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:
Oct. 23, 1984
Filed:
Jul. 11, 1983
William W Blake, Kewanee, IL (US);
Alan R Coutant, Chillicothe, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A pressure modulating and reducing valve (10) communicates pressurized hydraulic fluid from a pump (11) to a hydraulically actuated clutch of a transmission at a modulated rate of pressure rise and at a reduced pressure. In order to provide a compact valve, the valve (10) has a pressure reducing valve spool (61) slidably nested within a sleeve member (46) of a load piston to provide a valving action therebetween for controlling fluid flow between an inlet port (24), a load port (26) and a drain port (27) in a body (19). Movement of the sleeve member (46) causes an increase in the pressure at the load port (26) which causes the pressure reducing valve spool (61) to move against a spring (77,78) to establish a pressure in the load port (26) proportional to the travel distance of the sleeve member (46). Movement of the sleeve member (46) is controlled by a solenoid control valve (85) having a spool (86) slidably nested within a projection (54) of an end wall (51) extending into a bore (62) of the pressure reducing valve spool (61).