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. 19, 1982
Filed:
May. 29, 1980
Kiyonobu Hirose, Ibaraki, JP;
Taizo Izumiyama, Toride, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
An excavator including a boom pivotally moved by boom cylinders, an arm pivotally moved by an arm cylinder and a bucket pivotally moved by bucket cylinders further includes a boom detecting device detecting a pivotal displacement of the boom and producing a first pilot pressure substantially proportional to the pivotal displacement of the boom and a bucket detecting device detecting a pivotal displacement of the bucket and producing a second pilot pressure substantially proportional to the pivotal displacement of the bucket. The first pilot pressure is supplied via a first conduit to a first valve switching pilot pressure port of a control valve device, and the second pilot pressure is supplied via a second conduit to a second valve switching pilot pressure port of the control valve device. The control valve device is connected to the bucket cylinders in such a manner that a piston side of the bucket cylinders can be drained.