US1362610A - Electric heating apparatus - Google Patents

Description

R. P. DUNNING.

ELECTRIC HEATlNG APPARATUS.

APPLICATION FILED JUNEZl, 1920.

Pata znted Dec. 21, 1920.

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His Attorney.

UNITED STATES PATENT .OFFICE.

RAYMOND I. DUNNING, OI BCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIO COMPANY, A CORPORATION OF NEWYOBK.

ELECTRIC HEATING APPARATUS.

Specification of Letters Patent.

Patented Dec. 21, 1920.

Application filed June 21, 1920. Serial No. 390,519.

, is a specification.

My invention relates to an electric heating apparatus and'particularly to a device adapted to heat articles such as rivets and the like by passing current therethrough in series.

An object of my invention is to provide a simple and compact device which shall provide a plurality of circuits for heating articles in series and which shall be capable of ready adjustment independently to control the current in the various circuits whereby articles of different size and cross section may be simultaneously heated on the same machine.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Figure 1 is a perspective view of an electric heating device embodying my invention; and Fig. 2 is a diagrammatic view representing the circuit connections of the device shown in Fig. 1.

Referring to Fig. 1, a shell-type transformer is illustrated provided with primary windings 1 and 2 wound on the outside legs of the core, the center leg 3 being left unwound. Electrodes lr, 5, 6 and 7 are mounted respectively on conducting bars 8, 9, 10 and 11 preferably made of copper, which are mounted for pivotal movement upon a rod 12 secured to brackets 13 mounted upon the supporting framework. This framework comprises front legs 14, 15, rear legs 16, 17 and suitable bracing members. The conducting bars 8 and 9 are electrically connected together at the rear by a flexible laminated conducting member 18, and a similar conducting member 19 connects the bars 10 and 11. The pairs of bars 8 and 9 being in inductive relation to the primary winding 2, form a secondary winding for this primary winding and the bars 10 andll likewise form a secondary winding for the primary winding 1. The secondary circuit comprising the bars 8 and 9 is adapted to be completed in series through the articles 20 to be heated interposed between the electrodes 4. and 5 and the conductlng member 21. In like manner the circuit of the secondary winding comprising bars 10 and 11 is adapted to be completed in series through .the articles interposed between the electrodes 6 and 7 and conducting member 22. The conducting members 21 and 22 are supported on the adjustable member 23 mounted on the supporting frame of the device. Insulating locks 24. are provided to insulate the conducting members from the supporting member 23. Any convenient means may be used to raise and lower the movable electrodes to permit of ready insertion and removal of the articles to be heated and in the drawmg a foot lever 25 is shown connected to each of the bars 8, 9, 10 and 11 through rods 26 in which insulating joints 27 are interposed. n

Fig. 2 shows the circuit connections to the primary windings 1 and 2 of the transformer, the bars 8, 9, 10 and 11 comprising the secondary windings being shown in section. Means indicated as a switch 28 is rovided in the circuit of the primary win ing 1 for adjusting the number of turns thereof I and a similar switch 29 is provided for varying the number of turns of the primary winding 2. The windings 1 and 2 are shown as supplied in parallel from any convenient source of alternating current represented by the mains 30. I preferably arrange the transformer windings so that when the same number of turns are used in each of the windings 1 and 2, no flux flows in the middle leg 3 of the transformer core. With this adjustment the electromotive force induced in the secondary winding comprising the bars 8 and 9 is equal to the electromotive force induced in the secondary winding comprising the bars 10 and 11. With this adjustment, it is apparent that the device is adapted to heat articles of the same size and cross section in each side of the device. ent, however, that the arrangement of windings upon the core permits of independently adjusting the number of turns and magnetomotive forces in the respective primary windings 1 and 2, since flux may flow in the leg 3 equal to the resultant or unbalanced flux when the transformer primaries are given difi'erent adjustments. This makes it pos.

sible simultaneously to heat articles of one size in one side of the device, while articles of It is appara different size are heated in the other side of the device, the heating current being adjusted to the best value for each size of article.

While I have shown one particular embodiment of my invention, it will be apparent to those skilled in the art that various modifications and variations may be made therein, and I desire to cover all such changes as fall within the scope of my invention, which is defined in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. An electric heating apparatus of the class described comprisinga magnetic core having a plurality of legs, primary windings arranged upon said legs, secondary windings arranged in inductive relation to each of said primary windings, electrodes connected to said secondary windings and arranged to engage and supply heating current to the articles to be heated, means whereby the number of turns in said primary windings may be independently adjusted and means on said core providing a path for unbalanced fluxes in said core legs.

2. An electric heating device of the class described comprising a shell-type transformer having a primary winding on each of the outer legs, secondary windings each comprising a pair of conducting bars mounted in inductive relation to each of said primary windings, electrodes carried by said conducting bars arranged to engage and supply heating current to the articles to be heated.

3. An electric heating apparatus of the class described comprising a shell-type transformer having a primary winding on each of the outer legs, means for independently adjusting the magneizing effect of said windings, secondary windings for said primary windings comprising a plurality of conducting bars arranged in inductive relation to said primary windings, and electrodes carried by said conducting bars arranged to enga e and supply heating current to the artic es to be heated.

4. An electric heating apparatus of the class described comprising a shell-type transformer having a primary winding on each of the outer legs, means for independently adjusting the number of turns in said windings, secondary windings for said primary windings comprising independently movable conducting bars mounted in inductive relation to said primary windings, electrodes carried by said conducting bars, stationary electrodes between which and the said movable electrodes the articles to be heated are adapted to be interposed to complete circuits for said secondary windings in series through a plurality of articles to be heated.

In witness whereof, I have hereunto set my hand this 18th day of June, 1920.

RAYMOND P. DUNNING".

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