Door reinforcement with alarm initiation - uses metal strips fixed to surface to provide mechanical strength and generate signal in piezoelectric transducer for alarm

摘要

The device includes a series of metal pieces attached to the door to provide mechanical strength or to generate an alarm signal in the event of an attempt to force the door. The re-inforcement comprises lengths of standard size metal strip or angles fixed to the door surface by an overlapping joint which is covered by a metal embellisher. The fixture uses a threaded bolt screwing into an insert in the door panel. The bolt is driven by a threaded driver to make illicit removal difficult. The electrical protection uses a piezoelectric transducer fitted between the fixed strips and their attachment. Any relative motion due to force on the door is thus transmitted to a transistor alarm circuit.