Pressure-sensitive metering valve

Claim 2

In a metering valve the combination including a body defining a bore, an inlet port leading to said bore, an outlet port leading from said bore, a valve seat in said bore surrounding said inlet port, a fiRst valve in said bore having a sealing element engageable with said seat, a second valve in said bore engageable with said sealing element, a first spring urging said sealing element against said seat, pressure-responsive means in said bore supporting said first spring, said pressure-responsive means being retractable in response to increased pressure in said bore, a second spring supported at one end by said body and urging said pressure-responsive means toward said first spring, said pressure-responsive means urging said second valve away from said sealing element, whereby said first and second valves initially permit communication of fluid between said inlet port and said outlet port through bore and thereafter withhold the application of fluid pressure to said bore over a predetermined range of fluid pressure and subsequently are effective to reduce the pressure differential at a linear rate over a second range of fluid pressure.

Claim 3

The combination as set forth in claim 1, wherein said pressure-responsive means is in the form of a diaphragm.

Claim 4

In a pressure-sensitive metering valve, the combination including a body defining a bore extending inwardly from one end of said body, said body defining an inlet port connected to the inner end of said bore, said body defining an outlet port communicating with said bore, a first valve controlling the flow of fluid between said inlet port and said bore, a seat for said first valve, said seat and said first valve defining a passageway permitting the flow of fluid between said inlet port and said bore, a second valve disposed in the passageway defined by said first valve and said seat and adapted to engage said first valve in sealing relation to close said passageway, pressure-responsive means disposed in said bore in spaced relationship with respect to said first valve, a first spring disposed in said bore between said first valve and said pressure-responsive means, a second spring disposed in said bore between said pressure-responsive means and said one end of said body, both said springs opposing opening movement of said first valve, said pressure responsive means being effective to reduce the biasing force of said springs acting upon said first valve in proportion to an increase in pressure in said bore, means opposing closing movement of said second valve relative to said first valve, said pressure-responsive means being effective to overcome said last-mentioned means permitting said second valve to engage said first valve in sealing relation, and means permitting relative movement between said second valve and said pressure-responsive means.

Claim 5

In a pressure-sensitive metering valve, the combination including a body defining a bore extending inwardly from one end of said body, said body defining an inlet port connected to the inner end of said bore, said body defining an outlet port communicating with said bore, a first valve controlling the flow of fluid between said inlet port and said bore, a seat for said first valve, said seat and said first valve defining a passageway permitting the flow of fluid between said inlet port and said bore, a second valve disposed in the passageway defined by said first valve and said seat and adapted to engage said first valve in sealing relation to close said passageway, pressure-responsive means disposed in said bore in spaced relationship with respect to said first valve, a first spring disposed in said bore between said first valve and said pressure-responsive means, a second spring disposed in said bore between said pressure-responsive means and said one end of said body, both said springs opposing opening movement of said first valve, said pressure responsive means being effective to reduce the biasing force of said springs acting upon said first valve in proportion to an increase in pressure in said bore, means opposing closing movement of said second valve relative to said first valve, said pressure-responsive means being effective to overcome said last-mentioned means permitting said second valve to engage said first valve in sealing relation, and means permitting relative movement between said second valve and said pressure-responsive means.

Claim 6

The combination as set forth in claim 3, said second spring being supported at one end by said body and urging said pressure-responsive means toward said first spring whereby the pressure differential between said inlet and outlet ports decreases as a linear function in proportion to the inlet pressure and is reduced to zero at a predetermined inlet pressure.

Claim 7

The combination as set forth in claim 3, said first valve and said second valve having mutually engageable surfaces separable in response to a decrease in fluid pressure at said inlet port whereby fluid may flow from said outlet port to said inlet port through said passageway when the pressure in said bore is greater than the pressure at said inlet port.

Claim 8

In a pressure-sensitive metering valve, the combination including a body defining a bore extending inwardly from one end of said body, said body defining an inlet port communicating with the inner end of said bore, said body also defining an outlet port communicating with said bore, a first valve controlling the flow of fluid from said inlet port to said bore, a valve seat in the inner end of said bore, said first valve and said seat defining aligned passageways permitting the flow of fluid between said inlet port and said bore, a second valve disposed in the passageway defined by said seat and engageable with said first valve, a diaphragm mounted in said bore in sealed relationship with said body and in spaced relation with said first valve, a first spring disposed in said bore between said first valve and diaphragm, a second spring disposed in said bore between said diaphragm and said one end of said body, both said springs opposing opening movement of said first valve with the biasing force of said springs acting upon said first valve being reduced in proportion to an increase in pressure in said bore, piston means opposing movement of said second valve toward first valve, said diaphragm being effective to counteract said piston means and permitting said second valve to engage said first valve to close said passageways when the pressure in said bore reaches a predetermined value.

Claim 9

In a pressure-sensitive metering valve, the combination including a body defining a bore extending inwardly from one end of said body, said body defining an inlet port communicating with the inner end of said bore, said body also defining an outlet port communicating with said bore, a first valve controlling the flow of fluid from said inlet port to said bore, a valve seat in the inner end of said bore, said first valve and said seat defining aligned passageways permitting the flow of fluid between said inlet port and said bore, a second valve disposed in the passageway defined by said seat and engageable with said first valve, a diaphragm mounted in said bore in sealed relationship with said body and in spaced relation with said first valve, a first spring disposed in said bore between said first valve and diaphragm, a second spring disposed in said bore between said diaphragm and said one end of said body, both said springs opposing opening movement of said first valve with the biasing force of said springs acting upon said first valve being reduced in proportion to an increase in pressure in said bore, piston means opposing movement of said second valve toward first valve, said diaphragm being effective to counteract said piston means and permitting said second valve to engage said first valve to close said passageways when the pressure in said bore reaches a predetermined value.

Claim 10

The combination as set forth in claim 6, said second spring being supported at one end by said body and urging said diaphragm toward said first spring whereby the pressure differential between said inlet and outlet ports decreases as a linear function in proportion to the inlet pressure and is reduced to zero at a predetermined inlet pressure.

Claim 11

The combination as set forth in claim 7, said first valve and said seat having mutually engageable surfaces separable in response to an increase in fluid pressure at said inlet port, said first valve and said second valve having mutually engageable surfaces engageable in response to an increase in fluid pressure in said bore and separable in response to a decrease in fluid pressure in said bore whereby fluid may flow from said bore to said inlet port when the pressure in said bore is greater than the pressure at said inlet port.

Claim 12

The combination as set forth in claim 8, including means permitting relative movement between said second valve and said diaphragm upon movement of said first valve relative to said seat.

Claim 13

The combination as set forth in claim 9, said second valve having a reduced diameter stem portion passing through the passageway defined by said first valve and terminating at a pointed end, said diaphragm having a resilient boss portion engageable with said pointed end of said second valve, said pointed end of said second valve penetrating said boss upon opening movement of said first valve relative to said seat whereby said second valve is maintained in engagement with said first valve upon movement of said first valve relative to said diaphragm.