| 摘要 |
<p>A glazing alarm consists of a pane of toughened glass (28) and a device which when the glass pane (28) is broken sends an electrical pulse. The device that sends the electrical pulse comprises a physical support (a housing 26) joined to the glass pane (28) and a spring under elastic deformation (a helical spring 39). When compressed, one end of the spring (39) bears against the end (31) of the housing (26) and the other end through an intermediate pusher (37) against the surface of the pane of glass (28). When the pane of glass (28) is broken, the spring (39) expands owing to the disappearance of the fragments of glass. The physical contact between the contacts (34, 37) is consequently interrupted, triggering the signal setting off the alarm. <IMAGE></p> |
