Title:
HYDRAULIC CIRCUIT AND ATTACHMENT EMERGENCY DRIVE METHOD FOR CONSTRUCTION MACHINERY
Document Type and Number:
WIPO Patent Application WO/2001/092651
Kind Code:
A1
Abstract:
A hydraulic circuit for construction machinery, comprising a hydraulic pilot-operated control valve for controlling an actuator driving a front attachment and a pilot pipeline leading a hydraulic pilot pressure to the control valve having a pressure oil filling port allowing a manual hydraulic pump to be connected thereto, wherein pressure oil is fed from the port to the pilot pipeline by the manual hydraulic pump so as to switch over the control valve, whereby the front attachment can be driven urgently only with a very simple improvement without a bypass pipeline and a selector valve.
Inventors:
ONOUE HIROSHI
TANAKA YASUSHI
TANAKA YASUSHI
Application Number:
PCT/JP2001/004625
Publication Date:
December 06, 2001
Filing Date:
May 31, 2001
Export Citation:
Assignee:
HITACHI CONSTRUCTION MACHINERY (JP)
International Classes:
E02F9/22; E02F9/24; F15B11/08; F15B20/00; (IPC1-7): E02F9/22; E02F9/24
Foreign References:
| JPH07317713A | 1995-12-08 | |||
| JP2000096631A | 2000-04-04 | |||
| JPH0617885Y2 | 1994-05-11 | |||
| JPH0693630A | 1994-04-05 | |||
| JPS5976659A | 1984-05-01 | |||
| JPH0693630A | 1994-04-05 |
Other References:
See also references of EP 1300519A4
Attorney, Agent or Firm:
Nagai, Fuyuki (3-2-4 Kasumigaseki Chiyoda-ku, Tokyo, JP)
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