Pilot-operated directional control valve
AssigneeHerion-Werke KG
InventorErich Ruchser
Life of this patent
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Abstract
A sliding-spool direction control valve wherein the valve body has a central space for a center land which is rigid with the shank of the valve spool. The outer lands of the spool have axially extending recesses for the respective end portions of the shank. The center space is disposed between two seats and communicates with a pressure port flanked by two working ports which, in turn, are flanked by two return ports. The outer lands are disposed between the respective working and return ports and are connected with pistons which are movable in the valve body to thereby shift the spool so that the center land engages the one or the other seat. The movements of spool can be initiated by a single electromagnetic pilot valve or by two discrete pilot valves.
Claims13
In a pilot-operated directional control valve, a combination comprising a hollow valve body having a pressure port, an internal space communicating with said pressure port, spaced-apart first and second seats in said space, first and second working ports flanking said pressure port and respectively communicating with said first and second seats, and first and second return ports respectively adjacent to said first and second working ports;
- a spool reciprocable in said body and including an elongated shank having first and second end portions, a center land rigid with said shank and disposed in said space between said seats, and first and second outer lands respectively disposed intermediate and having permanent freedom of movement between said first working port and said first return port and between said second working port and said second return port, said first and second outer lands respectively having first and second recesses reciprocally receiving said first and second end portions of said shank;
- and first and second pistons mounted in said body and respectively cooperating with said first and second outer lands, said pistons being movable in said body so that lengthwise movement of said shank and said lands is effected, and said end portions of said shank being reciprocally moved relative to said outer lands in said recesses of the latter.
Dependencies are inferred from the claim text.