US Patent 7896769 Manual valve control for multi-speed planetary transmission

Patent 7896769 was granted and assigned to Allison Transmission on March, 2011 by the United States Patent and Trademark Office.

Overview Structured Data Issues Contributors Activity

Is a

Patent

Patent attributes

Current Assignee

Allison Transmission

Patent Jurisdiction

United States Patent and Trademark Office

Patent Number

78967690

Patent Inventor Names

Charles T. Taylor0

Charles F. Long0

Date of Patent

March 1, 2011

Patent Application Number

121705660

Date Filed

July 10, 2008

Patent Primary Examiner

Dirk Wright

Patent abstract

A manual valve control for a multi-speed vehicle transmission is provided. Electronic and hydraulic components are provided, including trim valve systems that are multiplexed by a shift valve and a manual valve. The trim valves and shift valve are self-diagnosing via a plurality of multiplexed pressure switches. The control enables single and double range shifts among the multiple forward speed ratios, including shifts to and from sixth and higher forward ratios, reverse and neutral. The control also includes a reduced engine load at stop feature. In addition, a power off/limp home feature provides a plurality of failure modes, including a failure mode for sixth and higher forward speed ratios.