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US 4,245,671 AGranted
Solenoid pilot operated valve
AssigneeShoketsu Kinzoku Kogyo Kabushiki Kaisha
InventorSeiji Kosugui
Life of this patent
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Abstract
There is described an improvement in solenoid pilot operated valve using a spool/piston assembly which is operated by fluid pressure in a pilot chamber, wherein a piston is slidably mounted on one or both ends of a spool and independently returnable to its initial position upon relieving the pilot chamber of fluid pressure.
Claims10
A solenoid pilot operated valve comprising:
- a spool casing internally defining a spool chamber and having an input port and a number of output and drain ports in communication with said spool chamber;
- a spool valve slidably received in said spool chamber and having a number of seal ridges to connect said output ports selectively with either said input port or one of said drain ports;
- a fluid passage formed axially through said spool valve in communication with said input port;
- a piston slidably mounted on one end of said spool within a piston chamber formed contiguous to the outer end of said spool chamber and having an axial bore communicating at the inner end thereof with said axial fluid passage of said spool and terminating at the outer end in a pilot valve seat opening into a pilot chamber provided contiguously on the outer side of said piston chamber;
- a plunger accommodated within said pilot chamber and movable toward and away from said pilot valve seat and a drain valve seat provided at the outer end of said pilot chamber;
- plunger biasing means for constantly urging said plunger to seat on said pilot valve seat on said piston;
- operating means for driving said plunger to unseat from said pilot valve seat and seat on said drain valve seat of said pilot chamber thereby bringing said pilot chamber into fluid communication with said input port through said axial fluid passage and allowing the fluid pressure to act on said piston to shift said spool to a different change-over position;
- and
- spool shifting means provided at the other end of said spool chamber and acting to return said spool to the initial position.
6 more elements
A solenoid pilot operated valve comprising, in combination:
- (a) a spool casing internally defining a cylindrical spool chamber and having an input port and a plurality of output and drain ports in communication with said spool chamber;
- (b) a spool valve axially slidably received in said spool chamber and having a plurality of seal ridges to selectively connect said output ports with either said input port or one of said drain ports;
- (c) a fluid passage formed axially through said spool valve in communication with said input port;
- and
- (d) a solenoid pilot provided at each end of said spool casing in association with said spool valve, comprising:
- (i) a piston slidably mounted on one end of said spool within a piston chamber formed contiguously on the outer side of said spool chamber and having an axial passage communicating at the inner end thereof with said axial fluid passage of said spool and terminating at the outer end thereof in a pilot valve seat opening into a pilot chamber provided contiguously on the outer side of said piston chamber;
- (ii) a plunger accommodated within said pilot chamber and axially movable toward and away from said pilot valve seat and a drain valve seat provided at the outer end of said pilot chamber;
- (iii) plunger biasing means adapted to constantly urge said plunger to seat on said piston pilot valve seat;
- and
- (iv) a solenoid device actuatable to unseat said plunger from said pilot valve seat and seat said plunger onto said drain valve seat of said pilot chamber to bring said pilot chamber into fluid communication with said input port through said axial fluid passages of said spool valve and piston, thereby allowing the fluid pressure from said input port to act on said piston to shift said spool valve to another change-over position.
7 more elements
Dependencies are inferred from the claim text.