US4568921A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Theft detection apparatus and target and method of making same
Assignee: Sentry Technology Corp
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Filing: 1984-07-13
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Granted: 1986-02-04
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Expires: 2004-07-13
Abstract
Abstract Items of merchandise (30) are protected from shoplifting or theft by affixing to them, special responder targets (32), which are formed by drawing a material of high magnetic permeability into a thin wire, then heat treating the wire to substantially increase its magnetic permeability and thereafter severing the wire into individual lengths. Several wires (32a, 32b and 32c) may be positioned on a common adhesively coated base strip (42) and covered by a peel strip (46) and wire like deactivation elements (48) of hard magnetic material may be positioned adjacent the wires for deactivating them.
Inventors
- 👤 Peter A. Pokalsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:55
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2428; G08B13/2437; G08B13/2442; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/916
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
80 words
A magnetic type electronic theft detection apparatus comprising means for generating an alternating magnetic interrogation field in an interrogation zone, means for detecting magnetic response fields having predetermined characteristics in said interrogation zone and responder targets mounted on protected items which must be carried through said interrogation zone when taken from a protected area, said responder targets each comprising a length of drawn wire of an easily saturable magnetic material, heat treated, after drawing, to substantially increase its magnetic permeability.
Claim 2
Dependent Claim
80 words
A magnetic type electronic theft detection apparatus comprising means for generating an alternating magnetic interrogation field in an interrogation zone, means for detecting magnetic response fields having predetermined characteristics in said interrogation zone and responder targets mounted on protected items which must be carried through said interrogation zone when taken from a protected area, said responder targets each comprising a length of drawn wire of an easily saturable magnetic material, heat treated, after drawing, to substantially increase its magnetic permeability.
Claim 3
Dependent Claim
24 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said wire is drawn from an iron base alloy containing 45-80% nickel.
Claim 4
Dependent Claim
27 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said wire is drawn to a diameter of less than about 0.009 inches (0.023 centimeters).
Claim 5
Dependent Claim
25 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said wire is drawn to a diameter of about 0.005 inches (0.013 centimeters).
Claim 6
Dependent Claim
44 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein at least one wire of a hard magnetic material, capable of being semi-permanently magnetized with spaced apart alternate north and south magnetic poles along its length, is positioned adjacent a responder target.
Claim 7
Dependent Claim
28 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein at least one of said responder targets is mounted along a corner of a protected item.
Claim 8
Dependent Claim
24 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said responder targets are secured to said protected items by an adhesive.
Claim 9
Dependent Claim
23 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said responder targets are fitted into openings in said protected items.
Claim 10
Dependent Claim
45 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said responder target is an assembly of drawn wires of an easily saturable magnetic material, heat treated, after drawing, to substantially increase their magnetic permeability, said wires being positioned close to each other.
Claim 11
Dependent Claim
24 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said wires are placed parallel to each other on a base strip.
Claim 12
Dependent Claim
35 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein said wires are held by adhesive to said base strip and in turn are held by said base strip onto a protected item.
Claim 13
Dependent Claim
50 words
A magnetic type electronic theft detection apparatus according to claim 1 wherein a plurality of wires of a hard magnetic material, capable of being semi-permanently magnetized with spaced apart alternate north and south magnetic poles along their length, extend alongside and are interspersed among said drawn and heat treated wires.
Claim 14
Dependent Claim
76 words
A responder target for use in a magnetic theft detection system of the type in which an alternating magnetic interrogation field is generated in an interrogation zone and magnetic response fields produced by a responder target passing through said interrogation zone are detected and, in response thereto, an alarm is actuated, said responder target comprising a drawn wire of easily saturable magnetic material, said wire being heat treated after drawing to substantially increase its magnetic permeability.
Claim 15
Dependent Claim
76 words
A responder target for use in a magnetic theft detection system of the type in which an alternating magnetic interrogation field is generated in an interrogation zone and magnetic response fields produced by a responder target passing through said interrogation zone are detected and, in response thereto, an alarm is actuated, said responder target comprising a drawn wire of easily saturable magnetic material, said wire being heat treated after drawing to substantially increase its magnetic permeability.
Claim 16
Dependent Claim
20 words
A responder target according to claim 13 wherein said wire is drawn from an iron base alloy containing 45-80% nickel.
Claim 17
Dependent Claim
23 words
A responder target according to claim 13 wherein said wire is drawn to a diameter of less than about 0.009 inches (0.023 centimeters).
Claim 18
Dependent Claim
21 words
A responder target according to claim 13 wherein said wire is drawn to a diameter of about 0.005 inches (0.013 centimeters).
Claim 19
Dependent Claim
39 words
A responder target according to claim 13 wherein at least one wire of a hard magnetic material, capable of being semi-permanently magnetized with spaced apart alternate north and south magnetic poles along its length, is positioned adjacent said wire.
Claim 20
Dependent Claim
41 words
A responder target according to claim 13 wherein said responder target is an assembly of drawn wires of an easily saturable magentic material, heat treated, after drawing, to substantialy increase their magnetic permeability, said wires being positioned close to each other.
Claim 21
Dependent Claim
20 words
A responder target according to claim 18 wherein said wires are placed parallel to each other on a base strip.
Claim 22
Dependent Claim
31 words
A responder target according to claim 19 wherein said wires are held by adhesive to said base strip and in turn are held by said base strip onto a protected item.
Claim 23
Dependent Claim
46 words
A responder target according to claim 18 wherein a plurality of wires of a hard magnetic material, capable of being semi-permanently magnetized with spaced apart alternate north and south magnetic poles along their length, extend alongside and are interspersed among said drawn and heat treated wires.
Claim 24
Independent Claim
87 words
A method of manufacturing a responder target for use in a magnetic theft detection system of the type in which an alternating magnetic interrogation field is generated in an interrogation zone and magnetic response fields produced by a target passing through said interrogation zone are detected, and in response thereto an alarm is actuated, said method comprising the steps of drawing an easily saturable magnetic material into a wire, heat treating the drawn wire to substantially increase its magnetic permeability and cutting the wire into individual lengths.
Claim 25
Independent Claim
87 words
A method of manufacturing a responder target for use in a magnetic theft detection system of the type in which an alternating magnetic interrogation field is generated in an interrogation zone and magnetic response fields produced by a target passing through said interrogation zone are detected, and in response thereto an alarm is actuated, said method comprising the steps of drawing an easily saturable magnetic material into a wire, heat treating the drawn wire to substantially increase its magnetic permeability and cutting the wire into individual lengths.
Claim 26
Dependent Claim
19 words
A method according to claim 22 wherein said wire is drawn from an iron base alloy containing 45-80% nickel.
Claim 27
Dependent Claim
22 words
A method according to claim 22 wherein said wire is drawn to a diameter of less than about 0.009 inches (0.023 centimeters).
Claim 28
Dependent Claim
20 words
A method according to claim 22 wherein said wire is drawn to a diameter of about 0.005 inches (0.013 centimeters).
Claim 29
Dependent Claim
20 words
A method according to claim 22 wherein said wire is heat treated prior to cutting the wire into individual lengths.
Claim 30
Dependent Claim
24 words
A method according to claim 22 wherein a plurality of said wires are placed adjacent to each other on an item to be protected.
Claim 31
Dependent Claim
41 words
A method according to claim 22 wherein said plurality of wires are positioned on a base strip having an adhesive coating, and the base strip together with the wires is severed into predetermined lengths and affixed to items to be protected.
Claim 32
Dependent Claim
28 words
A method according to claim 22 wherein the wires are each positioned adjacent a wire of a magnetically hard substance capable of being semi-permanently magnetized along its length.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |