| 摘要 |
<p>The acoustic warning device comprises a casing (1) in which at least one resiliently deformable diaphragm (10, 11) is mounted. In the casing (1) there is also mounted, in a fixed position, at least one excitation winding (19, 20). A movable ferromagnetic member (8, 9), subjected in use to the magnetic field generated by the winding (19, 20), is connected to the diaphragm (10, 11). The movable ferromagnetic member (8, 9) includes a substantially bell-shaped axial end portion (8a, 9a), disposed around the winding (19, 20).</p> |
