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Anti-theft screen construction

  • US 4,293,778 A
  • Filed: 02/12/1979
  • Issued: 10/06/1981
  • Est. Priority Date: 03/06/1978
  • Status: Expired due to Term
First Claim
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1. A partially conductive security screen arrangement for use with an intrusion alarm system designed to operate in a normally closed sensing circuit condition and to produce a warning signal when the sensing circuit is broken, said arrangement comprising:

  • screen apparatus including a frame defining a central aperture, screening material comprising a mesh of interwoven strands covering said aperture and having a plastic coating, and means for securing the periphery of said screening material to said frame to close said aperture, said screen apparatus positionable to cover an opening in a building;

    electrically conductive means continuous between two ends thereof, including wire means having a plastic coating and at least partially overlying said screen apparatus, said wire means being bonded to the screening material by thermal fusing of the respective plastic coatings to prevent passage of a human being through said aperture unless said conductive means is severed,means for connecting said conductive means at the two ends thereof into the sensing circuit as a series element thereof;

    whereby passage of a human being through the opening for said screen apparatus in position to cover said opening breaks the sensing circuit.

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