Patent GB-412184-A (GB)
Title: Improvements in clutch control mechanism for automobiles
IPC: B41F5/02
Filed: 1932-12-19
Abstract: 412,184. Operating clutches. BENDIX AVIATION CORPORATION, 105, West Adams Street, Chicago, U.S.A. Dec. 19, 1932, No. 35927. Convention date, July 14. [Class 80 (ii).] In an engine-suction servomotor for operating the clutch of a motor-vehicle wherein a bleed passage controls the speed of clutch engagement, an inertia-operated governor valve arranged in the bleed passage acts, in the event of excessive acceleration or deceleration of the vehicle during clutch engagement, to prevent or retard further movement of the clutch. As shown in Figs. 1 and 2, a valve 32 connected to the accelerator 46 acts to put the chamber 20 of the servomotor 12, the piston 14 of which is connected to the clutch linkage 10, into communication with the atmosphere, for clutch engagement, or with the engine intake manifold 22, for clutch disengagement, when the accelerator is depressed or released respectively. A cut-out valve 38 is adapted to be operated by Bowden mechanism 40 and a check valve 28 allows entry of air to the chamber 26. The clutch moves rapidly to the point of initial engagement due to the provision of a groove 56 on the piston rod 16, but thereafter the speed of engagement is dependent solely on the degree of depression of the accelerator 46, the valve 32, which serves also as a bleed valve, having a tapered groove controlling the bleed from the chamber 26 through a pipe 50. A casing 62 interposed in the pipe 50 has pivoted thereto a weight 70 formed with lugs 72, 74 which coact with a spring-loaded governor valve 78 within the casing. The valve 78 is normally open, but if the acceleration or deceleration of the vehicle during clutch engagement becomes excessive, for either direction of movement of the vehicle, the weight swings and causes the valve wholly or partially to close the pipe 50. The spring loading of the valve may be adjusted by a screw 86. As shown in Fig. 5, the governor valve 106 is controlled by a float 102 dipping into mercury 100, the level of which varies with the acceleration. Other forms of inertia-operated governor valves are described. The governor valve may have associated therewith an adjustable needle valve, and the accelerator-controlled bleed valve may be dispensed with. In the form shown in Fig. 8, wherein a single-ended servomotor 147 is employed, the bleed from the atmosphere into the servomotor is under the control of an inertia-operated governor valve 156 and of plungers 160 connected to the clutch 140. A rotary valve 162 operated by the gear lever is provided with ports 186 adapted to register selectively with ports 188 in a casing 158 according to the position of the gear lever, and the plungers have reduced extensions 190. Up to the point of initial engagement of the clutch there is a free passage of air through the selected port 188, resulting in a rapid clutch movement, but thereafter the extension 190 restricts the flow to retard the final movement, the extensions 190 being of different sizes so as to regulate the speed of final clutch engagement according to the setting of the gear lever.