -a lever 25 and a member 28 thereon completes an alternative circuit for the motor 33 through a contact 27 or 27<1>. When the accelerator pedal 1 is depressed the contact-piece 7 leaves the contacts 11, 12, but if the clutch members are rotating at different speeds, the circuit of the motor 33 will be completed through one of the contacts 27, 27<1>, so that the clutch will still be held disengaged. The accelerator is now manipulated so as to control the engine speed in such a manner that the clutch members will rotate at the same speed ; when this is the case the lever 25 breaks the motor circuit at 27'or 271 and the clutch is engaged. Instead of the differential gear arrangement, two centrifugal governors, each driven by one of the clutch members, may control a single sliding sleeve which acts on the lever 25 in the same manner as the differential gear. In the construction shown in Fig. 7, the clutch is disengaged by means of a solenoid 43 having a core 44 connected by a link 46 to the operating arm 47 of the clutch. When the parts are in the position shown the clutch is disengaged and the core is held in that position by a sliding bolt 49 which is urged into the retaining position by a spring 50. The movement of the bolt 49 simultaneously rocks a lever 51 and breaks the solenoid circuit at 54 to avoid waste of electricity while the clutch is held disengaged. One arm 55 of the lever 51 is connected, by means not shown, to the lever 25 of the differential speed device, so that when the accelerator pedal is depressed, and on the clutch members being brought to the same speed, the lever 51 is rocked by the lever 25 and retracts the bolt 49 to allow the clutch to disengage. This movement of the lever 51 simultaneously closes the contact 54 so that on the next release of the pedal 1 the solenoid circuit is completed through the contacts 11, 12 and disengages the clutch. A similar arrangement for preventing waste of electricity by means of a sliding bolt 49 may be provided with the electric motor shown in Fig. 5. In the construction shown in Figs. 8 and 9 the clutch is disengaged by a piston 67 connected to the clutch pedal lever 66 and working in a vacuum cylinder 68 connected through a valve-box 56 to a pipe 57 leading to the induction pipe of the engine (not shown). When the accelerator pedal 71 is depressed it first, through a spring 75 and lever 70, pushes in a valve 58 which puts the cylinder 68 in communication with the atmosphere through ports 61, 60, so that the clutch is engaged ; further movement of the pedal compresses the spring 75 and opens the engine throttle (not shown). When the accelerator pedal is released the valve 58 moves outwards and puts the cylinder 68 in communication with the induction pipe 57 through a port 62, so that the clutch is disengaged. In order to prevent engagement of the clutch unless the clutch members are synchronized an auxiliary valve 64 having ports 65 is operated by an arm 63 connected to a differential speed device such as that shown in Fig. 3 ; if the clutch parts are not moving at the same speed this valve is open and the clutch is held disengaged by the piston 67, but when the speeds synchronize the valve is closed and the clutch is engaged. In a wholly mechanical construction, Figs. 11 and 12 (not shown) the clutch is disengaged by means of an engine-driven shaft connected through an auxiliary clutch and slipping devices to the clutch operating lever, the auxiliary clutch being controlled by the accelerator pedal. When the clutch is disengaged it is held out of engagement by a sliding bolt similar to that shown in Fig. 7, this bolt being retracted, when the clutch parts synchronize, by a differential speed device.