Abstract: A hydraulic control for an automatically shifted power transmission has an electronically controlled governor pressure source which provides a speed and throttle sensitive pressure for controlling the shift points and trim boost in the transmission control. An inhibitor circuit is activated in the event of a discontinuance of the electrical control, resulting in maximum governor pressure, to permit selected vehicle operation in one forward ratio and a reverse ratio. Each ratio interchange is controlled by a respective shift valve and clutch control valve. Each clutch control valve has an integral trim control which is effective to control the pressure rise in the on-coming clutch without bypassing fluid to an exhaust. Also during a ratio interchange, an off-going clutch is controlled at a reduced pressure during a portion of the ratio interchange.

Abstract: A hydraulic control for an automatically shifted power transmission has an electronically controlled governor pressure source which provides a speed and throttle sensitive pressure for controlling the shift points and trim boost in the transmission control. An inhibitor circuit is activated in the event of a discontinuance of the electrical control, resulting in maximum governor pressure, to permit selected vehicle operation in one forward ratio and a reverse ratio. Each ratio interchange is controlled by a respective shift valve and clutch control valve. Each clutch control valve has an integral trim control which is effective to control the pressure rise in the on-coming clutch without bypassing fluid to an exhaust. Also during a ratio interchange, an off-going clutch is controlled at a reduced pressure during a portion of the ratio interchange.

Abstract: A piston and seal assembly that has a rigid core with an elastomeric seal bonded thereto. The core has an annular outer cylindrical edge, a forwardly facing surface and a rearwardly facing surface. The elastomeric member is bonded to the core so as to encase the annular cylindrical edge. The elastomeric member extends outboard of the rearwardly facing surface of the core to provide a sealing lip. An annular concave surface merges with an annular convex surface located axially rearwardly of the rearward facing surface on the core. A radially outwardly directed surface on the lip portion merges tangentially with the convex surface.

Abstract: A neutral-reverse shift control actuator is provided in a countershaft transmission. The actuator is operatively connected through a resilient detent mechanism to a forward shift control mechanism. During a neutral-reverse shift maneuver, the drive connection partially manipulates the forward synchronizer, such that synchronization between the input and output shaft is achieved during a reverse shift maneuver. During a five-six or six-five shift, a detent structure is available to reduce the 3-4 neutral force of the centering spring in the shift control mechanism.

Abstract: An automatic transmission drive ratio control for operating a five speed automatic transmission is provided. The control is particularly adapted for use with a twin countershaft automatic transmission that requires only one torque transfer device for each drive ratio. A system of valves is employed to direct the flow of pressurized fluid necessary for the on-going actuation of each drive ratio and the simultaneous off-going actuation of the previously actuated drive ratio. The flow control for actuating and deactuating the torque control devices is directly effected by a two-position spool valve operating in concert with a rotary valve, pressurized hydraulic fluid used to position the spool valve and the rotary valve is primarily provided by three on/off solenoid shift control valves.

Abstract: A hydraulic control for an automatically shifted power transmission has an electronically controlled governor pressure source which provides a speed and throttle sensitive pressure for controlling the shift points and trim boost in the transmission control. An inhibitor circuit is activated in the event of a discontinuance of the electrical control, resulting in maximum governor pressure, to permit selected vehicle operation in one forward ratio and a reverse ratio. Each ratio interchange is controlled by a respective shift valve and clutch control valve. Each clutch control valve has an integral trim control which is effective to control the pressure rise in the on-coming clutch without bypassing fluid to an exhaust. Also during a ratio interchange, an off-going clutch is controlled at a reduced pressure during a portion of the ratio interchange.

Abstract: The present invention is directed to a retarder control system for protection against transmission overspeed. The system operates in conjunction with a rotatable input member and an output member that is rotatable relative to the input member. A torque transfer device is operatively connected between the relatively rotatable input and output members. Specifically, a piston assembly is operated by an input control chamber that selectively receives pressurized hydraulic fluid which effects translation of the piston assembly to actuate the torque transfer device and thereby effect a driving connection between the relatively rotatable input and output members. The present system is adapted to control a hydrodynamic retarder assembly having a work cavity to receive hydraulic fluid. The retarder input valve assembly is supported from one of the relatively rotatable members selectively to deliver pressurized hydraulic fluid from the input control chamber to the retarder cavity.

Abstract: A power transmission has three axes on which rotatably supported gears and selectively operable clutches are disposed to provide five forward speed ratios. The two highest speed ratios (fourth and fifth) have identical input clutch and gear units. The fourth ratio, the torque transmission path, includes a transfer gear ratio and utilizes the second speed ratio gears to develop a speed ratio different from the fifth speed ratio.

Abstract: An electro-mechanical hybrid powertrain uses the electric motor during engine starting. A planetary gear arrangement is disposed in torque transmitting relation between the prime mover, the electric motor and the transmission output. A pair of brake members, which are self-engaging, are provided to establish reaction members in the planetary gear arrangement during engine starting. A fluid-operated piston selectively enforces disengagement of the brakes after the engine has started.

Abstract: A power transmission has a plurality of parallel axes on each of which is disposed a shaft supporting a pair of selectively operable friction torque transmitting devices and gear members. One of the parallel axes supports an input shaft, which is drivingly connected to two of the other shafts through one-way devices and a chain drive. A transfer shaft is disposed in parallel with the other axes to transmit drive forces from the interconnected shafts to an output shaft. The transfer shaft has a gear member meshing with the gear members on the input driven shafts, which is effective to transmit the drive to the output shaft, which in turn is connected to a conventional output assembly such as a differential.

Abstract: A reaction carrier assembly that provides zero relative planetary gear support-pin deflection in order to prolong the useful life of the planetary gear set within which the reaction carrier assembly is incorporated. The improved carrier assembly includes a spider and a base portion, such that when a torsional load is applied to the assembly, at least those parts from which the planet gear support pin is supported will deflect equally, thereby effecting zero relative pin deflection. The base portion has an annular flange with a plurality of circumferentially spaced teeth extending radially outwardly selectively to receive the reactive force. The flange also has annularly spaced first ears that extend radially inwardly and are provided with a receiving bore. The first ears alternate with leg-engaging faces that are disposed radially outwardly with respect to the first ears.

Abstract: An engine direction reversing gear arrangement has a drive gear on the engine centerline and a driven gear, meshing with the drive gear, on the an idler shaft. The transmission input is an angle gear such that a V-drive is provided between the engine and the vehicle output drive members. The direction reversing is accomplished with two gear meshes, the gear pair on the engine and transmission centerline and the angle input drive to the transmission.

Abstract: A pair of selectively operable torque transmitting devices, such as a clutch and brake, are provided to control the torque and speed ratio in a planetary gear set. One device, a clutch, is spring engaged, to provide direct drive in the planetary set, and fluid released by a selectively operable piston assembly. The other device, a brake, is pressure engaged by a selectively operable piston assembly to establish a drive ratio in the planetary set. A torque responsive mechanism is incorporated in the piston assembly to control the overlap between the clutch/brake exchange during a ratio interchange.

Abstract: A retarder control embodying the concepts of the present invention utilizes a spool valve having a spool valve member axially translatable between an on- and an off-position. A spring is employed to bias the spool valve member toward its off-position. A torque converter, a cooler and a retarder each have an input and an output that are ported through the spool valve. The retarder is selectively ported to a hydraulic return through the spool valve, and a modulating solenoid may be employed to feed pressurized hydraulic fluid against the spool valve member not only to move the spool valve member against the spring toward its on-position but also to regulate the axial translation of the spool valve member in order to control the pressure at the retarder discharge that is also ported through the spool valve. A cooler communicates directly with the converter when the spool valve member is in its off-position.

Abstract: A transmission has a manual selector valve which is reciprocally and rotatably mounted in a valve body and operable in a conventional "H" shift pattern to permit selection of first through fifth forward drive conditions, a neutral condition and a reverse drive condition in a planetary transmission. The selector valve has a line pressure chamber formed thereon that remains in fluid communication with a line feed passage in the valve body throughout the "H" pattern. This line pressure chamber is selectively alignable with respective clutch and brake apply passages formed in the valve body to control the flow of pressurized oil for the engagement of respective clutches and brakes. A plurality of exhaust chambers formed therein are also selectively connectible with the clutch and brake apply passages to control disengagement of the respective clutches and brakes not required for the selected drive condition.

Abstract: A single wrap brake band mechanism has a hydraulic piston apply structure and an anchor support structure which permit one end of the band to be the apply end and the other end of the band to be the anchor end and vice versa.

Abstract: A neutral-reverse shift control actuator is provided in a countershaft transmission. The actuator is comprised of a spring member and utilizes one of the forward ratio synchronizers. During a neutral-reverse shift maneuver, the spring member is effective to enforce engagement of the cone clutch of the forward synchronizer which, through a connection with a stationary output shaft, will retard rotation of the input shaft.

Abstract: A hydraulic control for a power transmission has an electronically operated mode during normal operation. In the event of loss of electrical power, a power interrupt valve is operable in conjunction with a manual valve to direct fluid pressure to the proper devices as selected by the operator, thereby permitting operation to continue in a manual override mode.

Abstract: A dual-drive electric transmission operated by a generator that may be powered, for example, by an internal combustion engine. Left and right motor networks have a rotation rotor, the motor networks being powered by the generator. A speed control assembly independently effects rotation of the rotor in each motor network at selected speeds. Left and right combining differentials are associated with the respective left and right motor networks. Each combining differential has a sun gear, a ring gear and a plurality of planetary gears meshing with the sun and ring gears. An output carrier supports the planetary gears. The sun gear in each left and right combining differential is driven by the respective left and right motor network. The ring gears are conjoined for unitary rotation in order to provide a mechanical regenerative path between the combining differentials.

Abstract: A hydraulic control for operating a five speed automatic transmission with two modulating solenoid valves. The control is particularly adapted for use with a twin countershaft automatic transmission that requires only one torque transfer device for each drive ratio. A system of valves is employed to direct the flow of the pressurized fluid necessary for the on-going actuation of each drive ratio and the simultaneously off-going deactuation of the previously actuated drive ratio. The flow control for actuating and deactuating the torque control devices is directly effected by two, two-position spool valves which operate in concert with two, two-position shuttle valves. Pressurized hydraulic fluid used to position the two-position spool valves and the two-position shuttle valves is primarily provided by two on/off solenoid control valves, but a third on/off inhibitor solenoid valve may also be employed.