US5225807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for sensitizing and desensitizing targets for electronic article surveillance systems
Assignee: 3M Innovative Properties Co
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Filing: 1991-09-16
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Granted: 1993-07-06
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Expires: 2011-09-16
Abstract
Abstract Magnetically desensitized targets or sensor elements on protected articles are resensitized by means of rotating permanent magnets which are moved relative to the magnetized target desensitizer elements such that the elements become subjected to reversing magnetic fields of gradually decreasing intensity.
Inventors
- 👤 Peter Y. Zhou
- 👤 Dexing Pang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:06
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2411
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
124 words
A sensitizer for sensitizing electronic surveillance system targets of the type that have a plurality of spaced apart magnetizable elements along their length, said sensitizer comprising a base, a motor mounted in said base, a carrier mounted in said base for rotation about a given axis and connected to be rotated by said motor, and at least one permanent magnet mounted on said carrier at a location and orientation such that upon rotation of said carrier, the poles of said magnet revolve around said given axis and the magnetic field from said magnet extends out from said base and means for positioning a target to be sensitized such that magnetized elements extending along the length thereof become successively exposed to cyclically reversing magnetic fields.
Claim 2
Dependent Claim
124 words
A sensitizer for sensitizing electronic surveillance system targets of the type that have a plurality of spaced apart magnetizable elements along their length, said sensitizer comprising a base, a motor mounted in said base, a carrier mounted in said base for rotation about a given axis and connected to be rotated by said motor, and at least one permanent magnet mounted on said carrier at a location and orientation such that upon rotation of said carrier, the poles of said magnet revolve around said given axis and the magnetic field from said magnet extends out from said base and means for positioning a target to be sensitized such that magnetized elements extending along the length thereof become successively exposed to cyclically reversing magnetic fields.
Claim 3
Dependent Claim
29 words
A sensitizer according to claim 1, wherein said means for positioning a target comprises a sensitizer wall having a surface mounted at a fixed position relative to said axis.
Claim 4
Dependent Claim
36 words
A sensitizer according to claim 1, and further including a brake for holding said carrier at a predetermined fixed rotational position about said given axis whereby said sensitizer is converted to operate as a target desensitizer.
Claim 5
Dependent Claim
42 words
A sensitizer according to claim 3, wherein said brake comprises an element located at a fixed position relative to said given axis and arranged to produce a magnetic interaction with said permanent magnet which is greatest at said predetermined fixed rotational position.
Claim 6
Dependent Claim
31 words
A sensitizer according to claim 1, wherein a plurality of magnets are arranged on said carrier with polar axes parallel to each other and perpendicular to and intersecting said given axis.
Claim 7
Dependent Claim
58 words
A sensitizer according to claim 1, wherein said carrier comprises a cylindrically shaped element of non-magnetic material mounted with its longitudinal axis extending along said given axis for rotation about said given axis and wherein said permanent magnet extends through said carrier with the polar axis of said permanent magnet intersecting and extending perpendicular to said given axis.
Claim 8
Dependent Claim
24 words
A sensitizer according to claim 6, wherein a plurality of permanent magnets extend through said carrier with their polar axes parallel to each other.
Claim 9
Dependent Claim
48 words
A sensitizer according to claim 7, wherein said permanent magnets are closely spaced to each other with their respective North poles close to each other and their South poles close to each other to produce a band of magnetic flux extending around the outer surface of said carrier.
Claim 10
Dependent Claim
58 words
A sensitizer according to claim 1, wherein said motor, carrier and magnet are mounted in a housing and wherein said housing includes a sensitizer wall for positioning an article containing a target to be sensitized, said sensitizer wall being closely spaced to a plane defined by the poles of said magnet as they revolve around said given axis.
Claim 11
Dependent Claim
15 words
A sensitizer according to claim 9, wherein said sensitizer wall extends in a flat plane.
Claim 12
Dependent Claim
44 words
A sensitizer according to claim 10, wherein said housing includes a guide wall at a substantially right angle to said sensitizer wall and intersecting said sensitizer wall along a line which extends in a direction substantially perpendicular to the direction of said given axis.
Claim 13
Dependent Claim
20 words
A sensitizer according to claim 1, wherein said means for positioning a target comprises a handle attached to said carrier.
Claim 14
Dependent Claim
21 words
A sensitizer according to claim 12, wherein said permanent magnet is oriented with its polar axis perpendicular to said given axis.
Claim 15
Dependent Claim
18 words
A sensitizer according to claim 13, wherein the polar axis of said permanent magnet intersects said given axis.
Claim 16
Dependent Claim
32 words
A sensitizer according to claim 14, wherein said carrier comprises a cylindrical element whose longitudinal axis extends along said given axis and wherein said permanent magnet is embedded in said cylindrical element.
Claim 17
Dependent Claim
32 words
A sensitizer according to claim 12, wherein said motor and said carrier are enclosed within a common housing and wherein said handle is attached to and forms part of said common housing.
Claim 18
Dependent Claim
29 words
A sensitizer according to claim 16, wherein said motor is enclosed within said handle and wherein a portion of said housing which contains said carrier extends beyond said handle.
Claim 19
Dependent Claim
21 words
A sensitizer according to claim 17, wherein said common housing supports a battery for supply of electrical power to said motor.
Claim 20
Dependent Claim
19 words
A sensitizer according to claim 1, wherein said motor and said carrier are driveably connected by a drive belt.
Claim 21
Independent Claim
70 words
A method of sensitizing electronic surveillance system targets of the type that have a plurality of spaced apart magnetizable elements along their length, said method comprising the steps of causing the poles of at least one permanent magnet to revolve around a given axis to produce, in a given region, a cyclically reversing magnetic field and causing a desensitized target to enter into and exit from said reversing magnetic field.
Claim 22
Independent Claim
70 words
A method of sensitizing electronic surveillance system targets of the type that have a plurality of spaced apart magnetizable elements along their length, said method comprising the steps of causing the poles of at least one permanent magnet to revolve around a given axis to produce, in a given region, a cyclically reversing magnetic field and causing a desensitized target to enter into and exit from said reversing magnetic field.
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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) | 1996-07-05 | 1997-01-04 | 1997-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-05 | 2001-01-04 | 2001-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-05 | 2005-01-04 | 2005-07-06 | $7700.00 | Window Closed / Lapsed |