US5368948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic materials for security applications
Assignee: Meto International GmbH
•
Filing: 1993-04-09
•
Granted: 1994-11-29
•
Expires: 2013-04-09
Abstract
Abstract A tag or marker is disclosed which comprises a substrate; an `active` magnetic material which is a soft magnetic material having a high magnetic permeability and a low coercive force; and a deactivating material which is a hard or semi-hard magnetic material having a moderate or high coercive force and a moderate magnetic permeability, whereby the deactivating material, when subjected to a sufficiently high magnetising force, is able to clamp the magnetic properties of the `active` material so as to deactivate the `active` material. The tag or marker is characterised in that the deactivating material is formed by an electrodeposition process, and in that the deactivating layer is nickel.
Inventors
- 👤 Dafydd G. Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 09:48
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2408; G08B13/2411; G08B13/2414; G08B13/2417; G08B13/2428; G08B13/2437; G08B13/2442; H; H01; H01F; H01F41/00; H01F41/14; H01F41/24; H01F41/26; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12389; Y10T428/12396; Y10T428/12465
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
122 words
A magnetically active tag or marker which comprises a substrate; an `active` magnetic material which is a soft magnetic material having a high magnetic permeability and a low coercive force; and a deactivating material which is a hard or semi-hard magnetic material having a moderate or high coercive force and a moderate magnetic permeability, whereby the deactivating material, when subjected to a sufficiently high magnetizing force, is able to clamp the magnetic properties of the `active` material so as to deactivate the `active` material, characterized in that said deactivating material consists of nickel with a columnar crystal grain structure and substantially isotropic magnetic properties in the plane of said substrate, said deactivating material being formed by electrodeposition, electroforming or electroless chemical deposition.
Claim 2
Dependent Claim
122 words
A magnetically active tag or marker which comprises a substrate; an `active` magnetic material which is a soft magnetic material having a high magnetic permeability and a low coercive force; and a deactivating material which is a hard or semi-hard magnetic material having a moderate or high coercive force and a moderate magnetic permeability, whereby the deactivating material, when subjected to a sufficiently high magnetizing force, is able to clamp the magnetic properties of the `active` material so as to deactivate the `active` material, characterized in that said deactivating material consists of nickel with a columnar crystal grain structure and substantially isotropic magnetic properties in the plane of said substrate, said deactivating material being formed by electrodeposition, electroforming or electroless chemical deposition.
Claim 3
Dependent Claim
49 words
A tag or marker as claimed in claim 1, characterised in that said deactivating material is formed as a discontinuous foil or layer or as a plurality of islands carried by a substrate, by means of an electrodeposition process in which selective deposition is achieved by a masking technique.
Claim 4
Dependent Claim
35 words
A tag or marker as claimed in claim 1, characterized in that said deactivating material is planar and has a columnar grain structure and substantially isotropic magnetic properties in the plane of said deactivating material.
Claim 5
Dependent Claim
27 words
A tag or marker as claimed in 1, characterised in that said columnar grain structure is coated with a thin layer of a planar crystal grain structure.
Claim 6
Dependent Claim
28 words
A tag or marker as claimed in claim 1, characterised in that said deactivating material is subjected to a deformation process after being formed by an electrodeposition method.
Claim 7
Dependent Claim
26 words
A tag or marker as claimed in claim 1, characterised in that said deactivating material has been subjected to a stamping, rolling, pressing or embossing process.
Claim 8
Dependent Claim
23 words
A tag or marker as claimed in claim 1, characterised in that said deactivating material is subjected to mechanical deformation or cold working.
Claim 9
Dependent Claim
28 words
A tag or marker as claimed in claim 1, characterised in that a portion of the area of said deactivating material has been subjected to said deformation process.
References Cited (Backward Citations)
US3378357A
Cited
US4495487A
Cited
US4439294A
Cited
US4636448A
Cited
US4743890A
Cited
EP0295028B1
Cited
US5175499A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-11-28 | 1998-05-30 | 1998-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-11-28 | 2002-05-30 | 2002-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-11-28 | 2006-05-30 | 2006-11-29 | $7700.00 | Window Closed / Lapsed |