| 摘要 |
The warning horn (1) comprises a support casing (2, 3) in which a vibratory diaphgram (4) is mounted. An excitation winding (7), also disposed in the casing (2, 3), is carried in a fixed position by an annular support (6). A movable ferromagnetic core (5) is connected to the diaphragm (4). The horn (1) also comprises a stationary magnetic circuit (10, 11) for conducting the magnetic flux (L) generated by the winding (7) and linked by the movable core (5). This stationary circuit comprises two annular, planar elements (10, 11a) of ferromagnetic material disposed parallel to one another and adjacent the opposite ends of the support (6) of the winding (7), and a substantially cylindrical, annlar wall (11b) also of ferromagnetic material, disposed around the support (6) of the winding (7). This cylindrical wall (11b) is preferably integral with one of the two planar elements (10, 11a). |
