Patent ID: 6659247
Filing Date: 2003-12-09
Classification: B60T,G05D,Y10T

Abstract:
A valve assembly, comprising:a pilot port that receives pilot gas pressure; an operating gas supply port that receives operating gas pressure; an exhaust port; a housing having a first portion, a second portion, and an intermediate portion between said first and second portions, said pilot port passing through said first portion only and said operating gas supply port and said exhaust port both passing through said second portion; a pilot chamber that receives the pilot gas pressure from the pilot port, wherein said pilot chamber is located within said first portion; a first diaphragm located between said first and intermediate portions; a second diaphragm located between said second and intermediate portions; and a piston located between said first diaphragm and said second diaphragm and mounted for movement within said housing, wherein said first diaphragm and said second diaphragm are mounted in parallel and substantially in a planar relaxed position prior to any piston movement and whereby gas pressure from said supply port exceeds pressure in said pilot chamber, said piston moves said second diaphragm away from said supply port and said exhaust port, thereby permitting air flow from said supply port to said exhaust port.