Abstract: A shift valve arrangement for incorporation into a hydraulic control system of an automatic power transmission, comprising a shift valve including separate switching and control valve elements arranged and movable in series with each other, the control valve element havind different pressure acting areas to be acted upon by a fluid pressure when the control valve element is in upshift and downshift positions, respectively, under kickdown condition and a pressure acting area to provide an upshift pattern of the transmission for part-throttle conditions of the engine, and a downshift valve having pressure acting areas to provide a downshift pattern for the part-throttle conditions of the engine.

Abstract: In an automatic power transmission having a transmission mechanism including a fluid operated frictional unit to be actuated to make shifts between predetermined forward drive gear ratios or between the neutral and reverse drive gear positions, there is provided a hydraulic transmission control system having incorporated therein a shock control arrangement by means of which a fluid pressure lower than the fluid pressure to be supplied to the frictional unit during shifting between the neutral and reverse drive gear positions is supplied to the frictional unit during shifting between the predetermined forward drive gear ratios.

Abstract: A transmission includes a plurality of friction units to effect shifting between gear ratios, one of which includes driving and driven elements which may operate with a speed differential at the time of shifting between gear ratios. A first or line pressure is generated which is variable in a first pattern corresponding approximately to the pattern of torque output of the vehicle engine. This pressure is supplied to a friction unit other than the one friction unit to operate such other friction unit. A second pressure is generated which is variable in a second pattern corresponding approximately to a combination of the pattern of the engine torque output and the pattern of differential speed between the driving and driven elements of said one friction unit at the time of engagement of the elements. The second pressure is directed to said one friction unit to operate such one friction unit.

Abstract: In a hydraulic control system of an automatic power transmission for an automotive vehicle, the frictional units in the transmission mechanism are operated by a line pressure which is regulated to vary with torque output of the engine and which is reduced to be variable with energy output of the engine when one frictional unit is to be actuated to make an upshift between predetermined forward drive gear ratios or reduced to a substantially constant when another frictional unit is to be actuated to make a downshift between other predetermined forward drive gear ratios for thereby reducing or eliminating shocks which would otherwise be created during the upshift or downshift.

Abstract: In a hydraulic control system of an automatic power transmission for an automotive vehicle, a shift gear operable between a higher gear condition and a lower gear condition is designed to provide a satisfactory shift pattern to dictate the schedule for making an upshift from the gear ratios allocated to the shift valve and is arranged with a downshift which provides a satisfactory shift pattern to dictate the schedule for making a downshift between the particular gear ratios so that the respective shift patterns for the upshifting and downshifting schedules between the gear ratios can be selected independently of each other.

Abstract: In a hydraulic control system for an automatic power transmission, there is provided an upshift scheduling valve by means of which the release of a frictional unit contributive to the second forward drive gear ratio is retarded in relation to the rate at which a frictional unit contributive to the third forward drive gear ratio and further with the load on the engine so that the two frictional units are permitted to be concurrently operative for an adequate period of time preventing the engine from racing during shifting from the second gear ratio to the third gear ratio in the automatic forward drive range.

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: 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 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: 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 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 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 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: 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: 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 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.