초록 ▼

A rotary switch, used to select the operating range of an automatic transmission, controls solenoid-operated valves corresponding to the selected range to open and close a connection between a range valve assembly and a control pressure source. A forward range selection electric circuit includes a f

A rotary switch, used to select the operating range of an automatic transmission, controls solenoid-operated valves corresponding to the selected range to open and close a connection between a range valve assembly and a control pressure source. A forward range selection electric circuit includes a forward range high side driver, a solenoid-operated control valve, the rotary switch, a power source, and a current monitor. There is a similar circuit for the reverse range. A forward range valve and reverse range valve respond to control pressure produced by the circuit to open a fluid pressure source to a line that is pressurized to produce forward drive, a second position opens a connection between the fluid pressure source and a line that is pressurized to produce reverse drive and vents those lines to sump.

대표청구항 ▼

[ Having described a preferred embodiment of our invention, what we claim and desire to secure by U.S. Letters Patent is:] [1.] A system for selecting operating ranges of an automatic transmission, comprising:a line pressure sourcea source of control pressure;a vent port;range selector means, respon

[ Having described a preferred embodiment of our invention, what we claim and desire to secure by U.S. Letters Patent is:] [1.] A system for selecting operating ranges of an automatic transmission, comprising:a line pressure sourcea source of control pressure;a vent port;range selector means, responsive to selection of a first range and second range, for opening and closing hydraulic connections to the control pressure source;hydraulic circuit means having a first portion associated with operation of the transmission in the first range and a second portion associated with said operation in the second range; andvalve means, responsive to said connections produced by the range selector means, for alternately hydraulically connecting the line pressure source and one of the first portion and second portion, and for hydraulically connecting the vent port to the other of the first portion and second portion, wherein the first range corresponds to one of the group consisting of forward drive and reverse drive, and the second range corresponds to the other of the group consisting of forward drive and reverse drive.