US2223507A - Induction heating method - Google Patents

Induction heating method Download PDF

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Publication number
US2223507A
US2223507A US252923A US25292339A US2223507A US 2223507 A US2223507 A US 2223507A US 252923 A US252923 A US 252923A US 25292339 A US25292339 A US 25292339A US 2223507 A US2223507 A US 2223507A
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US
United States
Prior art keywords
charge
coil
pieces
heating
inductor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US252923A
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English (en)
Inventor
Jr Robert N Blakeslee
Harry G Remmers
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ajax Electrothermic Corp
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Ajax Electrothermic Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ajax Electrothermic Corp filed Critical Ajax Electrothermic Corp
Priority to US252923A priority Critical patent/US2223507A/en
Priority to GB1043/40A priority patent/GB534417A/en
Priority to FR863058D priority patent/FR863058A/fr
Application granted granted Critical
Publication of US2223507A publication Critical patent/US2223507A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/101—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces
    • H05B6/102—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces the metal pieces being rotated while induction heated
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/101—Induction heating apparatus, other than furnaces, for specific applications for local heating of metal pieces

Definitions

  • a purpose of the invention is to provide a method and apparatus for heating the ends of tubes, rods, bars or like charges for forging or for other purposes.
  • a further purpose is to provide a relatively simple method and apparatus for uniformly inductively heating the ends of attenuated or bulky charges with a minimum of handling eifort.
  • Figure 1 is a perspective view showing one form of applicants invention as applied to the heating of the ends of tubes.
  • Figure 2 is a diagrammatic view showing how tubes, as in Figure 1, have been heated heretofore by induction.
  • Figures 3 and 4 are cross-sectional views of an ordnance shell and a section of pipe shown as examples of charges that might be heated by the method described.
  • Heating of the ends of tubes, rods or like charges by induction has been accomplished heretoforeand although the methods are successful and efficient the handling of the charge pieces is sometimes troublesome. In most such instances individual coils having good coupling with the charge pieces are used. The charge pieces are inserted in these and are heated to the desired temperature after which they are removed for working. Since the heating time required for a single charge is generally too long to fit into usual production'schedules several coils are required, and the charge pieces are inserted and taken out of these in rotation to maintain the 40 desired production speed. To eifect such a continuous cycle it is necessary to jump the charge pieces over one another in feeding them to and in removing them from the proper heating coils.
  • the ends of the charge pieces are fed consecutively into one side of a long narrow coil opening to a depth approximate wlththelengthottheparttoboheated. After aninitialheatinginthfloeeflonthquestepped along in the coil where the heat has a chance to distribute itself in the pieces. They are then carried to the far side of the coil where they are raised rapidly to the working temperature and are removed for working.
  • the pieces may be fed to and along the coil on a continuous belt or they may be fed into the coil proper by a crane. Once in the furnace they do not need to be handled again until they have been heated and are removed for working.
  • Each piece, on entering the furnace, is subjected to induction about a large portion of its periphery and since the currents induced in it are circumferential the end may be heated at a rapid and uniform rate. If the charge piece is magnetic the heating rate is faster than if it is non-magnetic. As charge pieces are taken out of the coil the pieces remaining therein are rolled or are shifted toward the end position. When in the central portions of the coil the charge pieces absorb energy at a much slower rate due to the poorer coupling with the inductor. This allows for equalization of temperature differences. When the charge pieces arrive at the end of their travel in the coil they are again placed in good coupling with the inductor and are given the final boost to the working temperature. High temperature is not required to be maintained for along period and trouble from scale is thus greatly reduced.
  • the method has been found to have great advantages over previous methods of heating.
  • the rapid initial heating, the somewhat slower heating immediately following, and the rapid heating at the end insure overall speed, uniformity and efiiciency of production. Almost allguesswork regarding temperatures is eliminated.
  • the pieces come to temperature in a regular order and the temperature may be controlled automatically on all as a group. There is no such overshooting in temperature as can result when separate coils and rapid heating are involved.
  • the furnace as a unit has substantially a constant loading at all times and the wide fluctuations usual when a single load is placed in a single coil or when that load becomes non-magnetic, cannot exist.
  • FIG 2 a plurality of inductor coils A, B, C are shown. They are separate and articulate and each is designed to heat a charge piece to a desired temperature in a desired time.
  • the coils may be connected either in series or in parallel relation to a source of power supply, usually of intermediate or high frequency alternating current.
  • a source of power supply usually of intermediate or high frequency alternating current.
  • a load is inserted in coil A, then say a half minute later a load is placed in coil B and so on.
  • the heating characteristics being substantially uniform the established rotation and heating schedule is A, B, C, A, B, etc., on a half minute schedule.
  • the inductor coil I is wound as an elongated oval. Its dimensions are adapted to the particular job in hand. The coil length is such that the charge pieces are heated only as far back as is desired. The height is as small as practicable to admit the charge Also, as in the method
  • the inductor coil I is adapted with the usual supporting members 2,. terminals 3 and water connections 4. Insulation 5 is used between the charge pieces 6 and the inductor proper. One side of the inductor assembly may be raised giving the assembly a slight angle of tilt to cause the charge pieces to roll or slide progressively to the other side as successive pieces are removed, or the charge pieces maybe progressed by moving them bodily on a belt or rack 1.
  • the method of heating a charge piece having substantial length which comprises placing it within and along one side of a cylindrical helical type inductor coil having a length along the ness, energizing said coil by passing an alternating current therethrough, moving said charge piece across the width of said inductor coil from a position where the coupling between the coil and charge is close about a substantial portion of the perimeter of the charge, through intermediate positions where the coupling is close only on opposite sides of the charge, to a position where the coupling is again good about a substantial portion of the perimeter of the charge, maintaining the length axes of charge and coil substantially parallel at all times and removing the charge piece from the coil.
  • the method of heating a succession of charge pieces having substantial length which comprises placing them successively within and along one side of a cylindrical helical type in-' ductor coil having a length along the axis of the coil approximately equal to the portions of the charge pieces to be heated, a thickness approximately equal to the thickness of the charge pieces and a width many times-greater than said thickness, energizing said coil by passing an alternating current therethrough, moving said charge pieces across the width of said inductor coil from a position where the coupling between the coil and a charge piece is close about a substantial portion of the perimeter of the charge piece through intermediate positions where the coupling is close only on opposite sides of the charge piece, to a position on the opposite side of the coil where the coupling is again good about a substantial portion of the perimeter of the charge piece, maintaining the length axes of charge pieces and coil substantially parallel'at all times and successively removing the charge pieces from said opposite side of the coil.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Induction Heating (AREA)
US252923A 1939-01-26 1939-01-26 Induction heating method Expired - Lifetime US2223507A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US252923A US2223507A (en) 1939-01-26 1939-01-26 Induction heating method
GB1043/40A GB534417A (en) 1939-01-26 1940-01-17 Method of electric induction heating
FR863058D FR863058A (fr) 1939-01-26 1940-01-25 Procédé de chauffage par induction

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US252923A US2223507A (en) 1939-01-26 1939-01-26 Induction heating method

Publications (1)

Publication Number Publication Date
US2223507A true US2223507A (en) 1940-12-03

Family

ID=22958114

Family Applications (1)

Application Number Title Priority Date Filing Date
US252923A Expired - Lifetime US2223507A (en) 1939-01-26 1939-01-26 Induction heating method

Country Status (3)

Country Link
US (1) US2223507A (fr)
FR (1) FR863058A (fr)
GB (1) GB534417A (fr)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539903A (en) * 1946-12-05 1951-01-30 Smith Corp A O Piston fabrication
DE914088C (de) * 1944-04-05 1954-06-24 Rheinische Roehrenwerke Ag Verfahren zum Erzeugen nockenfoermiger Erhoehungen an Hohlkoerpern
DE932364C (de) * 1944-01-22 1955-08-29 Rheinische Roehrenwerke Ag Verfahren und Vorrichtung zur Erzeugung von Wellen, Sicken od. dgl. an Rohren
DE953842C (de) * 1950-12-31 1956-12-06 Phoenix Rheinrohr Ag Vereinigt Verfahren und Vorrichtung zum Erzeugen oertlicher Verstaerkungen an zylindrischen Hohlkoerpern
DE1047581B (de) * 1955-04-09 1958-12-24 Austin Motor Co Ltd Verfahren und Vorrichtung zum Herstellen von Turbinenschaufeln
DE975493C (de) * 1943-11-02 1961-12-07 Deutsche Edelstahlwerke Ag Verfahren und Vorrichtung zum Anstauchen von Flanschen, Verdickungen u. dgl. an Rohren
DE1254659B (de) * 1963-01-16 1967-11-23 Acec Vorrichtung zur induktiven Erwaermung der Enden von Staeben
US4766664A (en) * 1987-02-17 1988-08-30 Alumax Extrusions, Inc. Process for formation of high strength aluminum ladder structures
US20110090933A1 (en) * 2009-10-21 2011-04-21 Steven Thomas Gibbs Electric Glass Hot Shop System

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1013809B (de) * 1954-03-05 1957-08-14 Siemens Ag Verfahren zum induktiven Erwaermen von metallischen Werkstuecken

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE975493C (de) * 1943-11-02 1961-12-07 Deutsche Edelstahlwerke Ag Verfahren und Vorrichtung zum Anstauchen von Flanschen, Verdickungen u. dgl. an Rohren
DE932364C (de) * 1944-01-22 1955-08-29 Rheinische Roehrenwerke Ag Verfahren und Vorrichtung zur Erzeugung von Wellen, Sicken od. dgl. an Rohren
DE914088C (de) * 1944-04-05 1954-06-24 Rheinische Roehrenwerke Ag Verfahren zum Erzeugen nockenfoermiger Erhoehungen an Hohlkoerpern
US2539903A (en) * 1946-12-05 1951-01-30 Smith Corp A O Piston fabrication
DE953842C (de) * 1950-12-31 1956-12-06 Phoenix Rheinrohr Ag Vereinigt Verfahren und Vorrichtung zum Erzeugen oertlicher Verstaerkungen an zylindrischen Hohlkoerpern
DE1047581B (de) * 1955-04-09 1958-12-24 Austin Motor Co Ltd Verfahren und Vorrichtung zum Herstellen von Turbinenschaufeln
DE1254659B (de) * 1963-01-16 1967-11-23 Acec Vorrichtung zur induktiven Erwaermung der Enden von Staeben
US4766664A (en) * 1987-02-17 1988-08-30 Alumax Extrusions, Inc. Process for formation of high strength aluminum ladder structures
US20110090933A1 (en) * 2009-10-21 2011-04-21 Steven Thomas Gibbs Electric Glass Hot Shop System
US8891582B2 (en) * 2009-10-21 2014-11-18 Corning Museum of Glass Electric glass hot shop system
US9676655B2 (en) 2009-10-21 2017-06-13 Corning Museum of Glass Electric glory hole insulation package
US9957186B2 (en) 2009-10-21 2018-05-01 Corning Museum of Glass Electric glory hole video camera assembly
US10059620B2 (en) 2009-10-21 2018-08-28 Corning Museum of Glass Electric furnace for processing glass
US10059619B2 (en) 2009-10-21 2018-08-28 Corning Museum of Glass Electric glory hole heating element baffle

Also Published As

Publication number Publication date
GB534417A (en) 1941-03-06
FR863058A (fr) 1941-03-22

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