Hydraulic pressure feedback control valve

Claim 2

A hydraulic valve comprising a valve body having an axial bore, a plunger reciprocally received in said bore, said body having an inlet port and an outlet port, a first passage connecting said inlet port to said outlet port, means defining a metering chamber in said body, a vent passage communicating with said metering chamber, means defining a metering orifice in said metering chamber, a second passage affording communication between said first passage and said metering chamber, a metering valve member having a portion with a variable cross section movable in said orifice, means for supporting and guiding one end of said metering valve member and means connecting said metering valve member to said plunger to afford movement of said valve member in said orifice in response to movement of said plunger to vary output pressure at said outlet port.

Claim 3

A hydraulic valve in accordance with claim 1 wherein said means for supporting and guiding one end of said meterIng valve member comprises a guide sleeve having an axial aperture which freely receives said one end of said metering valve member and interfits with said one end to provide a fluid seal between said valve member and said sleeve.

Claim 4

A hydraulic valve in accordance with claim 1 wherein said metering valve member is cylindrical and said variable cross section of said metering valve member is in the form of axially tapered flat.

Claim 5

A hydraulic valve in accordance with claim 1 wherein said metering valve member has a frustoconical portion intermediate two cylindrical portions.

Claim 6

A hydraulic valve in accordance with claim 1 including a free piston, means for supporting said free piston in said valve body for axial movement, said free piston having one end exposed to said first passage adjacent said outlet port and another end engaging said metering valve member to transmit a counter force from said piston to said plunger in a direction opposite to the input force on said plunger.

Claim 7

A hydraulic valve in accordance with claim 5 wherein said means for supporting said free piston comprises a guide sleeve having an axial aperture with said piston freely slidable therein and interfitting in said aperture to provide a fluid seal, a spacer in said valve body and a spring biasing said sleeve against said spacer.

Claim 8

A hydraulic valve in accordance with claim 6 wherein said valve body has an output chamber communicating with said first passage, an adapter threadably received in said valve body and having an aperture defining said valve outlet, said outlet communicating with said output chamber, a counterbore in said adapter providing a stop for said piston and wherein said spring is arranged around the path of travel of said piston to permit movement of said piston within the interior of said spring.

Claim 9

A hydraulic valve comprising a valve body having a bore, a valve inlet and a valve outlet, a first passage connecting said inlet and outlet, a plunger reciprocally received in said bore for controlling flow through said first passage from said inlet to said outlet, a metering chamber, a second passage communicating with said first passage and said metering chamber, a metering valve assembly including means defining an orifice and a metering valve member located axially of said plunger and movable with said plunger, said valve member having a portion with a variable cross section receivable in said orifice, a vent passage communicating with said metering chamber, a free piston located in tandem with said metering valve member and having one end engaging said metering valve member and another end exposed to said first passage downstream from said second passage so that fluid pressure on said exposed end causes a counterforce on said piston which is transmitted to said plunger by said metering valve member and which opposes the input force on the plunger.

Claim 10

A hydraulic valve comprising a valve body having a bore, a valve inlet and a valve outlet, a first passage connecting said inlet and outlet, a plunger reciprocally received in said bore for controlling flow through said first passage from said inlet to said outlet, a metering chamber, a second passage communicating with said first passage and said metering chamber, a metering valve assembly including means defining an orifice and a metering valve member located axially of said plunger and movable with said plunger, said valve member having a portion with a variable cross section receivable in said orifice, a vent passage communicating with said metering chamber, a free piston located in tandem with said metering valve member and having one end engaging said metering valve member and another end exposed to said first passage downstream from said second passage so that fluid pressure on said exposed end causes a counterforce on said piston which is transmitted to said plunger by said metering valve member and which opposes the input force on the plunger.

Claim 11

A hydraulic valve comprising a valve body having an axial bore, a plunger reciprocally received in said bore, said valve body having an inlet port and an outlet port, a first passage connecting said inlet port and said outlet port, a metering chamber in said body, a vent passage communicating with said metering chamber and adapted to communicate with a reservoir, an orifice for permitting fluid flow into said metering chamber, a second passage connecting said first passage to said metering chamber, a valve member having a free end and one end connected to said plunger and reciprocally received in said orifice to control fluid flow through said orifice and into said metering chamber, a first guide sleeve in said valve body for supporting the free end of said valve member and permitting movement of said free end axially of said guide sleeve, an output chamber in said body in communication with said first passage, a second guide sleeve, a spacer located between and separating said first and second guide sleeves, said spacer having an interior which receives the free end of said valve member, a free piston Reciprocal in said second guide sleeve and having one end exposed to said output chamber and the other end engaging the free end of said valve member.

Claim 12

A hydraulic valve comprising a valve body having an axial bore, a plunger reciprocally received in said bore, said valve body having an inlet port and an outlet port, a first passage connecting said inlet port and said outlet port, a metering chamber in said body, a vent passage communicating with said metering chamber and adapted to communicate with a reservoir, an orifice for permitting fluid flow into said metering chamber, a second passage connecting said first passage to said metering chamber, a valve member having a free end and one end connected to said plunger and reciprocally received in said orifice to control fluid flow through said orifice and into said metering chamber, a first guide sleeve in said valve body for supporting the free end of said valve member and permitting movement of said free end axially of said guide sleeve, an output chamber in said body in communication with said first passage, a second guide sleeve, a spacer located between and separating said first and second guide sleeves, said spacer having an interior which receives the free end of said valve member, a free piston Reciprocal in said second guide sleeve and having one end exposed to said output chamber and the other end engaging the free end of said valve member.