| 摘要 |
1,274,684. Buzzer. P. SPADINI. 16 June, 1969 [17 June, 1968 (2)], No. 30343/69. Heading G5J. An armature 20 is secured to the centre of a spring blade 19 anchored at both ends to a base 1, the armature being coupled to a magnetic circuit 4, 5, 6 carrying coils 11, 12 forming part of a transistor oscillator circuit mounted on the same base. As the blade 19 vibrates a central projection 21 strikes a plastics diaphragm 22 carried on a threaded ring 24 adjustable against a gasket 28 and locked by a threaded cover 27. Alternatively, the magnetic assembly may be adjustable relatively to the diaphragm. The whole buzzer, including oscillator, may be formed as a self contained unit detachable from associated apparatus but with plug and socket connection for the power supply. |
