US4048458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction heating core structure and method of heating
Assignee: Illinois Tool Works Inc
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Filing: 1976-05-21
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Granted: 1977-09-13
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Expires: 1996-05-21
Abstract
Abstract An induction heating coil and core structure which provides two distinct magnetic circuits, with the materials to be heated also forming a part of the circuits so that juxtaposed workpieces can be joined together with a layer of heat activatable adhesive by a unitary core structure. A pair of nested U-shaped cores have a differing number of exciter coil turns with at least one common turn wrapped about each of the members to produce a greater amount of flux density in one core than the other to effect a different heat rate between the workpieces which complete each magnetic circuit.
Inventors
- 👤 Robert Louis Zirk, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:09
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/101
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
98 words
A composite core and coil structure for use in heating workpieces by induction, including a first generally U-shaped core and a second generally U-shaped core nestably associated with the first core, exciter coil means wrapped about portions of each core providing at least one turn which simultaneously encircles portions of both cores, the coil means providing a predetermined number of turns about the first core different than the number of turns about the second core, the length of the legs portions of the first core are greater than the length of the leg portions of the second core.
Claim 2
Dependent Claim
98 words
A composite core and coil structure for use in heating workpieces by induction, including a first generally U-shaped core and a second generally U-shaped core nestably associated with the first core, exciter coil means wrapped about portions of each core providing at least one turn which simultaneously encircles portions of both cores, the coil means providing a predetermined number of turns about the first core different than the number of turns about the second core, the length of the legs portions of the first core are greater than the length of the leg portions of the second core.
Claim 3
Dependent Claim
20 words
The composite coil and core structure of claim 1, wherein the exciter coil encircles the bight portions of both cores.
Claim 4
Dependent Claim
29 words
The composite coil and core structure of claim 1, wherein the first core is provided with a greater number of turns of the exciter coil than the second core.
Claim 5
Dependent Claim
38 words
The composite coil and core structure of claim 1, wherein the cores are arranged so that the bight and leg portions of the first core are substantially coplanar with the bight and leg portions of the second core.
Claim 6
Dependent Claim
43 words
The composite coil and core structure of claim 1, wherein the cores are arranged so that the bight and leg portions of the first core extend in a plane transverse to the plane including the bight and leg portions of the second core.
Claim 7
Dependent Claim
34 words
The composite coil and core structure of claim 4, wherein the length of the bight of the first core is greater than the lengths of the bight and leg portions of the second core.
Claim 8
Independent Claim
135 words
A method of adhesively securing a first metallic workpiece of predetermined volume to a second metallic workpiece of a greater total volume, including the steps of placing the first workpiece on the second workpiece with a layer of heat activable adhesive therebetween, heating by induction, both workpieces simultaneously from a single side so that the faying surface of each will reach a predetermined temperature substantially simultaneously, wherein the induction heat is provided by a pair of nested U-shaped cores with an exciter coil wound about their bight portions so that the outermost core has more windings than the inner core, the outermost core legs contacting the second workpiece while the inner core legs contact the first workpiece whereby the second workpiece will be subjected to a greater amount of heating flux than the first workpiece.
Claim 9
Independent Claim
135 words
A method of adhesively securing a first metallic workpiece of predetermined volume to a second metallic workpiece of a greater total volume, including the steps of placing the first workpiece on the second workpiece with a layer of heat activable adhesive therebetween, heating by induction, both workpieces simultaneously from a single side so that the faying surface of each will reach a predetermined temperature substantially simultaneously, wherein the induction heat is provided by a pair of nested U-shaped cores with an exciter coil wound about their bight portions so that the outermost core has more windings than the inner core, the outermost core legs contacting the second workpiece while the inner core legs contact the first workpiece whereby the second workpiece will be subjected to a greater amount of heating flux than the first workpiece.
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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) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |