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. 05, 1998
Filed:
Apr. 09, 1996
Kenji Matsuda, Sakai, JP;
Kubota Corporation, Osaka, JP;
Abstract
A hydraulic system for controlling a mower unit through a raising and lowering mechanism. This system includes a hydraulic cylinder connected to the raising and lowering mechanism, a control lever for controlling the mower unit, and a valve unit including a main control valve, an auxiliary control valve and a throttle valve connected in series between a hydraulic pressure source and the hydraulic cylinder. In response to operation of the control lever, the valve unit selectively produces a raising state for supplying pressure oil to the hydraulic cylinder to raise the mower unit, a lowering state for draining pressure oil from the hydraulic cylinder to lower the mower unit by gravity, a neutral state for stopping supply and drainage of pressure oil to/from the hydraulic cylinder to maintain mower unit still, and a half floating state for supplying pressure oil to the hydraulic cylinder and draining pressure oil from the hydraulic cylinder through the throttle valve to apply to the mower unit a raising force less than a gravitational lowering force. The auxiliary control valve is controllable in response to movement of the main control valve, to produce the half floating state when the control lever moves from a lowering position to a neutral position.