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:
Sep. 09, 2025
Filed:
Dec. 07, 2022
Caterpillar Sarl, Geneva, CH;
Hideki Nakajima, Akashi, JP;
Koichi Kiyasu, Akashi, JP;
Caterpillar SARL, Geneva, CH;
Abstract
PROBLEM: To avoid the pressure of the actuator oil passage from becoming higher or equal to the upper limit pressure that is set depending on an individual option hydraulic actuator, during non-operation of an option operation lever, even if the actuator oil passage connected to the option hydraulic actuator is not provided with a variable relief valve. SOLUTION: It is configured to release the pressure of the actuator oil passage into the oil tank via the option control valve, the load pressure introducing oil passage, the variable relief valve, by switching the option control valve to load pressure relief positions at which the pressure of the actuator oil passage is allowed to flow into the load pressure introducing oil passage, when the pressure of the actuator oil passages exceeds the upper limit pressure during non-operation of the option operation lever; as well as by controlling the relief setting pressure of the variable relief valve connected to the load pressure introducing oil passage so as to be less than or equal to the upper limit pressure.