Abstract: A regulator valve assembly adapted to be used in conjunction with a torque converter in a vehicular transmission having a pressurized hydraulic distribution system, a cooling system and a torque converter. The regulator valve assembly has a stepped valve chamber to receive a spool valve member for axial translation. The spool valve member defines first, second, third and fourth subchambers within the stepped valve chamber. Axial translation of the valve member effects selective communication between the subchambers. A first land on the spool valve member is interposed between the first and second subchambers. A second land is interposed between the second and third subchambers. A third land is interposed between the third and fourth subchambers, and a fourth land is exposed to the fourth subchamber. A first outlet communicates with the first subchamber. A first inlet and a second outlet communicate with the second subchamber. A second inlet and third outlet communicate with the third subchamber.

Abstract: An accumulator and relay valve is operable to isolate a fluid operated electric switch from the transient pressure pulses present at the output of a pulse-width-modulated pressure control valve. The accumulator and relay valve is further operable to control a minimum pressure level that is communicated from the pressure control valve to the switch.

Abstract: A hydraulic retarder and control composed of an accumulator, for rapid filling of the retarder; a pulse valve, for controlling fluid flow to and from the accumulator; a regulator valve, for limiting the inlet pressure to the retarder; and a pair of check valves, for preventing fluid flow from the retarder to a pressure source and from the retarder to the accumulator. The pulse valve is controllable to provide rapid filling of the retarder, while the regulator valve will direct fluid from a secondary source to the retarder and control the pressure at the retarder inlet. The accumulator is filled from the main pressure source, between retard requests, at a rate that does not disturb the main transmission pressure level. One of the check valves and the pulse valve prevent the fluid in the accumulator from returning to the system other than when a retard request is present.