Improvements in the Manufacture of Tin Cans.
Year: 1892

page_text: Date of Application, 24th May, 1892
Complete Specification Left, 16th June, 1892-Accepted, 16th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Tin Cans.
I, EDWIN NORTON, residing in Maywood, in the County of Cook, in the State
of Illinois, United States of America, Manufacturer, do hereby declare the nature
of this invention to be as follows:
My invention relates to the construction of tin cans which are adapted to be
hermetically sealed and which are used for putting up fruit, vegetables, condensed
milk fish, meats and other hermetically sealed goods. Cans of this class are made
of tin plate, that is thin sheets or plates of iron or steel coated on both sides
with tin.
In the manufacture of these cans the tin plate is necessarily manipulated cold or
at such low degree of heat as will not melt the tin coating and thus destroy injure
or discolor the plate or material out of which the can is made. These cans are
used simply as a wrapper or casing for the goods which are sold in them, the can
being of no value after it is once opened. And one of the necessities of the manu-
facture therefore is that the cans be made very cheap, as any construction of can
which would be expensive to make would, on this ground alone, be an absolute
failure and impracticable and could not be used. •
As the practical sole value of a can of ordinary size, say a one-pound two-pound
or three-pound can is only a fraction of a cent more than the cost value of the tin
plate or material used in its construction, it is obvious that the construction of a
practical or successful can must be such that good or perfect cans may be made with
uniformity and certainty, that is to say without any appreciable percentage
of defective or spoiled cans or injured stock in the process of manufacture.
If for example, the construction of the can were such that with ordinary care
only 90 or 95 perfect cans could be made out of a hundred, the tin plate or stock of
the remaining five or ten being spoiled, that construction of can would necessarily
be for this reason alone entirely impracticable. For economy in the amount
of material or stock necessary to make a can of a given capacity, and for con-
venience and economy in packing the cans in cases for shipment and for safety
in shipment especially when the cans are filled, these cans are usually made of
cylindrical form, and for the same reasons the height or length of most cans equals
or exceeds their diameter, though a limited number of cans commonly called "flats'
are used for certain special purposes in which the height or length is somewhat less
than the diameter of the cans.
Heretofore these cans have been usually made of three separate pieces or blanks
of tin plate; one piece being a rectangular blank which is folded into cylindrical
form and its meeting edges soldered together to form the body or cylindrical
portion of the can and the other two blanks being cylindrical flanged discs, the
flanges of which are soldered to the ends of the body portion of the can and
constitute its two heads or its bottom and top.
The cans made in this way necessarily have three soldered seams or joints, one
being the side seam of the can body and the other being the two end seams which
unite the two heads to the can body. This old construction of can can be made
cheaply but to do so requires large and expensive plants of labour saving machinery,
though even with such machinery the manufacture is attended with considerable
labour and expense, owing to the great number of different manipulations or acts to
be performed to make the cans, such as cutting the blanks forming the can body,
soldering its side seam, assembling the heads and bodies and applying the heads io
the bodies, soldering the end seams and finally testing the can.. The expense of the

page_text: manufacture is also materially increased by the amount of solder and flux required
for forming the several soldered joints.
In the old construction of can there is also unavoidably some percentage of
defective or leaky cans, arising from defects in the soldering of some of the seams
of the cans, and especially in the side seam or at the point where the end of the
side seam is united to the flange of the head as the folds or laps of the stock forming
the side seam necessarily leave a small crevice or shoulder between the flange of
the can head and the end of the can body at this point.
This crevice is sometimes not properly filled and closed by the solder in the
operation of soldering the head upon the can body. And though this percentage of
leaky or defective cans may be very small, say for example only five or six cans in
a thousand, still it will be seen that this loss becomes a serious and heavy charge
against the can manufacturer and materially diminishes his legitimate profits in the
business when it is remembered that it is the general custom of the business or trade
for the packer or user of the cans to charge back to the can manufacturer as a
rebate not only the cost of the leaky cans, but the value of the goods packed in
such cans spoiled by reason of the leaks.
When the cans are filled with valuable goods it often happens that the reclama-
tions for leaks in a thousand cans exceeds over and over again the can manufacturers'
profit on the entire thousand. In this old construction of can having a soldered
side seam and end seams there is also danger of tainting of injuring the contents
with the acid of the flux or solder used in soldering the seams and which often to a
greater or less extent flows through the soldered seams into the interior of the can
so that the contents of the can may come in contact therewith. This is of special
importance in relation to condensed milk and other special articles of food which
are commonly put up in cans.
The object of my invention is to provide an efficient and practical can made of tin
plate, which in its construction and method of manufacture will obviate the
objections to the old construction of can heretofore in general use, and which at the
same time may be manufactured more cheaply.
To this end my invention consists in a drawn tin plate can of cylindrical form
having its bottom, head and body all in one seamless piece, thus avoiding the
soldered side seam of the can body and also the soldered end seam for uniting the
bottom head to the can body. It further consists in a drawn cylindrical can having
its bottom, head and body all in one seamless piece of tin plate and furnished at its
mouth or upper end with a rolled edge to strengthen the same and to enable the
flange of the can head to be readily placed on the can body, while at the same time
it fits the same tightly and snugly so that a perfect soldered seam may be formed
with certainty and uniformity between the smooth die-formed wall of the can body
and the similarly die-formed wall or flange of the can head.
any
By this means I am enabled to produce such a tight close fit between the flange
of the can head and the end of the can body, that a comparatively small quantity of
solder is required for forming this end seam and so that there is little danger of
portion of the solder or flux coming in contact with the contents of the can. This
latter result is also in part effected by an internal bead which I form at the upper
end of the can body. This bead also constitutes a shoulder or stop for the lower
edge of the flange of the can head to fit against and thus prevents the can head
being too far inserted in the can body.
By combining the die-made cover or can head with the die-made or drawn can
body furnished with such rolled edge, the fit between the can head and body
may be made so tight and close that a practically liquid tight joint may be formed
by simply forcing the head in or upon the body and before the soldering is done,
while at the sanie time owing to the roll at the mouth of the can body, the head or
covering may be conveniently applied to the body. The rolled edge of the drawn
can body when combined with the head fitting inside the can body also forms a
guide or channel for the solder or soldering tool in the operation of soldering the
final head or cover in the can after the cau has been filled. By combining the

page_text: drawn or die-made can body with the drawn or die-made cover I entirely avoid
the shoulder or crevice caused by the side seam of the old cans and which heretofore
has been such a frequent cause for leaky cans.
The body of the can and its bottom or lower head are made in one seamless
piece or blank of tin plate and formed into cylindrical shape by drawing the blank
with suitable dies. As the can body is die made or drawn to the required shape
the can bodies can be readily made of an exact size or diameter and perfectly true
so that a perfect fit may be produced between the same and the flange of the die
made cover.
To facilitate the application of the tight fitting die-made cover to the
die-made can body, the upper end of the can body is furnished with a roll or turned
edge. The roll is an external roll as the flanged head is designed to fit inside the
can body. The can body is further provided with an internal bead which in
the combination of the can body with the can head serves as a shoulder or stop for
the edge of the can head flange to rest against and also to prevent any possibility
of the solder or flux employed to solder the head to the can body coming in
contact with the contents of the can. The outward roll also serves in this com-
bination to form a guide or channel for the solder and soldering tool in the act of
soldering the head upon the body. To better accomplish this latter result also the
can head is provided with a slightly inclined rim. The rolled edge of the seamless
can body and rim of the can head together constitute two opposing inclined surfaces
which serve to direct the solder into the seam or joint between the flange of the
can head and the cylindrical wall of the can body below the roll and above the bead.
The seamless flange of the die-made cover is united by solder with the seamless
cylindrical wall of the die-made can body. The rolled or folded edge of the can
body, it will be observed, gives the seamless die-made can body a kind of tapering
or wedging mouth which very greatly facilitates the application of the like die-
made can head to the can body and permits the two parts to be made very close and
tight fitting, so that the parts may be perfectly soldered together with certainty
and uniformity, and by the use of a comparatively small quantity of solder. This
wedging mouth of the seamless die-made can body in connection with the seamless
die-made cover also causes or enables the cover when it is inserted within the can
body after the latter is filled with food or other articles to scrape or clean the
mouth or wall of the can body by the mere act of inserting the cover. This latter
result is one of great practical utility and importance in the art of putting up
hermetically sealed goods as it is very necessary in order to form a perfectly tight
soldered joint that the two tin coat surfaces which are to be united by the solder
should be perfectly clean and free from all substances which might interfere with
the complete and perfect soldering of the parts together. This result is due to
combining the seamless can body with the seamless can head because if the can
body was provided with a side seam the crevice or shoulder formed by and left at
the side seam would form a lodgement for dirt or material which could not be
removed or scraped away by the flange or cover when it is inserted. As the
internal bead forms a kind of inclined or wedging shoulder when the flange of the
head is pressed home against this shoulder, the shoulder and flauge together form a
very close frictional contact with each other uniform all around as both parts are
seamless, so that there is scarcely any possibility for the solder or flux to come in
contact with the contents of the can.
1003
HASELTINE; LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Tin Cans.
I, EDWIN NORTON of Maywood in the County of Cook State of Illinois United
States of America, Manufacturer, 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:-
My invention relates to the construction of tin cans which are adapted to be
hermetically sealed and which are used for putting up fruit, vegetables, condensed
milk, fish, meats and other hermetically sealed goods. Cans of this class are made
of tin plate, that is thin sheets or plates of iron or steel coated on both sides with
tin. In the manufacture of these cans the tin plate is necessarily manipulated cold
or at such low degree of heat as will not melt the tin coating and thus destroy
injure or discolor the plate or material out of which the can is made. These cans
are used simply as a wrapper or casing for the goods which are sold in them, the
can being of no value after it is once opened. And one of the necessities of the
manufacture therefore is that the cans be made very cheap, as any construction of
can which would be expensive to make would, on this ground alone, be an absolute
failure and impracticable and could not be used. As the practical sole value of a
can of ordinary size, say a one-pound, two-pound or three-pound can, is only a
fraction of a cent more than the cost value of the tin plate or material used in its
construction, it is obvious that the construction of a practical or successful can
must be such that good or perfect cans may be made with uniformity and certainty,
that is to say without any appreciable percentage of defective or spoiled cans or
injured stock in the process of manufacture. If, for example, the construction of
the can were such that with ordinary care only 90 or 95 perfect cans could be made
out of a hundred, the tin plate or stock of the remaining five or ten being spoiled,
that construction of can would necessarily be for this reason alone entirely
impracticable. For economy in the amount of material or stock necessary to
make a can of a given capacity, and for convenience and economy in packing the
cans in cases for shipment and for safety in shipment especially when the cans are
filled, these cans are usually made of cylindrical form, and for the same reasons
the height or length of most cans equals or exceeds their diameter, though a
limited number of cans commonly called "flats" are used for certain special
purposes in which the height or length is somewhat less than the diameter of the
Heretofore these cans have been usually made of three separate pieces or
blanks of tin plate; one piece being a rectangular blank which is folded into
cylindrical form and its meeting edges soldered together to form the body or
cylindrical portion of the can and the other two blanks being cylindrical flanged
disks, the flanges of which are soldered to the ends of the body portion of the
can and constitute its two heads or its bottom and top. The cans made in this way
necessarily have three soldered seams or joints, one being the side seam of the
can body and the other being the two end seams which unite the two heads to
the can body. This old construction of can can be made cheaply but to do so
requires large and expensive plants of labor saving machinery, though even with
such machinery the manufacture is attended with considerable labor and expense,
owing to the great number of different manipulations or acts to be performed to
make the cans, such as cutting the blanks, forming the can body, soldering its side
seam, assembling the heads and bodies and applying the heads to the bodies,
soldering the end seams and finally testing the can. The expense of the manu-
facture is also materially increased by the amount of solder and flux required for
forming the several soldered joints. In the old construction of can there is also
unavoidably some percentage of defective or leaky cans, arising from defects in
the soldering of some of the seams of the cans, and especially in the side seam or
at the point where the end of the side seam is united to the flange of the head as
the folds or laps of the stock forming the side seam necessarily leave a small
cans.

page_text: crevice or shoulder between the flange of the can head and the end of the can
body at this point. This crevice is sometimes not properly filled and closed by
the solder in the operation of soldering the head upon the can body. And though
this percentage of leaky or defective cans may be very small, say for example
only five or six ca is in a thousand, still it will be seen that this loss becomes a
serious and heavy charge against the can manufacturer and materially diminishes
his legitimate profits in the business when it is remembered that it is the general
custom of the business or trade for the packer or user of the cans to charge back
to the can manufacturer as a rebate not only the cost of the leaky cans, but the
value of the goods packed in such cans spoiled by reason of the leaks. When the
cans are filled with valuable goods, often happens that the reclamations for
leaks in a thousand cans exceeds over and over again the can manufacturers' profit
on the entire thousand. In this old construction of can having a soldered side
seam and end seams there is also danger of tainting or injuring the contents with
the acid of the flux or solder used in soldering the seams and which often to a
greater or less extent flows through the soldered seams into the interior of the
can so that the contents of the can may come in contact therewith. This is of
special importance in relation to condensed milk and other special articles of food
which are commonly put up in cans.
The object of my invention is to provide an efficient and practical can made of
tin plate, which in its construction and method of manufacture will obviate the
objections to the old construction of can heretofore in general use, and which at
the same time may be manufactured more cheaply.
To this end my invention consists in a drawn tin plate can of cylindrical form
having its bottom, head and body all in one seamless piece, thus avoiding the
soldered side seam of the can body and also the soldered end seam for uniting
the bottom head to the can body. It further consists in a drawn cylindrical can
having its bottom, head and body all in one seamless piece of tin plate and
furnished at its mouth or upper end with a rolled edge to strengthen the same and
to enable the flange of the can head to be readily placed on the can body, while
at the same time it fits the same tightly and snugly so that a perfect soldered
seam may be formed with certainty and uniformity between the smooth die-formed
wall of the can body and the similarly die-formed wall or flange of the can head.
By this means I am enabled to produce such a tight close fit between the lange
of the can head and the end of the can body, that a comparatively small quantity
of solder is required for forming this end seam and so that there is little danger of
any portion of the solder or flux coming in contact with the contents of the can.
This latter result is also in part effected by an internal bead which I form at the upper
end of the can body. This bead also constitutes a shoulder or stop for the lower
edge of the flange of the can head to fit against and thus prevents the can head
being too far inserted in the can body. By combining the die-made cover or can
head with the die-made or drawn can body furnished with such rolled edge, the fit
between the can head and body may be made so tight and close that a practically
liquid tight joint may be formed by simply forcing the head in or upon the body
and before the soldering is done, while at the same time owing to the roll at the
mouth of the can body, the head or covering may be conveniently applied to the
body. The rolled edge of the drawn can body when combined with the head
fitting inside the can body also forms a guide or channel for the solder or soldering
tool in the operation of soldering the final head or cover in the can after the can
has been filled. By combining the drawn or die-made can body with the drawn
or die-made cover I entirely avoid the shoulder or crevice caused by the side
seam of the old cans and which heretofore has been such a frequent cause for
leaky cans.
In the accompanying drawing, which forms a part of this Specification, and in
which similar letters of reference indicate like parts,
Fig. 1 is a central longitudinal section of a can embodying my invention, showing
the cover or top head in place before it is soldered;

page_text: Fig. 2 is a similar section showing the cover soldered in place;
Fig. 3 is a horizontal section on line 3-3 of Fig. 1.
In the drawing A represents the body of the can and B its bottom or lower
head, both these parts being in one seamless piece or blank of tin plate and formed
into cylindrical shape by drawing the blank with suitable dies. As the tin plate
can body A is die made or drawn to the required shape the can bodies can he
readily made of an exact size or diameter and perfectly true so that a perfect fit
may be produced between the same and the flange c of the die-made cover C. To
facilitate the application of the tight fitting die-made cover C to the die-made can
body A, the upper end of the can body is furnished with a roll or turned edge a.
The roll is an external roll as the flanged head C is designed to fit inside the
can body. The can body is further provided with an internal bead a' which in
the combination of the can body with the can head serves as a shoulder or stop for
the edge of the can head flange c to rest against and also to prevent any possibility
of the solder or flux employed to solder the head C to the can body coming in
contact with the contents of the can. The outward roll a also serves in this
combination to form a guide or channel for the solder and soldering tool in the act
of soldering the head upon the body. To better accomplish this latter result also
the can head C is provided with a slightly inclined rim c. The rolled edge a of
the seamless can body and rim e' of the can head together constitute two opposing
inclined surfaces which serve to direct the solder into the seam or joint between
the flange c of the can head and the cylindrical wall a² of the can body below the
roll a and above the bead a'. D represents the solder which unites the seamless
flange c of the die-made cover C with the seamless cylindrical wall a² of the die-
made can body A. The rolled or folded edge a of the can body, it will be observed
gives the seamless die-made can body a kind of tapering or wedging mouth which
very greatly facilitates the application of the like die-made can head to the can
body and permits the two parts to be made very close and tight fitting, so that the
parts may be perfectly soldered together with certainty and uniformity, and by
the use of a comparatively small quantity of solder. This wedging mouth of the
seamless die-made can body in connection with the seamless die-made cover also
causes or enables the cover when it is inserted within the can body after the latter
is filled with food or other articles to scrape or clean the mouth or wall a² of the
can body by the mere act of inserting the cover. This latter result is one of
great practical utility and importance in the art of putting up hermetically sealed
goods as it is very necessary in order to form a perfectly tight soldered joint that
the two tin coat surfaces which are to be united by the solder should be perfectly
clean and free from all substances which might interfere with the complete and
perfect soldering of the parts together. This result is due to combining the seam-
less can body with the seamless can head because if the can body was provided
with a side seam the crevice or shoulder formed by and left at the side seam would
.form a lodgment for dirt or material which could not be removed or scraped away
by the flange or cover when it is inserted. As the internal bead a forms a kind of
inclined or wedging shoulder when the flange c of the head C is pressed home
against this shoulder, the shoulder and flange together form a very close frictional
contact with each other uniform all around as both parts are seamless, so that there
is scarcely any possibility for the solder or flux to come in contact with the contents
of the can.
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
a
1. The improvement in the construction of sheet metal cans, herein shown and
described.
2. The drawn or die-made tin can for hermetically sealed goods herein shown
and described and consisting of a seamless cylindrical body A. and bottom head B,
both of said parts being drawn up out of one and the same piece or blank of tin

page_text: plate, and a die-made cover C having a cylindrical flange e fitting the cylindrical
body A at the mouth or end thereof, and soldered or adapted to be soldered thereto,
substantially as specified.
3. The drawn or die-made tin can for hermetically sealed goods herein shown
and described and consisting of a seamless cylindrical body A and bottom B, both
of said parts being drawn up out of one and the same piece or blank of tin plate
and a die-made cover C having a cylindrical flange c fitting the cylindrical body A
at the mouth or end thereof, and soldered or adapted to be soldered thereto, said
seamless body A having a rolled edge a at its end or mouth to facilitate the
application of said cover head C to the body, substantially as specified.
4. The drawn or die made tin can for hermetically sealed goods herein shown
and described, and consisting of a seamless cylindrical body A and bottom B, both
said parts being drawn up out of one and the same piece or blank of tin plate, and
a die-made cover having a cylindrical flange e fitting the cylindrical body A at
the mouth or end thereof and soldered or adapted to be soldered thereto, said
seamless body A having an externally rolled edge a at the end or mouth thereof
and an internal bead a to form a stop for the seamless flange c of said cover to fit
against, substantially as specified.
5. The drawn or die-made tin can for hermetically sealed goods herein shown
and described and consisting of a seamless cylindrical body A and bottom head B,
both said parts being drawn up out of one and the same piece or blank of tin
plate, and a die-made cover C having a cylindrical flange c fitting the cylindrical
body A at the mouth or end thereof, and soldered or adapted to be soldered thereto,
said seamless body A having an externally turned or rolled edge a and said
cover Chaving a slightly inclined or flaring rim c¹ to form a guide or channel
for the solder in soldering the cover head (upon the body, substantially as
specified.
6. The drawn or die-made tin can for hermetically sealed goods herein shown
and described and consisting of a seamless cylindrical body A and bottom head B,
both said parts being drawn up out of one and the same piece or blank of tin
plate, and a die-made cover C having a cylindrical flange c fitting the cylindrical
body A at the mouth or end thereof, and soldered or adapted to be soldered
thereto, said seamless body A having an externally turned or rolled edge
said cover C having a slightly inclined or flaring rim e' to form a guide or channel
for the solder in soldering the cover head C upon the body, and said body being
also provided with an internal bead or shoulder u' to form a stop for said flange c
of the cover to fit against, substantially as specified..
and
7. The combination with a seamless tin plate die-made can body and bottom head
made from one piece or blank, of a seamless die-made tin plate cover C having
flange accurately and smoothly fitting the mouth or end of said seamless can
body and united thereto by a soldered seam D, substantially as specified.
Chicago, Illinois. U.S.A.. this 26th day of April A.D. 1892
EDWIN NORTON.
Witnesses:
H. M. MUNDAY.
LEWIS ELEUrtis.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.