Dual stage fluid clutch motor with electric controls including time delay

摘要

A vehicle transmission with an automatic clutch is disclosed in which for gear shifting the clutch is disengaged with the assistance of a vacuum from a source of vacuum, via a control valve having a solenoid actuated clutch release valve and a clutch servo. Disengagement of the clutch is carried out when a gear shift lever is manipulated with an engine accelerator released. The reengagement of the clutch commences as soon as the flow of current to the solenoid for the clutch release valve is cut. The clutch release valve then disconnects the clutch servo from the source of vacuum. The reduction of the vacuum in the clutch servo takes place in two stages. In the first stage, the vacuum is reduced very quickly by means of a solenoid actuated air-on (air bleed) valve for a predetermined time after the flow of current to the solenoid for the clutch release valve has been cut until the clutch begins to engage or is about to engage. Current is supplied to the solenoid for the air-on valve when current is supplied to the solenoid for the clutch release valve. A delay means is provided whereby, after the predetermined time after the flow of current to the solenoid for the clutch release valve has been cut, the flow of current to the solenoid for the air-on valve is cut.