US2576767A - Metal container and method of manufacture - Google Patents

Description

A Nova 27, 1951 F A'HEARN 2576 757 METAL CONTAINER AND METHOD OF MANUFACTURE Filed Feb. 13, 1948 Patented Nov. 27, 1951 METAL CONTAINER AND METHOD OF MANUFACTURE Frank L. AHearn, Sharon, Pa., assignor to United States Steel Products Company, a corporation of Delaware Application February 13, 1948, Serial No. 8,156

4 Claims. (Cl. 220--67) This invention relates generally to a container, such as a shipping drum of the type comprising a substantially cylindrical body or shell having a flanged-disc head telescoped into one or both ends thereof, the edge of the shell and the flange of the head being seamed together. In particular, the invention concerns a tight-head drum having a continuous fillet in the crevices normally existing between the heads and shell, the fillet being composed of metal from either the head or shell, or a ring of metal therebetween. The fillet is integral with the head and shell and tends to prevent lodgment of the contents of the container, thus permitting it to be thoroughly cleansed by flushing.

This is in part a continuation of my copending application Serial No. 687,490, filed July 31, 19%, for Method of Making Containers and Product Thereof, now abandoned.

Containers of the type mentioned above, as made heretofore, have been subject to the objection that, because they are ordinarily used without a lining, the V-section crevices existing between the heads and body have trapped small portions of the contents so tightly as to defy removal by flushing. Since this is the only method available for cleansing tight-head drums, i. e., drums having permanently aifixed heads at both ends, there has for many years been a demand, particularly on the part of the food, beverage and pharmaceutical industries, for a tight-head drum without the crevice which is inevitably formed when a flanged-disc head is telescoped into a cylindrical drum shell or body. I have invented a novel tight-head steel drum, having a continuous fillet in the crevices between the heads and shell composed of metal from either of these parts, or a metal ring inserted therebetween, and serving to prevent the trapping of small amounts of the contents of the drum, as well as a method for causing the metal of the shell, head or ring to flow into the crevice and form such fillet, at least partially filling the crevice.

In a preferred embodiment and practice, I soften or fuse the shell of a steel drum or the flange of a steel drum head, progressively and continuously along a line around the circumference thereof adjacent the plane of the head, by applying heat from the exterior of the drum or head in such manner as to cause a slight flow of metal sufiicient to form a continuous fillet at least partially filling the crevice or sealing off the bottom thereof, thereby preventing lodgment of the contents of the drum. In general, the method consists in applying heat circumferentially of the crevice to either the drum shell or the head flange in the vicinity of the crevice, with an intensity and for a time such as to cause the heated part to soften and fuse slightly and flow into the crevice thereby producing a weld in the form of a continuous fillet between the shell and head. Preferably the heat is applied by a welding arc, i. e., either an arc shielded by inert gas or a submerged arc, and is closely controlled to prevent excessive heating and displacement of metal which might result in a burn-through or perforation. That is to say, the heat is so controlled as to cause the fusion necessary for slight flow of metal into the crevice without destroying the integrity of the stock, whether that of the drum shell, head flange or a metal ring inserted therebetween. Various types of steel have the characteristic that they will flow slightly on softening under a Welding are, but will not run so freely as to get out of control. Stainless steel is one example.

The heating and fusion are preferably effected after the drum shell and head flanges have been seamed together, by placing the drum in a chuck for rotation with its axis horizontal and applying a welding arc to the exterior of the drum shell. The arc is formed between the drum shell and an electrode inclined both in the direction of travel thereof relative to the drum, and laterally thereof to cause the metal when sufficiently softened to flow toward and into the crevice. The electrode must be so positioned relative to the drum as to produce fusion of metal along a cir-. cumferential line representing the intersection with the shell or head flange of a plane parallel to the disc of the head and spaced slightly outward therefrom. If the arc is applied to the head flange, the drum should be supported for rota-- tion with its axis substantially vertical.

If the stock of which the head and shell are composed is relatively thin, I may insert a metal ring between the adjacent surfaces thereof to afford the thickness of metal necessary to permit the desired slight flow on softening and fusion without danger of causing a burn-through.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present preferred embodiment and practice. In the drawmgs,

Figure 1 is a diagrammatic elevation showing the progressive fusion of the shell of a drum adjacent the plane of the head by an electric welding arc;

Figure 2 is an end elevation thereof with a part in section; v I

Figure 3 is a partial section through the chime of a drum before the formation of a fillet in the crevice in accordance with the invention;

Figure 4 is a view similar to Figure 3 showing in greater detail the formation of a fillet by the process shown diagrammatically in Figures 1 and 2;

Figure 5' is a view similar to Figure 4 showing a fillet formed by a slightly modified method;

Figure 6 is a view similar to Figure 3 show ing a modified form of shell to which the inven tion may be applied, before the heads are seamed to the shell; v

Figure 7 is a view similar to'Figu're 5 showing a fillet formed in the crevice of a drum like that of Figure 6;

Figure 8 is a view similar to Figure 4 show= ing the formation of a fillet by fusion of the head-flange adjacent the disc; and

Figure 9 is a cross-section through a drum during' formation of the fillet showing diagram-- 1 less steel, but the invention is applicable to drums of other'metals, such as plain carbon steel. Each head includes a disc '14 dished or bumped slightly and a flange IS. The outer ends of the flanges rent flowing through the electrode and the speed of travel of the drum are coordinated to heat the shell to a temperature of from 2500 to 2650 F. along the circumferential line aforesaid and produce the fusion of the metal necessary to effeet the desired 'fiow without causing a burnthrough or otherwise destroying the integrity of the shell along the line of fusion. Electrode metal may or may not be deposited as the fusion proceeds. Generally, the slight displacement of themetal of the shell will leave a shallow groove along the line of fusion and if this be undesirable, a consumable electrode of stainless steel may be used so as to fill the groove by progressively depositing fused electrode metal therein. Figure 4 shows this mode of operation.

Ordinarily I prefer to use either the arc-welding process employing a consumable coated metallic electrode or the submerged arc, in the manner shown in Figure 4, if the presence of the flux used therein (which adheres strongly to the line of fusion and can be removed only by chipping) is not objectionable. Using the submergedarc, for example, with the drum shell and head both of 16 gaugestainless steel, a speed of 120 inches per minute at the weld and a current of from 400 to 500 amperes has been found satisfactory. It is also possible to use a metallic arc employing an inert gaseous envelope of argon or of the heads are double-seamed with the ends of 1 the shell forming chimes, indicated at l6, as best shown in Figure 3. This forms a V-section crevice l1 between the shell and the inner end of the flange of each head. As shown, the sides of the crevices converge toward the chimes It.

In order to provide a fillet at least partially filling the crevices H, the drum is mounted on spaced chucks l3 and I9 entering the chimes, as shown in Figure 1. The chucks are mounted on coaxial horizontal shafts 2D and 2| journal'ed in suitable bearings (not shown) and one of them is provided with any convenient driving means. One of the chucks is retractable to permit the drum to be introduced therebetween and later removed therefrom. A welding electrode 22 is mounted in any suitable support or holder (not shown) preferably provided with means for ad'- justing it toward and from the drum adjacent the chime and axially thereof. When the electrode is positioned relative to the drum as shown in Figure 4, an electric arc is initiated in the known manner between the electrode and the: shell of the drum, after connecting them to a suitable source of alternating or direct current, such as a welding generator, and the chucks l8 and I 9 are driven to turn the drum at a suitable speed.

The result is to fuse the shell progressively from v the exterior along a circumferential line substantially'in the plane of the disc M of the head,

and form a fillet 23' (see Figure 4) by gravity flow of the metal of thelshell, which is continuous around the entire circumference of the drumand at least partially fills the crevice H or seals off the extreme outer portion or bottom thereof. The fusion proceeds through the shell wall and into the head flange so that the fillet is welded. to the latter. Thus the fillet is. composed of metal which was initially integral with the shell butfinally becomes integral with the flange as 7 helium to shield it, with a speed of 30 to 40 inches per minute at the weld and a current of 300 to 450 amperes at a voltage of between 38 and 48' volts, using either a permanent electrode or a consumable electrode to deposit additional metalalong the line of fusion.

The electrode is inclined downwardly, as shown in Figure 2, in the direction of travel of the drum- (indicated by an arrow). I find that the desired flow of the metal of the shell to form a fillet along the line of fusion is aided by inclining the electrode downwardly toward the end of the drum, at a slight angle from the vertical, say 7, in the direction of the drum axis as shown in Figure 1. When the line of fusion has been completed around one end of the shell, the same procedure is followed at the other end. Alternatively, fillets may be formed at both heads simultaneously by providing a second electrode and a mounting therefor.

Figure 5 shows the result of using a permanent electrode for the fusion, without the debosition of additional metal. This leaves a shallow groove 24 which is ordinarily not objectionable.

Figure 6 shows a shell provided with circum ferential ribs or beads 25 displaced inwardl'y'before assembly of the heads and shell and the seaming thereof together. The ribs are spaced a distance L from the ends of the shell equal to the height of the head flanges. The ribs thus curve inwardly over the rounded edge of the discs when the shell and heads are assembled and seamed together, forming crevices 25 shallower than crevices !'I. This permits a fillet 2'? to be formed in the crevices, as shown in Figure 7, by the method explained above, with a minimum fiowof fused metal from the shell.

Figure 8 shows a modified practice in which the drum is supported for rotation with its axis vertical and the electrode is so. disposed that the arc plays on the surface of the head flange exposed at the, end. of thedrum, adjacent the disc. The resulting fusion of the flange causes the formation of a fillet 28.

In. order. to minimize carbide segregatioaat the grain boundaries which would reduce corrosion resistance, it is desirable to cool the line of fusion rapidly after formation of the fillet. To this end, I provide a nozzle 29 adjacent the electrode, as shown in Figure 9,, delivering a jet of air and atomized water onto the line of fusion in a region spaced from the arc in the direction of travel of the surface of the shell (indicated by an arrow) If the shell and head are made from stock so thin that there is danger of burn-through even though the necessary precautions are taken to prevent it, I may provide additional metal thickness by inserting a metal ring of suitable thickness between each end of the shell and the flange of each head. On heating either the shell or head flange to fusion and softening, the inserted ring will also be fused to some extent and supply additional fillet-forming metal while tending to prevent burn-through from occurring.

While the fillets should be continuous circum ferentially, it is not necessary that they fully fill the crevices between the shell and heads. In most cases, a small fillet will suffice. All that is necessary is that the metal fiow sufficiently to fill the portion of the crevices wherein the sides converge closely together to form a lodgment for the contents of the drum by wedging therein. If the crevice is unusually deep, it will suifice to seal off the portion adjacent the chime by a fillet of small size. In either case, the presence of the fillet prevents the trapping of portions of the drum contents so tightly that they cannot be thoroughly removed by flushing with hot water and steam. The advantage thereof is obvious, i. e., it makes feasible the use of stainless-steel drums as containers for food, beverages and the like, which must be rendered absolutely clean and sterile when returned for refilling. The fillet does not require any surface finishing. It ordinarily presents a fairly smooth exposed surface as a result of the tendency of the metal to level itself when fused.

Some degree of irregularity in the surface, however, does not prevent thorough cleaning by flushing.

It will be aparent that the invention provides a cheap simple method by which the head flanges may be sealed at their inner edge to the drum shell so as to afford corners or intersections free from narrow crevices and presenting a well exposed, substantially smooth and easily cleaned surface inwardly oi the container.

The glue usually employed to make the double seam liquid-tight is unnecessary when a continuous fillet is formed in the crevices and is, therefore, omitted. Any defect or lack of con tinuity in the fillet which would render it impossible to clean the drum satisfactorily by flushing will thus show up by leakage through the double seam under a conventional pressure test.

Although I have illustrated and described a preferred embodiment and practice with slight modifications, it will be understood that changes in the construction and procedure disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a method of making containers, the steps including telescoping a metal flanged-disc head into one end of a cylindrical metal shell, whereby the contiguous portions thereof form a V-section crevice adjacent the joint, progressively applying an electric arc to a circumferential band on the exterior of one of said portions adjacent the plane of the disc, thereby softening the metal of said band sufficiently to cause it to flow into and at least partially fill said crevice continuously throughout the circumference of the shell.

2. In a method of filling the cir umferential end crevice in a metal container comprising a body member in the form of a cylindrical metal shell and a head member in the form of a flanged metal disc snugly telescoped into the end of the shell, the steps including progressively applying an electric arc to the surface of one of said members exposed on the exterior of the container, along the line of said crevice and adjacent the plane of said disc, thereby fusing the metal of said one of said members adjacent said line sufficiently to cause it to flow into and at least partially fill said crevice.

3. In a method of sealing the inner edge of a metal flanged-disc head to a metallic container shell having an open end into which the head is telescoped snugly, and partly filling the crevice formed between the head and shell on the in terior of the container, the steps including applying an electric arc to one of said head and shell along a line around the circumference thereof exposed on the exterior, adjacent the plane of the disc of the head, for a time suffi cient to cause the metal of said one of the head and shell to soften and flow into the crevice be tween the shell and head flange at the inner edge of the head, thereby forming a fillet joining said edge to the shell.

In a tight-head metal container including a cylindrical shell of metal and a flanged-disc head of like metal fitted into each end thereo the outer ends of the flanges of the heads bei connected to the shell and the flanges curving inwardly away from the shell at their inner ends,

said shell having a continuous annular band circumferentially thereof substantially in the plane of the disc of each head, and integrally connected with the head flange and also said shell throughout the circumference thereof, which band has been subjected to heat-softening thereby providing a continuous fillet at least partially filling the V-shaped crevice originally existing between the shell and the head fiange Where the latter curves inwardly away from the former, said fillet being formed by metal dis placed from its original position in at least one of the container parts and being of the same composition as the latter.

FRANK L. AHEARN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,158,596 Wacker Nov. 2, 1915 1,241,900 Armstrong Oct. 2, 1917 2,031,138 Taylor Feb. 18, 1936 2,057,347 Reed Oct. 13, 1936 2,219,352 Andrus i Oct. 29, 1940 2,223,312 Briggs Nov. 26, 1940 2,315,358 Smith Mar. 30, 1943 2,345,037 DeGray Mar. 28, 1944 2,350,532 Richardson June 6, 1944 FOREIGN PATENTS Number Country Date 220,391 Great Britain Aug. 18, 1.924

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