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:
May. 29, 2012
Filed:
Oct. 23, 2009
Osamu Sato, Minokamo, JP;
Yoshitake Sakai, Toki, JP;
Shiro Nishioka, Kani, JP;
Kayaba, Tokyo, JP;
Abstract
There is provided a fluid pressure drive unit that can fulfill a position holding function stably even when an external force acts during the time when the position is held, the unit being used, for example, for the right and left angle adjustment of a snow plow blade. There is provided a first excessive load relief valvefor letting a working fluid escape from a bottom-side pipe line, which connects the bottom-side port of a single-rod double acting cylinderto the bottom side of an operate check valve, to a rod-side pipe line, which connects the rod-side port of the single-rod double acting cylinderto the rod side of the operate check valve, and there is provided a second excessive load relief valvefor letting the working fluid escape from the rod-side pipe lineto a tank. Also, there is provided a negative pressure preventing check valvefor allowing the working fluid to flow into the bottom-side pipelinefrom the tank