US3825920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laminated security window system
Assignee: Sierracin Corp
•
Filing: 1972-11-16
•
Granted: 1974-07-23
•
Expires: 1992-11-16
Abstract
Abstract A security window system having a transparent structure having high resistance to penetration is described. A transparent conductive layer is provided over most of the area of the window and the resistance of the layer is monitored for sensing penetration. Preferably the layer is subdivided into a number of conductive regions for substantially increasing the sensitivity of the system to minor interruptions in the layer. Temperature and stress effects can be minimized by connecting different conductive areas of the layer as arms of a resistance bridge. An alarm may be sounded when a small steady state change in resistance is sensed or when a rapid change in resistance is sensed.
Inventors
- 👤 R Nelson
- 👤 C Lucky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:56
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/04; B; B32; B32B; B32B17/00; B32B17/06; B32B17/10; B32B17/10005; B32B17/10009; B32B17/10036; B32B17/10082; B32B17/10091; B32B17/10165; B32B17/10174; B32B17/1055; B32B17/10761
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
73 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude.
Claim 2
Dependent Claim
73 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude.
Claim 3
Dependent Claim
35 words
A security window system as defined in claim 1 further comprising means for resetting the system after a change in resistance for providing an output signal in response to a subsequent analog change in resistance.
Claim 4
Dependent Claim
104 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer; means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude; means for resetting the system after a change in resistance for providing an output signal in response to a subsequent analog change in resistance; and means for recording cumulative changes in resistance.
Claim 5
Dependent Claim
104 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer; means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude; means for resetting the system after a change in resistance for providing an output signal in response to a subsequent analog change in resistance; and means for recording cumulative changes in resistance.
Claim 6
Dependent Claim
95 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window and divided into at least two conductive areas; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer comprising means for detecting a change in the relative resistances of the two areas; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude.
Claim 7
Dependent Claim
95 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window and divided into at least two conductive areas; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer comprising means for detecting a change in the relative resistances of the two areas; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude.
Claim 8
Dependent Claim
29 words
A security window system as defined in claim 4 wherein the means for detecting comprises a bridge and the two conductive areas are in adjacent arms of the bridge.
Claim 9
Dependent Claim
29 words
A security window system as defined in claim 1 wherein the means for detecting comprises a bridge and wherein the conductive layer is in one arm of the bridge.
Claim 10
Dependent Claim
97 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer comprising a resistance bridge; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude; and wherein the conductive layer is divided into at least four conductive areas each in an arm of the bridge.
Claim 11
Dependent Claim
97 words
A security window system comprising: a transparent electrically conductive layer extending over most of the area of the window; a set of bus bars in electrical contact with opposite edge portions of the conductive layer; means connected to the bus bars for detecting an analog change in resistance of the conductive layer comprising a resistance bridge; and means for providing an output signal in response to a detected change in resistance in excess of a predetermined magnitude; and wherein the conductive layer is divided into at least four conductive areas each in an arm of the bridge.
Claim 12
Dependent Claim
26 words
A security window system as defined in claim 1 comprising: a frangible layer; and a resilient layer isolating the electrically conductive layer from the frangible layer.
Claim 13
Dependent Claim
38 words
A security window system as defined in claim 1 wherein the electrically conductive layer is laminated between a pair of rigid face plies and including a resilient layer between the conductive layer and each of the rigid plies.
Claim 14
Dependent Claim
70 words
A security window system comprising: a transparent sheet; an electrically conductive layer extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit.
Claim 15
Dependent Claim
70 words
A security window system comprising: a transparent sheet; an electrically conductive layer extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit.
Claim 16
Dependent Claim
33 words
A security window system as defined in claim 10 further comprising means for resetting the system after a change in resistance for detecting a subsequent change in resistance greater than a predetermined limit.
Claim 17
Dependent Claim
109 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least two conductive areas and the means for detecting is connected thereto for detecting a change in the relative resistances of the two areas.
Claim 18
Dependent Claim
109 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least two conductive areas and the means for detecting is connected thereto for detecting a change in the relative resistances of the two areas.
Claim 19
Dependent Claim
99 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variatiOn in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least two conductive areas in adjacent areas in adjacent arms of a resistance bridge.
Claim 20
Dependent Claim
99 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variatiOn in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least two conductive areas in adjacent areas in adjacent arms of a resistance bridge.
Claim 21
Dependent Claim
97 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least four conductive areas each in an arm of a resistance bridge.
Claim 22
Dependent Claim
97 words
A security window system comprising: a transparent sheet; an electrically conductive layer laminated within the transparent sheet and extending over most of the area of the transparent sheet for making an analog variation in an electrical signal applied thereto in response to penetration of the transparent sheet; means for applying an electrical signal to the conductive layer; and means connected to the conductive layer for detecting a variation in electrical signal greater than a predetermined limit; and wherein the conductive layer is divided into at least four conductive areas each in an arm of a resistance bridge.
Claim 23
Dependent Claim
88 words
A laminated security window system comprising: an electrically conductive layer within the laminated window and extending over most of the area of the window; means for making electrical contact with edge portions of the conductive layer for applying an electrical signal thereto; means for detecting a change in resistance of the conductive layer from a first value to a second value; and means for providing an output signal when the change in resistance from the first value to the second value is in excess of a predetermined magnitude.
Claim 24
Dependent Claim
88 words
A laminated security window system comprising: an electrically conductive layer within the laminated window and extending over most of the area of the window; means for making electrical contact with edge portions of the conductive layer for applying an electrical signal thereto; means for detecting a change in resistance of the conductive layer from a first value to a second value; and means for providing an output signal when the change in resistance from the first value to the second value is in excess of a predetermined magnitude.
Claim 25
Dependent Claim
42 words
A security window system as defined in claim 15 further comprising means for resetting the system after a change in resistance for providing an output signal in response to a subsequent change of resistance from the second value to a third value.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-22 | 1978-01-21 | 1978-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-22 | 1982-01-21 | 1982-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-22 | 1986-01-21 | 1986-07-23 | $7700.00 | Window Closed / Lapsed |