Regulator second stage for scuba

Claim 1

A regulator device of an underwater breathing apparatus of the type including a housing having an inlet adapted to be connected to a source of compressed gas and a mouthpiece outlet adapted to be connected to a mouthpiece means, and demand valve means for controlling the flow of breathing gas from said inlet to said outlet, the improvement comprising: said housing having a first partition means mounted in and separating the interior of said housing into a respiratory chamber communicating with said mouthpiece outlet, and an ambient chamber communicating to the exterior of said regulator device; said first partition means having first and second closely spaced openings therein; diaphragm means adapted to overlay said first of said closely spaced openings in said first partition means, said diaphragm means flexibly responsive to pressure differences between said respiratory chamber and said ambient chamber; exhaust valve means overlaying said second of said closely spaced openings, said exhaust valve means arranged to selectively provide unidirectional fluid flow from said respiratory chamber to the exterior of said regulator device via said ambient chamber; second partition means situated within said ambient chamber and separating said ambient chamber into first and second outer chambers, each outer chamber having at least one opening communicating separately to the exterior of said regulator device, exhaust fluids flowing through said exhaust valve means to the exterior of said regulator device exclusively via said first outer chamber, said diaphragm means being exposed to ambient pressure exclusively via said second outer chamber; and said each exterior opening of said first outer chamber being disposed below said diaphragm means, and said exhaust valve means being disposed above said diaphragm means, when said mouthpiece outlet is disposed above said diaphragm means.