Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Hydraulic control valve system for an automatic multiple-speed transmission with a lockup torque converter and electronically operated lockup control

Patent ·
OSTI ID:6053526
This patent describes a control system for an automatic transmission in an engine powered vehicle comprising a pressure source; a clutch and brake means for effecting ratio changes including two top ratios and at least one lower, underdrive ratio; a hydrokinetic torque converter having a turbine connected to torque input portions of the gearing and an impeller connected to the engine; a pressure operated lockup clutch means in the converter for directly connecting the turbine and the impeller; a control circuit including pressure operated means for sequentially actuating the clutch and brake means and ratio shift valve means for controlling distribution of pressure from the source to the pressure operated means; a converter clutch shift valve and a converter clutch shuttle valve in portions of the circuit connecting the pressure source to the lockup clutch means; and a source of an engine torque signal and a source of a vehicle speed signal connected to the converter clutch shift valve whereby the latter is shifted between a lockup clutch engaging position and lockup clutch disengaging position depending upon the relative values of vehicle speed and engine torque.
Assignee:
Ford Motor Co., Dearborn, MI
Patent Number(s):
US 4817473
OSTI ID:
6053526
Country of Publication:
United States
Language:
English