Automatic transmission for automotive vehicle

An automatic transmission for an automotive vehicle, including an input shaft connected to an engine of the vehicle via a primary clutch, an output shaft parallel to said input shaft and operatively connected to drive wheels of the vehicle, a plurality of pairs of gears for transmitting a drive force of the input shaft to the output shaft at different speed reduction ratios, respectively, at least one shift member for selecting one of said pairs of gears into an operative position, and an actuator device for automatically activating said at least one shift member, comprising:

• a secondary clutch connected to said primary clutch by said input shaft, and disposed so as to engage said input shaft with said output shaft:
• an intermediate shaft operatively connecting said input shaft to said output shaft, said intermediate shaft being provided with one of the gears of each of at lest one of said pairs of gears;
• a one-way clutch disposed between said intermediate shaft and one of said input and output shafts, said one-way clutch permitting power to be transmitted only in a direction from said input shaft toward said output shaft;
• an engine-brake clutch disposed in operatively parallel relation with said one-way clutch, said engine-brake clutch being engaged to permit power to be transmitted from said output shaft to said input shaft, and thereby permit an engine brake to be applied to the vehicle;
• and
• control means for controlling said actuator device, said primary and secondary clutches, and said engine-brake clutch, said control means operating said actuator device to place said selected one of said pairs of gears in said operative position while holding said primary clutch in a fully engaged position thereof and said secondary clutch in a partially engaged position thereof, said control means activating said engine-brake clutch to apply the engine brake to the vehicle, depending upon running conditions of the vehicle.

An automatic transmission for an automotive vehicle, including an input shaft connected to an engine of the vehicle via a primary clutch, an output shaft parallel to said input shaft and operatively connected to drive wheels of the vehicle, a plurality of pairs of gears for transmitting a drive force of the input shaft to the output shaft at different speed reduction ratios, respectively, at least one shift member for selecting one of said pairs of gears into an operative position, and an actuator device for automatically activating said at least one shift member, comprising:

• a secondary clutch connected to said clutch by said input shaft, and disposed so as to engage said input shaft with said output shaft;
• an intermediate shaft comprising a sleeve disposed concentrically with and radially outwardly of said output shaft for operatively connecting said input shaft to said output shaft, said sleeve having one of the gears of each of at least two pairs of said plurality of pairs of gears;
• said input shaft having the other of said gears of said each of said at least two pairs of gears;
• at least one of said at least one shift members being operable to select one of said at least two pairs of gears into said operative position;
• and
• a one-way clutch disposed between said intermediate shaft and one of said input and output shafts, said one-way clutch permitting power to be transmitted only in a direction from said input shaft toward said output shaft, when each of said at least two pairs of gears is placed into said operative position.