Global Patent Index - EP 0000303 B1

EP 0000303 B1 19800109 - AUTOMATIC HYDRAULIC VALVE

Title (en)

AUTOMATIC HYDRAULIC VALVE

Publication

EP 0000303 B1 19800109 (FR)

Application

EP 78400021 A 19780614

Priority

FR 7718951 A 19770621

Abstract (en)

[origin: US4223694A] In a hydraulic circuit breaker comprising a housing with an inlet orifice connectable to the outlet of a hydraulic pump, a first outlet orifice connectable to the pressure chamber of a hydraulic pressure accumulator, and a second outlet orifice connectable to an open-center hydraulic circuit, a stepped bore in said housing, a piston of the differential type slidable in a fluid-tight manner in said bore and defining therewith an inlet chamber communicating with the inlet orifice and a control chamber, a constriction orifice of variable cross-section being provided between the inlet chamber and the second outlet orifice, and said inlet chamber communicating with said control chamber through a first passage comprising a first restriction and being also connected to the first outlet orifice by a connection comprising a non-return valve, there is further provided a resilient vessel having a variable-volume compartment connected to said control chamber, said vessel being adapted to connect said compartment to a second leakage passage forming a restriction when the pressure in said compartment reaches a first predetermined value, and to interrupt said connection to said leakage passage when the pressure in said compartment falls below a second predetermined value.

IPC 1-7

F15B 1/02

IPC 8 full level

F15B 1/027 (2006.01)

CPC (source: EP US)

F15B 1/027 (2013.01 - EP US); Y10T 137/2663 (2015.04 - EP US)

Designated contracting state (EPC)

DE FR GB SE

DOCDB simple family (publication)

EP 0000303 A1 19790110; EP 0000303 B1 19800109; DE 2857514 D1 19800214; FR 2395442 A1 19790119; FR 2395442 B1 19820312; IT 1096475 B 19850826; IT 7824676 A0 19780619; US 4223694 A 19800923

DOCDB simple family (application)

EP 78400021 A 19780614; DE 2857514 T 19780614; FR 7718951 A 19770621; IT 2467678 A 19780619; US 91638278 A 19780616