GB868229A - Improvements in and relating to automatically actuated clutches - Google Patents

Abstract

868,229. Clutch control. FICHTEL & SACHS A.G. Dec. 19, 1958 [Feb. 6, 1958], No. 41090/58. Class 80 (2). In a motor vehicle clutch control wherein the resistors of an electromagnetically operated clutch are actuated or, as shown, a spring- engaged clutch is disengaged during gear shift, by a servomotor actuated by pressure or depression, equalization of pressure difference in the servomotor, and hence the rate of engagement, is effected in dependence on depression in the choke of the usual engine carburetter 9 which depression is substantially proportional to engine power, to prevent excessive slip or premature engagement. Manifold depression, vehicle acceleration, engine speed and throttle setting may also assist. As shown, a servomotor 1 controlling a clutch lever 2 is evacuated to declutch by inlet manifold depression through pipes 7, 4 when an electromagnetic valve 12 in a block 5 is actuated by movement of a gear shift lever 6, and is vented for engagement, when the lever 6 is released, through pipes 7, 15 and a valve 14 which opens for initial pressure balance against an adjustable spring 16, the usual bleed hole 18 providing slow residual balance. To control the rate of residual balance and thereby the rate of final clutch engagement the valve 14 is also opened, through a stem 20, against the spring 16, in response to depression in the choke of the carburetter 9 which acts on a diaphragm 19 through a pipe 8 communicating with a bore 10 positioned in the choke as shown in Fig. 2. The pipe 8 may be restricted at 23 to retard the operation. A sealing diaphragm 21 guides the stem 20. In Fig. 3(a), not shown, the stem 20 comprises a spring along part of its length above the diaphragm 21 which tends to overcome the spring 16 and is axially compressed in response to inlet manifold depression acting on a further diaphragm motor. This combination ensures engagement which is not too gradual at low speeds when, at sudden wide throttle opening, both choke and inlet manifold depressions are low, and is not too quick at high speeds when, at sudden throttle opening, both depressions are high. In Fig. 4, not shown, a pivoted inertia mass, subject to vehicle acceleration, acts on the diaphragm which is loaded by choke depression. Choke depression may also be used in conjunction with known throttle valve or speed governor connected, inlet manifold depression and vehicle acceleration devices.