Patent GB-888192-A (GB)
Title: An improved combined control device for the carburettor and clutch of a motor vehicle
IPC: F16C1/10
Filed: 1960-03-07
Abstract: 888,192. Clutch control; Bowden mechanism. SOC. D'ETUDES ET D'APPLICATIONS INDUSTRIELLES COMMERCIALES ET IMMOBILIERES INTER-TECHNIQUE. March 7, 1960 [March 6, 1959], No. 8038/60. Classes 80 (2) and 80 (3). In the feed circuit of the winding E of an electromagnetic clutch in a motor vehicle, two resistors, one, Rr, reducing current at idling speed to lessen the risk of clutch engagement and driving of the vehicle, and the other, Re, reducing current for economy during normal running, are successively short-circuited for starting, before throttle opening, and for high torque transmission, respectively, by means comprising a switch device 1 combined with a throttle-controlling Bowden mechanism 2, 7 interposed between the accelerator pedal PA and the carburetter throttle-regulator S. Depending on a change-over relay R 2  actuated by a centrifugal switch IC, the winding E is fed either by the usual dynamo D (by the usual, or, as shown, an auxiliary third brush b), or the usual battery B. A relay R 1  breaks the clutch energizing circuit when a manual switch P is closed and, for demagnetizing, feeds to the winding a reduced reverse current through a resistor r. C is a switch and A a lighting coil. The resistor Rr connected to contact studs 25, 26 is inserted in the common battery and dynamo feed circuit, whilst the resistor Re connected to contact studs 19, 20 is inserted in the battery feed circuit only. The switch device 1 comprises a fixed casing of insulating material comprising an intermediate plate 11 and two covers 12, 13, respectively pedal and carburetter side. The contact studs 25, 26 and 19, 20 are respectively fixed to the intermediate plate 11 and the cover 12 by conducting, spring blades 23, 17. A push-rod 29 housing the end of the Bowden sheath 7 slides freely through the cover 13 and passes through an axially guided conducting plate 31 which carries studs 32, 33 and is urged towards the end of the cover 13 by a spring 36 reacting on the intermediate plate 11. An axially-guided plate 40 carrying studs 41, 42 is carried by a cup 38 which is axially urged against an abutment 39 by a spring 37 reacting on the push-rod 29. The abutment 39 is fixed to the Bowden cable 2 which is connected at one end to the accelerator pedal PA by a spring connection 5 (Fig. 3, not shown) and at the other to the throttle regulator S. The sheath 7 is curvi-linearly arranged and fixed at the carburetter end. In operation, when the pedal PA is depressed the free end of the sheath 7 reacts via the pushrod 29 firstly to urge the plate 31 to contact the studs 25, 26 and short-circuit the resistor Rr and then to bend the blades 23 until the pushrod bears against the plate 11, all before the regulator S is turned. As pedal travel is increased the regulator S begins to turn and the plate 40 moves, urged by the spring 37, until it contacts the studs 19, 20 to short-circuit resistor Re, the blades 17 bending. Continuation of pedal depression turns the regulator S until the throttle is fully opened. The reverse sequence due to pedal release, which sequence provides firstly insertion of economy resistor Re in the circuit and then the idling speed resistor Rr when the pedal is completely released, differs from the pedal depression sequence in respect of the friction of the cable and sheath. The springs 36, 37 and blades 23 of the device 1 and the return-spring RC of the throttle regulator S are selected to ensure that whilst the throttle remains open the reaction of the sheath 7 on the push-rod 29 is greater than the opposing efforts of the springs 36, 37 and the resistor Rr is shortcircuited to avoid clutch slipping due to part declutching. Slight relative movement between the studs 32, 33 and 25, 26 and 41, 42 and 19, 20 due to blade bending frictionally cleans the contact surfaces. Clearances J (Fig. 2) and j (Fig. 4) are provided to allow for sheath expansion. Specification 809,490 is referred to.