US1821530A - Induction heater - Google Patents

Description

w. H. SPIRE 1,821,530

INDUCTION HEATER 2 Sheets-Sheet 1 Filed Dec. 1, 1927 w ff/4272 @0012 Patented Sept. 1, 193'! PATENT WILLIAM H. SPIRE, F CLEVELAND, OHIO, ASSIGNOR Ti) THOMPSON PRODUCTS,

A CORPORATION OF OHIU INDUCTION HEATER Application filed December 1, 1927.

This invention relates to improvements in induction heaters, and more particularly to improvements in induction heaters of the type wherein the articles to be heated are {q intimately associated with the secondary element of the heater, as well as, to a novel method of utilizing an induction heater.

The present invention contemplates the provision of an induction heating device which will effectively heat a plurality of articles having many varying natures and forms, and is found highly desirable for the heating of automotive engine valves and the like during the manufacture of the same.

In the past, devices of this character have proven more or less objectionable and undesirable due to the fact that, in many cases, an electric current was passed directly through the articles to be heated the heating was not continuously intermittent, a longer time was necessitated to place and remove the articles to be heated and to operate the heat ing unit, and in most instances, these previously known induction heaters did not provide a work carrying secondary.

This invention is designed to overcome the above noted defects and objections in the provision of an induction heater having therein-a rotatable work carrying, secondary.

The invention also seeks to provide a comparatively simple and readily operable machine in which articles are continuously heated and may be removed and replaced without in any degree retarding the action of the machine.

It is also an important object of this invention to provide a machine of the type doseribed herein, which is adapted to be cooperatively connected to and actuated by another mechanisi'n performing an entirely ditl fercut and individual function.

A further objectof the present invention is to provide a novel method of heating articles, which method is found highly desirable for the articles during the process of their manufacture wherein the articles are to be subjected to one or more additional operations.

WVhile some of the more salient features and characteristics of a machine embodying serial No. $336,5i9F-3.

parts hereinafter described and shown in preferred form in the drawings. and particularly indicated by the claims.

On the drawings:

F igure 1 is an elevational view of embodying principles of the present tion.

Figure 2 is a plan view taken from right side of the device as shown is ure 1.

Figure 3' is a fragmentary vcr' tional view, with parts in elevation, ta? substantially along lines UI-HT of ,3 are 2.

Figure 4 is a fragmentary top view of a portion of the device.

Figure 5 is a fragmentary sectionai view. with parts in elevation, taken subsitautiaii along line IV-IV of Figure 2. V

Figure 6 is a fragmentary elevational vi" OI a part of the actuating); mechanism tai substantially as indicatedhy the arrow 6 in Figure 1.

Figure 7 is a sectional view in elevati taken substantially along" line Vi H m Figure 2.

Figure 8 is a fragmentary sectional vi with parts in elevation, taken suhstantiaiiv along line VTH-VIH of Figure 5. I

As shown in the drawings:

In the illustrated embodiment of this invention, there is disclosed in g'encrai, a. frame A which supportsatransformer and a rotatable element C adjacent the trans-v former. L" r.

The frame It comprises a base portion it) with upright members 11 thereon. The uprights are Formed at the top thereof to pro vide bearing: surfaces for a plurality of shafts 12 (three being shown) upon each of which shafts a roller 13 is mounted. Upon the inner end oi each of these shafts 1Q. beveled gear M is mounted which meshes with a bevel gear 15 miimntcd on a verticai shaft 16. One of the shafts 16 is disposed.

adjacent each of the shafts 12. The shafts 16 are mounted in sleeves on extremities of brackets secured to the uprights 11, as at 17, and in bearing members 18 disposed on the base 10. Adjacent the bearing members 18, each shaft 16 is provided with a gear 19, and journaled in a hub 20 on the base 10 is a relatively large gear 21 which meshes with each of the gears 19.

One of the rollers 13 is directly driven through its shaft 12 by means of a ratchet wheel 22. The ratchet wheel 22 is actuated by means of a spring pressed pawl 23 pivoted to a link 24 to which a second link 25 is pivoted. The roller 13 directly driven by the rotation of the ratchet wheel 22, drives the remaining rollers 13 through the gears 14, 15, 19, and 21, whereby all the rollers are actuated simultaneously. The rollers have the form of truncated cones, for a purpose that will later appear. I

The transformer B is mounted in any desired manner upon the base 10, and comprises a laminated core 26, around the inner leg of which a primary winding 27 is wound. The inner leg of the transformer is embraced by the substantially circular mem ber C which contains the secondary element.

The circular member C comprises, in this instance, a trouglrlike casing 28, preferably of non-magnetic material, having on its under side an integral ring-like portion 29 which is beveled as at 30 to fit the cone-like rollers 13. The inwardly sloping rollers and the beveled portion 30 riding thereon effectively prevent the rotatable member C from becoming even slightly ofl center.

Disposed within the casing 28 is a secondary element 31, of high electrical resistance and of high resistance to oxidation such for example as a nickel chromium ferrous alloy, in which current is induced through the action of the transformer B. The secondary 31 is separated from the casing 28 by a plurality of insulating members 32 which, if so desired, may provide thermal insulation as well as electrical insulation. As shown clearly in Figures 4 and 7, the ring-like secondary 31 is provided with a plurality of recesses 33 therein to receive articles to be heated. The secondary is also provided with a plurality of slots 34 through a large portion of its cross-section to substantially group radially aligned recesses 33 and which reduce the effective cross-sectional area to prevent excessive primary current flow. The recesses 33 are inwardly threaded adjacent the tops thereof to accommodate sleeves 35, which are outwardly flared adjacent the upper extremities and provide substantially containers for articles to be heated. These sleeves 35 project through the upper layer of insulation 32 so that only the outwardly flared tops are exteriorly exposed. They thereby provide means for quickly and easily placing articles therein or removing the same therefrom.

To interrupt what would otherwise be a closed electrical circuit through the casing 28, this casing is split up as at 36, to several relatively short sections or segments which are insulated one from the other. Adjacent each of these sections the casing is provided with an inwardly extending flange 37 (Figure 3) which aids in maintaining the insulation 32 and secondary 31 tightly in their place.

To give adequate indications of the temperature of the secondary element a pair of brushes 38 are attached to the under side of the casing 28. Resilient contacts 39 ride upon these brushes and are connected through binding posts by conductors 40 to a pyrometer 41 or the like.

The invention hereinabove set forth may obviously be used to heat many and various articles, but for the purpose of clarity the operation and method of using the invention in conjunction with the heating of automotive engine valves, will now be described.

In the manufacture of automotive engine valves after the same have been formed it is necessary to cut the stems to the proper size, they being too long after the formation of the valves. The present invention may be driven by the machine used for cutting the valve stems by suitably connecting the link 25 to the said cutting machine, so that the casing 28 will be rotated substantially one-third the distance between the adjacent groups of radially aligned containers 35 by every downward stroke of the cutting machine. Of course, this rotation of the casing 28 and the secondary 31 will be intermittent to allow an operator ample time to remove all of the valve stems in one radial row of containers before the next row reaches a position for removal.

The valve stems, of course, are placed in the containers 35 and the lower extremities of the stems project into the recesses 33 in the secondary 31. The current is applied to the primary 27 and the secondary 31 rotated intermittently through the electromagnetic field established by the transformer B. Such rotation will obviouslyinduce a current in the secondary 31 sufficient to heat the same to a relatively high temperature and the lower ends of the valve stems projecting thereinto will also be heated to a high temperature. It is found desirable to remove the valve stems from the containers 35 just after they have passed through the core 26, thereby taking advantage of the added temperature produced in the valve stems by the eddy current. After a valve stem is removed it is immediately replaced by a cold valve and so the process is continuous. The temperature, of course, may be controlled by controlling the current in the primary and the pyrometer 41 indicates substantially the temperature of the secondary and articles contained therein, at all times.

From the foregoing it will be apparent that I have provided an induction heater wherein the articles to be heated are carried directly by the secondary, wherein the action of heating, removing, and replacing articles, is continuous and not interrupted. Moreover, the present invention is composed of comparatively few and simple parts, it is easily operable and may be economically manufactured.

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention and I, therefore, do 'not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. In a device of the class described, means for producing a magnetic field, a normally closed circuit circular secondary element of conductive material, a plurality of containers associated with said element and adapted to hold articles, and means for rotating said element and containers through said magnetic field to heat'said articles.

2. In a device of the class described, a frame, rollers mounted thereon, a rotatable casing on said rollers, an element of conductive material associated with said casing, means forproducing a magnetic field adjacent said casing, and means to actuate said rollers to move said element through said magnetic field.

3. In a device of the class described, a casing composed of segments insulated one from the other, a normally closed circuit conductive element in said casing and insulated therefrom, means for producing a magnetic field in proximity to said casing, and means to intermittently move said casing and conductive element through said magnetic field to thereby induce currents in said element.

4. In an induction heater, means for producing a magnetic field, a secondary element, means for moving said element through said field, said element having a plurality of recesses therein, and sleeves secured to said element in alignment with said recesses to form containers for articles.

5. In an induction heater, a movable secondary having a plurality of recesses therein to receive articles to be heated, said secondary having slots through a portion of its cross-section to form substantially unitary groups of said recesses.

6. In an induction heater, means for producing a magnetic field, a casing rotatable through said field, a secondary element in said casing, insulating means separating said element from said casing, said element having a plurality of recesses therein, and sleeves engaged in said element in alignment with said recesses and projecting through a portion of said insulation to form substantially containers for articles to be heated.

7. In an induction heater, a movable sec ondary element having a plurality of recesses therein for individually carrying articles to be heated, said element also having slots therein to group said recesses and to prevent excessive current flow.

8. In an induction heater, a primary, a normally closed circuit secondary rotatable about a vertical axis with only a portion thereof Within said primary at any one time, said secondary having a plurality of recesses therein for holding articles to be heated.

9. In an induction heater, a transformer having a core and a primary element mounted thereon, a support, a casing rotatably mounted on the support, a secondary element on the casing, and means adapted to maintain the said casing and the said secondary element in alined relat on to the said core, the said means comprising cone-like rollers on the support, and beveled means on the casing slidable on the rollers.

10. In an induction heater having a primary element, a permanent s"condary element, the said secondary element comprising a continuous ring of conducting material having a plurality of spaced radial slots therein.

11. In an induction heater having a primary element, a secondary element, the said secondary element consisting of a continuous ring of conducting material having a plurality of spaced conducting elements secured thereon and in circuit association therewith.

12. In an induction heater having a primary element, a secondary element, the said secondary element consisting of a continuous ring of conducting material having a plurality of spaced superimposed conducting elements secured thereon and in circuit association therewith, the said conducting elements being apertured to carry articles therein.

13. In an induction heater having a pri mary element, a secondary element, the said secondary element comprising a continuous ring of conducting material having a plurality of spaced apertured conducting elements thereon and integral therewith.

In testimony whereof I have hereunto subscribed my name at Cleveland, Cuyahoga County, Ohio.

WILLIAM H. SPIRE.

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