Abstract: A fluid filter system for use with a positive displacement pump in an automatic power transmission having a main filter located on the suction side of the power transmission pump and an auxiliary bypass filter located on the pressure side of the pump wherein provision is made for controlling the fluid flow through the auxiliary filter whereby bypass flow path through the auxiliary filter is decreased when the flow demand on the pump is increased, the auxiliary filter being adapted to filter small particle sizes and the main filter being adapted to filter and to retain larger particles.

Abstract: A control valve for a selectively engageable friction device has two flow rates for controlling piston movement during the application of the friction device. The valve includes a spring-loaded valve capsule slidably disposed in a stepped diameter bore between a feed passage and a control passage. When the fluid pressure in the feed passage exceeds the fluid pressure in the control passage by a predetermined amount, the capsule is moved in the bore against the spring so that, the outer cylindrical surface of the capsule and the largest portion of the bore cooperate to form an orifice which permits a high flow rate resulting in a rapid fill operation of the piston cylinder of the friction device. The pressure in the piston cylinder, sensed in the control passage, and the spring move the capsule into the next largest diameter portion of the bore to provide a reduced flow during the final pressurization of the piston cylinder of the friction device.

Abstract: A liquid level control for a transmission sump wherein excess fluid is stored in an external reservoir. The external reservoir is connected to a vacuum source, such as the engine manifold, above the liquid level in the external reservoir. The external reservoir is connected through a passage to the transmission sump. The passage is connected to the external reservoir at a position above the liquid level, such that the vacuum in the external reservoir can be imposed upon the passage and terminates in the transmission sump at the desired level. The vacuum is thus transmitted to the transmission sump to withdraw liquid when the level therein is above the desired level whereby the sump liquid level is determined at a substantially constant level dependent upon the position of the passage in the transmission sump. If the sump level is below the passage terminus, fluid enters the sump, from the external reservoir, through a fill passage connected at the bottom of the external reservoir.

Abstract: A drive arrangement for an engine driven vehicle in which the clutch engaging pressure is controlled in response to engine speed and vehicle speed during startup. The fluid output pressure from an engine driven control pump, which supplies fluid for clutch engagement and transmission control, is directed through a control valve and a control restriction. As engine speed is increased, the fluid pressure and clutch engagement force increase at a controlled rate, due to the increasing line pressure caused by the control restriction, to permit controlled starting of the vehicle. An output driven governor supplies pressure proportional to vehicle output speed to the control valve such that, at a predetermined vehicle output speed, the control valve is shifted to discontinue fluid communication between the engine driven pump and the control restriction at which instant the pump pressure is controlled by the transmission control regulator valve.