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:
Mar. 30, 1999
Filed:
Jun. 24, 1997
Kazuo Fujishima, Ibaraki-ken, JP;
Hiroshi Watanabe, Ushiku, JP;
Masakazu Haga, Ibaraki-ken, JP;
Takashi Nakagawa, Ibaraki-ken, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
In an oil temperature detecting/calculating portion 9p, threshold values T.sub.1, T.sub.2 are set beforehand to divide a range of oil temperature into a first oil temperature range a representing the lowest level, a second oil temperature range b representing a relatively low level, and a third oil temperature range c representing a normal level. The calculating portion 9p executes an alarm control process for making the alarm lamp 14 light up continuously when the detected oil temperature is in the first oil temperature range a, making the alarm lamp 14 blink when it is in the second oil temperature range b, and making the alarm lamp 14 turn out when it is in the third oil temperature range c. This enables a front control system for a construction machine to perform front control accurately and safely even when the temperature of hydraulic oil is low.