GLAZING

• US 20160101603A1
• Filed: 05/29/2014
• Published: 04/14/2016
• Est. Priority Date: 05/29/2013
• Status: Active Grant

• Current Assignee: Pilkington Group Limited
• Original Assignee: Pilkington Group Limited
• Inventors: BOOTE, Joseph Jeremy
• Granted Patent: US 9,764,533 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10394 Alarm wires
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: G01N 27/00 Investigating or analysing materials by the use of electric, electrochemical, or magnetic means G01N3/00 – G01N25/00 take precedence; measurement or testing of electric or magnetic variables or of electric or magnetic properties of materials G01R
• CPC Class Codes: G08B 13/04 by breaking of glass

Abstract

A glazing having a device for detecting a crack in the glazing comprises a sensor, substantially circumscribing a ply of glazing material. A surface contact, bonded to the glazing, is configured with a portion of the sensor to form a capacitive coupling for transferring AC signals in a frequency range. Preferably the sensor is frangible and voltage may be applied by a second surface contact. Alternatively, the glazing further comprises an electrically resistive element, such as a coating for heating the glazing, and voltage may be applied to the sensor by a spur from a busbar such that damage to coating, busbar or sensor resulting in arcing is detectable at the surface contact. An electronics module attached to the surface contact generates an alarm.

Claims

1. A glazing comprising:

a ply of glazing material having a surface;

a sensor for sensing a voltage modulated by damage to the ply of glazing material, said sensor substantially circumscribing the ply of glazing material; and

a surface contact bonded to the surface configured with a portion of the sensor to form a capacitive coupling for transferring AC signals in a frequency range.

2. A glazing according to claim 1, wherein the sensor is frangible and the voltage is induced by an ambient AC signal and modulation of the voltage occurs when damage to the ply of glazing material causes the sensor to break and reduce an amplitude of the ambient AC signal.

3. A glazing according to claim 1, wherein the sensor is frangible and further comprising a second surface contact bonded to the surface of the ply of glazing material configured with a sensor portion to form a capacitive coupling for transferring AC signals in a frequency range and an AC voltage is applied to the sensor via the second surface contact.

4. A glazing according to claim 3, wherein modulation of the voltage occurs when damage to the ply of glazing material causes the sensor to break and arcing occurs adding a characteristic AC signal to the voltage.

5. A glazing according to claim 1, further comprising an electrically resistive element on a surface of the ply of glazing material.

6. A glazing according to claim 5, wherein modulation of the voltage occurs when damage to the ply of glazing material causes arcing which induces a characteristic AC signal in the sensor.

7. A glazing according to claim 5, wherein the electrically resistive element is on an inner surface of the ply of glazing material.

8. A glazing according to claim 5, wherein the electrically resistive element is on an inner surface of an inner ply of glazing material.

9. A glazing according to claim 5, wherein the sensor comprises a sensor portion which is electrically connected to a busbar by a connecting section for applying a heater circuit voltage to the sensor and modulation of the heater circuit voltage occurs when damage to the ply of glazing material causes a discontinuity in the electrically resistive element, a busbar or the sensor resulting in arcing which adds a characteristic AC signal in the sensor.

10. A glazing according to claim 5, further comprising a second surface contact bonded to the surface of the ply of glazing material configured with a sensor portion to form a capacitive coupling for transferring AC signals in a frequency range and an AC voltage is applied to the sensor via the second surface contact and modulation of the AC voltage occurs when damage to the ply of glazing material causes a discontinuity in the electrically resistive element, a busbar or the sensor resulting in arcing which adds a characteristic AC signal in the sensor.

11. A glazing according to claim 1, further comprising an obscuration band on a surface of the ply of glazing material.

12. A glazing according to claim 1, wherein the surface contact further comprises an electronics module.

13. A glazing according to claim 1, wherein the sensor is configured in a periphery of the ply of glazing material.

14. A glazing according to claim 1, wherein the voltage modulated by damage to the ply of glazing material is in the range 0.1 MHz to 6 GHz.

15. A crack detector comprising a glazing according to claim 1 and an electronics module, wherein the voltage modulated by damage to the ply of glazing material is detected at the surface contact by the electronics module and compared with at least one reference value.