Title (en)

SAFETY VALVE

Publication

EP 0347562 A3 19901017 (DE)

Application

EP 89107714 A 19890427

Priority

DE 3817122 A 19880519

Abstract (en)

[origin: EP0347562A2] The invention relates to a hydraulic safety valve which is driven by servo valves that are operated electromagnetically. It has two valve bodies, which can move in opposite directions to one another and which control the connections between a pump connection, two operating connections and two tank connections. In the event of incorrect connection, the two valve bodies go into a hydraulically locked limit position from which the safety valve cannot be taken back into operation until the fault is remedied. The pressure build-up and speed of a load connected downstream of the safety valve can be controlled with the aid of a proportional-pressure reducing valve, coupled to the safety valve. <IMAGE>

IPC 1-7

F16K 31/40

IPC 8 full level

F16K 31/42 (2006.01); F15B 20/00 (2006.01)

CPC (source: EP US)

F15B 20/001 (2013.01 - EP US); Y10T 137/87209 (2015.04 - EP US); Y10T 137/87225 (2015.04 - EP US)

Citation (search report)

• [A] DE 1284231 B 19690220 - HERION ERICH
• [A] DE 3104957 C2 19861204
• [A] US 3171435 A 19650302 - LANSKY ZDENEK J, et al
• [A] DE 1245665 B 19670727 - ERICH HERION
• [A] DD 96321 A1 19730312
• [A] DE 1750358 A1 19710211 - BOSCH GMBH ROBERT

Designated contracting state (EPC)

CH DE FR GB IT LI SE

DOCDB simple family (publication)

EP 0347562 A2 19891227; EP 0347562 A3 19901017; DE 3817122 A1 19891130; JP H0242289 A 19900213; US 4903728 A 19900227

DOCDB simple family (application)

EP 89107714 A 19890427; DE 3817122 A 19880519; JP 12549689 A 19890518; US 34435189 A 19890426