Aerosol operated horn

Claim 1

An audio frequency signal device operated by gas under pressure supplied from a container of pressurized fluid, the container having a normally closed discharge valve; the device having a body and an outwardly flared horn converging to a throat within the body; the discharge valve of the container having a valve element urged by a compression spring against a seat having a discharge port normally closed by the valve element, the port having a side wall, the valve being adapted so that inward movement of the valve element away from the seat opens the valve so that gas under pressure discharges through the port; the audio frequency device being characteriZed by a combination including: a. means to secure the signal device to the container, b. means to open and release the discharge valve of the container when the signal device is secured to the container including, i. a push rod having outer and inner ends, the rod extending transversely through the device, and being adapted for longitudinal movement relative thereto, ii. an outer transverse bore through the body to the throat, an inner transverse bore from the throat through the body, the bores being aligned, with the push rod slideable longitudinally of the bores between an extended position at which the discharge valve is open, and a released position at which the discharge valve is closed, iii. means to move the push rod between the extended and released positions, constructed and arranged for movement as aforesaid of the push rod to open and to release the discharge valve; and wherein, iv. the inner bore has a counterbore forming a discharge port, v. a passage extends from the counterbore to an annular chamber of the signal device, constructed and arranged so that, when the discharge valve is open, gas under pressure flows to the counterbore, thence through the passage to the annular chamber so causing the device to operate emitting an audio frequency signal; and wherein vi. the inner end of the push rod has a diameter less than that of the discharge port, constructed and arranged so that the inner end of the push rod in its extended position passes through the discharge port opening the valve as aforesaid, discharge from the exhaust port being through a space defined between the push rod and the port side wall; and wherein the means (c) includes: vii. a push rod portion of reduced diameter near its inner end, the reduced diameter portion being in a position such that, in the extended position, it is within the discharge port, discharge through the port then being maximum, viii. means to limit outward movement of the push rod.