Diaphragm valve sound transmitters operating on gaseous pressure medium

Claim 1

A gaseous pressure medium operated diaphragm valve sound transmitter comprising a housing, a diaphragm in said housing dividing the interior of said housing into an inlet chamber and a back pressure chamber, first inlet means for introducing gaseous pressure medium into the inlet chamber of said housing, second inlet means for introducing gaseous pressure medium into the back pressure chamber of said housing, control means for controlling the pressure of the gaseous pressure medium in the back pressure chamber of said housing resonance horn means connected to said housing, outlet passage means having one end positioned in said housing and merging at the other end into said resonance horn means, a valve seat at said one end of said outlet passage means in said housing, said diaphragm being blocked in abutment against said valve seat when said control means maintain full pressure of the gaseouS pressure medium in the back pressure chamber, and oscillating towards and away from said valve seat when said control means are adjusted to maintain lower than full pressure of the gaseous pressure medium in the back pressure chamber, and support means in said outlet passage means adjacent said valve seat, said support means being spaced from said diaphragm a distance greater than the deflection of said diaphragm towards said support means during oscillation but smaller than the maximum diaphragm deflection permissible in view of stresses.