Variable flow-modulated valve

Claim 2

A variable flow modulated valve having a body with a bore, an inlet opening communicating with the bore, an outlet opening communicating with the bore and spaced axially from the inlet opening, a spool reciprocably mounted in the bore to close communication between the inlet and outlet openings, said spool having an annular recess arranged to open such communication upon axial adjustment of the spool, and grooves in the spool of varying widths communicating with each other and with the annular recess, said grooves extending axially toward the outlet opening to communicate therewith prior to the annular recess to effect modulated flow through the valve, said spool having a neutral position in the bore with the annular recess being in communication with the outlet opening, said spool being adjustable in the bore from its neutral position for permitting variable fluid flow through the valve, said grooves including a small groove arranged for communication with the inlet opening when the spool is in its neutral position to provide limited fluid communication through the valve for preventing cavitation and a larger groove arranged intermediate said small groove and the annular recess.

Claim 3

The valve of claim 1 in which there are two outlet openings spaced axially from the inlet opening in appropriate directions, two annular reCesses in the spool each disposed for communication between the inlet opening and one outlet opening and each annular recess having flow modulating grooves extending toward one of the outlet openings.

Claim 4

The valve of claim 2 with feel-back spring means operable upon wide opening of the spool in either direction.

Claim 5

The valve of claim 1 with resilient means to oppose adjustment of the spool toward the flow position as the annular recess communicates with the outlet opening to transmit feel-back through the spool when it is adjusted manually.

Claim 6

The valve of claim 1 further comprising a drain opening communicating with the bore and spaced axially from the outlet opening opposite the inlet opening, said spool being also adjustable in the bore for communicating the outlet opening with the drain opening by means of the annular recess, an additional small groove being in communication with the annular recess and with the drain opening when said spool is in its neutral position.

Claim 7

The valve of claim 5 in which there are two outlet openings spaced axially from the inlet opening in appropriate directions and two drain openings spaced axially from the respective outlet openings opposite the inlet opening, two annular recesses with similar groove arrangements being respectively disposed in the spool for communicating one outlet opening with the inlet opening and the adjacent drain opening.

Claim 8

The valve of claim 6 further comprising means in communication with the inlet opening to regulate fluid pressure therein.

Claim 9

A variable flow modulated valve for operating a double-acting hydraulic jack, the valve having a body with a bore, an inlet opening communicating with the bore, two outlet openings for communicating the valve with opposite ends of the jack, the outlet openings communicating with the bore and being spaced axially from the inlet opening in appropriate directions, a spool reciprocably mounted in the bore to close communication between the inlet and outlet openings, said spool having two annular recesses arranged to respectively open such communication with the outlet openings upon axial adjustment of the spool, each annular recess having an associated arrangement of grooves of varying size formed in the spool in communication with each other and with the associated annular recess, said spool having a neutral position in the bore with the annular recesses being in respective communication with the outlet openings, said spool being adjustable in the bore from its neutral position for permitting variable fluid flow through the valve, each groove arrangement including a small groove arranged for communication with the inlet opening when the spool is in its neutral position and a larger groove arranged intermediate said small groove and the associated annular recess and means in communication with the inlet opening to regulate fluid pressure therein.

Claim 10

A variable flow modulated valve for operating a double-acting hydraulic jack, the valve having a body with a bore, an inlet opening communicating with the bore, two outlet openings for communicating the valve with opposite ends of the jack, the outlet openings communicating with the bore and being spaced axially from the inlet opening in appropriate directions, a spool reciprocably mounted in the bore to close communication between the inlet and outlet openings, said spool having two annular recesses arranged to respectively open such communication with the outlet openings upon axial adjustment of the spool, each annular recess having an associated arrangement of grooves of varying size formed in the spool in communication with each other and with the associated annular recess, said spool having a neutral position in the bore with the annular recesses being in respective communication with the outlet openings, said spool being adjustable in the bore from its neutral position for permitting variable fluid flow through the valve, each groove arrangement including a small groove arranged for communication with the inlet opening when the spool is in its neutral position and a larger groove arranged intermediate said small groove and the associated annular recess and means in communication with the inlet opening to regulate fluid pressure therein.

Claim 11

The valve of claim 8 further comprising two drain openings communicating with the bore in axially spaced apart relation from the respective outlet openings opposite the inlet opening, each groove arrangement including an additional small groove being in communication with the annular recess and with the drain opening when said spool is in its neutral position.

Claim 12

The valve of claim 9 further comprising centering spring means tending to maintain the spool in its neutral position and feedback spring means tending to resist further adjustment of the spool upon either of the annular recesses entering into direct communication with the inlet opening.