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:
Dec. 21, 1976
Filed:
Mar. 24, 1975
William W Blake, Kewanee, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A hydraulic system responsive to movement of a shift lever energizes selected pairs of drive engaging devices in a vehicle transmission by applying a gradual rise in pressure to the selected speed drive engaging device and by applying a delayed and a lesser gradual pressure rise to a selected directional drive engaging device. The circuit neutralizes the transmission by blocking fluid pressure from at least one of the devices if the vehicle engine is started with the shift lever at a position other than neutral and also neutralizes the transmission when the vehicle brakes are applied while still maintaining full fluid pressure to other vehicle components. These functions are accomplished by a combination of a pair of selector valves, a pressure modulation valve assembly and a greatly simplified and compact spool differential check and safety valve.