United States Patent [19] Essex, Jr. et al.
[451 Oct. 14, 1975 METAL CONTAINER AND METHOD FOR MAKING SAME [73] Assignee: American Can Company,
Greenwich, Conn.
[22] Filed: Nov. 15, 1973 [21] Appl. No.: 416,091
Primary ExaminerJohn Petrakes Attorney, Agent, or FirmRobert P. Auber; Ira S. Dorman; George P. Ziehmer [57] ABSTRACT A two piece metal can comprising a seamless, cylindrical container of circular cross section having integral side and bottom walls, and a top closure joined to the top portion of the side wall by a double seam consisting of five adjacent layers of metal. The bottom profile of the container includes a shoulder extending outwardly from the bottom portion of the side wall at an angle of about 25 fora distance such that the outside diameter of the container at the bottom end of the shoulder is substantially equal to the maximum outside diameter of the can across the double seam, and a flange having a first segment extending downwardly for a distance about equal to the length of the double seam from the bottom of the shoulder substantially parallel to the side wall and a second segment doubled back on and within the first segment thereof. The bottom panel has a curved periphery joining the second segment of the flange to the bottom wall.
3 Claims, 9 Drawing Figures US. Patent O ct.14,1975 Sheet 1 of2 3,912,109
US. Patent Oct. 14, 1975 Sheet 2 of2 3,912,109
PIC-3.7
FIG.6
PIC-5.9
FIG. 8
METAL CONTAINER AND METHOD FOR MAKING SAME BACKGROUND OF THE INVENTION The instant invention relates to two piece metal cans and more particularly to two piece metal cans which simulate the conventional three piece metal cans.
The conventional three piece metal can is gradually being replaced by the two piece metal can, which is characterized by a seamless cylindrical container having integral side and bottom walls. Gen'rally, the manufacture of cans is a business separate from the filling of the cans, the latter being referred to asfihe canning operation. Both businesses are highly mechanized. The conventional three piece can includes transverse ends joined to a tubular body by means of double seams that form chines on either end, which present the only geometric parts which can be relied upon for reinforcement of and/or engagement of and/or handling of the can. The two piece can generally lacks any kind of chine on its bottom that resembles the chine of the three piece can, although US. Pat. No. 3,272,383 does disclose the need for substantially equal diameters at the top and bottom of a two piece can.
The presence of some type of a chine on the bottom of a two piece can is known to be necessary during filling of the can, to engage and hold the cans during application of a lid, to prevent lifting of the can when the lid applying means is retracted, to engage the can with conveying means and thereby prevent tipping and/or dislodgement, to prevent tilting when packaged, to insure uniform spacing of adjacent cans whereby defacing of the labels is avoided by preventing touching of adjacent cans and to withstand internal pressures, especially extraordinary pressures which are invariably imposed during handling inthe canning equipment. However, it is especially desirable that the two piece can be able to ,run in any of the equipment presently being utilized in the canning operation for three piece cans. Furthermore, since some cans are wrapped in paper which is folded into the recess at either end of the can provided by the chine, it becomes desirable that the bottom chine of a two piece can present the same bottom profile as a three piece can. The instant invention meets all the objectives set forth above.
SUMMARY OF THE INVENTION The instant invention provides a two piece metal'can comprising a seamless, cylindrical container of circular cross section having integral side and bottom walls, and a top closure joined to the top portion of the side wall by a double seam consisting of five adjacent layers of metal. The container has a bottom profile including a shoulder extending outwardly from the bottom portion of the side wall at a angle of about 25 for a distance such that the outside diameter of the container at the bottom end of the shoulder is substantially equal to the maximum outside diameter of the can across the double seam, and a flange having a first segment extending downwardly for a distance about equal to the length of the double seam from the bottom of the shoulder substantially parallel to the side wall and a second segment doubled back and within the first segment thereof. The bottom wall has a curved periphery joining the second segment of the flange to the bottom wall.
BRIEF DESCRIPTION'OF THE DRAWINGS FIG. 1 is a perspective view of the can of the instant invention.
FIG. 2 is an enlarged, partial sectional view taken on thevertical plane indicated by the line 2-2 of FIG. 1.
FIG. 3 is a central, vertical sectional view of thecontainer shown in FIG. 1 after it has been drawn but before it has been beaded.
FIG. 4 shows the container of FIG. 3 after the beading operation.
FIG. 5 showsthe container of FIG. 4 after the bottom profile has been formed. FIG. 6 is an enlarged, partial, central, vertical sectional view showing the container of FIG. 3 about to undergo the beading operation. FIG. 7 is an enlarged, partial, central vertical sectional view showing the beading operation.
FIG. 8 is an enlarged, partial, central vertical sectional view showing the container of FIG. 7 immediately prior to the bottom profile being formed.
FIG. 9 is an enlarged, partial, central vertical sectional view showing the container of FIG. 8 after the bottom profile has been formed.
DESCRIPTION OF THE PREFERRED EMBODIMENT The preferred embodiment of the instant invention is set forth in the drawings, wherein FIG. 1 illustrates a two piece metal can 11 which includes a seamless, cylindrical container 13 of circular cross-section. As best seen in FIG. 2, the container 13 includes a side wall 15 and a bottom wall 17 which are integral. A top closure 19 (see FIG. 2) is joined to the top portion of the side wall 15 by means of a double seam 21 which consists of five adjacent layers of metal.
Again referring to FIG. 2, the container 13 presents a bottom profile which includes a shoulder 23 extending outwardly from the bottom portion of the side wall 15 at an angle a of about 25 for a distance such that the outside diameter of the container 11 at-the bottom end of 25 of the shoulder 23 is substantially equal to the maximum outside diameter of the can 11 as measured across the outer layer 27 of the double seam 21. The container bottom profile further includes a flange 29 having a first segment 31 extending downwardly from the bottom end 25 of the shoulder 23 substantially parallel to the'side wall 15 anda second segment 33 doubled back on and within the first segment 31. It can be seen that the length of each segment of the flange 29 is about equal to the length of the outer layer 27 of the double seam 21. The bottom profile further includes a curved periphery 35 on the bottom wall 17 which joins the second segment 33 of the flange 29 to the bottom wall 17.
In describing the process for forming the can 11 shown in FIGS. 1 and 2, reference is now made to FIG. 3-9. A blank metal disc is first drawn and trimmed to form the seamless, cylindrical container 13 of circular cross sectin having integral side and bottom walls 15 and 17 respectively. A lower cylindrical segment of the side wall 15 of the container 13 shown in FIG. 3 is then converted into a higher frustrum section 37 and a lower frustrum section 39. As best seen in FIGS. 6 and 7, a male beading roll 41 mounted on a shaft (not shown) is inserted within the container 13 and expanded to form the two frustrum sections 37 and 39. A female beading roll 43 surrounds and supports the container 13 during the expansion of the male beading roll 41. As best seen in H6. 8, the higher frustrum section 37 forms an angle b with the side wall 15 of about 12 while the lower frustrum section 39 forms an angle with the side wall of about 60.
The final step in forming the bottom profile of the container 13 is illustrated in FIGS. 8 and 9, wherein the bottom wall 17 is moved upwardly to about the middle of the higher frustrum section 37. The movement of the bottom wall 17 is achieved by moving upward a lower die tool 45 while the inside of the container 13 is supported by an upper die tool 47 which stops the advance of the lower die tool 45.
it should be noted that although the flange 29 is shown as being parallel to the side wall 15, the flange 29 may be angled outwardly almost as much as is the shoulder 23. It should also be noted that the two segments 31 and 33 of the flange 29 may be separated by a greater distance than illustrated in the drawings, and that the two segments 31 and 33 need not necessarily be parallel to each other. If any or all of these modifications are made, then it is apparent that some changes will have to be made in the steps of forming the bottom profile, but none of these changes should involve any substantial variation from the method set forth above.
It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction and arrangement of the parts of the article and that changes may be made in the steps of the method described and their order of accomplishment without departing from the spirit and the scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof What is claimed is:
1. ln an improved two-piece metal can having a seamless, container body of circular cross-section provided with integral side and bottom walls, a circular closure adapted to be joined to said side-wall by an annular double seam having five adjacent layers of metal,
the improvement wherein the profile of the area adjacent both said side and bottom wall includes:
a shoulder extending outwardly from the bottom portions of said side-wall at an angle of about 25 to the plane of said side-wall for a distance such that the maximum outside diameter of said shoulder is substantially equal to the maximum outside diameter of said double seam, and
a flange extending from the bottom of said shoulder substantially parallel to the plane of said side-wall said flange having both a first segment extending downwardly for a distance about equal to the length of said double seam and a second substantially linear segment doubled back on and within said first segment,
said bottom wall being substantially planar and having a curved periphery joining the second linear segment of said flange to said bottom wall in a substantially perpendicular plane.
2. In an improved seamless, container of circular cross-section having integral side and bottom walls, said container adapted to be engaged with a closure by means of a double seam,
the improvement wherein the profile of said portion adjacent both said side and bottom wall includes:
a shoulder extending outwardly from the bottom portion of said side-wall at an angle of about 25 to the plane of said side-wall and a flange extending from the bottom of said shoulder substantially parallel to the plane of said side wall,
said flange having both a first segment extending downwardly and a second linear segment doubled back on and within said first segment,
said bottom wall being substantially planar and having a curved periphery joining said second linear segment of said flange to said bottom wall in a substantially perpendicular plane.
3. A method of forming in the area adjacent both said side and bottom wall of a single-piece, seamless container body of circular cross-section, a profile of the outer surface of a double seam having five adjacent layers, comprising the steps of:
Displacing outwardly, in a controlled manner, a segment of said side-wall so as to convert said segment into two opposed frustrum sections, one above the other, the higher frustrum section making an angle with the plane of said side wall of about 12 and the lower frustrum section making an angle of about 60 also with said plane; and
Moving said bottom wall upwardly to about the middle of said higher frustrum section to provide the area adjacent said side and bottom walls of said container with a profile having a shoulder extending outwardly from the plane of said side wall at an angle of about 25, and a flange having a first and second annular segment, said first segment extending downwardly from said shoulder and being substantially parallel to the plane of said side-wall, and said second segment being doubled back on and lying within said first segment, so that said bottom wall, said shoulder, and said segments thereby form a profile of said double seam.