EP 1387089 A3 20080305 - Hydraulic actuator circuit
Title (en)
Hydraulic actuator circuit
Title (de)
Schaltkreis eines hydraulischen Stellglieds
Title (fr)
Circuit pour un vérin hydraulique
Publication
Application
Priority
JP 2002222000 A 20020730
Abstract (en)
[origin: EP1387089A2] This invention provides with a hydraulic actuator circuit comprising a holding valve (17) disposed in a boom extension-side pipeline (13) in the circuit an opening of which is controlled by a control valve (15) and an assist cylinder (20) for controlling an opening of the holding valve in such a way that, in a condition wherein a holding pressure drops to a valve of not larger than a given value, the opening of the holding valve is reduced, whereby the circuit can prevent an unusual sudden lowering of a boom with a load.
IPC 8 full level
F15B 11/00 (2006.01); E02F 9/22 (2006.01); E02F 9/24 (2006.01); F15B 11/04 (2006.01); F15B 11/08 (2006.01); F15B 20/00 (2006.01)
CPC (source: EP)
E02F 9/226 (2013.01); E02F 9/2296 (2013.01); F15B 11/003 (2013.01); F15B 20/005 (2013.01); F15B 2211/20546 (2013.01); F15B 2211/30505 (2013.01); F15B 2211/30515 (2013.01); F15B 2211/30525 (2013.01); F15B 2211/3058 (2013.01); F15B 2211/3116 (2013.01); F15B 2211/3138 (2013.01); F15B 2211/31576 (2013.01); F15B 2211/329 (2013.01); F15B 2211/40515 (2013.01); F15B 2211/40584 (2013.01); F15B 2211/413 (2013.01); F15B 2211/41527 (2013.01); F15B 2211/422 (2013.01); F15B 2211/428 (2013.01); F15B 2211/46 (2013.01); F15B 2211/55 (2013.01); F15B 2211/8636 (2013.01)
Citation (search report)
- [XA] DE 4342565 A1 19950622 - BOSCH GMBH ROBERT [DE]
- [A] EP 0952358 A2 19991027 - HITACHI CONSTRUCTION MACHINERY [JP]
- [A] EP 0331076 A1 19890906 - KOBE STEEL LTD [JP]
- [A] US 6173639 B1 20010116 - A HEARN MICHAEL A [US], et al
- [AD] JP H10267009 A 19981006 - TOSHIBA MACHINE CO LTD
Designated contracting state (EPC)
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
Designated extension state (EPC)
AL LT LV MK
DOCDB simple family (publication)
EP 1387089 A2 20040204; EP 1387089 A3 20080305; JP 2004060821 A 20040226; JP 3915622 B2 20070516
DOCDB simple family (application)
EP 03254648 A 20030725; JP 2002222000 A 20020730