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. 20, 2003
Filed:
Jun. 04, 2001
Shinobu Nagura, Oyama, JP;
Seita Hayashi, Oyama, JP;
Komatsu Ltd., Tokyo, JP;
Abstract
In a direct drive type hydraulic pump, the displacement of the hydraulic pump is forcedly changed to a desired displacement according to an instruction of a channel different from a usual instruction, thereby changing to a desired displacement quickly with good responsivity. When an emergency brake switch is turned on, an emergency brake signal is entered an emergency brake control valve. Thus, an emergency brake signal pressure is entered a piston through an emergency brake signal oil passage, and a piston is forcedly positioned in a neutral position. In other words, the piston can be forcedly positioned in the neutral position according to the emergency brake signal regardless of the entry of a usual brake signal. Therefore, the displacement of the hydraulic pump can be forcedly changed to the neutral position (minimum displacement).