GB654453A - Improvements in or relating to hydraulically operated clutches - Google Patents

Abstract

654,453. Friction clutches. CLEVELAND, F. J. (Windfields (1946), Ltd.). May 31, 1948, No. 14623. [Class 80(ii)] An aperture 30 in the piston 5, sealed when the clutch is engaged but open on initial clutch release to allow the passage of fluid therethrough and effect quick release characterizes a hydraulically operated clutch wherein the piston 5, located in a cylinder 2 having a fluid inlet 4, is operable first to co-operate with a pressure ring 9 to cause initial engagement of clutch elements 22, 24 and then to progressively compress springs 12 to apply progressively increasing pressure to, and to operatively engage the clutch elements. In the embodiment shown, the clutch plates 22 are splined in the casing 28 and the plates 24 to the gear carrier 3, in which the cylinder 2 is also formed, of the transmission device described in Specification 639,675. Compression springs 21, weaker than springs 12, load the pressure ring 9 to the disengaged position, and stop pins 14, screwed into the piston 5, provide a pre-set adjustment of the springs 12. Quick release of the clutch is further facilitated by a permanently open aperture 31 in the cylinder wall, and the speed of fluid flow is controlled by a valve 27. Rings 6, 7 seal the piston 5 in the cylinder 2. In a modification, the clutch plates are located between the piston 5 and pressure ring 9, to be pushed axially during the gradual build up of clutch pressure.