Abstract: In a hydraulic control system of an automatic power transmission is provided a line pressure control device which is operative to supply the pressure regulator valve of the control system a fluid pressure equal to the throttle pressure when the throttle pressure is lower than a predetermined value and a fluid pressure maintained at the predetermined value when the throttle pressure is higher than such a value or under conditions in which the transmission mechanism is in a forward drive gear condition in which engine braking can be effected in a vehicle.

Abstract: In a hydraulic control system for an automatic power transmission system, an interlock preventive is provided by one of the two frictional units to be made operative to produce the first gear ratio in the manual forward drive range is forcibly rendered inoperative in the event a third frictional unit is accidentally brought into operative condition due to a failure occurring in the hydraulic control system in which shift valves contributive to the shifting between the first, second and third forward drive gear ratios are arranged in parallel with each other with respect to the fluid circuit through which the fluid pressure to be distributed by one of the shift valves to the third frictional unit is to be directed to the shift valves.

Abstract: An automotive automatic power transmission system having a torque converter contained in a converter housing and a planetary gear system powered by the torque converter. The planetary gear system is contained in a gear housing detachably secured to the converter housing. The planetary gear system has an output shaft carrying an output gear meshing with an idler gear which is in turn in meshed relationship with a driven gear of a final drive unit. The aforesaid gears are of the helical type and are rotatable about parallel axes, with a resulting axial thrust on the output shaft in a direction towards the planetary gear system during rotation of the output gear in the forward direction. The output shaft is journalled between first and second thrust bearings, with the first thrust bearing being carried on a hollow member detachably fixed to the converter housing and protruding axially therein to support the torque converter stator on a one-way clutch.

Abstract: In a hydraulic control system for an automatic power transmission for an automotive vehicle, a line pressure booster valve is provided to boost the line pressure to be developed by the pressure regulator valve of the control system when a downshift is to be made from the highest one of the gear ratios in the automatic forward drive range to the higher one of the gear ratios in a manual forward drive range of the transmission system.

Abstract: A hydraulic control system for an automatic power transmission for an automotive vehicle, comprising a pressure regulator valve for producing a line pressure, at least the shift valve predominant over shifts between predetermined gear ratios and operable to distribute the line pressure selectively to the frictional units, and a transmission throttle valve engaged by the accelerator pedal of the vehicle through a mechanical linkage and operative to supply the pressure regulator valve and the shift valve a throttle pressure variable with movement of the accelerator pedal in the absence of a failure in the mechanical linkage and to interrupt supply of the throttle pressure to the pressure regulator valve and the shift valve and pass the line pressure to the pressure regulator valve in response to a failure invited in the mechanical linkage.

Abstract: A lock-up torque converter includes a converter cover secured to a pump impeller and a clutch piston drivingly connected to a turbine runner. The clutch piston is engageable with the end wall of the converter cover and forms therewith a clutch chamber which is adapted to be pressurized or exhausted. A feed passageway and a discharge passageway communicate with the inside of the pump impeller and with the inside of the turbine runner, respectively, and cooperate with each other to feed a pressurized fluid into the pump impeller and to discharge the pressurized fluid from the turbine runner. A third passageway communicates with the clutch chamber and a lock-up control valve. The lock-up control valve selectively pressurizes and exhausts the clutch chamber.

Abstract: Simple passage structure of a lock-up torque converter is disclosed. A first spacer is mounted within an annular space between an output shaft and a stationary sleeve to divide the annular space into a first annular chamber communicating with the inside of a turbine runner and into a second annular chamber communicating with a clutch chamber. The first spacer is formed with a first cutout mating with a radially extending drain passage formed within a pump cover and a second cutout mating with a radially extending passage formed within the pump cover and communicating with the control valve. The first cutout is open to the first annular chamber so that communication between the first annular chamber and the radial drain passage of the pump cover is provided. The second cutout is open to the second annular chamber so that communication between the second annular chamber and the other radial passage of the pump cover is provided.

Abstract: A shift valve for use in a hydraulic control system of an automatic power transmission, having valve spools formed with a plurality of pressure acting areas which can be selected independently of each other for providing shift points for upshifting and downshifting under part-throttle and full throttle conditions of the engine.

Abstract: A lock-up control valve is operated into a position to effect a lock-up condition of a torque converter by a governor pressure fed by way of a shift valve when the vehicle operates at high speeds in high gear.

Abstract: A change-speed transmission comprises: an input member; an output member; a planetary gearing unit; a hydrokinetic unit having a pump connected to the input member for simultaneous rotation therewith and a turbine; and first, second and third clutches. The transmission has a condition in which all of the torque of the input member is transmitted to the output member through the hydrokinetic unit, a condition in which all of the torque of the input member is transmitted to the output member bypassing the hydrokinetic unit, and a condition in which a portion of the torque of the input member is transmitted to the output member bypassing the hydrokinetic unit and the remaining portion of the torque of the input member is transmitted to the output member through the hydrokinetic unit.

Abstract: A transmission throttle valve for use in a hydraulic control system of an automotive automatic power transmission, comprising a valve plunger movable with the accelerator pedal of an automotive vehicle, a valve spool arranged and movable in line with the valve plunger, a spring urging the valve spool and the valve plunger in opposite directions to each other for enabling the valve spool to produce a throttle pressure variable with the distance of movement of the valve plunger in the presence of a line pressure directed into the transmission throttle valve, and a plunger guide member arranged so that the throttle pressure developed in the valve is augmented to the level of the line pressure in the event a failure takes place in a mechanical linkage providing engagement between the valve plunger and the accelerator pedal of the vehicle.

Abstract: In an automatic power transmission having a transmission mechanism including fluid operated frictional units to be actuated to select automatic forward drive and reverse drive gear conditions and make a shift between the first, second and third gear ratios in the automatic forward drive range, a shock control arrangement is provided in the hydraulic control system for the transmission mechanism, comprising a pressure accumulator unit which takes up the fluid pressure to be applied to any of the frictional units during selection of the automatic forward drive range or reverse drive gear position or during upshifting between the aforesaid gear ratios in the automatic forward drive range, and a pressure reducing valve for eliminating or reducing the fluid pressure in one of the frictional units when a fluid pressure is being supplied to another frictional unit during upshifting between the second and third gear ratios in the automatic forward drive range.

Abstract: In an automatic power transmission having a transmission mechanism including fluid operated frictional units to be actuated to select automatic forward drive and reverse drive gear conditions and make a shift between the first and second gear ratios in the automatic forward drive range condition, a shock control arrangement is provided in the hydraulic control system for the transmission mechanism, comprising a pressure accumulator unit which takes up the fluid pressure to be applied to any of the frictional units during selection of the automatic forward drive range or reverse drive gear position or during upshifting between the first and second gear ratios in the automatic forward drive range, the level at which the pressure accumulator unit is to commence taking up of the fluid pressure for one of the frictional units being varied with engine load.

Abstract: A transmission throttle valve for use in a hydraulic control system of an automatic power transmission, comprising a valve spool contributing to the development of a throttle pressure, a valve plunger arranged in series with the valve spool and engaged by the accelerator pedal through a mechanical linkage for being movable toward and away from the valve spool as the accelerator pedal is moved toward and away from the released position thereof, a spring urging the valve spool and the valve plunger away from each other and a spring included in the mechanical linkage for urging the valve plunger to move in a direction opposite to the direction in which the valve plunger is to be moved when the accelerator pedal is depressed, wherein the valve plunger is formed with a pressure acting area for urging the valve plunger to move against the forces of the springs so that the vehicle driver is saved from an effort to overcome the force of the spring acting on the valve spool and plunger when in depressing the accelerat

Abstract: A hydraulic control system for a torque converter including a lockup clutch is disclosed in which a first or feed passageway communicates with a source of pressurized fluid and with a torque converter chamber, a second or discharge passageway communicates with the torque converter chamber and a third passageway communicates with a lock-up control or clutch chamber of the lockup clutch. A lock-up control valve communicates with the same source of pressurized fluid and with the third passageway. The first passageway is provided with a flow restrictor. With the provision of the flow restrictor, the disengagement of the lockup clutch will be assured upon pressurization of the third passageway.

Abstract: Front-drive automatic transmission includes an output gear positioned between a planetary gear system and a hydrokinetic torque converter. A differential is provided to deliver torque from the output gear to each of two axle shafts. A transmission case for the planetary gear system and a torque converter housing for the torque converter are connected to each other to define an interface which lies in a plane disposed outboard of the inboard face of the output gear with respect to the gear system. The transmission case is formed with a valve cover attachment surface which extends up to a location adjacent the plane.

Abstract: A lock-up control system in which the engagement of a lock-up mechanism of a torque converter is effected in delayed timing relation with the shifting operation in the associated automatic transmission.

Abstract: A drum member has a circular base portion and a cylindrical side portion which is formed with holes at positions facing a brake band wrapping the drum member. A cylindrical member is coaxially disposed within the drum member with its one longitudinal end entirely secured to the inside surface of the circular base portion of the drum member. The cylindrical member is formed with holes or openings and is formed with longitudinally extending spline portions to which clutch plates are splined. The other end of the cylindrical member is entirely in contact with the inner surface of the cylindrical side portion of the drum member so that an enclosed chamber is defined by the drum member and the cylindrical member.

Abstract: A transmission case of an automatic transmission is formed with a fluid passage fluidly connecting a fluid pressure pump to a hydraulic control valve body for controllably operating a planetary gear system disposed in the case. The fluid passage is located adjacent a closed end of the transmission case and connected to control valve body in order to reduce the overall length of the transmission case in its axial direction.

Abstract: A transmission throttle valve for use in a hydraulic control system of an automotive automatic power transmission, comprising a valve plunger movable with the accelerator pedal of an automotive vehicle and, a valve spool engaging the valve plunger through a spring urging the valve plunger and the valve spool to axially move in opposite directions relative to each other for producing a fluid pressure variable with the displacement of the accelerator pedal, wherein the valve spool is formed with an axial bore open at both ends and has the valve plunger slidably passed through the bore while the valve plunger is formed with a laterally enlarged axial portion forming a variable-volume space in which the fluid pressure developed by the transmission throttle valve is to be admitted to urge the valve plunger to axially move against the force of the spring so as to save the driver's effort for depressing the accelerator pedal.