Importance

Loading Importance Indicators...

Abstract

The invention is directed to a metering device for lung-demand valves and includes prepressure compensation. The metering device includes a valve body coacting with a valve seat for metering gas and a compensating piston is arranged between a primary pressure chamber and a secondary pressure chamber for transmitting the compensating force to the valve body. The compensating piston is guided in a compensating housing. The metering device is improved in that the compensating piston is movable without friction and a seal is easily secured. For this purpose, a membrane made of elastic material defines the seal unit. The membrane is tightly held and has a cylindrical side wall which is fixed in the compensating housing. The membrane has regions of reduced wall thickness on the periphery of the side wall and these regions are subdivided into segments or extend as one continuous portion around the periphery. The regions of reduced wall thickness act as a sealing lip.

Loading the Abstract Image...

First Claim