| 摘要 |
<p>The safe detection and alarm system has a frame (1) which is closed by a panel (7). The frame (1) can project from or be buried in a vertical or horizontal plane such as a wall, floor or ceiling. The frame (1) encloses a pneumatic cushion (4) whose deformation or destruction triggers an electrical alarm circuit. The cushion (4) is formed by a rubber or plastic envelope which contains air or a neutral gas at a certain pressure. The cushion is in permanent contact with control levers of two microswitches (2, 3). These microswitches (2, 3) close the alarm circuit in the case of external pressure exerted on the cushion or for fall in pressure due to perforation of the cushion.</p> |
