Patent ID: 8066645

Claim:
A bleed valve assembly for controlling the pressure change rate in a reservoir under pressure when venting fluid from the reservoir, said bleed valve assembly comprising: a bleed valve defining an interior chamber; a first flexible diaphragm disposed within and extending across the interior chamber of said bleed valve and sectioning the interior chamber into a first pressure chamber on a front side of said first diaphragm and a second pressure chamber on a rear side of said first diaphragm, said first diaphragm providing a seal between the first pressure chamber and the second pressure chamber, the first pressure chamber connected in direct pneumatic communication with the reservoir; a first vent passage between the first pressure chamber of said bleed valve and ambient pressure exterior of said bleed valve, said first vent passage having a regulated flow area; a second vent passage between the second pressure chamber of said bleed valve and an outlet, said second vent passage having a variable flow area; a selectively positionable control valve operatively associated with, and connected in pneumatic communication with, the interior chamber of said bleed valve, said control valve being selectively positionable in a first position for pressurizing the first pressure chamber, the second pressure chamber, and the reservoir; in a second position for venting the reservoir through the first vent passage and for simultaneously venting the second pressure chamber to ambient pressure through the second vent passage at a substantially constant pressure decrease rate, and in a third position for rapidly venting the reservoir to ambient pressure; a second flexible diaphragm disposed within the interior chamber of said bleed valve in spaced relationship with said first diaphragm to establish a third pressure chamber, the second pressure chamber extending between the rear side of said first diaphragm and a front side of said second diaphragm, the third pressure chamber being on a rear side of said second diaphragm, said second diaphragm having a hole passing therethrough providing pneumatic communication between the second pressure chamber and the third pressure chamber; and an axially elongated rod having a tapered tip positioned within the hole in said second flexible diaphragm, said second flexible diaphragm being moveable axially in operative association with the tapered tip of said rod to form said variable flow area.