The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 06, 1977
Filed:
Sep. 18, 1975
Masanao Hashimoto, Toyota, JA;
Takaaki Suzuki, Obara, JA;
Toyota Jidosha Kogyo Kabushiki Kaisha, Toyota, JA;
Abstract
A control apparatus for automatic transmissions of the type having an output shaft of an engine connected to an input shaft of a speed-change gear mechanism through a torque converter. A frictional engagement device is disposed in parallel to the torque converter for directly linking the output shaft to the input shaft and mechanically transmitting the engine power when it is actuated. The control apparatus automatically and hydraulically controls both the selective actuation of the speed-change gear mechanism and the selective actuation of the direct-linkage frictional engagement device through an arrangement of a governor valve, throttle valve, shift valve, pressure-reducing device, operation element, direct-linkage valve and an interlock valve. The direct-linkage valve introduces pressure to the interlock valve in response to a predetermined relationship of pressures generated by the throttle and governor valves, particularly during a relatively high speed drive condition of the vehicle. The interlock valve actuates the direct-linkage frictional engagement device during this period but temporarily relieves the direct-linkage frictional engagement device when the shift valve establishes a shift operation of the speed-change gear mechanism. The pressure-reducing device is provided between the shift valve and the speed-change gear mechanism to control the timing of the actuation of the speed-change gear mechanism. The operation element transmits pressure variations occurring before and after the pressure-reducing device to the interlock valve for actuation of that valve.