US2177811A - Annealing box cover - Google Patents

Description

Patented Oct. 31, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to annealing boxes and, more particularly, to an improved inner cover adapted for use especially in radiant tube-type annealing furnaces.

Various types of annealing boxes have been suggested and are used, as is generally known, to

protect the articles placedtherein from the intense heat in the annealing furnace. One of the older types of annealing boxes still used in an-; nealing large sheets of thin gauge metal consists of two parts, a bottom and a top or cover, which are usually made from heavy cast steel. The cover has the form of a rectangular box-like hood, the inner dimensions of which are slightly greater than the corresponding dimensions of the largest sheet to be annealed. The outside of these cast steel covers usually carries a number of heavy ribs, at least around the sides thereof to prevent them from warping and buckling after the repeated heating and cooling of many charges. which the metal sheets are adapted to be placed and on which the cover or hood rests when in use. The bottom of the box is adapted to rest on large steel balls on which the charged boxesv are adapted to be moved into and out of the furnace. These heavy cast steel covers are not only expensive but are heavy and bulky. Also, they have relatively thick walls which absorb largelarger than the largest sheets to be annealed and which is adapted to enclose the sheets within the removable furnace cover; and it is to this inner-cover that this invention refers.

It has been proposed to make these inner-covers of ordinary carbon steel with or without heat resisting alloy sides, but such ordinary carbon steel covers are not practical as they have a limited life and oxidize quite rapidly and are distorted after very few repeated heatings and coolings, which necessitates them being straightened and repaired at frequent intervals, resulting in high maintenance and replacement costs. Although the heat resisting metal alloy covers have a much longer life the initial cost of such The bottom of the box is a flat area on alloys is high which makes these covers expensive.

It is an object of the present invention to provide an improved annealing box cover which is practical and inexpensive.

It is another object of this invention to provide an annealing box cover of relatively light weight and having much longer lifethan any heretofore proposed.

It is a further object. of this invention to provide a means for protecting those points of an annealing box inner cover which are most susceptible to oxidation and distortion from the intense heat within an annealing furnace.

Various other objects and advantages of my invention will more fully appear during the course of the following specification, and will be particularly pointed out in the appended claim.

In the accompanying drawing I have shown, for the purpose of illustration, one embodiment of my invention which may be assumed in practice.

In'the drawing:

, Figure 1 is a side elevation of my improved annealing box cover;

Figure 2 is an end view, partly in section, of the same; and,

Figure 3 is a sectional view taken on the line IIIIII of Figure 1.

There is shown in the drawing an annealing box inner cover comprising a relatively large boxlike metal member 2, having vertical, preferably corrugated, end walls 3 and 4, vertical corrugated side-walls 5 and 6, a top portion 1 and an open bottom 8 which is adapted to rest on a permanent base. This member is preferably made from a low-carbonsteel, but may be made from any relatively inexpensive metal or other suitable material.

According to the present invention there is provided a heat resisting metal band 9, preferably made of alloy steel of from .045 to .050 of an inch in thickness, which is arranged around the outside of the box-like member intermediate the top and bottom thereof, or points where the cover is most susceptible to oxidation and distortion. This band is preferably welded to the sides of the cover but may be secured thereto in any other suitable manner, and the ends of the band are lap-welded together at 9, thus making a continuous band around the cover. If desired, heat resisting metal plates or members may be disposed only on the sides of the covers or at other points thereon which are subject to excessive oxidation and distortion. It will be understood that the purpose of this heat resisting a1- loy band is to repel the heat and to prevent the steel sides of the box-like member from absorbing such heat.

It will be seen, as a result of this invention, there is provided a means for insulating annealing box inner-covers from the intense heat in an annealing furnace which prevents them from warping and buckling, thus greatly increasing the life of such covers and permitting them to be used indefinitely.

While I have in this application specifically shown and described one embodiment which my invention may assume in practice, it will be understood that this embodiment is merely for the purpose of illustration and description and that various other forms may be devised within the scope of my invention, as defined by the appended claim.

I claim:

An annealing cover for use in enclosing a1- ticles in an annealing furnace comprising an open-bottomed box-like body member of a terrous material which is readily subject to oxidation, said body member having vertically cormgated side walls and a top enclosing portion, and a flat metallic band of a heat resistant material which is not subject to oxidation arranged around said body member encircling the same, said heat resistant band having a thickness of from .045 to .050 of an inch and a width less than the height of the side walls of said body member and being constructed and arranged so as to cover only the lower middle portions thereof to which it is securely welded, thereby adapting to protect that portion of the side walls of the body member which it covers from the heat so as to prevent the same from buckling and becoming distorted.

JOHN B. RICHARDS.

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