Patent ID: 11961380
Assignee: ELECTRONIC MODULAR SERVICES LTD.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 9:
10. A method of propagating sound from a audible alarm device (AAD), wherein the AAD includes:
a housing extending upwardly in an axial direction and outwardly in a radial direction, the housing including a bottom portion that is an axial bottom portion that is cylindrical and a top portion that is an axial top portion that is frustoconical,
the top portion including a smoke chamber defined by:
a top surface that is substantially planar and having a first diameter, a bottom surface separating the top portion from the bottom portion, the bottom surface being substantially planar and having a second diameter that larger than the first diameter, a side surface that connects the top surface with the bottom surface, and a circumferential opening in the side surface providing fluid egress to the smoke chamber,

a piezo sounder being disposed in the smoke chamber, radially centered within the top portion and axially proximate the top surface of the top portion,
the method comprising directing sound from the piezo sounder to the bottom surface, whereby the sound resonates in the smoke chamber and spreads while propagating out of the smoke chamber through the circumferential opening,
wherein the smoke chamber includes a deflector ring connected within the top portion, the deflector ring being axially proximate and radially outside the piezo sounder, wherein the deflector ring has an arcuate cross section that opens in an axially downward direction to redirect sound that is resonating off the bottom surface, whereby the sound propagates out toward the circumferential opening.