Abstract: A hydraulically operated friction clutch wherein a spring-urged piston is provided to effect engagement of the friction elements, received in a casing mounted on the driving shaft for axial reciprocation relative to this casing and defining with this casing two coaxially arranged variable volume chambers communicating with each other, adapted to receive liquid under pressure the first one of said chambers is in permanent communication with a pressure liquid supply passage, while the other chamber is communicable via a valve means with a drain passage and the pressure liquid supply passage. The pressure liquid supply passage and the drain passage have a portion common to both of them, wherein the valve means is mounted so that the movable valve member thereof can reciprocate in a direction substantially perpendicular to the axis of rotation of the clutch, by which reciprocation it selectively connects the other chamber with the drain passage and with the pressure liquid supply passage.

Abstract: The end-type seal according to the present invention, including a gland mounted in a casing, against which gland a sealing ring made from a graphite-containing material and having face surfaces is urged. Annular ridges are provided on the end surface of the sealing ring facing the gland. These ridges tightly bear against the gland surface until they are worn out to allow the sealing ring to come into close mating contact with the gland.

Abstract: A vehicle drive transmission comprising an air released main clutch connected between a torque convertor and multiple ratio gear transmisson. A lock up clutch for the convertor turbine and impeller is engaged by hydraulic pressure when an engine drive governor reaches a predetermined speed and opens a governor valve. The main clutch is released by a motor controlled by a solenoid valve which selectively connects the motor to a source of air pressure or to atmosphere via a restricted orifice and a normally closed air inlet valve. The restriction retards the engagement of the main clutch when the engine is rotating below the predetermined speed, and above said predetermined speed, the governor valve opens to engage the lock-up clutch and to open the air inlet valve whereby the main clutch may be engaged at a faster rate.