| 摘要 |
<p>The alarm initiating system when actuated sends an alarm signal by interrupting an electric current to a central surveillance centre. The device uses a manometer capsule (19), which, when one of its walls is deformed, actuates a contact (31) in a voltage supplied alarm circuit. An airtight pneumatic box communicates with the manometer capsule (19.) The pneumatic box (7) has a spring tensioned membrane (9) which the user in cases of danger presses with his foot. The membrane (9) is made from a sheet of supple material, soft rubber for example and has a thickness such that it is not easily perforated. The pneumatic box (7), manometer capsule (19) and electrical contacts (33,31,43) are mounted inside a housing (5) having means (43,41) for sending an alarm signal by current interruption if opening of the housing is attempted by unauthorised persons.</p> |
