3805640 is referenced by 73 patents and cites 4 patents.

A power transmission includes an engine-driven lock-up type torque converter for driving a speed changing gear shift mechanism shiftable to different speed ranges by solenoid operated clutch valves. An electronic controller provides output signals to operate the clutch valves and also to inhibit lock-up in certain speed ranges. The controller receives input signals from a manually operable multiposition speed range selection switch; from speed sensors on the torque converter and the gear shift mechanism; and from an engine throttle position control. The control effects automatic shifting to selected speed ranges and automatically shifts itself to maintain selected speeds; introduces a time delay in each transitional speed range to prevent hunting; effects downshifting, shifting to neutral and reversal only when correct speed ranges are reached; avoids shifting to neutral unless that position is actually selected; and performs other functions.

Title
Electronically controlled power transmission
Application Number
05/287,585
Publication Number
3805640
Application Date
September 8, 1972
Publication Date
April 23, 1974
Inventor
Snoy Joseph B
Schneider Raymond C
Agent
Nilles James E
Assignee
Twin Disc Incorporated
IPC
F16h 03/08
B60k 21/00
F16h 47/00
F16H 59/04
F16H 61/684
F16H 61/68
F16H 61/02
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