Hand held induction tool
First Claim
1. A method for controlling energy delivered by a work coil, said method comprising:
- (a) providing a heating apparatus having a work coil, and an electrical circuit that provides an electrical current to said work coil;
(b) emitting a magnetic field from said work coil, increasing a first electrical characteristic of an electrical signal of said electrical circuit to a predetermined first magnitude, and substantially at said predetermined first magnitude, determining a second magnitude of a second electrical characteristic of said electrical signal of said electrical circuit to determine a distance value; and
(c) based substantially upon said distance value, adjusting said first electrical characteristic and said second electrical characteristic of said electrical signal to emit said magnetic field at a predetermined desired power level.
8 Assignments
0 Petitions
Accused Products
Abstract
An apparatus and system for using magnetic fields to heat magnetically susceptible materials within and/or adjacent to adhesives, resins, or composites so as to reversibly or irreversibly bond, bind, or fasten opaque or non-opaque solid materials to one another. The system makes use of the effect that alternating magnetic fields induce eddy currents and generate heat within susceptors, and the effect that alternating magnetic fields additionally induce magnetic hysteresis that occurs in magnetic materials and thereby generate heat. An induction heating tool is used to emit the magnetic field at its work coil, and an electronic controller measures the energy being used by a power converter that generates the alternating current driving the work coil which creates the magnetic field. The distance between the susceptor and work coil is repeatedly analyzed based upon the power converter'"'"'s input energy, and the work coil is driven at a repeatedly corrected power level during the heating cycle. Once a sufficient accumulated energy has been delivered to the susceptor, the magnetic field is turned off automatically by the tool, thus preventing overheating of the susceptor.
218 Citations
53 Claims
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1. A method for controlling energy delivered by a work coil, said method comprising:
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(a) providing a heating apparatus having a work coil, and an electrical circuit that provides an electrical current to said work coil;
(b) emitting a magnetic field from said work coil, increasing a first electrical characteristic of an electrical signal of said electrical circuit to a predetermined first magnitude, and substantially at said predetermined first magnitude, determining a second magnitude of a second electrical characteristic of said electrical signal of said electrical circuit to determine a distance value; and
(c) based substantially upon said distance value, adjusting said first electrical characteristic and said second electrical characteristic of said electrical signal to emit said magnetic field at a predetermined desired power level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
adjusting a third electrical characteristic of a second electrical signal at a second predetermined point of said power converter that is upstream from said first predetermined point, and emitting said magnetic field at a predetermined desired power level useful at said distance value, thereby operating said heating apparatus in a feedback configuration.
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14. A method for controlling energy dissipated in a susceptor being delivered by a work coil, said method comprising:
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(a) providing a heating apparatus having a work coil, and an electrical circuit including a power converter;
(b) emitting a magnetic field from said work coil, and directing said magnetic field toward a susceptor that contains an electrically conductive portion that produces eddy currents due to said magnetic field;
(c) adjusting a first electrical characteristic of an electrical signal of said power converter to a first predetermined magnitude, determining a second electrical characteristic of said electrical signal of said power converter substantially at said first predetermined magnitude, then determining a distance value substantially corresponding to a physical distance between said work coil and said susceptor; and
(d) based upon said distance value, automatically adjusting said first and second electrical characteristics of said electrical signal of the power converter to thereby emit said magnetic field at a power level sufficient to raise a temperature of the electrically conductive portion of said susceptor. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
after the softening or melting of the adhesive occurs, significantly reducing said power level to allow the temperature of the electrically conductive portion of said susceptor to decrease and thereby allow said adhesive to solidify, thereby creating a bond between said first and second structures.
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21. The method as recited in claim 20, wherein said bond is either a mechanical bond or a chemical bond.
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22. The method as recited in claim 20, wherein said adhesive is either a thermoplastic adhesive or a thermosetting adhesive.
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23. The method as recited in claim 20, further comprising:
reverse assembling the bond between said first and second structures, by directing said magnetic field toward said susceptor, which had previously been bonded to said first and second structures, until a sufficient temperature rise has occurred to re-melt or re-soften said adhesive, then detaching said first and second structures.
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24. The method as recited in claim 14, further comprising:
- permanently bonding said susceptor to a first structure, and providing a second structure that is to be bonded to said first structure by said susceptor, wherein said susceptor includes at least one surface of a temperature-actuated adhesive;
raising the temperature of the electrically conductive portion of said susceptor by an amount sufficient to soften or melt the adhesive against said second structure; and
after the softening or melting of the adhesive occurs, significantly reducing said power level to allow the temperature of the electrically conductive portion of said susceptor to decrease and thereby allow said adhesive to solidify, thereby creating a bond between said susceptor and said second structure.
- permanently bonding said susceptor to a first structure, and providing a second structure that is to be bonded to said first structure by said susceptor, wherein said susceptor includes at least one surface of a temperature-actuated adhesive;
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25. The method as recited in claim 24, further comprising:
- reverse assembling the bond between said susceptor and said second structure, by directing said magnetic field toward said susceptor, which had previously been bonded to both said first and second structures, until a sufficient temperature rise has occurred to re-melt or re-soften said adhesive, then detaching said susceptor and said second structure.
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26. The method as recited in claim 14, wherein the electrically conductive portion of said susceptor comprises a substantially thin layer having a thickness in the range of 0.01 mils (0.25 microns) through 3.0 mils (76 microns), and the operating frequency of said magnetic field is in the range of 1 kHz through 10 MHz.
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27. The method as recited in claim 26, wherein the electrically conductive portion of said susceptor comprises a substantially thin layer having a thickness in the range of 0.05 mils (1.3 microns) through 2.0 mils (51 microns), and the operating frequency of said magnetic field is in the range of 1 kHz through 10 MHz.
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28. The method as recited in claim 27, wherein the electrically conductive portion of said susceptor comprises a substantially thin layer having a thickness in the range of 0.1 mils (2.5 microns) through 0.7 mils (18 microns), and the operating frequency of said magnetic field is in the range of 1 kHz through 10 MHz.
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29. The method as recited in claim 14, wherein the electrically conductive portion of said susceptor comprises one of a substantially large sheet, or a substantially narrow strip, of either a solid construction or of a construction containing openings.
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30. The method as recited in claim 29, wherein said heating apparatus is used to sequentially create a plurality of bonds between said susceptor and at least one surface of a substrate sheet material.
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31. The method as recited in claim 29, wherein said heating apparatus is used to sequentially create a plurality of bonds in an ironing mode of operation between said susceptor and at least one surface or edge of a substrate.
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32. The method as recited in claim 14, further comprising:
- automatically indicating to a user/operator when a susceptor has been found, based upon a determination that said distance value is within a predetermined range, wherein said automatic indication is one of a visible or tactile indication.
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33. The method as recited in claim 14, wherein said susceptor withstands a power density of up to 2 kW per square inch of area during a heating cycle induced by the magnetic field of said heating apparatus.
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34. The method as recited in claim 14, wherein said heating apparatus applies sufficient magnetic energy to said susceptor to create a bond in less than one-half second.
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35. A heating apparatus, comprising:
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an electronic circuit including a power converter stage, and a work coil, said electronic circuit being configured to control a current magnitude and a voltage magnitude at an input of said power converter stage;
said electronic circuit being configured to adjust one of said current magnitude or voltage magnitude at the input of said power converter stage to a first predetermined magnitude, and to use the other magnitude to determine a distance value; and
based upon said distance value, said electronic circuit is further configured to adjust said current magnitude and voltage magnitude at the input to said power converter stage so as to cause said work coil to emit a magnetic field at a predetermined desired power level. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53)
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Specification