Abstract: An apparatus for controlling a multi-speed, oil pressure operated type vehicle transmission connected to an engine through a torque converter wherein each drive train includes an oil pressure operated clutch and the low speed drive train also includes a one-way clutch engagement element, such as an oil pressure clutch or the like, interposed in each of said driving trains such that each driving train is established by oil supply to each said clutch. The apparatus includes a holding device for the highest speed drive train which is actuated when the brake operation is detected and the vehicle is stopped, which actuation provides a pressurized oil supply to the highest speed oil pressure operated clutch interposed in said high speed drive train to minimized the torque transmitted from the engine even though the pressurized oil is continuously supplied to the low speed oil pressure clutch interposed in said low speed driving train.

Abstract: A clutch operation control system for a fluid torque converter of a vehicular transmission in which the fluid torque converter is equipped with a clutch for mechanically connecting the input side and output side of said torque converter. The clutch has its clutch plate supplied at its one side with oil pressure in a control chamber to release the clutch and at its other side with the torque converter oil pressure in said fluid torque converter for operating the clutch by the differential pressure across the clutch plate. An oil line leading to the control chamber is connected at a vehicular speed equal to or higher than a predetermined level to an oil drain port by means of a control valve to operate the clutch with an engaging force of the torque converter pressure. The clutch plate has an orifice for providing communication between the two sides of said clutch plate.

Abstract: A control system for a hydraulic transmission for a vehicle powered by an internal combustion engine has a low speed clutch and a high speed clutch, both actuated hydraulically. An oil draining line is connected to a low speed clutch when a control valve assembly is in its high speed position. The control valve assembly has an orifice and a drain oil control valve arranged in parallel. The valve is moved toward closed position when there is an increase in the throttle valve opening of the engine driving the hydraulic transmission. The drain oil control valve includes a valve having an intermediate throttling position between open and closed positions. The drain oil control valve is moved to its open position when oil pressure fed to the high speed clutch increases to a predetermined pressure, which pressure varies in response to the opening of the engine throttle valve.

Abstract: An operation control system for a hydraulically operated clutch of a fluid torque converter wherein the clutch mechanically couples the input and output of the torque converter under certain conditions. Pressure chambers on either side of the clutch plate are pressurized to operate the clutch. An orifice through the clutch plate allows flow from one chamber to the other. A regulator valve is connected to both pressure chambers and is responsive thereto. The regulator valve is also responsive to external signals such as vehicle speed and throttle opening to regulate the pressure difference in the two chambers for operation of the clutch.

Abstract: A control apparatus for a vehicle transmission is provided which has at least two transmission trains, which includes a high speed transmission train and a low speed transmission train. The low speed transmission train includes a one-way clutch. Each of the transmission trains have a clutch therein. The control apparatus comprises a hydraulic circuit coupled to the clutch and a creep-preventer which is coupled to the hydraulic circuit for operating in response to the idling of the vehicle engine when the vehicle is stopped, and to make the one-way clutch inoperative to prevent transmission of power through the low speed transmission when the clutch of the high speed transmission is engaged, to thereby permit operation of the clutch of the low speed transmission train without the transmission of power therethrough.

Abstract: The present invention discloses a control apparatus for an oil pressure operated transmission in an automotive vehicle. The apparatus comprises a transmission with at least two stages of low speed and high speed forward driving trains and it is so arranged that, in an automatic shift range of a manual valve connected through first oil passage to an oil pressure source, low speed and high speed oil pressure clutches are selectively supplied with pressure oil through a shift valve in communication with the manual valve through a second oil passage. In a hold range of the manual valve, the valve is interposed between the low speed oil pressure clutch and the shift valve means for dividing the oil passage into third oil passage on its upstream side and fourth oil passage on its downstream side, having no communication between third and fourth passage and establishing a communication between fourth and first oil passage without through the shift valve means.

Abstract: In an automatic transmission apparatus for a vehicle of the type having a high speed clutch of oil pressure operated type interposed in a high speed power transmission system and a low speed clutch of oil pressure operated type interposed in a low speed power transmission system, the clutches being selectively connected through a shift valve to an oil pressure source, a safety apparatus comprising an automatic control valve coupled to the said low speed clutch to operate when the low speed clutch rotates above a predetermined speed to bring the low speed clutch into inoperative condition.

Abstract: A control apparatus for motorcars having an automatic transmission with a speed-change sensor and a shift valve therein, for controlling the operation of the latter, the apparatus comprising oil-pressure operated high-speed and low-speed clutches interposed in respective high-speed and low-speed systems of the transmission, the system being selectively connectable through the shift valve to a line pressure supply passage connected to an oil-pressure source, wherein the shift valve is operable by the oil pressure and has at one end an oil-pressure chamber connectable to the supply passage through an electromagnetic pilot valve that is responsive to the sensor. Preferably a manually operable valve is interposed between the supply passage and the oil-pressure source, for selectively operating the oil-pressure controlled shift valve in one of a plurality of operational modes of the transmission.

Abstract: Apparatus for preventing faulty operation in automatic transmissions of motorcars, the transmission having a speed-change sensor and a shift valve therein, for controlling the operation of the latter, the apparatus comprising oil-pressure operated high-speed and low-speed clutches interposed in respective high-speed and low-speed systems of the transmission, the system being selectively connectable through the shift valve to a main line pressure circuit connected to an oil-pressure source, wherein the shift valve is operable by the oil pressure and has at one end an oil-pressure chamber connectable to the main circuit through a pilot valve that can be opened by operation of the sensor.