Poclain Hydraulics Industrie

Eric Gest

Jean-Philippe Raisin

Louis B Bigo

Philippe Raymond Lucienne

Jean-Pierre Lebrun

An open hydraulic circuit comprising a main pump (P), a hydraulic motor (M), two main ducts () constituting a feed main duct and a discharge main duct and connected to the pump or to a reservoir (R) via a feed selector (). The circuit further comprises a multifunction valve device comprising a multifunction selector () for connecting the main duct that is at the higher pressure to a pressure limiter () and for connecting the main duct that is at the lower pressure to booster means (), and for interconnecting the main ducts by connecting them to the pressure limiter when the pressures in the main ducts are substantially mutually equal.

Hydraulic circuit having a multifunction selector

The circuit includes a main pump, a hydraulic motor, two main ducts, a selector for connecting the main ducts to the main pump or to a reservoir or for isolating them therefrom, a boost duct, and two pressure limiters disposed between the main ducts. A relief valve device that can take up a retention position and a relief position in which it connects one main duct () to a relief enclosure can take up its relief position when, with the selector isolating the main ducts from the main pump and from the reservoir, the difference between the pressure in the main duct to which the control duct is connected and a relief pressure higher than the boost pressure changes sign.

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Compiegne, France

Eric Gest