Title: Small siren having protective screen

Abstract: A siren for an alarm adapted to be driven by a fractional horsepower motor and provided with a cup shaped rotor cooperating with a stator provided with perforations in the cylindrical flange thereof, and a drawn, cup-shaped screen or grille seated over the inlet to said stator and having a cylindrical flange extending over the perforations of the stator but spaced outwardly therefrom, the base of the screen being engaged on the stator rim. The intake air flow of the siren is restricted by the perforations of the screen which increases the velocity of the intake air, thereby increasing the efficiency of the siren which enables reduction of the current usage requirements. The harmonics of the output sound are increased by the perforated cylindrical flange of the screen thereby increasing the volume and pitch of the emitted sound.

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Inventors: Faust, James H. (Cicero, IL, US)

Application Number: 841120
Filing Date: 1977-10-11
Publication_date: 1979-02-06
Assignee: A B C Auto Alarms, Inc. (Elk Grove Village, IL)
Primary Class(es): 340/404.2 116/147
Other Classes:
US Patent Ref:

1428684	Sep, 1922	Erick	340/405.
2015387	Sep, 1935	Seiss	116/147.
2172413	Sep, 1936	Scott	340/405.
2528515	Nov, 1950	Heigis	116/147.
3121220	Feb, 1964	Buckwalter	116/147.
3991703	Nov, 1976	Faust	116/147.

Other Refs: 405649

Jan, 1910	FR

Primary Examiner: Swisher, S. Clement
Assistant Examiner: Corr, Denis E.
Attorney: Silverman, Cass & Singer, Ltd.