US5378879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction heating of loaded materials
Assignee: Tyco International Ltd Bermuda
•
Filing: 1993-04-20
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Granted: 1995-01-03
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Expires: 2013-04-20
Abstract
Abstract A system for employing induction heating to heat a non-magnetic, electrically non-conductive material in situ quickly, uniformly, selectively and in a controlled fashion. Particles which are essential to the improved use of induction heating for this type of application are added to the host material and exposed to high frequency alternating electromagnetic fields such as those produced in an induction coil. The particles are ferromagnetic, having high magnetic permeability and high electrical conductivity. The heat-generating efficiency of these particles when exposed to alternating magnetic fields, permits a smaller volume fraction of these particles in the host material such that the desired properties of the article remain essentially unchanged. Overheating of the article may be prevented by selecting the particle Curie point such that the particle autoregulates at a temperature about equal to the temperature to which the article is to be heated. These particles preferably have the configuration of a flake, i.e., a thin disk-like configuration. This configuration includes a first, second and third orthogonal dimension, wherein the first and second orthogonal dimensions are each greater than the skin depth of the particle and are each at least about 5 times the third orthogonal dimension.
Inventors
- 👤 Yiannis A. Monovoukas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:30
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H01; H01R; H01R43/00; H01R43/02; H01R43/0242; B; B29; B29C; B29C35/00; B29C35/02; B29C35/08; B29C70/00; B29C70/58; H01R4/00; H01R4/70; H01R4/72; H05B6/10; H05B6/105; H05B6/106; B29C35/0805; B29C2035/0811; B29C2035/0816; B29K; B29K2705/00; B29K2705/02; B29K2705/08
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
101 words
A heat generating article for use in an alternating magnetic field, said article comprising a host material in which particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein: said first and second orthogonal dimensions are between 1 μm and 300 μm and greater than the skin depth of the particle when subjected to an alternating magnetic field of a selected frequency; and said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension.
Claim 2
Dependent Claim
101 words
A heat generating article for use in an alternating magnetic field, said article comprising a host material in which particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein: said first and second orthogonal dimensions are between 1 μm and 300 μm and greater than the skin depth of the particle when subjected to an alternating magnetic field of a selected frequency; and said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension.
Claim 3
Dependent Claim
35 words
The article as defined in claim 1 wherein the article is oriented such that an axis parallel to the greatest dimension of the article is disposed generally parallel with respect to the magnetic field lines.
Claim 4
Dependent Claim
24 words
The article as defined in claim 1, wherein said article contains particles in an amount of between about 0.1% and about 50% by volume.
Claim 5
Dependent Claim
24 words
The article as defined in claim 3, wherein said article contains particles in an amount of between about 0.5% and about 10% by volume.
Claim 6
Dependent Claim
30 words
The article as defined in claim 1, wherein said ferromagnetic material has a Curie temperature at least about equal to the temperature to which said article is to be heated.
Claim 7
Dependent Claim
17 words
The article as defined in claim 1, wherein said article undergoes a change in shape upon heating.
Claim 8
Dependent Claim
17 words
The article as defined in claim 1, wherein said article undergoes a change in volume upon heating.
Claim 9
Dependent Claim
17 words
The article as defined in claim 1, wherein said article undergoes a change in viscosity upon heating.
Claim 10
Dependent Claim
22 words
The article as defined in claim 1, wherein said host material is a fusible material having a melt temperature T m .
Claim 11
Dependent Claim
29 words
The article as defined in claim 9, wherein said ferromagnetic material has a Curie temperature at least about equal to the melt temperature T m of said host material.
Claim 12
Dependent Claim
17 words
The article as defined in claim 1, wherein said ferromagnetic material comprises a metal or metal alloy.
Claim 13
Dependent Claim
14 words
The article as defined in claim I wherein said ferromagnetic material comprises nickel flakes.
Claim 14
Dependent Claim
18 words
The article as defined in claim 1, wherein said particle comprises a central carrier portion and a coating.
Claim 15
Dependent Claim
17 words
The article as defined in claim 13, wherein said coating comprises a highly magnetic, highly conductive material.
Claim 16
Dependent Claim
21 words
The article as defined in claim 1, wherein the initial magnetic permeability of said ferromagnetic material is greater than about 70.
Claim 17
Dependent Claim
27 words
The article as defined in claim 1, wherein said material has an electrical conductivity of more than at least about 10 6 ohm -1 m -1 .
Claim 18
Dependent Claim
34 words
The article as defined in claim 1, wherein said article contains particles in an amount of up to about 5% by volume, such that the properties of the host material are, thereby, essentially unchanged.
Claim 19
Dependent Claim
15 words
The article as defined in claim 1, wherein said ferromagnetic material is a nickel alloy.
Claim 20
Dependent Claim
16 words
The article as defined in claim 1, wherein said ferromagnetic material is a nickel aluminum alloy.
Claim 21
Dependent Claim
17 words
The article as defined in claim 1, wherein said particles are uniformly dispersed within said host material.
Claim 22
Dependent Claim
31 words
The article as defined in claim 1, wherein said particles are non-uniformly dispersed such that at least a portion of said particles are concentrated near a surface of the host material.
Claim 23
Dependent Claim
142 words
An arrangement for forming a block in a cable against transmission of fluid along the cable, the cable including a plurality of wires, the arrangement comprising: a heat activatable blocking construction capable of being positioned in proximity to the wires of the cable, said blocking construction comprising a host material in which particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein said first and second orthogonal dimensions are between 1 μm and 300 μm and greater than the skin depth of the particle when subjected to an alternating magnetic field of a selected frequency and said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension; and a cover disposed around said blocking construction.
Claim 24
Dependent Claim
142 words
An arrangement for forming a block in a cable against transmission of fluid along the cable, the cable including a plurality of wires, the arrangement comprising: a heat activatable blocking construction capable of being positioned in proximity to the wires of the cable, said blocking construction comprising a host material in which particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein said first and second orthogonal dimensions are between 1 μm and 300 μm and greater than the skin depth of the particle when subjected to an alternating magnetic field of a selected frequency and said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension; and a cover disposed around said blocking construction.
Claim 25
Dependent Claim
23 words
The arrangement as defined in claim 22 wherein said blocking construction comprises a body having a plurality of openings for receiving the wires.
Claim 26
Dependent Claim
82 words
The arrangement as defined in claim 22 wherein said cover comprises a host material in which ferromagnetic particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein said first and second orthogonal dimensions are greater than the skin depth of the particle and wherein said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension.
Claim 27
Dependent Claim
18 words
The arrangement as defined in claim 22 wherein said cover comprises an inner layer and an outer layer.
Claim 28
Dependent Claim
83 words
The arrangement as defined in claim 25 wherein said inner layer comprises a host material in which ferromagnetic particles are dispersed, said particles comprising ferromagnetic material having high magnetic permeability and high electrical conductivity, said particles having a skin depth and a configuration including first, second and third orthogonal dimensions, wherein said first and second orthogonal dimensions are greater than the skin depth of the particle and wherein said first and second orthogonal dimensions are at least 5 times said third orthogonal dimension.
Claim 29
Dependent Claim
14 words
The arrangement as defined in claim 26 wherein said outer layer is heat recoverable.
Claim 30
Dependent Claim
16 words
The arrangement as defined in claim 22 wherein said host material comprises a fusible polymeric sealant.
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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) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |