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.
Patent No.:
Date of Patent:
Aug. 11, 2026
Filed:
Jul. 17, 2024
Allison Transmission, Inc., Indianapolis, IN (US);
Allison Transmission, Inc., Indianapolis, IN (US);
Abstract
Technologies for variable retarder control include a control valve for controlling operation of a hydraulic retarder. The control valve includes a valve body having a retarder valve including multiple ports and a valve bore extending through the ports. A valve spool is located in the valve bore and movable to selectively block or connect one or more of the ports. The ports include a retarder-out port and an exhaust port, which are fluidly coupled to each other via an exhaust passageway. In use, the exhaust passageway bleeds lubrication fluid from the retarder-out port to the exhaust port as the valve spool is moved from a fully-off position to a fully-on position. The exhaust passageway is shaped so as to provide a linear relationship between the positioning of the valve spool between the fully-off and fully-on positions and the power of the hydraulic retarder. The control valve may also include a lubrication regulator valve configured to supply lubrication oil to the system while the hydraulic retarder is being bled to the exhaust port via the exhaust passageway to maintain appropriate lubrication pressures in the system.