Armoured siren for motor vehicle

摘要

The siren has a sound production assembly (3) to transform an electrical signal created by an electronic card into a sound signal. The assembly forms a cover for an inner casing (5). A closure unit closes the assembly on the inner casing. An inner surface (29) of a main wall (20) and an outer surface (34) of the assembly, placed in opposite to the inner surface, forms an air compression chamber (8) for producing sound. The sound production assembly is constituted of a piezoelectric or electromagnetic unit associated to a diaphragm.