Improvements in and relating to the Manufacture of Cans or Tins, the Opening of which is to be effected by the Removal of a Strip of the Metal.
Year: 1892

page_text: Date of Application, 22nd Nov., 1892-Accepted, 31st Dec., 1892
COMPLETE SPECIFICATION.
Improvements in and relating to the Manufacture of Cans or Tins,
the Opening of which is to be effected by the Removal of a
Strip of the Metal.
I, JOHN ZIMMERMAN, of No. 3715 Forest Avenue, in the City of Chicago, County
of Cook, and State of Illinois, United States of America, Merchant, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention has for its object to provide an improved construction in key-
opening cans of that class in which a free tongue is provided on the sheet forming
the body of the can at the side seam thereof and in prolongation of a detachable
strip of the body sheet, for the purpose of giving a hold to a suitable instrument
for tearing out the detachable strip to open the vessel. By "detachable strip" is
meant a strip forming a part of the body and rendered separable from the body
by reason of the latter having been weakened in a line or lines bounding the strip.
Heretofore sheet metal cans of this description have been provided with the free
tongue in either of two ways, that is to say, either by employing a separate piece
for the tongue, such piece being partly inserted beneath the overlapping or external
edge of the body sheet at the side seam, or by forming the tongue integrally with
the overlapping or external edge of the sheet and making it project beyond the side
seam by cutting away a portion of said edge to leave the tongue. The last
mentioned method has been preferred notwithstanding the waste of material
occasioned thereby, because such waste has been found less costly than the extra
labor involved in the employment of a tongue formed of a separate piece. It is the
purpose of the present invention to avoid both the waste occasioned by one of said
methods and the extra labor demanded by the other, and also to provide a con-
struction, by which the can may have all the advantages of being cheaply made,
certainly sealed, and surely opened. To these ends the invention consists in the
method and in the construction hereinafter described by aid of the accompanying
drawings.
In said drawings :-
Figure 1 is a perspective view of a can constructed in accordance with my
invention in one of its forms.
Figure 2 is a fragmentary, vertical section of a can having the general form of
my invention shown in Figure but having the inserted head provided with an
upwardly directed marginal flange.
Figure 3 is a fragmentary, vertical section similar to Figure 2 but having the
interior head formed with a downwardly or inwardly turned flange, as indicated in
Figure 1..
Figure 4 is a section representing a head resting upon the end of the can body.
Figure 5 is a vertical section similar to Figures 2 and 3 but showing the can as
having an externally applied head.
Figure 6 is a fragment of the blank from which the can body of Figures 1, 2, 3
and 4 is formed.
Figure 7 illustrates the manner of bringing the opposite edges of the blank
together when prepared as illustrated in Figure 6.
Figure 8 is a top edge view of Figure 7.
Figure 9 is a section in the line 9-9 of Figure 6, looking in the direction of the
arrow applied to said line.
Figure 10 illustrates a fragment of the blank prepared for an externally applied
head, as shown in Figure 5.

page_text: Figure 11 illustrates the two edges of the body blank brought together, when
constructed in accordance with Figure 10.
Figures 12 and 13 illustrate the slit or slits cut in the edge of the blank by
removing a triangular piece, instead of by making a simple straight cut, as shown
in the preceding Figures 6, 7, 10 and 11.
A represents the body of a sheet metal can and B its head. The body A is
formed from a blank C which, as shown in Figures 6, 7 and 12, is provided with a
single slit or notch e cut inwardly from one of its vertical edges c¹ substantially
parallel with the top or bottom edge of the blank, such slit being of the depth of
the proposed lap of the side seam of the can. In bringing the two edges c¹ c² of
the blank, so slitted, together to form a lapped side seam, the edge c², which is
straight, is inserted in the slit e so as to bring the laterally detached tongue e³ upon
the outside of the can body. In this position of the edges c¹ c² solder is applied
along the exposed edge c² in the usual manner, and, if necessary, the iron by which
the solder is applied may be continued in its motion over the base of the tongue or
over a part thereof, for the purpose of more certainly flowing the solder through
the inner end of the slit e to fill the hole at this point, or to solder the base of the
tongue to the subjacent portion of the edge 2. The end of the tongue is left free
so that it may be seized by the usual key or other instrument by which the can is
to be opened. . In continuation of the slit c and at the dotted line et the metal of
the body is weakened in the usual or any suitable manner to insure severance of the
metal in the proper direction by operation of such key or instrument. The head B,
if provided with a marginal, cylindric flange and inserted within the end of the
can body, as indicated in Figures 1, 2 and 3, or if resting upon the end of the body
as shown in Figure 4, is soldered only to the detachable strip of which the
tongue forms a part, and by tearing off said strip the can body is severed and
the vessel opened.
If it be desired to apply the can head B externally to the body, as indicated
in Figure 5, the edge of the body blank is provided with two slits e, forming
the tongue between them, as indicated in Figures 10 and 13, and in bringing
the edge of the body blank having this arrangement of the tongue into union
with the opposite edge c² the latter is made to overlap the edge c' at both sides of
the tongue but to underlap the tongue itself, as indicated in Figure 11. The
soldering iron is then drawn along the exposed edge e² as before and desirably over
the base of the tongue c³, with the effect of making a close seam throughout the
length of the can body.
In the act of forming or after forming the tongue c³ I prefer, as an additional
improvement, to give it the offset relation to the body of the blank indicated in
Figures 8 and 9 in which it will be seen to accupy a plane or curve outside that of
the remainder of the body. The tongue being thus offset, the edge e² of the blank
may be quickly and without deflection inserted beneath said tongue in proper
position to be soldered.
In applying solder to the lapped joint of the can, in the manner hereinbefore
described, the solder must evidently flow beneath the base of the tongue for its
entire width in order to make a tight joint, and while this result may be obtained
by making rapid movements of the soldering iron back and forth over the tongue,
yet in order to avoid all delay and uncertainty in making a tight joint beneath the
tongue, I propose as a further improvement to provide in the detachable strip one
or more perforations, as seen at c in the several figures of the drawing; said
perforations being located at or near the base of the tongue and over the under-
lapped portion of the body sheet. The solder flows through these perforations to
the joint beneath the tongue with a single rapid movement of the iron over the
tongue. The effect of these perforations c is obviously to produce two or more
narrow necks of metal, beneath which severally the solder enters from its edges, in
place of the one broad neck presented by the entire width of the tongue, and by
reason of the limited width of these narrow necks the solder is certainly made to

page_text: extend the full width of the tongue, with the result of insuring a perfectly tight
joint without especial care and without delay.
It will be observed that in the construction above described the tongue, though
itself external to the can body, is a part of the underlapping margin of the body
blank, instead, as heretofore, of being a projection formed upon and extending beyond
the overlapping or external edge of said blank. While for the general purposes of
my invention the weakened line et may be produced by any suitable means, as for
example, by a longitudinal incision, by compression in a narrow line which will
render the metal more dense and brittle, or by forming a more or less sharp bead
and opposite groove, by which means the metal is partially fractured, I prefer to
form such weakened line or lines of severance by which a strip in continuation of
the tongue may be more readily detached, by first forming a sharp groove in the
sheet and then flattening the elevated surface or bead. This produces two flexures
in the metal and reduces the cohesion of the fibers in the line when so bent
successively in opposite directions, to such an extent that the strip is rendered very
easily detachable by means of the key or other instrument, while the can body is in
no degree injured for its legitimate purpose and the surface coatings of the metal
are not removed. In thus forming the weakened line or lines of severance I prefer
to use the familiar devices of tongued and grooved pressure rollers to first form a
narrow or sharp bead and then plain cylindric rollers between which to flatten
the bead. It will be desirable to compress the metal between the tongue of one
roller and the bottom of the groove in the other, thus rendering the metal more
dense or hard, so that it will be weakened in a greater degree when flattened
between the plain rollers.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1: The method of constructing the bodies of hermetically sealed sheet metal
key-opening cans of the class having a free lip or tongue which forms a pro-
longation of a detachable circumferential strip of the body sheet, which method
consists in slitting one side H of the sheet to form the tongue, forming a weakened
line parallel with the end of the sheet and continuous with the slit, or with each
slit if more than one, placing the opposite side edge of the sheet in the slit beneath
the tongue and over the remainder of the slitted edge, and finally passing a
soldering tool along the superposed edge and over the base of the tongue whereby
the oppositely overlapping surfaces are soldered in a straight line from end to end
of the body, leaving the end of the tongue free.
2: A hermetically sealed sheet metal can having the body described, said body
consisting of a sheet of single thickness throughout, which has as a part thereof a
circumferential detachable strip the extremity of which is a free tongue that is
laterally disconnected from the body by a slit or slits in one margin of the sheet,
the opposite margin of the sheet being beneath the tongue and elsewhere through-
out superposed upon the slitted edge of the sheet to form a lapped side seam, and a
straight continuous line of solder extending along the said superposed edge and
beneath the base of the tongue.
3: A sheet metal can formed of a sheet which is lapped and soldered at its
opposite margins, said sheet having a circumferential detachable strip terminating
at one of the soldered margins in a free tongue which is perforated at or near its
base and has its perforation or perforations filled with solder.
4-A blank for sheet metal can-bodies having one or more weakened lines to
afford a detachable strip at or parallel with the edge of the blank, said strip having
one of its extremities laterally disconnected from the blank by a slit or slits formed
in continuation of the weakened line or lines, to constitute a tongue, said tongue
being offset, substantially as described and for the purpose set forth.
5-A sheet metal blank for a can or other closed vessel, having a detachable

page_text: strip terminating at one edge of the blank in a free tongue and provided with one
or more apertures in said strip at or the base of the tongue, substantially as and for
the purpose set forth.
Dated this 24th day of September 1899
JOHN ZIMMERMAN.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C..
Agents for the Applicant.