Control of a vehicle automatic transmission

Claim 1

Automatic transmission for motor vehicles which comprises a torque converter having an input member adapted to be connected with an engine and an output member, a transmission gear mechanism having a plurality of gear trains of different gear ratios, said transmission gear mechanism including an input member connected with the output member of the torque converter, hydraulic actuator means for selecting one of said gear trains in the transmission gear mechanism, electromagnetic means for controlling a supply of hydraulic fluid to said hydraulic actuator means, sensing means for detecting vehicle operating conditions and producing an operating condition signal, control means provided with mode selecting manual switch means for selecting one of a plurality of operating modes having the same number greater than three of gear stages provided by selecting the gear trains and producing a mode signal depending on an actuated position of the switch means, said control means including gear train series selecting means responsive to said mode signal for selecting one of a plurality of series of the gear trains in accordance with the operating mode, said plurality of series of the gear trains having at least first gear stages which are of different gear ratios, a plurality of shift patterns corresponding to said operating modes, respectively, for defining shift zones for each operating mode and governing gear shifting operations among said plurality of gear trains of said transmission gear mechanism depending on the vehicle operating condition, one of the shift patterns having shift zones which are on a high speed side with respect to corresponding shift zones in another shift pattern, said one shift pattern having a first gear stage which is of a higher gear ratio than a first gear stage of said other shift pattern, shift pattern selecting means responsive to said mode signal for selecting one of said shift patterns, shifting means for comparing the operating condition signal with the selected one of the shift patterns and producing a shift signal when it is judged that the operating condition is shifted from one shift zone to another and that gear shifting is necessary, said shift signal being applied to said electromagnetic means to effect gear shifting in accordance with the selected series of the gear trains.