US4745264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency autoregulating heater
Assignee: Delaware Capital Formation Inc
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Filing: 1984-10-30
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Granted: 1988-05-17
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Expires: 2004-10-30
Abstract
Abstract The impedance of an autoregulating heater is greatly increased by employing in one embodiment a return conductor in the form of a helix surrounded by and insulated from a magnetic conductor; the two conductors connected in series or as a transformer across an a.c. source whereby the current in the magnetic material is forced to follow a helical path. In a preferred embodiment, a multilayered coil is wrapped about and insulated from a magnetic sleeve disposed about a copper rod; the sleeve and rod forming the secondary of a transformer. The helical path of the current in the secondary plus the impedance transformation effect of the transformer greatly enhances the impedance of the load as presented to a current source. The winding is enclosed within another magnetic sleeve which provides another magnetic shield about the heater and if connected at one end to the inner magnetic layer increases the width to thickness ratio for purposes to be described.
Inventors
- 👤 Philip S. Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:21
CPC Classifications
B; B23; B23K; B23K3/00; B23K3/04; B23K3/047; B23K3/0475; B23K3/02; B23K3/03; B23K3/0338; B23K3/0353
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
153 words
A temperature autoregulation heater comprising a layer of magnetic material, an electrical conductor means for inducing in said magnetic material layer an induced current constrained to follow a circuitous path through said magnetic layer to increase the resistive component of the input impedance of said electrical conductor below Curie temperature of said layer of magnetic material, said electrical conductor means including means for connecting said electrical conductor means to a source of high frequency, substantially constant conductor current, said induced current being substantially confined to said layer, said electrical conductor means and said layer of magnetic material being configured to produce a coupling approaching unity to cause said magnetic material when said conductor is connected to a high frequency, substantially, constant current source to be heated to a temperature at least approaching the Curie temperature thereby to reduce substantially its permeability and cause said resistive component of the input impedance to reduce substantially.
Claim 2
Dependent Claim
153 words
A temperature autoregulation heater comprising a layer of magnetic material, an electrical conductor means for inducing in said magnetic material layer an induced current constrained to follow a circuitous path through said magnetic layer to increase the resistive component of the input impedance of said electrical conductor below Curie temperature of said layer of magnetic material, said electrical conductor means including means for connecting said electrical conductor means to a source of high frequency, substantially constant conductor current, said induced current being substantially confined to said layer, said electrical conductor means and said layer of magnetic material being configured to produce a coupling approaching unity to cause said magnetic material when said conductor is connected to a high frequency, substantially, constant current source to be heated to a temperature at least approaching the Curie temperature thereby to reduce substantially its permeability and cause said resistive component of the input impedance to reduce substantially.
Claim 3
Dependent Claim
30 words
A heating device according to claim 1 wherein said sheet of magnetic material and said conductor are coaxial, further comprising a conductive member surrounded by said layer of magnetic material.
Claim 4
Dependent Claim
159 words
A heating device comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, said current conductor having means for connecting it across a source of high frequency constant current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said series of parallel turns from said sheet, and a source of high frequency alternating current for feeding a constant current through said conductor, to induce current in a confined region of said sheet thereby heating said sheet, said series of parallel turns and said sheet being arranged in such close proximity and the permeability of said sheet and the frequency of said alternating current being such that, the path of current induced in the sheet is substantially lengthened, and the impedance of the current path substantially increased, said sheet being heated to a sufficiently high temperature that its permeability substantially declines.
Claim 5
Dependent Claim
159 words
A heating device comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, said current conductor having means for connecting it across a source of high frequency constant current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said series of parallel turns from said sheet, and a source of high frequency alternating current for feeding a constant current through said conductor, to induce current in a confined region of said sheet thereby heating said sheet, said series of parallel turns and said sheet being arranged in such close proximity and the permeability of said sheet and the frequency of said alternating current being such that, the path of current induced in the sheet is substantially lengthened, and the impedance of the current path substantially increased, said sheet being heated to a sufficiently high temperature that its permeability substantially declines.
Claim 6
Dependent Claim
51 words
A temperature autoregulating heater according to claim 1 wherein said conductor is a multilayer winding, said layer of magnetic material and said conductor being coaxial, said winding being electrically insulated from said layer whereby said layer constitutes the secondary winding of a transformer with said conductor forming the primary winding thereof.
Claim 7
Dependent Claim
39 words
A temperature autoregulating heater according to claim 4 wherein said multilayer winding is disposed about said sheet, a hollow layer of magnetic material disposed about said multilayer winding, and a conductive shield disposed about said layer of magnetic material.
Claim 8
Dependent Claim
28 words
A temperature of autoregulating heater according to claim 5 wherein said magnetic sheet and layer are joined by a magnetic member at at least one end of each.
Claim 9
Dependent Claim
28 words
A temperature autoregulating heater according to claim 5 wherein said magnetic sheet and layer are joined by magnetic members at both ends of said magnetic sheet and layer.
Claim 10
Dependent Claim
30 words
A temperature autoregulating heater according to claims 3, or 2, or 4, or 5, or 6, or 7 further comprising a conductive rod about which said magnetic sheet is secured.
Claim 11
Dependent Claim
24 words
A temperature autoregulating heater according to claim 8 wherein said heater is a soldering iron including a soldering iron tip extending from said rod.
Claim 12
Dependent Claim
43 words
A temperature autoregulating heater according to claim 4 further comprising, means for connecting an alternating constant current across said winding and means for matching said heater to a source of current, said means comprising a capacitor approximately matching the inductance of said winding.
Claim 13
Dependent Claim
67 words
The device according to claim 3 wherein said electrical conductive means is a return conductor axially surrounded by and insulated from said sheet of magnetic material, said sheet and said conductor being electrically connected together at one end of each and having means for applying alternating constant current applied across opposite ends of each, said return conductor being circuitous in the region surrounded by said magnetic material.
Claim 14
Dependent Claim
12 words
The device according to claim 11 wherein said return conductor is helical.
Claim 15
Dependent Claim
17 words
The device according to claim 11 wherein said magnetic material is a sleeve surrounding said return conductor.
Claim 16
Dependent Claim
46 words
The device according to claim 12 or claim 13 further comprising an impedance matching network having a parallel resonant circuit resonant at the operating frequency of the device, said resonant circuit having a capacitor and an inductor, said heating device being in series with said inductor.
Claim 17
Dependent Claim
20 words
The device according to claim 14 wherein said parallel resonant circuit has a Q of at least 4.5 and less.
Claim 18
Dependent Claim
15 words
The device according to claim 15 wherein said heater has a Q of approximately 1.5.
Claim 19
Dependent Claim
16 words
The device according to claim 16 wherein said inductor has a Q in the range 50-250.
Claim 20
Dependent Claim
14 words
The device according to claim 14 wherein said inductor as an iron dust inductor.
Claim 21
Dependent Claim
21 words
The device according to claim 13 wherein said magnetic material is laminated and electrically in contact with a further conductive material.
Claim 22
Dependent Claim
22 words
The device according to claim 19 wherein said laminated magnetic material and conductive material are coaxial with and insulated from the helix.
Claim 23
Dependent Claim
45 words
The device according to claim 20 wherein said conductive material is copper and said high mu material has a thickness equal to 0.5 to 1.8 skin depths of the high mu material at the frequency of alternating constant current source connected to said heating device.
Claim 24
Dependent Claim
16 words
A heating device according to claim 3 having a soldering iron tip heated by said sheet.
Claim 25
Dependent Claim
108 words
A soldering iron, comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, a source of alternating current for feeding current through said conductor, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said conductor from said sheet, said sheet being heated at least in part by induction to a temperature sufficiently high to cause the sheet's permeability to decline substantially, a sheet of high electric and thermal conductivity in electrical and thermal contact with said magnetic sheet, and a heat transferral tip heated by one of said sheets.
Claim 26
Dependent Claim
108 words
A soldering iron, comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, a source of alternating current for feeding current through said conductor, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said conductor from said sheet, said sheet being heated at least in part by induction to a temperature sufficiently high to cause the sheet's permeability to decline substantially, a sheet of high electric and thermal conductivity in electrical and thermal contact with said magnetic sheet, and a heat transferral tip heated by one of said sheets.
Claim 27
Dependent Claim
18 words
A soldering iron according to claim 23, wherein: said magnetic sheet is substantially surrounded by said conductor turns.
Claim 28
Dependent Claim
18 words
A soldering iron according to claim 24, wherein: said conductive sheet is substantially surrounded by said magnetic sheet.
Claim 29
Dependent Claim
92 words
A soldering iron, comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, wherein said conductor is configured for connection across a source of high-frequecy alternating current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means of insulating said conductor from said sheet so that said sheet is heated by induction to a temperature sufficiently high to cause the sheet's permeability to decline substantially, and a heat transferral tip heated by one of said sheets.
Claim 30
Dependent Claim
92 words
A soldering iron, comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, wherein said conductor is configured for connection across a source of high-frequecy alternating current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means of insulating said conductor from said sheet so that said sheet is heated by induction to a temperature sufficiently high to cause the sheet's permeability to decline substantially, and a heat transferral tip heated by one of said sheets.
Claim 31
Dependent Claim
23 words
A soldering iron according to claim 26, further comprising: a sheet of high conductivity in electrical and thermal contact with said magnetic sheet.
Claim 32
Dependent Claim
20 words
A soldering iron according to claim 26, further comprising: a source of alternating electrical current for supplying said current conductor.
Claim 33
Dependent Claim
106 words
An article of manufacture constituting a heat generating cartridge comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, wherein said conductor is configured for connection across a source of high-frequency alternating current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said conductor from said sheet, said sheet being heated at least in part by induction to a temperature sufficiently high to cause the permeability of the sheets to decline substantially, and a heat transferral member in contact with and heated by one of said sheets.
Claim 34
Dependent Claim
106 words
An article of manufacture constituting a heat generating cartridge comprising: a current conductor having a plurality of serially connected substantially parallel turns sequentially spaced along a longitudinal axis, wherein said conductor is configured for connection across a source of high-frequency alternating current, a sheet of high permeability magnetic material closely adjacent to an extended area of said turns, means for insulating said conductor from said sheet, said sheet being heated at least in part by induction to a temperature sufficiently high to cause the permeability of the sheets to decline substantially, and a heat transferral member in contact with and heated by one of said sheets.
Claim 35
Dependent Claim
23 words
An article of manufacture according to claim 29, further comprising: a source of alternating substantially constant electrical current for supplying said current conductor.
Claim 36
Dependent Claim
27 words
An article of manufacture according to claim 29, further comprising; a sheet of high electric and thermal conductivity in electrical and thermal contact with said magnetic sheet.
Claim 37
Dependent Claim
18 words
A soldering iron according to claim 25, further comprising: a second magnetic sheet substantially surrounding said conductor turns.
Claim 38
Dependent Claim
21 words
A soldering iron according to claim 32, wherein: said second magnetic sheet is in electrical contact with said first magnetic sheet.
Claim 39
Dependent Claim
30 words
A soldering iron according to claim 32 or claim 33, wherein the Curie temperature of said second magnetic sheet is higher than the Curie temperature of said first magnetic sheet.
Claim 40
Dependent Claim
39 words
A soldering iron according to claim 34 wherein the Curie temperature of said second magnetic sheet is sufficiently high that the temperature of the soldering iron does not approach such temperature sufficiently closely to materially reduce the permeability thereof.
Claim 41
Dependent Claim
108 words
A tip construction for a heating device comprising, a tip of thermally and electricity conductive material, a rearward extension of said material of said tip, a layer of magnetic material disposed about in physical, thermal and electrical contact with said rearward extension, a coil of electrically conductive wire disposed about and in close relation to said layer whereby to induce eddy currents in said layer, and said close relation substantially increasing the impedance of said coil, means adapted to connect said coil to a source of alternating current whereby to heat said layer to a temperature sufficiently high to cause the permeability of said layer to decrease materially.
Claim 42
Dependent Claim
108 words
A tip construction for a heating device comprising, a tip of thermally and electricity conductive material, a rearward extension of said material of said tip, a layer of magnetic material disposed about in physical, thermal and electrical contact with said rearward extension, a coil of electrically conductive wire disposed about and in close relation to said layer whereby to induce eddy currents in said layer, and said close relation substantially increasing the impedance of said coil, means adapted to connect said coil to a source of alternating current whereby to heat said layer to a temperature sufficiently high to cause the permeability of said layer to decrease materially.
Claim 43
Independent Claim
111 words
The method of utilizing a soldering iron element to melt solder comprising: providing a source of radio frequency current, passing radio frequency current from said source along a generally helical path adjacent to said element to induce current therein and heat the element, distorting the path of the current in said element to elongate said path in said element and thereby increase the length of the path of the current in said element whereby to increase the impedance of said helical path to said radio frequency current, and substantially matching the impedance of said source to said helical path, whereby the increased impedance of said helical path facilitates said substantial matching.
Claim 44
Independent Claim
111 words
The method of utilizing a soldering iron element to melt solder comprising: providing a source of radio frequency current, passing radio frequency current from said source along a generally helical path adjacent to said element to induce current therein and heat the element, distorting the path of the current in said element to elongate said path in said element and thereby increase the length of the path of the current in said element whereby to increase the impedance of said helical path to said radio frequency current, and substantially matching the impedance of said source to said helical path, whereby the increased impedance of said helical path facilitates said substantial matching.
Claim 45
Dependent Claim
36 words
The method of claim 37 in which said element includes ferromagnetic material heated by said current in said element to a sufficiently high temperature as to effect a decline in the permeability of said ferromagnetic material.
Claim 46
Dependent Claim
39 words
A temperature autoregulating heater according to claim 1 wherein the ratio of the width of each turn of said winding to the spacing between said turns of the winding and said layer of magnetic material is at least 4:1.
References Cited (Backward Citations)
US1975436A
Cited
US1931607A
Cited
US1975437A
Cited
US2181274A
Cited
US2509713A
Cited
US2465102A
Cited
US2478857A
Cited
US2912553A
Cited
US3218384A
Cited
GB1076772A
Cited
US4185632A
Cited
US4091813A
Cited
US4256945A
Cited
US4456186A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |