The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jan. 10, 1989

Filed:

Dec. 22, 1987
Applicant:
Inventors:

Kenneth R Butts, Grosse Pointe Woods, MI (US);

Joseph L Wanamaker, Rochester, MI (US);

Assignee:

General Motors Corporation, Detroit, MI (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B60K / ;
U.S. Cl.
CPC ...
74866 ; 74877 ;
Abstract

A clutch-to-clutch power-on downshift in a motor vehicle automatic transmission is initiated by reducing the torque capacity of the off-going clutch, permitting the transmission input speed to increase toward its post shift value. When the slippage across the off-going clutch exceeds a reference, the reduction of its torque capacity is suspended, permitting continued increase of the transmission input speed. When the slippage across the on-coming clutch falls below a reference value, the on-coming and off-going clutches are concurrently applied and released to complete the shift. The transmission input speed substantially achieves its post shift value at the time of such apply and release, resulting in reduced shift-related output torque disturbance.


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