Patent GB-466543-A (GB)
Title: Improvements in hydraulically operated friction clutches
IPC: F16D43/28
Filed: 1936-08-29
Abstract: 466,543. Friction clutches; variablespeed gearing. KEGRESSE, A. Aug. 29, 1936, No. 23708. Convention date, Sept. 2, 1935. [Class 80 (ii)] A variable-speed gear for motor vehicles includes a number of individual plate clutches arranged in the engine flywheel, the driven plates of the various clutches being splined on nested gear-carrying shafts and each being disposed between a pair of plates rotating with the flywheel, one of which pair is axially fixed while the other is axially movable under the control of a flexible diaphragm closing an annular chamber supplied with oil by an enginedriven pump through a spring-loaded valve. Manual means may be provided for modifying the oil pressure. The loading of the valve corresponding to a chamber associated with a lower-speed clutch is smaller than that of the valve corresponding to a chamber associated with a higher-speed clutch, so that as the oil pressure increases the various clutches corne successively into action to bring in the higher-speed gears, free-wheel clutches arranged in the lower-speed gears then overrunning. In the two-speed gear shown in Fig. 1, the low-speed clutch comprises a driven plate 7 splined on a shaft 8 and arranged between the end face 3 of the flywheel 2 and a plate 6 carried by a diaphragm 5 secured at its edges to a plate 4 secured to the flywheel, while the high-speed clutch comprises a driven plate 12 splined on a hollow shaft 13 and arranged between the plate 4 and a plate 11 carried by a diaphragm 9 secured at its edges to a plate 10 secured to the flywheel. Oil is supplied through a pipe 14 to passages 20 and 21 in the plate 10 leading respectively to the chamber between the diaphragm 5 and the plate 4, and the chamber between the diaphragm 9 and the plate 10 through spring-loaded ball valves 18, the loading of the balls controlling the passages 20 being less than that of the balls controlling the passages 21. Small peripheral openings leading from the chambers permit the centrifugal discharge of oil from the chambers. In the four-speed gear shown in Fig. 3, the movable driving plate, such as 42, of each clutch is splined in a flanged part of the associated fixed plate 26, so as to relieve its controlling diaphragm 35 from torque, and is urged against that diaphragm by a spring 45. The diaphragm 35 co-operates with another diaphragm 36, bearing against the fixed driving plate 25 of the adjacent lowerspeed clutch or, in the case of the lowestspeed clutch, against the end wall 23 of the flywheel, to form the annular pressure chamber. The inner edges of each pair of diaphragms are united by a ring 37, and the outer edges are spaced by a ring 38 and are clamped in the flywheel, together with the fixed plates, by bolts 39. The fixed plate of each clutch houses a valve 46, which is urged by a spring 49 so as to cut off communication between a passage 50 leading to the pressure chamber and a passage 48 leading from an annular space 34 supplied with oil by the pump, while at the same time putting the passage 50 into communication with a discharge passage 53, Fig. 7. When the oil pressure overcomes the spring 49, the passage 50 is cut off from the passage 53 and put into communication with the passage 48. Alternatively, all the valves 46 may be housed in one of the fixed plates.