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Title: Electronically controlled automatic transmission

Patent ·
OSTI ID:5278898

This patent describes an electronically controlled automatic transmission control system for an automotive vehicle. It comprises multiple ratio gearing and multiple pressure operated clutches and brakes adapted to establish and disestablish multiple torque flow paths through the gearing from an engine; a source of regulated line pressure, a valve circuit connecting the line pressure source to the clutches and brakes; a hydrokinetic unit having a bladed impeller adapted to be driven by the engine and a bladed turbine connected to torque input elements of the gearing; a regulator valve means in the circuit for regulating pressure of fluid in the hydrokinetic unit; throttle pressure solenoid valve means communicating with the regulator valve means for developing an engine torque signal; a throttle pressure signal passage connecting the throttle pressure solenoid valve means with the source of regulated line pressure whereby the latter responds to the torque signal to increase line pressure with increasing torque; and fail-safe valve means communicating with the regulator valve means and the throttle pressure signal passage and responding to a decrease in the torque signal below a calibrated value to distribute the regulated pressure of the regulator valve means to the line pressure source thereby preserving line pressure above a calibrated minimum value.

Assignee:
Ford Motor Co., Dearborn, MI (United States)
Patent Number(s):
US 5083481; A
Application Number:
PPN: US 7-583932
OSTI ID:
5278898
Resource Relation:
Patent File Date: 17 Sep 1990
Country of Publication:
United States
Language:
English