IMPROVEMENTS IN SHEETMETAL CANS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, EDMUND EDWARDS, of the firm of Edwards and Co., Patent Agents and
Engineers, of 35, Southampton Buildings, Chancery Lane, London, in the County of
Middlesex do hereby declare the nature of the invention for "IMPROVEMENTS IN
SHEETMETAL CANS" (a communication to me from abroad by Edwin Norton, of
River Street, Chicago, United States of America Manufacturer) and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement and accmopanying drawings:-
This invention relates to metal cans or vessels such as are used for the purpose
of containing paints or chemical and other substances, where it is important to
have an airtight and perfect can in order to prevent injury and loss by leakago
in the transportation and storage of cans containing such substances.
It has for its object novel methods of making such metal cans so that the part
forming the junction of the can body with the cover or bottom is very strong and
less liable to be weakened in the process of manufacture or to leak when used than
such cans as ordinarily made.
The invention is more especially applicable to that class of such sheet metal_cans
in which the cap or cover is united to the body without the aid of solder. Here-
tofore ordinarily for this purpose a flange has been drawn out and formed from the
body of the can itself, so that the metal of the flange is necessarily much weakened
and injured in texture and is consequently liable to break or crack when it is
afterwards further drawn out and folded over in the operation of forming a double
seam joint, an aperturo being thus made through which the contents of the can
may leak, and moreover in the process of forming this flange upon the can body
itself, the side seam in such body is itself liable to open at the flange and even
when this does not happen the protuberant thicknesses or folds of the side seam
cause an uneven place in the flange at which air may find its way through the
double seam after it is formed.
The present invention consists in uniting the cover or the bottom of the can to
the can body by means of an improved double seam joint composed of an exterior
flauge upon the can body, such flange being without seam and being interlocked
Pina/1

page_text: and folded with the edge of the cover or bottom so as to form a perfect double
seam in the usual manner.
The flange described is formed of an annular blank of suitable metal, having its
inner edge stamped or otherwise turned at right angles to the flange so as to form
a cylindrical shoulder which fits upon or preferably inside the end of the can body
to which it may be soldered.
It will be seen that the metal constituting the Bange has been in no way
disturbed or injured by the forming tool or stamp but retains its original textura
so that when it is subsequently bent up and over by the action of the tools in
forming the double seam uniting it to the cover or bottom, there is no danger of its
giving way or breaking and thus leaving an aperture through which leakage can
take place; and moreover the flange being without seam and of a single plain
thickness of sheet metal throughout, it affords a perfectly smooth and even bearing
to receive the cover or end, ensuring an absolute uniformity in every part of the
joint when the two parts are lapped over and folded together by the action of the
seaming tools, a perfect can and one that can be relied upon with safety, being
produced with certainty every time.
In the accompanying drawing which is in illustration of the invention, Figure 1
is a side elevation, partly in section, of a can made in the method described;
figure 2 is a central vertical section of the same showing the bottom in the position
before it is finally secured. Figures 3, 4, 5, and 6 aro detailed sectional views
showing the improved double seam in different stages of formation, and figure 7
shows in plan the separate seamless flange described.
A represents the body of the cam which is of the usual construction, except that a
crimped in shoulder a is.formed at its upper part, so that when a thin inner cover
shewn by the black line B is crimped or folded over the upper edge of the
shoulder a and soldered or otherwise secured to the latter, the seam formed at b by
the several thicknesses of the joint so formed, is of the same or somewhat less
diameter than the exterior cylindrical surface of the can body A, so that a
removeable separate slip cover Ċ may pass over the joint b and fit smoothly upon
the can body.
The inner cover B is made of thin and sufficiently soft metal so that it can be
easily cut away when it is desired to use the contents of the can, and the outer or
slip cover C is provided as a protection to this thin cover B, and also as a moveable
cover to be replaced as often as desired when it has been taken off for the purpose
of removing a part only of the contents of the can.
To the other or lower end of the can, through which it is filled, is soldered a
Beamless flange d of the kind already described, consisting (as shewn in figure 2) of
a separate annular piece of sheet metal having its inner edge turned or stamped up
at right angles so as to form a cylindrical shoulder d' which fits into and is soldered
to the bottom of the can body A.
The bottom or cover D for this end of the can is provided with an annular
flange d² turned up at right angles to the bottom and fitting round the seamless
flange which is soldered to the bottom of the can body, as shewn in figure 2, so
that the former can be interlocked and folded in with the seamless flange, as shewn
in figure 1, the process being further illustrated in figures 3, 4, 5, and 6, which
shew the joint applied either to the top or the bottom of the can, in figure 3 the
edge of the end D being shewn turned up round the flat scaniless flange d
soldered to the can body A; in figure 4 the edge d' being turned down upon the
seamles flange d; in figure 5 the seamless flange d and the two thicknesses of the
edge which embrace it being shewn partially bent in toward the can body; and
in figure 6 the seamle-s flange d and the two thicknesses embracing it being shewn
Hattened down against the can body A so as to complete the joint.
As the fibre of the seamless flange d has not been previously injured or disturbed
by the process of stamping which acts only upon its inturned edge d', a very tight
and perfect double seain joint can be formed in this way with certainty, and the
'can when closed may be safely relied on.

page_text: It is obvious that some of the advantages of this invention may be obtained by
modifying the arrangement so that the can body is itself made seamless, and the
flanged at its end being also seamless and formed by turning out the end of
the body.
As shown in figures 1 and 2 the improved can there represented is intended to
be filled through the bottom end, the thin cover B being firat fitted and soldered to
the body and the slip cover C then applied over it. The bottom cover D is attached
by means of the separate seamless flange and the double seam as already described.
and shewn. When it is desired to open the can the slip cover C is first removed,
and the thin inner cover B can then be readily cut away with a knife or other
suitable instrument.
If the thin inner cover B be fitted inside the can body, instead of over and round
its end as shewn in figure 1, the crimping or turning in of the upper end of the
can body at a can be dispensed with as in such case the scam uniting the inner
cover to the can body will not prevent the slip cover C from being fitted over and
pressed upon the can in the ordinary way. This modified method of constructing
the upper end is shewn in figure 8, where A is the body of the can, B (shewn by a
black line) the thin inner cover having a flange soldered inside the can body, and
C is the slip cover fitted over the upper end of the can.
Where larger cans of considerable size are to be made, in order to strengthen.
them and to give them a finished appearance similar to that of wired cans or pails,.
the modified arrangements shewn in figures 9, 10, and 11, may be used with
advantage, the seamless flange being united to the can body by a firm interlocked
soldered seam in such manner that there will be no danger of such soldered seam
being broken or disturbed in the process of uniting the cover to the seamless
Bange, and thereby causing a leak in the can. This modification consists in turning
an interior flange or shoulder on the can body over which the edge of the annular.
seamless flange is folded and soldered, thus forming on the can body an interior
right-angle strengthening flange composed of three thicknesses of metal soldered
together, whilst the exterior edge of the seamless flange constitutes one part or
element of the double seamed joint by which the cover is united to the body of
the can.
Where an inner cover is used made of thin sheet metal, such as " taggers" tin,
an outer or slip cover being also used in the way already described, a shoulder is
turned in on the upper part of the can body so that the outer edge of the double
seam joint by which the inner cover is united to the can body is of the same
diameter as or less than the can body, and the moveable slip cover can be readily
removed and replaced.
Figure 9 is a vertical section, figure 10 a similar section before the double
seamed joints upon the seamless flange are completed, and figure 3 a section of a
modification applied to the bottom of a can or where no slip cover is to be used.
A (figures 9 and 10) is the can body having an inner flango or shoulder at its
upper end at a.
B is the seamless flange, the inner edge of which b is turned down
as shewn in figure 10 and then folded over and soldered to the flange a on the
can body as shewn in figure 9 forming a solid interior right angled flange of three
thicknesses of tin soldered together.
The exterior edge b1 of the seamless flange is united by a double seamed joint
at c to the thin inner cover C shewn as a black line.
The upper part of the can body is turned or shouldered in at A¹ so that the
slip cover D may fit over and upon the body of the can A. The double seam at c
may be formed without solder, and ordinarily after the can has been filled.
In figure 11 the turning in or shouldering of the can body as shewn at A' in
figures 9 and 10 is unnecessary as no slip cover is used. The seamless flange B is
shewn, in black line, its inner edge fitting round a flange a formed inside the end
of the can body, whilst its outer edge is formed at c into a double seamed joint
uniting the seamless flange to the end or bottom of the can D.

page_text: In the improved double seamed joint described and shewn in the drawings, the
seamless flange upon the can body is an exterior one and is thus adapted to be
readily acted upon in the ordinary process of forming a double seam, so that the
flange and cover can be properly compressed and folded together so as to forin a
tight and perfect joint.
I do not claim the precise form and proportions of the several parts forming the
seamless joint which may be varied more or less according to the size and character
of the cans, but having now particularly described and ascertained the nature of
my said Invention, and in what manner the same is to be performed, I declare that
what I claim is :-
1. In a sheet metal can, the improved double seam consisting of a separate
seamless exterior flange in the can body, interlocked and folded with the edge of
the cover substantially as described and shewn in the drawings.
2. The combination of a can body, with an exterior separate seamless flange d,
provided with turned-in edge d¹ soldered to the can body, and the cover D having
its edge folded with the said flange so as to form a double seam, substantially as
described and shewn in figures 1, 2, 3, 4, 5, 6, and 7.
3. The combination with a can body provided with an interior shoulder a, of a
separate seamless flange B having its inner edge b folded over and soldered to the
said interior shoulder a, and its outer edgo b¹ folded with the edge of the cover C
so as to form a double seam, substantially as described and shown in figure 11.
4. The combination with a can body A having its top turned in at A', of the
separate seamless flange B united to the can body, the thin inner cover C having
its edge united to the outer edge of the seamless flange B by a double seam of the
samo or less diameter than the exterior circumference of the can body A, and the
slip cover D fitting over the can body outside the said double seam, substantially
as described and shewn in figures 9 and 10.
T
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