US2030707A - Burning bar - Google Patents

Description

Feb. 11,1936.

L'. R. MOLEAN BURNING BAR Filed July 10, 1933 L as R M Lean 11v VENTOR A TTORNEVV Patented Feb. 11, 1936 UNITED STATES PATENT OFFICE Toledo Porcelain Enamel Products Company,

Toledo, Ohio, a corporation of Ohio Application July 10, 1933, Serial No. 679,662

1 Claim.

This invention relates generally to the art of vitreous enameling and in particular to means employed for supporting articles in furnaces while coats of vitreous enamel are being fused 5 thereon.

One vitreous enameling process comprises the following steps: A coat of pulverized enamel, frit and water is sprayed upon those surfaces of the cast or sheet metal articles which are to be enameled, the article having previously been thoroughly cleaned by sandblasting or pickling. After spraying, the water is evaporated in drying ovens or kilns so that only the pulverizedfrit adheres to the surfaces. The cast or sheet metal article is then placed with others in a furnace and heated to proper temperature for fusing the enamel. After the cast or sheet metal article has remained in the furnace for a sufficient period it is removed and allowed to cool.

It is an object of my invention to provide improved means for supporting cast or sheet metal articles within furnaces in such manner as to provide for even distribution of heat and to prevent sagging of the cast or sheet metal articles under the influence of the heat.

Heretofore such supporting means (called burning bars .or burning racks) have usually been cast in the form of a heavy bar with integral upstanding cast projections having pointed or chisel-shaped ends to engage the article upon which the vitreous coating was to be fused with minimum disturbance of the frit and minimum marring of the vitreous enamel surface produced. Fixtures consisting of wrought bars equipped with wrought projections or standards have also been proposed. The cast bars have the advantage of strength, rigidity and low material cost, but have the disadvantages of requiring so much material as to be prohibitively expensive if made from non-scaling, heat resisting alloys, and of being subject to accumulation of scale when subjected to the oxidizing action of highly heated air in the enameling furnace. The points on the integral projections of cast bars are more diflicult tofinish than points on separate, easily handled projections. Assembled wrought bars and projections have the advantage of comparative lightness and, therefore, of being more cheaply pro- 50 ducible from heat resisting alloys, but this advantage is obtained only at the sacrifice of some of the advantages of the cast support. It is another and a very important object of my invention to provide a support having the advantage 55 of such wrought and assembled fixtures without sacrifice of the rigidity of the heavy cast burning bar or of its low material cost.

Another object of my invention is the provision of a burning bar capable of ready arrangement for the support of objects of divers shapes and 5 having surfaces lying in different planes to be engaged by the contact points.

Another object is to provide a fixture with equipment including projections of different heights and/or points of various shapes. 10

Another object isto provide fixtures having standard bases or bars and equipment consisting of projections of different heights having points of various shapes, thereby eliminating the necessity of carrying complete fixtures so equipped. '5

And still another object is the provision of a burning bar or fixture having projections and points which are renewable when they have been injured or destroyed.

Other objects and advantages will be apparent 20 from the following description, in which reference is hadto. the accompanying drawing illustrating a preferred embodiment of my invention and wherein similar reference numerals designate similar parts throughout the several views. 25

In the drawing:-

Figure I is an elevational view showing a burning bar embodying my invention.

Figure II is a view in perspective showing a pair of burning bars embodying my invention 30 supporting an article to be enameled by engaging surfaces of the article which lie in different planes.

Figure III is an enlarged fragmentary perspective view showing a portion of the burning bar of my invention having a projection with a chisel-like point, the burning bar being shown in section through a socket receiving the lower end of the projection; and

Figure IV is an enlarged fragmentary detail 40 perspective view showing the end of a burning bar of my invention equipped with a projection having a point of center punch form.

Referring to the drawing in detail, the base of the fixture preferably consists of an elongated member or members I of rectangular or oblong cross section having an upstanding central rib 2 along which are distributed a plurality of sockets 3. The base so far described is integrally cast of relatively low cost metal, such as cast iron, which may be more or less alloyed with materials tending to render it heat and corrosion resistant.

Removably supported within the sockets 3 are 55 tenons 4 formed at the lower ends of upstanding projections 5; the upper ends of which may be chisel shaped as shown at 6 in Figure III, center punch shaped as shown at 6" in Figure IV, or

otherwise so shaped as to'support an article with V to withstand the heat, oxidation and abuse to which the comparatively fragile projections are subjected.

The article A illustrated in Figure I of the drawing is of such shape as to require projections V 5 of uniform height. Ofttimes, however, provision must be made to fuse enamel upon articles having several surfaces to be supported which lie in difierent planes as do those of the article A.

illustrated in Figure 11. When bars having integral projections are to be used in such cases it is necessary to shorten some of the projectionsby grinding or to break them off, thus destroying the effectiveness of the bar for use with articles which require the contact points to lie in a single plane. Where a burning bar or fixture of my invention is employed with an assortment of projections, it is only necessary to knock out such projections as are not of proper length and insert projections which are enough shorter or longer to meet the requirements. The original projections can be replaced whenever desired. Under the influence of the heat in the furnace nuts and other common fastening devices are liable to become stuck, but the tenons 4 can be easily driven out of the simple open bottom sockets 3 whatever the condition of the fixture.

Owing to their comparatively small cross sectional size the projections 5, if made of ordinary or abusewhile theheavy base remains in usable condition. In the device of my invention any of the projections which have become damaged may be readily replaced. The heights of projections may be adjusted by grinding or otherwise for special jobs without serious loss even if such adjustment of height makes it necessary to discard the projection after the special job is finished. Renewal and reshaping of the points on the projections is also facilitated by the fact that they can be removed from the base.

The embodiment of my invention herein shown and described is to be regarded as illustrative only, and it is to be understood that the invention is susceptible to variation, modification and change Within the spirit and scope of the subjoined claim.

Having described my invention, I claim:

A device for supporting articles of various shapes in furnaces under conditions of great heat and destructive oxidation, comprising, in combination, an integral cast iron bar having a heavy flat base and an upstanding central longitudinal rib, said rib being expanded at intervals to form material, are liable to become damaged by heat bosses, there being circular openings extending downwardly completely through said bosses and said heavy base, and a plurality of wrought metal members of heat-resistant alloy, ,each of said members being sharp at one end'and having at its other end a blunt tenon fitting said openings in said bosses and base and a collar above said tenon engageable with the upper 'faces of said bosses, said wrought metal members being of various lengths and adapted for selective arrangement on said bar to support such articles of various shapes.

LEE R. MCLEAN.

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