WIPO logo
Mobile | Deutsch | Español | Français | 日本語 | 한국어 | Português | Русский | 中文 | العربية |
PATENTSCOPE

Search International and National Patent Collections
World Intellectual Property Organization
Search
 
Browse
 
Translate
 
Options
 
News
 
Login
 
Help
 
Machine translation
1. (WO1981001034) HYDRAULIC LOAD LIFTING SYSTEM WITH AUTOMATIC BLOCKING VALVE
Latest bibliographic data on file with the International Bureau   

Pub. No.:    WO/1981/001034    International Application No.:    PCT/US1979/000859
Publication Date: 16.04.1981 International Filing Date: 15.10.1979
IPC:
F15B 11/00 (2006.01)
Applicants:
Inventors:
Priority Data:
US79/00859 15.10.1979 WO
Title (EN) HYDRAULIC LOAD LIFTING SYSTEM WITH AUTOMATIC BLOCKING VALVE
(FR) SYSTEME DE LEVAGE DE CHARGE HYDRAULIQUE AVEC SOUPAPE DE BLOCAGE AUTOMATIQUE
Abstract: front page image
(EN)In a hydraulic system (10) comprising a check valve (33, 34) with a main line (27) and a vent line (69), the improvement includes blocker means (100, 104) for closing said vent line (69) when the pressure in said main line (27) falls below a predetermined level. In prior art hydraulic systems, and in particular in hydraulic systems having a cylinder means for elevating and lowering a load, there exists the possibility that the hydraulic line from a control valve to the cylinder means could rupture, allowing the load to drop before the operator could react. The present invention solves this problem by providing a blocker valve (100) in the vent line (69) of a check valve (33, 34) which check valve is interposed in the main line (27) between a cylinder means (12) and a control valve (21). The blocker valve (100) is responsive to the back pressure in the main line (27) from the check valve (33, 34) to the control valve (27). Thus, when the pressure in said main line (27) drops below a predetermined level due, for example, to a break in said line (27) the blocker valve (100) automatically closes the vent line (69), preventing the check valve (33, 34) from releasing hydraulic fluid, and thus preventing the load (14) from dropping. In an aspect of the invention, a resolver valve (104) actuates the blocker valve (100). The resolver valve (104) communicates with the main line (27) at two positions and selects the lowest pressure between said positions.
(FR)Dans un systeme hydraulique (10) comprenant une soupape de retenue (33, 34) avec une canalisation principale (27) et une canalisation d"event (69), l"amelioration comprend des moyens de blocage (100, 104) pour fermer ladite canalisation d"event (69) lorsque la pression dans ladite canalisation principale (27) tombe en-dessous d"un niveau predetermine. Dans les systemes hydrauliques de l"art anterieur, et en particulier dans les systemes hydrauliques ayant des moyens de cylindre d"elevation et d"abaissement d"une charge, il existe la possibilite que la canalisation hydraulique reliant une soupape de commande aux moyens de cylindre se casse, laissant tomber la charge avant que l"operateur ne reagisse. Ce probleme est resolu en disposant une soupape de blocage (100) dans la canalisation d"event (69) d"une soupape de retenue (33, 34) laquelle soupape de retenue est interposee dans la canalisation principale (27) entre un cylindre (12) et une soupape de commande (21). La soupape de blocage (100) est sensible a la pression de retour dans la canalisation principale (27) qui relie la soupape de retenue (33, 34) a la soupape de commande (27). Ainsi, lorsque la pression dans ladite canalisation principale (27) tombe en-dessous d"un niveau predetermine a cause, par exemple, d"une rupture dans cette canalisation (27), la soupape de blocage (100) ferme automatiquement la canalisation d"event (69), empechant la soupape de retenue (33, 34) de liberer du fluide hydraulique, et empechant ainsi la charge (14) de tomber. Dans une variante, une soupape de resolution (104) agit sur la soupape de blocage (100). La soupape de resolution (104) communique avec la canalisation principale (27) en deux positions et selectionne la pression la plus basse entre ces positions.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)