No title available

• US 3,594,770 A
• Filed:
• Issued:
• Est. Priority Date: 10/28/1968
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Time in Patent Office: Days
• US Class Current: 340/550
• CPC Class Codes: G08B 13/126 for a housing, e.g. a box, a safe, or a room

Abstract

A guarding apparatus responsive to violation of the security of an area or space, comprising a printed or similar gridlike circuit configuration of conductors, preferably of resistance characteristic, connected to form one or several continuous trigger circuits. The configuration may be in the nature of printed circuit panels arranged to enclose, preferably completely, the desired area of security, as by constituting part of the walls, floor, junction or connector boxes and the like. The circuitry is connected, as by a cable, to an energized electrical detector which may comprise an instrument movement and a bridge, whereby any shorting or breaking of one or more of the printed or similar conductors will result in a response by the instrument movement.

Claims

2. An apparatus as in claim 1 wherein:

a. the grid comprises four independent circuits, b. said detection circuit comprising an electrical bridGe, c. said four independent circuits of the wire mesh being connected respectively in the four legs of the bridge.

3. An apparatus as in claim 2, wherein:

a. two of the independent circuits of the grid comprise conductors on one side of the sheet, b. the remaining two of the independent circuits of the grid comprising conductors on the other side of the sheet.

4. An apparatus as in claim 1, wherein:

a. the grid comprises a single continuous circuit constituted of insulated sets of conductors disposed on opposite sides of the insulating sheet.