| 摘要 |
PURPOSE: To prevent the trouble of a fire sensor due to the shock of its fall, etc., without reducing the sound volume of the alarm tone of the sensor. CONSTITUTION: A piezoelectric buzzer 6 is mounted on a printed board 7 and the board 7 is fixed on the bottom surface of a body 3 by a screw. A sensor part 4 is attached to the top part of an almost cone-shaped cover 2 which is connected to the body 3. A pair of pressure ribs 10 protrude over the inside face of the cover 2 opposite to the buzzer 6 and touche the buzzer 6. At the same time, a pair of side ribs 11 are provided on the bottom surface of the body 3 and touch the circumference face of the buzzer 6. The plane including the ribs 10 is almost orthogonal to the plane including the ribs 10 so that the up-down movement of the buzzer 6 is regulated by the ribs 10 and the front-back or right-left movement of the buzzer 6 is regulated by the ribs 11 respectively. As a result, the movement of the buzzer 6 is regulated against the external shock and the faults of the buzzer 6 due to the breakage of a terminal part 6b, etc., can be prevented. |
