Patent ID: 6532989
Filing Date: 2003-03-18
Classification: F15B,Y10T

Abstract:
Hydraulic distributor comprising a regulating balance able to perform a function of detecting a highest charge pressures an anti-saturation function and a delivery-dividing function independent of a charge, this balance comprising a housing hollowed in a distributor body in which a plunger is movable, the housing comprising:a first end able to receive selectively pressurized hydraulic fluid (P) delivered by a hydraulic source, a second end in communication with a channel conveying the highest charge pressure (LS), and a lateral orifice communicating selectively with a working orifice (A, B) of the distributor, said plunger including a passage provided with a restriction which opens, on one side, towards said first end of the housing and, on the other side, opens laterally so as to emerge in the above-mentioned second end of the housing when the plunger occupies a position determined by the excess of said intake pressure (P) reduced by the pressure drop (&Dgr;p) caused by the restriction, as compared to the highest charge pressure (LS) prevailing in the said second end of the housing, said plunger being arranged to uncover the lateral orifice of the housing and to connect the latter with the first end of the housing in proportion to the pressure differential (&Dgr;p) between the intake pressure and the highest charge pressure prevailing in the second end of the housing, characterized in that the balance includes; a fixed central core extending inside the housing coaxially with it, a tubular plunger interposed freely sliding, coaxially, between the core and the housing, said plunger having a length less than that of core and being externally configured to cover or uncover the lateral orifice of the housing more or less according to its position, the core and the plunger being mutually configured to define between them an annular chamber having a first radially-extending annular surface defined on the plunger, a second radially-extending annular surface located on the plunger and facing away from the first surface and being able to be subjected to the pressure (P) of the intake fluid, and a central passage formed in the core and including a first orifice emerging in the second end of the housing in which the higher charge pressure (LS) prevails, a second orifice emerging in the annular chamber between the core and the plunger so that the pressure (LS) is exerted on the annular surface of said annular chamber, and a third orifice located opposite the first end of the housing and closed by the plunger as long as the charge pressure of the distributor does not constitute the highest charge pressure.