US2295729A - Metallic container - Google Patents

Description

Egg. 2A. /10

Filed 001;. 14, 1939 w. l. GLADFELTER ErAl.

METALLIC CONTAINER Sept. l5, 194,2.

Patented Sept. 15, 1942 METALLIC CONTAINER Wiltie I. Gladfelter'and George Kauffmann, Philadelphia, Pa., assgnors to Crown Can Company, Philadelphia, Pa., a corporation of Penn- Sylvania Application October 14, 1939, Serial No. 299,530 1 claim. (c1. 22o-62) This invention relates to can bodies of the type adapted to have an end member secured thereto by a double seam. More particularly, the invention is directed to improvements in the side seams of can bodies, constructed to cooperate with the double seams at the ends of the bodies in an improved manner to produce a leakproof container.

It is a primary object of the invention to provide' a can body which, when seamed to end members by a conventional double seam, will provide a container capable of withstanding greater internal pressures or higher degrees of vacuum than are now possible, without danger of leakage.

It is a further object of the invention to provide a can body with improved end seaming flanges which result in an improved, leakproof joint when seamed to the end members by a double seam. To this end, the invention provides less metal in the double thickness, lapped portion of the seaming flanges, so that when the flanges are seamed to the end members, the usual protuberance or hump formed at the junction of the lap joint with the double seam is minimized or substantially eliminated.

It is a further object of the invention to provide a locked and lapped side seam of such character that the danger of the lapped portion being separated during the end ilanging operation is substantially eliminated.

It is a further object of the invention to provide a can body blank characterized by the presence of a minimum amount of solder at the lapped joint in the seaming flange, so that an excess amount of metal at this point is dispensed with, thereby increasing the eiciency of the joint between the side seam and the double seam. In order to accomplish this object, the lapped ends ofthe side seam are preferably pressed or bumped inwardly before the soldering and flanging operations, so that a lesser amount of solder is applied to the ends by the external soldering rollers.

In the accompanying drawing, a preferred embodiment of the invention is illustrated.

In the drawing:

Figure 1 is a plan view of a body blank in accordance with the invention, with the central portion thereof broken away.

Figure 2 is a similar View of the blank, after the ends have been bent to hook form along the portion of the ends which are to form the lock seam.

i I Figure 4.

Figure 8 is a similar section online 8--8 of Figure 4.

Figure 9 is a fragmentary section on an enlarged scale, taken on line 9 9 of Figure 5.

Figure 10 is a similar section, taken on lin Ill-I0 of Figure 9.

Figure 11 is a fragmentary sectional view of the side seam and the bumping hammer, and

Figure 12 is a fragmentary perspective View on an enlarged scale showing a slightly modied view of lapped joint in the seaming flange.

A rectangular body blank I0, in accordance with the present invention, has its corners I I, I2 provided with substantially L-shaped, two stepped notches, comprising steps I3,.I3', I4, I4', the margins of each step or notch being disposed in substantially right-angular relation to each other and to the edges of the blank. The opposite end of the blank is provided with slits I5, I5', disposed on lines parallel to the upper end lower edges of the blank.

As shown in Figure 2, the material extending outwardly from the inner points of the steps or notches I3, I3 is folded upwardly along a line I6 and rearwardly to provide a hook flange I'I. Thus, the inner margins of the steps I3, I3 define the ends of the hook I'I and serve to space said ends from the steps I4, I4 and from the seaming flange subsequently formed at the ends of the can body. Likewise, the material at the other end of the flange between the slits I5, I5' isturned downwardly along a line I8 to provide a hook flange I9. Thisv leaves, at the last-mentioned end, longitudinally projecting tabs 20, 20', and, at the other end, terminal portions 2I, 2l', which lap the tabs when the hook flanges I 1, I9 have been brought into engagement, as shown in Figures 3 and 6 with the tabs 20, 2 underlying the terminal portions 2|, 2l.

In the body making machine which forms the blanks to cylindrical shape and engages the hooked flanges, the side seam is bumped and preferably the terminal portions 2|, 2| are depressed radlally inwardly slightly below the in-` are pressed substantially .005 inwardly beyond the line of the intermediate lock seam portion, a lesser amount of solder willbe applied to the terminal portions by the conventional, externally disposed soldering rollers. However, since the lapped portions are in firm contact, theywill be securely soldered together and, because of the strains set up in the metal by the bumping ac-Y tion, there will be no tendency for the lapped portions to separate under the influence of the heat of the solder applying means. Thus, a secure lapped joint is effected with a minimum amount of solder.

It is important to note that the edges 26, 21B of the notches lil, ld are straight edges and are disposed on lines parallel to the axis of the can body. Moreover, it should be noted that the edges 2l, 2' of these notches are disposed at substantially right angles thereto and are spaced from the upper and lower edges of the can body, a distance substantially equal to or slightly greater than the width of the end seaming flanges subsequently formed. V

In the past, attempts have. been made to decrease the amount of metal in the lapped portion and to eliminate the sharp, outwardly projecting corner on the blank in the. outer layer of the lap by cutting away the corner 0n an angularly disposed line extending from the end of the blank to the adjacent end of the hook flange. of the lock portion of the side seam. This angularly disposed cut has been found to be disadvantageous for a number of reasons.

In the first place, when the end of `the cylindrical blank is turned outwardly to provide a seaming flange, there has been a marked tendency for the two layers of metal in the lapped joint adjacent the angular cut to pull apart, breaking the soldered connectionY therebetween. This tendency probably results from the fact that the flanging or curling action must take place on lines disposed axially of the cylindrical blank and at angle to the` edge of the lapped portion, thereby setting up strains in the lapped portion during curling which tend to shear the soldered connection.

Secondly, during the double seaming operation, when the end member is seamed to the blank, the seaming compound in the groove of the end member has a tendencyto wipe toward one end of the angular cut, during the rollingup of the flanges in the course of the seaming operation. Thus, an excess of seaming compound collects at one end of the angular cut, while at the other end, there is a deciency, with the result that an imperfect seal is often formed and leaks in the lled and closed container occur.

The foregoing diiculties are obviated, and other advantages are accomplished, when a square notch, in accordance with the present invention, is substituted for the angularly disposed cut. When a notch of, this type is used, the

hanging forces arev applied @n lines parallel to. or

coinciding with the straight edges 26, 26', with the result that there is no tendency for relative movement between the lapped portions, and the soldered joint is not adversely affected. As shown in Figure 4, the anges 30, 30 are formed by turning outwardly the end portions of the can body disposed axially beyond the edges 21, 21 of the notches I`4, I4. The edges 26, 26' are disposed substantially radially of the iianges, while the edges 21, 21 substantially coincide with, or are disposed inwardly a slight dista-nce beyond, the lines of junction 3|, 3| between the flanges and the body.

Since the edges 26, 26 are disposed radially of the flanges, the crevices adjacent thereto are not angularly disposed with respect to the lines of curling movement. Hence, there is no tendency for the sealing compound to move toward one end thereof. On the contrary, the compound simply lls the crevices and provides a leakproof joint.

In the can making. and closing art, the principal diiculty in providing a satisfactory seal of the sanitary type has always occurred at the point of junction between the lapped side seam of the body and thedouble seam joining the end member to the body. This di'iculty arises primarily because, at this point, a double thickness of metal in the body flange must be rolled Vinto and seamed with a single thickness of metal in the seaming flange of the end member, whereas at all other points the body flange consists of but a single thickness. Thisr double thickness leaves a pronounced protuberance or hump in i the double seam, requiring an excess of sealing compound, and numerous expedients have been tried in an attempt to eliminate this feature. In accordance with the present invention, the circumferential extent of the overlapped portion in the seaming ange of the can body has been reduced to a minimum, thereby reducing Vthe amount of metal that must be embraced in the double seam at this point. Also, the amount of solder at the lapped portion of the flange has been reduced to a minimum.

As indicated above, the edge 21 of the notch I4 may substantially coincide with the line of junction 3l between the ange and the cylindrical wall of the can body. If desired, however, and as indicated in Figure 12, the edge 21a of the notch may be spaced axially inwardly of the can body from the line 3|. In other words, the edge 21a may be positioned opposite the cylindrical wall portion, in spaced relation to the line of junction. Y

Although the invention has been described with considerable particularity, in the present specication, it must be understood that the invention is not limited to all details shown in the accompanying drawing and described above, but covers devices coming within the scope of the appended claim and their equivalents.

We claim:

A cylindrical can body having outwardly Y turned seaming flanges at its ends and a side seam characterized by a continuous, doublehooked lock section extending throughout the major axial height of the body and relatively short, lapped sections at both ends, said body being formed from a flatrrectangular blank having both corners at one end cut away with an L-shaped, two-stepped notch, the outermost steps of the notches each being of a depth, axially of the can body, equalto the radial width of the seaming anges and the other steps each being of a width, circumferentially of the body, equal to the Width of the hook in the lock portion of the side seam, the inner margins of the last named steps dening the ends of said hook and serving to space said ends from the rst i step and from the seaming flanges by a distance equal to the axial depth of the second step, the lock portion of the side seam being bumped inwardly and terminating in spaced relation to the seaming anges, thereby eliminating the inwardly bumped bulge adjacent the

Images