IMPROVEMENTS IN CANS, AND IN THE MEANS OF CLOSING THE SAME."
Year: 1880

page_text: LETTERS PATENT to Thomas George Fonnereau Dolby, of Dulwich, in the
County of Surrey, Manufacturer, for an Invention of "IMPROVEMENTS IN
CANS, AND IN THE MEANS OF CLOSING THE SAME."
PROVISIONAL SPECIFICATION left by the said Thomas George Fonnereau
Dolby at the Office of the Commissioners of Patents on the 20th November
1880.
THOMAS GEORGE FONNEREAU DOLBY, of Dulwich, in the County of Surrey,
Manufacturer. "IMPROVEMENTS IN CANS, AND IN THE MEANS OF CLOSING THE
SAME."
This Invention relates to cans of sheet metal adapted for a variety of uses, but
especially for preserving food, and it relates partly to the construction of the can
top and covering, and partly to the means adopted for closing the same, so that
they may be sealed air tight and protected against accidental opening by reason of
blows or jars, all as more fully hereinafter set forth.
The body of the can may be tapering or cylindrical as desired. It has a rim
with a screw formed in it. At its lower edge this rim is curved inwards to form,
firstly, an annular channel, and secondly, a rim or ledge which fits the top or
margin of the body, and is soldered or otherwise secured thereto. This rim may
turn up or down; these parts form the can proper.
The lid or cover is a disc provided by preference with a flange or edge turned
down all around its margin, which flange takes over the top of the can body when
the lid or cover is put in place. The ledge or flange drops into the annular channel
before described, and may extend to and rest upon the bottom of the same; so as to
raise the cover slightly above the top of the can body. This however is a matter
of little importance; the cover may rest upon the can and the flange may depend
into, but not to the bottom of, the annular channel.
When the cover rests on the top of the can the flange may be dispensed with.
I employ a ring composed of an upright portion provided with a screw to fit the
screw formed in the rim of the can body, and a horizontal part which rests upon
the cover when the ring is screwed down.
The method of closing the can is as follows:-
After the can has been snugly filled up to the top of the can body, the cover is

page_text: placed in position and pressed down to its seat, and the annular channel carefully
cleaned out if required. This channel is then filled with some putty like wax
which will not harden, but which will hermetically close the joint between the
cover and the can. The ring is now screwed firmly down upon the cover, whereby
it is held tightly in place, and protected against disengagement from accidental
causes. When the can is to be opened, the ring is unscrewed and the cover may
then be lifted out, as the wax will offer very little if any obstruction.
As a wax for this purpose I prefer to employ a compound composed of olive oil
one pint, and bees wax one pound, well mixed and kneaded together. This forms
a sticky tough wax having about the consistency of glazier's putty at ordinary
temperatures, and it will neither harden nor shrink. The wax is put in cold,
and the ordinary variations in temperature have no perceptible effect upon it;
consequently it provides at all times a secure air tight joint, but one which may be
unsealed readily without the application of artificial heat. Some other non-drying
oil might be substituted for that named, but I prefer olive oil.
In some cases the butter or other substance may be heaped a little, and be
compressed in pressing down the cover.
The cover is provided with a ring whereby it may be readily lifted off, and the
ring of the can body is provided with a bail hinged to it which serves as a handle,
whereby the can and its contents may be carried, and also as a means whereby the
ring may be screwed down upon the cover and also unscrewed.
The bail is arranged to turn down into the recessed top of the can, so as to be
out of the way when the cans are packed.
My can is especially adapted to packing butter, lard, paint, and similar
substances, and it is not injured by being opened, so that it may be used over and
over again. No rubber is employed for sealing the cover, as it is inevitably
destroyed by contact with oily substances, and is.. moreover apt to impart a
disagreeable odour. I also avoid sealing with wax, which chills and hardens
and which requires melting before it can be applied, partly because all such
waxes and cements are injured by heating, and partly because they shrink in
cooling and draw away from the smooth metal, or if the surface is rough and they
do not draw off they are liable to crack in cooling; being also brittle they are very
liable to crack in handling the cans. Any of these mishaps will invariably destroy
the air tight character of the joint.
I employ a putty like wax which will neither harden nor shrink, and which
adheres firmly to the metal of the can and cover. It constitutes what I may term
a cold solder, and by its use I gain the great advantage of avoiding all injurious
effect upon the butter or other contents of the can, such as is caused by the heat in
soldering in the ordinary way.
The screw ring does not aid materially in forming the hermetic joint; that is
formed by the wax alone, but it serves to hold the cover firmly in place and to
prevent the joint from being disturbed by the handling of the cans.
Another important feature of my can is that the screw whereby the cover is held
down is arranged entirely beyond or outside of the wall of the can, and the opening
in the can is the full size of the can-body. With this construction the contents of
the can body may be dumped or turned out without any interference with the
means for holding down the cover.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Thomas George Fonnereau Dolby in the Great Seal Patent Office
on the 19th May 1881.
THOMAS GEORGE FONNEREAU DOLBY, of Dulwich, in the County of Surrey,
Manufacturer. "IMPROVEMENTS IN CANS, AND IN THE MEANS OF CLOSING THE
SAME.
"
This Invention relates to cans of sheet metal adapted for a variety of uses, but
especially for preserving food, and it relates partly to the construction of the can
top and covering, and partly to the means adopted for closing the same, so that
they may be sealed air tight and protected against accidental opening by reason of
blows or jars, all as more fully hereinafter set forth.
In the accompanying Drawings, Figure 1 is a vertical mid section, and Figure 2 a
plan of my improved can and cover; Figure 3 is a detail view shewing the
parts in section and illustrating the arrangement of the same when partly
separated.
A is the body of the can, which may be tapering or cylindrical as desired. It
has a rim B with a screw a formed in it. At its lower edge this rim is curved
inwards to form firstly an annular channel b, and secondly a rim or ledge c which
fits the top or inargin of the body A, and is soldered or otherwise secured thereto.
This rim c may turn up, as in Figure 3; or down, as in Figure 1. These parts A
and B form the can proper.
C is the lid or cover. It is a disc provided by preference with a flange or ledge d
turned down all around its margin, which flange takes over the top of the can body
when the lid or cover is put in place. The ledge or flange d drops into the annular
channel b, and may extend to and rest upon the bottom of the same so as to raise
the cover slightly above the top of the can body, as in Figure 1. This however is
a matter of little importance; the cover may rest upon the can, and the flange d
may depend into but not to the bottom of the annular channel b.
When the cover rests on the top of the can the flange may be dispensed with, as
in Figure 3, but this I do not recommend.
D is a ring composed of an upright portion e provided with a screw to fit the
screw formed in the rim B, and a horizontal part f which rests upon the cover C
when the ring is screwed down.
The method of closing the can is as follows:-
After the can has been filled up to the top of the can body, the cover C is placed
in position and pressed down to its seat, and the annular channel b carefully
cleaned out if required.. This channel is then filled with some putty like wax
which will not harden, but which will hermetically close the joint between the
cover and the can. The ring D is now screwed firmly down upon the cover, whereby
it is held tightly in place and protected against disengagement from accidental
causes. When the can is to be opened the ring D is unscrewed, and the cover may
then then be lifted out, as the wax will offer very little, if any, obstruction.
As a wax for this purpose I employ a compound composed of olive oil one pint,
and beeswax one pound, well mixed and kneaded together. This forms a sticky
tough wax, having about the consistency of glaziers? putty at ordinary temperatures,
and it will neither harden nor shrink, and it is not affected by damp. The wax is
pressed in cold, and the ordinary variations in temperature have no perceptible
effect upon it, consequently it provides at all times a secure air tight joint, but one
which may be unsealed readily without the application of artificial heat.
My putty like wax may be made from other ingredients which will give it the
same properties; for example, some other non drying oil, or even lard, or other soft fat

page_text: '
(in larger proportions than the oil) may be substituted for the olive oil, but as lard
and other fats are liable to turn rank and therefore to taint the butter, I do not
recommend their use; I much prefer a non drying and pure oil, and particularly
olive oil mixed with beeswax so as to form a compound which is not in the slightest
degree deleterious.
The cover is provided with a ring g, whereby it may be readily lifted off, and the
ring D may be fitted with a suitable handle, such as the bail h, whereby the can
and its contents may be carried. The ring D. is provided with projections whereby
it may be screwed down upon the cover and also unscrewed, and these projections
may consist of the loops or staples i, which form the hinges of the bail h.
My can is especially adapted to packing butter, lard, paint, and similar substances,
and it is not injured by being opened, so that it may be used over and over again.
No rubber is employed for sealing the cover, as it inevitably destroyed by
contact with oily substances, and is moreover apt to impart a disagreeable odour.
I also avoid sealing with wax, which chills and hardens, and which requires melting
before it can be applied, partly because all such waxes and cements are injured by
heating, and partly because they shrink. in cooling and draw away from the
smooth metal. Or if the surface is rough and they do not draw off they are liable
to crack in cooling. Being also brittle they are very liable to crack in handling
the cans. Any of these mishaps will invariably destroy the air tight character of
the joint.
I employ a putty like wax which will neither harden nor shrink, and which
adheres firmly to the metal of the can and cover. It constitutes what I may term
a cold solder, and by its use I gain the great advantage of avoiding all injurious
effect upon the butter or other contents of the can, such as is caused by the heat
in soldering in the ordinary way.
The screw ring does not aid materially in forming the hermetic joint; that is
formed by the wax alone; but it serves to hold the cover firmly in place and to
prevent the joint from being disturbed by the handling of the cans.
Another important feature of my can is that the screw whereby the cover is
held down is arranged entirely beyond or outside of the wall of the can, and the
opening in the can is the full size of the can body. With this construction the
contents of the can body may be dumped or turned out without any interference
with the means for holding down the cover.
In cases where it is desirable to expel all the air from the can or to fill it up
with a liquid after it has been hermetically closed, as already described, I form an
opening in the lid C through which I pour in the liquid, such, for instance, as
brine in the case of butter, or juice in the case of fruits. I provide this opening
with a screw or other cap, and I hermetically close it with a putty like wax, in
the manner already described. This opening will also allow of the contents being
readily got at for tasting without removing the entire lid of the can.
Having now described the nature of my said Invention, and in what manner the
same is to be performed, I declare that I claim,—
First. The closing of cans hermetically by sealing the joint between the can and
cover with a soft, sticky, putty like wax, such as beeswax mixed with olive oil,
which will neither dry, shrink, nor harden perceptibly at ordinary temperatures,
and which is applied cold or without the aid of artificial heat, substantially in the
manner herein before described.
Second. In combination with the means of closing cans with a soft, sticky, putty
like wax, as above referred to, I claim the securing of the can cover in place by
mechanical means, substantially as hereinbefore described, to prevent accidental
displacement.
Third. I claim constructing cans and their covers, as hereinbefore described and
shown in the accompanying Drawings.
Fourth. I claim constructing cans of the character of those herein referred to
with the screw threaded attachment whereby the cover is held down, arranged

page_text: entirely beyond or outside the wall of the can, the opening in the can being the
full area of the can body, as hereinbefore described and shown in the accompanying
Drawings.
In witness whereof, I, the said Thomas George Fonnereau Dolby, have
hereunto set my hand and seal, this Sixth day of May, One thousand
eight hundred and eighty one.
T. G. F. DOLBY. (L.S.)