US4761527A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic flux induction heating
Assignee: Individual
•
Filing: 1985-10-04
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Granted: 1988-08-02
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Expires: 2005-10-04
Abstract
Abstract This relates to the induction heating of metal shapes and coils of metal strip wherein the element to be heated functions as a shorted out armature of a D.C. generator. Either the metal shape to be heated or field forming magnets are moved relative to each other wherein the metal shape cuts the flux field to effect an induced generation of electricity within the shape. The frequency of the induced current is such wherein the electrical energy is induced into the metal shape on the order of one third of the thickness of that shape wherein a most efficient conduction of the heat from the electrical energy is effected with a minimum heat loss to the atmosphere. The voltage involved is low while there is a very high amperance. The frequency of the induced current will normally be on the order of one to ten hertz and less than sixty hertz. The relative movement between the field and the shape to be heated may be rotary or linear.
Inventors
- 👤 Glenn R. Mohr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:44
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; H05B6/101; H05B6/103; H05B6/104; H05B6/102; H05B6/36; H05B6/365
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
105 words
A method of magnetic flux induction heating an armature formed of strip shapes or the like, said method comprising the steps of forming a direct current generator including a direct current generator field and the armature, with the armature being a dead short and all electrical energy induced into the armature is directly converted into heat and effecting a pulsed induction of electrical energy into the armature at a frequency wherein there is a controlled depth of penetration of the armature by the induced electrical energy well beyond the surface of the armature wherein heat absorbed by the armature is primarily retained within the armature.
Claim 2
Independent Claim
105 words
A method of magnetic flux induction heating an armature formed of strip shapes or the like, said method comprising the steps of forming a direct current generator including a direct current generator field and the armature, with the armature being a dead short and all electrical energy induced into the armature is directly converted into heat and effecting a pulsed induction of electrical energy into the armature at a frequency wherein there is a controlled depth of penetration of the armature by the induced electrical energy well beyond the surface of the armature wherein heat absorbed by the armature is primarily retained within the armature.
Claim 3
Dependent Claim
31 words
A method according to claim 1 wherein the pulsed induction of electrical energy into the armature is by cutting of the field through relative motion between the armature and the field.
Claim 4
Dependent Claim
13 words
A method according to claim 2 wherein said relative motion is solely linear.
Claim 5
Dependent Claim
13 words
A method according to claim 2 wherein said relative motion is solely rotational.
Claim 6
Dependent Claim
19 words
A method according to claim 2 wherein said cutting of said field is effected by varying the field intensity.
Claim 7
Dependent Claim
37 words
A method according to claim 1 wherein there is controlled penetration of electrical energy into said armature from the surface of said armature, said penetration varying in accordance with the rate of relative cutting of said field.
Claim 8
Dependent Claim
17 words
A method according to claim 1 wherein said direct current field effects operation at unity power factor.
Claim 9
Dependent Claim
29 words
A method according to claim 1 wherein said direct current field effects operation at unity power factor, and any I 2 R loss appears as heat in said armature.
Claim 10
Dependent Claim
18 words
A method according to claim 1 wherein any I 2 R loss appears as heat in said armature.
Claim 11
Dependent Claim
25 words
A method according to claim 1 wherein voltage of the electrical energy induced into said armature is on the order of 40 volts and less.
Claim 12
Dependent Claim
23 words
A method according to claim 1 wherein the frequency of the induced electrical energy is on the order of 60 hertz and less.
Claim 13
Dependent Claim
16 words
A method according to claim 1 wherein the direct current field is effected by permanent magnets.
Claim 14
Dependent Claim
57 words
A new article of manufacture comprising a magnetic flux induction heating apparatus including a metal workpiece to be heated in the form of a short circuited armature, said armature being positioned relative to a D.C. field, and means for effecting a pulsing induction of the electrical energy of said D.C. field into the armature as direct current.
Claim 15
Dependent Claim
57 words
A new article of manufacture comprising a magnetic flux induction heating apparatus including a metal workpiece to be heated in the form of a short circuited armature, said armature being positioned relative to a D.C. field, and means for effecting a pulsing induction of the electrical energy of said D.C. field into the armature as direct current.
Claim 16
Dependent Claim
42 words
An article of manufacture according to claim 13 wherein said means for effecting a pulsing induction of electrical energy are means for effecting a relative movement between said D.C. field and said armature for cutting of said D.C. field by said armature.
Claim 17
Dependent Claim
43 words
An article of manufacture according to claim 13 wherein said means for effecting a pulsing induction of electrical energy are means for effecting a relative linear movement between said D.C. field and said armature for cutting of said D.C. field by said armature.
Claim 18
Dependent Claim
43 words
An article of manufacture according to claim 13 wherein said means for effecting a pulsing induction of electrical energy are means for effecting a relative rotational movement between said D.C. field and said armature for cutting of said D.C. field by said armature.
Claim 19
Dependent Claim
18 words
An article of manufacture according to claim 13 wherein said D.C. field is provided by permanent magnetic means.
Claim 20
Dependent Claim
46 words
An article of manufacture according to claim 17 wherein the frequency of said pulsing induction is at a frequency on the order of 60 hertz and less to provide for induced current penetration of the workpiece on the order of one-third the thickness of the workpiece.
Claim 21
Dependent Claim
22 words
A new article of manufacture according to claim 16 wherein the armature is in the form of a large diameter elongated billet.
Claim 22
Dependent Claim
23 words
A new article of manufacture according to claim 16 wherein the armature is in the form of a coil of thin sheet metal.
Claim 23
Dependent Claim
26 words
A new article of manufacture according to claim 15 wherein the armature is in the form of an elongated member of sheet, web or slab type.
Claim 24
Dependent Claim
59 words
A new article of manufacture according to claim 15 wherein said armature is generally in the form of a plate, and the D.C. field is formed by fixed magnets positioned at one side of said armature and a series of moving magnets at the other side of said armature and moving parallel to said armature and said fixed magnets.
Claim 25
Dependent Claim
36 words
A new article of manufacture according to claim 22 wherein said fixed and moving magnets are permanent magnets, a loop type electromagnet encircles said fixed magnet, and said armature and the path of said moving magnets.
Claim 26
Dependent Claim
25 words
An article of manufacture according to claim 13 wherein said armature is in the form of a crucible having therein metal components to be melted.
Claim 27
Dependent Claim
33 words
A method according to claim 1 wherein the shape is in the form of a crucible having therein metal components, and the heating is to the extent that the metal components are melted.
Claim 28
Dependent Claim
24 words
A method according to claim 1 wherein the frequency and depth of penetration are such that overheating of edges of the shapes is prevented.
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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) | 1991-08-02 | 1992-02-01 | 1992-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-02 | 1996-02-01 | 1996-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-02 | 2000-02-01 | 2000-08-02 | $7700.00 | Window Closed / Lapsed |