Magnetic shielding
First Claim
1. A multi-part magnetic shield comprising:
- at least two magnetically-conductive structures substantially enclosing a predetermined volume, each structure enclosing a portion of the volume, but having a predetermined gap disposed between juxtaposed portions thereof and disposed substantially transversely to magnetic field lines passing through the magnetically-conductive structures; and
a filler material disposed within said gap and including a non-magnetically conductive carrier in a liquid or plastic state having single-magnetic-domain-sized particles of a magnetically conductive solid dispersed therewithin, said particles having a maximum cross-sectional dimension not exceeding 0.002 inch.
1 Assignment
0 Petitions
Accused Products
Abstract
A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient magnetic field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.
11 Citations
22 Claims
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1. A multi-part magnetic shield comprising:
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at least two magnetically-conductive structures substantially enclosing a predetermined volume, each structure enclosing a portion of the volume, but having a predetermined gap disposed between juxtaposed portions thereof and disposed substantially transversely to magnetic field lines passing through the magnetically-conductive structures; and a filler material disposed within said gap and including a non-magnetically conductive carrier in a liquid or plastic state having single-magnetic-domain-sized particles of a magnetically conductive solid dispersed therewithin, said particles having a maximum cross-sectional dimension not exceeding 0.002 inch.
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2. A multi-part magnetic shield comprising:
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at least two magnetically-conductive structures substantially enclosing a predetermined volume, each structure enclosing a portion of the volume, but having a predetermined gap disposed between juxtaposed portions thereof and disposed substantially transversely to magnetic field lines passing through the magnetically-conductive structures; and a magnetically-conductive filler material disposed within said gap, said filler material including (a) a carrier material, and (b) single-magnetic-domain-sized particles of a magnetically conductive material dispersed throughout said carrier material, said particles having a maximum cross-sectional dimension not exceeding 0.002 inch, said particles also having a maximum cross-sectional dimension which is substantially less than the size of said predetermined gap. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 19)
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11. A method of constructing a multi-part magnetic shield having plural magnetically conductive structures substantially enclosing a predetermined volume, each structure enclosing a portion of the volume, but having a pag disposed between juxtaposed portions thereof and substantially transverse to magnetic field lines passing through the structures, said method comprising the steps of:
substantially filling said gap with a magnetically conductive filler formed form a plastic or liquid non-magnetically conductive carrier substantially filled throughout with dispersed particles of a magnetically conductive material, said particles having a maximum cross-sectional dimension not exceeding 0.002 inch, said particles also having maximum cross-sectional dimension which is substantially less than the size of said predetermined gap. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 20)
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21. A magnetically conductive filler for filling a gap within a magnetically conductive structure, comprising:
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(a) a carrier material, and (b) single-magnetic-domain-sized particles of magnetically conductive material dispersed throughout said carrier material, said particles having a maximum cross-sectional dimension not exceeding 0.002 inch, said particles also having a maximum cross-sectional dimension which is substantially less than the size of a gap to be filled. - View Dependent Claims (22)
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Specification