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WIRELESS ALARM SYSTEM

  • US 3,641,540 A
  • Filed: 03/30/1970
  • Issued: 02/08/1972
  • Est. Priority Date: 03/30/1970
  • Status: Expired due to Term
First Claim
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1. An alarm system for detecting the movement of the top window or the bottom window of a double-hung window which in its closed position closes an opening comprising:

  • a transmitter for generating a wireless signal;

    a relatively constant voltage power source;

    switch means;

    said switch means being disposed so as to detect movement of the top window or the bottom window;

    said switch means being actuated upon the movement of the top window or the bottom window a predetermined amount;

    said switch means being automatically deactuated during normal opening of the top or bottom window after a relatively short period of time after actuation;

    means electrically interconnecting said transmitter, said relatively constant voltage power source and said switch means so that actuation of said switch means during normal opening of the top or bottom window causes said transmitter to draw power from said relatively constant voltage power source for said relatively short period of time and to thereby transmit a wireless signal for said relatively short period of time;

    said transmitter, said relatively constant voltage power source and said sWitch means being electrically interconnected so that upon the expiration of said relatively short period of time said switch means prevents said transmitter from drawing power from said relatively constant voltage power source and further prevents said transmitter from generating a wireless signal;

    means for receiving said wireless signal;

    alarm means;

    means connecting said receiving means to said alarm means so that reception of said wireless signal by said receiving means causes actuation of said alarm means for a period of time longer than said relatively short period of time;

    means for disconnecting said alarm means so that generation of said wireless signal does not function to actuate said alarm means;

    said switch means comprising a first switch unit mounted to either the bottom or the top window;

    a second switch unit mounted to the other of the bottom or the top window;

    said first switch unit being comprised of such a material as to be displaced by a magnetic field;

    said second switch unit comprising magnetic field generating means whereby displacement of the top window or displacement of the bottom window said predetermined amount causes actuation of said transmitter.

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