IMPROVEMENTS IN THE MANUFACTURE OF METAL CANS FOR CONTAINING ALIMENTARY AND OTHER SUBSTANCES, AND IN MEANS FOR OPENING THE SAME.
Year: 1881

page_text: LETTERS PATENT to Cyprien Laurent, of the Parish of St. Pancras, Chemist,
and Henderson William Brand, of Mount Street, in the Parish of St. George's,
Purveyor, both in the County of Middlesex, for an Invention of "IMPROVE-
M
PROVISIONAL SPECIFICATION left by the said Cyprien Laurent and
Henderson William Brand at the Office of the Commissioners of Patents on
the 23rd June 1881.
CYPRIEN LAURENT, of the Parish of Saint Pancras, Chemist, and HENDERSON
WILLIAM BRAND, of Mount Street, in the Parish of St. George's, Purveyor, both in
the County of Middlesex. "IMPROVEMENTS IN THE MANUFACTURE OF METAL
CANS FOR CONTAINING ALIMENTARY AND OTHER SUBSTANCES, AND IN MEANS FOR
OPENING THE SAME.'
"
Our Invention relates to, firstly, improvements in metal cans made of sheet metal
(preferably of sheet tin) for containing alimentary substances, such as preserved
meats and fruits, or any other substances which require to be packed up in air-
tight cans to secure their preservation; and secondly, to improved means of opening
said cans.
Up to the present time air-tight sheet metal cans for containing alimentary
substances, &c., have been open to the objection that one raw or cut edge of the
metal has always been left unguarded, so that the juices of the contents of the cans
coming into contact therewith have contracted a disagreeable flavour, or the contents
have sometimes been spoiled.
Our improved method of manufacture obviates the above inconveniences.
We make the body of the can (of a circular or other suitable and convenient
section) of sheet tin (or other metal) in any usual or well-known way. The bottom
is attached to the body in any convenient way. The top edge of the body is
swaged inwards to a greater or less degree according to the size of the can. The
ו”.

page_text: top or cover is stamped in dies with a shallow V groove projecting from its under
side. The distance of this groove from the edge is such as to allow it to lie truely
upon the face of the swaged edge of the can-body, at the same time we leave a
margin on the top sufficiently wide to leave (or form), when it is in its place, a
groove or recess for the reception of the solder.
The body of the can is swaged at such an angle that the cut edge thereof is in
a plane parallel with that of the contiguous surface of the V shaped groove in
the cover.
By making the can-body and cover according to the method just described, we
prevent the cut-edge of the metal from being touched by the contents of the can,
whatever those contents may be.
Our improvement in the means of opening cans, made according to our Invention,
is that they are not opened by hand in the ordinary way, e.g., cutting or tearing
the sheet-metal. We stamp in the dies in which the cover is made a tab upon the
side thereof, and provide a wrench made of half-round metal-rod bent.upon itself
and twisted, flat face to flat face, so as to form a handle-loop at one end and a slit
at the other. The slit grips the tab, and a rotary motion being given to the
wrench, the cover is rolled off the can-body.
The soldering referred to above is performed in any convenient way.

page_text: Fig. 1 is a plan, and Fig. 2 is an elevation partly in section of a can of a round-
shape made according to our Invention. We do not however confine ourselves to
the manufacture of round cans. The body of the can 1 is made of tin-plate or
other suitable metal. The bottom of the can is made in any convenient way, and
fastened to the body in any suitable way.
The top edge of the body is swaged inwards, as shown at 2, Fig. 2. Sometimes
in addition to simply swaging the edge we form a V-groove 3. The top or cover 4
is stamped in dies with a shallow V-groove 5 projecting from its under side, and
may have whatever beads, etc., may be considered advisable for either strengthening
or ornamenting it. The distance of this V-groove from the edge of the cover 4 is.
such as to allow its outer slope 6 to lie truly upon raw or cut edge 7 of the can-
body; at the same time we leave a margin 8 sufficiently wide to form, when the
cover is in its place a recess 9 for the reception of the solder. The angle which
the swage 2 makes with the side of the can may be more or less acute, provided
that the relation of parts and its purpose as pointed out is observed.
The swage 2 is made at such an angle with the side of the can that the cut edge 7
shall when the cover is applied be in the same plane with the under-face of the
outer slope 6 of the V-groove in the cover. We avoid making the angles them-
selves sharp'; we prefer to make them round, as drawn in Fig. 2, to prevent cracking
the metal.
When the can and cover are ready the can is filled, and the cover being placed
in position is soldered in the recess 9 in any convenient way.
Or in some cases,
as when preserved milk is being canned, the cover is soldered down first and the
can is filled at a filling-hole in either the cover or the bottom of the can, which
filling-hole is afterwards closed by a cap 10 or otherwise.
The cut or raw edge 7 of the body of the can is now truly face to face with and
protected by the under face of the slope 6, thus preventing the contents of the can,
whatever they may be, from coming into contact with said raw edge. In the act
of soldering it is essential that the cover be held firmly in its position, and if this
be attended to a safe and incorrodible junction of the can and cover is at once
secured. It is impossible with common care to make a bad joint, for from the
relative shapes of the top of the can and of its cover the latter fits into its place
automatically.
We do not confine ourselves to the groove in the cover, as said groove is drawn
in Fig. 1 and 2. We may make the cover with the outer slope only 6, as indicated
by the broken line in Fig. 2. The vertical broken lines in Fig. 2 shew the shape
of the sides of a can swaged only, not grooved.

page_text: For facilitating the act of opening the can, we form upon the cover, by the same
dies in which it is stamped, a tab 11; the sweep of its sides 12, 12, is such as to
render it sufficiently strong. Moreover, by making the tabs as drawn, we are
enabled to pack quantities of our cans in the smallest possible space. Close to the
end of the tab we form on its under (by preference) side a small stud 13, for the
purpose to be described further on.
Fig. 3 is an elevation of the opening key we use for opening our cans.
It is made of half round iron rod twisted flat-face to flat-face upon itself, and in
a direction opposite to that of the strain to which it is subjected when in use, so as
to form a bow-handle at one end and a notch at the other. For opening the can is
held in the left hand. The key is slipped over the tab just within the stud 13; it
is then revolved round its axis and the cover is rolled off from the can-body, the
solder yielding without a jerk, the stud preventing the key from slipping.
Having now particularly described and asertained the nature of our Invention,
and in what manner the same is to be performed, we wish it to be distinctly
understood that that in respect to means fo ropening metal cans we desire to make no
claim, but what we consider to be new and claim under the herein before in part
recited Letters Patent is as follows:-
First. The improved metal can and cover constructed and arranged as herein
described, so that the cover shall rest on the inside edges of the sides of the can,
whereby the raw edge of the plate is not exposed to the contents of the can.
Second. The combination, substantially as described, of the parts 2, 6, 7, and 9
resulting in the secure closing of the can, and in the protection of the raw edge
of the plate from contact with the contents.
In witness whereof, we, the said Cyprien Laurent and Henderson William
Brand, have hereunto set our hands and seals, this Twenty-first day of
December, in the year of our Lord 1881.
Witness,
CONRD. W. FULTON.
CYPRIEN LAURENT.
(L.S.)
HENDERSON WILLIAM BRAND. (L.S.)