Daimlerchrysler Corporation

Fca US LLC

Daniel H Black

David Parenti

Edward W Czarnecki

Margaret C Novacek

Dustin B Skavang

A transmission having an input shaft, piston, dog clutch, sensor sleeve and control system is provided. The dog clutch includes male and female members, where one of the members is coupled to the piston for common movement therewith. The sleeve includes a through channel and a reduced diameter sensor portion terminating at a shoulder. The control system is configured to: command a supply of hydraulic fluid against an engagement side of the piston, determine when a terminal end of the sensor portion contacts a control, and determine that the dog clutch members are in a predetermined partially engaged state less than a fully engaged state of the dog clutch members. A length of the reduced diameter sensor portion directly corresponds to the predetermined partially engaged state of the dog clutch that is less than a fully engaged state of the male and female members of the dog clutch.

System and method for improved transmission shifting

A method and system adjusts powertrain controls to avoid significant deviations from set speed during speed control operation. Low vacuum conditions of a reservoir vacuum resulting from high load conditions are detected and eliminated through the initiation of downshifts. Detection is based on the determination that speed control mode has been initialized, the throttle is extended, vehicle acceleration is low, and there has been a significant deviation from set speed. The downshift creates an increase in engine rpm and a reduction in throttle angle to increase the manifold vacuum and thereby recharge the reservoir vacuum and eliminate the low vacuum condition. The transmission can be returned to normal operation and the pre-adjustment gear upon elimination of the low vacuum condition or the occurrence of a driver override condition.

Vacuum actuated vehicle speed control system

A transmission assembly and method for controlling a torque converter of a transmission assembly in which an electronic controller monitors the load on the vehicle power train in addition to a number of other vehicle dynamics, including the currently engaged gear ratio and the temperature of the transmission fluid. The electronic controller is operable for causing the activation of the converter clutch in response to a number of predetermined operating conditions, one of which includes the operation of the vehicle when the fluid in the torque converter exceeds a predetermined temperature and the vehicle power train is operated under a heavy load for a period of time which exceeds a predetermined time interval. Engagement of the converter clutch during such times inhibits relative rotation between the torque converter turbine and impeller, improving fuel economy and preventing the torque converter from generating a substantial amount of heat. The use of the time interval prevents the engagement of the converter clutch during transient operating conditions and eliminates concerns relating to the 'driveability' of the vehicle.

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Shelby Township, MI, United States of America

Daniel H Black