Patent ID: 7038576

Claim:
An electropneumatic acoustic horn ( 1 ; 100 ; 200 ; 300 ) comprising: at least an electric compressor unit ( 2 ) provided with at least a suction inlet ( 5 ) of air from outside and at least an outlet ( 6 ) for the compressed air; a sound wave generator ( 3 ) comprising at least an acoustic chamber ( 7 , 8 ; 107 , 108 ) provided with at least an opening ( 9 , 10 ) for introduction of pressurised air, an elastic membrane ( 11 , 12 ) being provided in said opening for sound generation and at least a volute wound acoustic duct ( 13 , 14 ; 213 ; 313 ; 314 ) defined between an outer shell ( 15 , 16 ; 115 , 116 ; 215 ; 315 ; 316 ) and a diaphragm ( 17 ; 217 ; 317 ), said acoustic duct ( 13 , 14 ; 213 ; 313 ; 314 ) being in communication with said acoustic chamber ( 7 , 8 ; 107 , 108 ) and adapted to propagate to the outside the sound produced by said membrane ( 11 , 12 ); air channelling means ( 4 ) adapted to put said outlet ( 6 ) of said the compressor ( 2 ) in communication with said opening ( 9 , 10 ) of said the acoustic chamber ( 7 , 8 ; 107 , 108 ); characterized in that said at least a compressor unit ( 2 ) and said sound wave generator ( 3 ) are mechanically connected in a removable way by fitting slidingly a collar ( 34 ; 234 ; 334 ).