US4532398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction coil
Assignee: ABB Norden Holding AB
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Filing: 1982-12-01
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Granted: 1985-07-30
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Expires: 2002-12-01
Abstract
Abstract An induction coil, preferably for an induction heater, comprises a working coil, an outer casing and an inner lead-through channel for the workpieces, such as rods or tubes, which are to be treated in the induction coil. The region of the outer casing closest to the working coil consists of a layer of a rubber-elastic compound outside which is arranged a concrete casing. Using a two-part outer casing of this kind avoids the use of asbestos which is increasingly suspect because of its health hazard.
Inventors
- 👤 Bengt Henriksson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:09
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/101; H05B6/103; H05B6/104; H05B6/36
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
70 words
An induction coil comprising an electrically conducting working coil, an outer casing for the coil and a lead-through channel disposed within the working coil for workpieces which are to be treated therein, the outer casing comprising at least one compressible hollow body of a temperature-resistant silicone rubber, capable of withstanding temperature of about 200 degrees C., adjacent to the working coil and a mass of concrete over said hollow body.
Claim 2
Dependent Claim
70 words
An induction coil comprising an electrically conducting working coil, an outer casing for the coil and a lead-through channel disposed within the working coil for workpieces which are to be treated therein, the outer casing comprising at least one compressible hollow body of a temperature-resistant silicone rubber, capable of withstanding temperature of about 200 degrees C., adjacent to the working coil and a mass of concrete over said hollow body.
Claim 3
Dependent Claim
19 words
An induction coil according to claim 1, in which a silicone rubber layer is cast around the working coil.
Claim 4
Dependent Claim
33 words
An induction coil according to claim 2, in which the working coil is of substantially rectangular cross-section and a layer of silicone rubber is between the working coil and the mass of concrete.
Claim 5
Dependent Claim
28 words
An induction coil as claimed in claim 3, in which a plurality of hollow bodies are located along the shorter side of the cross-section of the working coil.
Claim 6
Dependent Claim
21 words
An induction coil as claimed in claim 4, in which means is provided to pressurize the interior of each hollow body.
Claim 7
Dependent Claim
15 words
An induction coil according to claim 1, in which the concrete is a refractory concrete.
Claim 8
Dependent Claim
16 words
An induction coil according to claim 6, in which the concrete is reinforced with glass fibers.
Claim 9
Dependent Claim
20 words
An induction coil according to claim 1, in which a ceramic lining defines the lead-through channel within the working coil.
Claim 10
Dependent Claim
23 words
An induction coil according to claim 8, in which a layer of felt is arranged between the ceramic lining and the working coil.
Claim 11
Dependent Claim
25 words
An induction coil according to claim 1, in which an axial end of the induction coil is defined by an end wall of refractory material.
Claim 12
Dependent Claim
15 words
An induction coil as claimed in claim 10, in which the end wall is replaceable.
Claim 13
Dependent Claim
23 words
An induction coil according to claim 1, in which the mass of concrete is formed from a plurality of prefabricated blocks secured together.
Claim 14
Dependent Claim
22 words
An induction coil according to claim 12, in which the working coil and the lead-through channel are each of substantially rectangular cross-section.
Claim 15
Dependent Claim
89 words
An induction coil comprising a helix of electrically conducting tubular material, a refractory electrically insulating tube disposed within the helix to define a through-channel for elements to be treated within the coil and an electrically insulating casing surrounding the helix, the casing being in two parts, an inner part of at least one compressible hollow body of temperature resistant silicone rubber, capable of withstanding temperature of about 200 degrees C., about the helix, and an outer part of a refractory asbestos-free set hydraulic cementitious mixture over the inner part.
Claim 16
Dependent Claim
89 words
An induction coil comprising a helix of electrically conducting tubular material, a refractory electrically insulating tube disposed within the helix to define a through-channel for elements to be treated within the coil and an electrically insulating casing surrounding the helix, the casing being in two parts, an inner part of at least one compressible hollow body of temperature resistant silicone rubber, capable of withstanding temperature of about 200 degrees C., about the helix, and an outer part of a refractory asbestos-free set hydraulic cementitious mixture over the inner part.
Claim 17
Dependent Claim
25 words
A coil as claimed in claim 14, in which the inner part includes a layer formed by casting a hardenable fluid silicone around the helix.
Claim 18
Dependent Claim
17 words
A coil as claimed in claim 15, in which the outer part is reinforced with glass fibers.
Claim 19
Dependent Claim
44 words
A coil as claimed in claim 14, in which the outer part of the casing comprises prefabricated blocks clamped together around the inner part of the casing and the helix, and the interior of the helix is lined with an electrically insulating refractory sleeve.
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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) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |