The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1994
Filed:
Apr. 09, 1993
Applicant:
Inventor:
Dafydd G Davies, Cambridge, GB;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ; B32B / ;
U.S. Cl.
CPC ...
428611 ; 340551 ; 340572 ; 428601 ;
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.