US3979572A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Induction heating apparatus
Assignee: Mitsubishi Electric Corp
•
Filing: 1974-10-29
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Granted: 1976-09-07
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Expires: 1994-10-29
Abstract
Abstract An induction heating apparatus which comprises a ferromagnetic member; a non-magnetic highly conductive member connected to the ferromagnetic member on one side thereof; a non-magnetic high electrical resistance member forming a vacuum space between itself and the side of the non-magnetic highly conductive member not connected to the ferromagnetic member; an exciter which is excited by a low frequency power source to generate an alternating magnetic field and to form a magnetic circuit passing through the non-magnetic high resistance member, the non-magnetic highly conductive member and the ferromagnetic member; whereby the non-magnetic highly conductive member is heated by induction heating and is insulated by the vacuum space.
Inventors
- 👤 Toshio Ito
- 👤 Masahiro Hibino
- 👤 Tetsuya Kohya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:10
CPC Classifications
A; A47; A47J; A47J36/00; A47J36/02; H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/12
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
185 words
Induction heating apparatus comprising: an inner member for holding material to be heated, an outer member of non-magnetic high electrically resistive material joined to the inner member, a planar magnetic member joined to the inner member, a planar non-magnetic high electrically conductive member joined to the magnetic planar member to be disposed between the magnetic planar member and the outer member, a thermally insulative space between the outer member and the inner member and between the outer member and the planar non-magnetic high electrically conductive member, an exciter excited by a 60 cps power source to generate an alternating magnetic field and to form a magnetic circuit through the outer member, the planar magnetic member and the planar non-magnetic high electrically conductive member, the outer member being of stainless steel with a diameter of 15-25 cm. and a thickness of 0.3-0.5 mm., the inner member being of stainless steel with a thickness of 0.4-0.7 mm., the planar magnetic member being an iron plate with a thickness greater than 2.6 mm., the planar non-magnetic high electrically conductive member being aluminum with a thickness of 0.3-2.7 mm.
Claim 2
Dependent Claim
185 words
Induction heating apparatus comprising: an inner member for holding material to be heated, an outer member of non-magnetic high electrically resistive material joined to the inner member, a planar magnetic member joined to the inner member, a planar non-magnetic high electrically conductive member joined to the magnetic planar member to be disposed between the magnetic planar member and the outer member, a thermally insulative space between the outer member and the inner member and between the outer member and the planar non-magnetic high electrically conductive member, an exciter excited by a 60 cps power source to generate an alternating magnetic field and to form a magnetic circuit through the outer member, the planar magnetic member and the planar non-magnetic high electrically conductive member, the outer member being of stainless steel with a diameter of 15-25 cm. and a thickness of 0.3-0.5 mm., the inner member being of stainless steel with a thickness of 0.4-0.7 mm., the planar magnetic member being an iron plate with a thickness greater than 2.6 mm., the planar non-magnetic high electrically conductive member being aluminum with a thickness of 0.3-2.7 mm.
Claim 3
Dependent Claim
26 words
Induction heating apparatus in accordance with claim 1 wherein the outer member has a plurality of projections which contact the planar non-magnetic high electrically conductive material.
Claim 4
Dependent Claim
21 words
Induction heating apparatus in accordance with claim 1 wherein the thermally insulative space contains an inert gas having low heat conductivity.
Claim 5
Dependent Claim
31 words
Induction heating apparatus in accordance with claim 1 wherein the thickness of the thermally insulative space between the outer member and the planar non-magnetic high electrically conductive member is 0.5-1.0 mm.
Claim 6
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 1 wherein the thermally insulative space is a vacuum.
Claim 7
Dependent Claim
22 words
Induction heating apparatus in accordance with claim 1 wherein the thermally insulative space has heat insulating material disposed therein within a vacuum.
Claim 8
Dependent Claim
22 words
Induction heating apparatus in accordance with claim 6 wherein the heat insulative material comprises small segments of heat resistant inorganic insulating material.
Claim 9
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 7 wherein the small segments are pellets of ceramic.
Claim 10
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 7 wherein the small segments are pellets of glass.
Claim 11
Dependent Claim
185 words
Induction heating apparatus comprising: an inner member for holding material to be heated, an outer member of non-magnetic high electrically resistive material joined to the inner member, a planar magnetic member joined to the inner member, a planar non-magnetic high electrically conductive member joined to the magnetic planar member to be disposed between the magnetic planar member and the outer member, a thermally insulative space between the outer member and the inner member and between the outer member and the planar non-magnetic high electrically conductive member, an exciter excited by a 60 cps power source to generate an alternating magnetic field and to form a magnetic circuit through the outer member, the planar magnetic member and the planar non-magnetic high electrically conductive member, the outer member being of stainless steel with a diameter of 15-25 cm. and a thickness of 0.3-0.5 mm., the inner member being of stainless steel with a thickness of 0.4-0.7 mm., the planar magnetic member being an iron plate with a thickness greater than 2.6 mm., the planar non-magnetic high electrically conductive material being copper with a thickness of 0.2-1.7 mm.
Claim 12
Dependent Claim
185 words
Induction heating apparatus comprising: an inner member for holding material to be heated, an outer member of non-magnetic high electrically resistive material joined to the inner member, a planar magnetic member joined to the inner member, a planar non-magnetic high electrically conductive member joined to the magnetic planar member to be disposed between the magnetic planar member and the outer member, a thermally insulative space between the outer member and the inner member and between the outer member and the planar non-magnetic high electrically conductive member, an exciter excited by a 60 cps power source to generate an alternating magnetic field and to form a magnetic circuit through the outer member, the planar magnetic member and the planar non-magnetic high electrically conductive member, the outer member being of stainless steel with a diameter of 15-25 cm. and a thickness of 0.3-0.5 mm., the inner member being of stainless steel with a thickness of 0.4-0.7 mm., the planar magnetic member being an iron plate with a thickness greater than 2.6 mm., the planar non-magnetic high electrically conductive material being copper with a thickness of 0.2-1.7 mm.
Claim 13
Dependent Claim
26 words
Induction heating apparatus in accordance with claim 10 wherein the outer member has a plurality of projections which contact the planar non-magnetic high electrically conductive material.
Claim 14
Dependent Claim
21 words
Induction heating apparatus in accordance with claim 10 wherein the thermally insulative space contains an inert gas having low heat conductivity.
Claim 15
Dependent Claim
31 words
Induction heating apparatus in accordance with claim 10 wherein the thickness of the thermally insulative space between the outer member and the planar non-magnetic high electrically conductive member is 0.5-1.0 mm.
Claim 16
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 10 wherein the thermally insulative space is a vacuum.
Claim 17
Dependent Claim
22 words
Induction heating apparatus in accordance with claim 10 wherein the thermally insulative space has heat insulating material disposed therein within a vacuum.
Claim 18
Dependent Claim
22 words
Induction heating apparatus in accordance with claim 15 wherein the heat insulative material comprises small segments of heat resistant inorganic insulating material.
Claim 19
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 16 wherein the small segments are pellets of ceramic.
Claim 20
Dependent Claim
16 words
Induction heating apparatus in accordance with claim 16 wherein the small segments are pellets of glass.
References Cited (Backward Citations)
GB1157711A
Cited
US3745290A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-09-07 | 1980-03-08 | 1980-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-07 | 1984-03-08 | 1984-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-07 | 1988-03-08 | 1988-09-07 | $7700.00 | Window Closed / Lapsed |