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:
Sep. 14, 1999
Filed:
Jun. 30, 1997
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
In a construction machine of a small rotational inertia such as an intrawidth swing machine or a small-sized excavator, a rotative operability varies depending on the posture of a working attachment, and in a reduced state of reach, a change in rotating force is oversensitive to the operation of a working lever, so operation is difficult. To cope with this point, means for detecting the operation of a rotating direction control valve is provided, and an outlet of a center bypassing oil path in the rotating direction control valve and an oil tank are brought into communication with each other through a cut-off valve used for controlling the bleed-off thereof. Further, a pilot port of the cut-off valve and a source of a pilot oil pressure are brought into communication with each other through an electromagnetic proportional pressure reducing valve, and an operation command signal is issued from a controller to the electromagnetic proportional pressure control valve to control the acceleration of rotation and the maximum rotating speed.