Method to detect penetration of a surface and apparatus implementing same

• US 5,568,124 A
• Filed: 05/20/1993
• Issued: 10/22/1996
• Est. Priority Date: 05/20/1993
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Joyce, Richard J., Kramer, Allan R.
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/064,680
• Time in Patent Office: 1,251 Days
• Field of Search: 340/550, 340/544, 109/29, 109/31, 109/38, 109/42, 109/34, 385/13
• US Class Current: 340/550
• CPC Class Codes: G08B 13/126 for a housing, e.g. a box, a safe, or a room

Abstract

Apparatus and method for detecting unauthorized disturbance of a protected surface, includes a substrate adapted to conformably encase and adhere to the surface that is to be protected. A plurality of layers, each comprising a plurality of frangible conduits is embedded in the substrate and randomly overlays a majority of the protected surface. Each of the conduits has its ends protruding from the substrate to permit a monitor to be coupled thereto for monitoring the integrity of the continuity of each conduits, and for switching from a first state to a second state whenever the continuity of any of the conduits is broken. A warning alarm is coupled to the monitor for displaying the state of the monitor.

Claims

1. Apparatus for detecting unauthorized disturbance of a protected surface, comprising:

a substrate adapted to conformably encase and adhere to the protected surface, wherein said substrate is comprised of a conductive compound;

a plurality of frangible conduit means embedded in said substrate and randomly overlaying at least a first portion of the protected surface, each of said plurality of frangible conduit means having its ends protruding from said substrate, wherein said plurality of frangible conduit means embedded in said substrate comprises a plurality of electrically conductive wires having a frangible insulative covering thereon;

monitor means, coupled to said protruding ends of said plurality of frangible conduit means, for monitoring the integrity of the continuity of each of said plurality of frangible conduit means and for switching from a first state to a second state whenever the continuity of any of said plurality of frangible conduit means is broken, wherein said monitor means is further coupled to said substrate and switches from said first state to said second state whenever conduction is detected between any of said plurality of frangible conduit means and said substrate, and

display means coupled to said monitor means for displaying said first and second states of said monitor means.

2. Apparatus for detecting unauthorized disturbance of a protected surface, comprising:

a substrate adapted to conformably encase and adhere to the protected surface wherein said substrate is comprised of a conductive compound;

at least one frangible conduit means embedded in said substrate and randomly overlaying at least a first portion of the protected surface and having, for each of said at least one frangible conduit means, at least one end protruding therefrom, wherein said at least one frangible conduit means embedded in said substrate comprises a plurality of electrically conductive wires having a frangible insulative covering thereon;

monitor means, coupled to each of said protruding ends of said at least one frangible conduit means, for monitoring the integrity of the continuity of said at least one conduit means and for switching from a first state to a second state whenever the continuity of any of said conduit means is broken, wherein said monitor means is further coupled to said substrate and switches from said first state to said second state whenever conduction is detected between any of said plurality of conduit means and said substrate; and

display means coupled to said monitor means for displaying said first and second states of said monitor means.