Alarm system for safeguarding against the break-through of a surface

• US 4,578,670 A
• Filed: 03/04/1983
• Issued: 03/25/1986
• Est. Priority Date: 07/06/1981
• Status: Expired due to Fees

• Current Assignee: Poul R. Joergensen
• Original Assignee: Poul R. Joergensen
• Inventors: Joergensen, Poul R.
• Primary Examiner(s): Swann, III, Glen R.
• Application Number:
  US06/485,126
• Time in Patent Office: 1,117 Days
• Field of Search: 340/550
• US Class Current: 340/550
• CPC Class Codes: G08B 13/126 for a housing, e.g. a box, a safe, or a room
• CPC Class Codes: H05K 1/02 Details

Abstract

An alarm system for safeguarding against the breakthrough of a wall includes a network of electrically conducting wires distributed over the wall and arranged to lie in at least two layers which are spaced a small distance from each other. The wires are comprised of a series consisting of a predetermined number of wires running uninterrupted through the layers with each wire having an input terminal in a corresponding output terminal. Some of the input terminals are provided with a first voltage or signal and other input terminals are provided with a second voltage or signal which is different from the first voltage or signal. An electronic device is connected to the output terminals for actuating an alarm when the voltage or signal on any one of the output terminals does not correspond to the voltage or signal on the corresponding input terminal.

Claims

1. An alarm system for safeguarding against the breakthrough of a wall comprising:

a network of electrically conducting wires distributed over the wall and arranged to lie in at least two layers which are spaced a small distance from each other;

said wires comprised of a group consisting of a predetermined number of wires running uninterrupted through the layers;

each wire having an input terminal and a corresponding output terminal;

the input terminals provided with respective set input voltages or signals;

the respective set input voltages or signals producing corresponding set output voltages or signals on corresponding output terminals when the alarm system is set and unactivated;

at least one of the input terminals being provided with a set input voltage or signal which is different from the set input voltage or signal of at least one of the other input terminals; and

electronic means connected to the output terminals for activating an alarm when the output voltage or signal on at least one of the output terminals does not correspond to the set output voltage for that terminal.

2. A system according to claim 1 wherein the wires in each layer are connected in series to the wires in at least one other layer so that the group of wires runs first over the whole of a first layer and from there runs over the whole of another layer.

3. A system according to claim 1 wherein the wires in each layer are parallel with the wires within the layer over the greater part of the surface area but are positioned at angles to wires in at least one other layer.

4. A system according to claim 1 wherein the wires are at least partially surrounded by an insulating material.

5. A system according to claim 1, including an insulating printboard support layer, said insulating support layer including a printed circuit on each side to comprise two electrically connected wire surfaces connected in series.

6. A system according to claim 5 wherein the printboard is less than 0.5 mm thick.

7. A system according to claim 1 wherein the distance between the individual wires in each layer is less than 5 mm.

8. A system according to claim 1 wherein the group is comprised of four wires.

9. A system according to claim 1 wherein the input terminal of each wire has either the same voltage as the first of said input terminals or the same voltage as the second of said input terminals.

10. A system according to claim 1 wherein the wires are uniformly distributed over said wall.

11. A system according to claim 10 wherein the electronic means includes means for converting a binary input received from the output terminals into a non-binary output.