IMPROVEMENTS IN AND RELATING TO THE MANUFACTURE OF TIN AND OTHER PLATES, LINED OR COATED WITH VITREOUS OR SIMILAR MATERIAL, AND IN VESSELS OR ARTICLES MADE THEREOF FOR THE PRESERVATION OF FOOD AND FOR OTHER PURPOSES."
Year: 1880

page_text: LETTERS PATENT to Edward Parry, of New Bridge Street, in the City of
London, Iron Morchant, and Thomas Henry Cobley, of Dunstable, in the
County of Bedford, for an Invention of "IMPROVEMENTS IN AND RELATING
TO THE MANUFACTURE OF TIN AND OTHER PLATES, LINED OR COATED
WITH VITREOUS OR SIMILAR MATERIAL, AND IN VESSELS OR ARTICLES MADE
THEREOF FOR THE PRESERVATION OF FOOD AND FOR OTHER PURPOSES."
PROVISIONAL SPECIFICATION left by the said Edward Parry and Thomas
Henry Cobley at the Office of the Commissioners of Patents on the 4th
September 1880.
EDWARD PARRY, of New Bridge Street, in the City of London, Iron Merchant,
and THOMAS HENRY COBLEY, of Dunstable, in the County of Bedford. "IMPROVE-
MENTS IN AND RELATING TO THE MANUFACTURE OF TIN AND OTHER PLATES,
LINED OR COATED WITH VITREOUS OR SIMILAR MATERIAL, AND IN VESSELS OR
ARTICLES MADE THEREOF FOR THE PRESERVATION OF FOOD AND FOR OTHER
PURPOSES."
Our Invention relates to improvements in the manufacture of tin, zinc, or other
plates with a vitreous or similar coating; also to vessels or articles made with such
coated plates, and to a composition forming the said coating.
The said Invention is designed to provide such plates or articles with a special
surface above the tin, zinc, or other metal, which surface will protect the metal
from the injurious effects of the acids or salts contained in some classes of goods or
merchandize ordinarily packed or put up in boxes or cases made of tin or similar
plates, and thus prevent the said goods from becoming unfit for food or otherwise
deteriorated in quality.
It is well known that when preserved fruit, vegetables, or other substances
containing acids are packed in boxes or cans made of ordinary tin plate, the acids
and salts frequently affect the metal in such a manner that certain chemical actions
take place whereby the contents are damaged, and many attempts have heretofore
been made to render the tin or other plate impervious to the action of these acids
and salts. These attempts have, however, been only partially successful, but by

page_text: means of our said Invention the metal is entirely protected against the action of
such acids or salts, and, therefore, the contents of the box or vessel will not be
injuriously affected as heretoforo.
In carrying the said Invention into practice we coat or cover the tin or other
plates with a mixture or composition consisting of an insoluble silicate or fluo-
silicate, and a soluble silicate or fluo-silicate. We prefer to employ as the insoluble
portion of the composition silicate of lime or fluo-silicate of lime, or what is known
as glass powder previously acted upon by fluoric acid; and as the soluble portion
of the composition silicate of soda and potash. We prefer that kind of silicate of
lime which has been produced by double decomposition from polysulphido of
calcium, chloride of calcium, and hydrate of lime; or we may use a silicate of the
earthy bases or metals, or precipitated gelatinous silica. To fix the alkali or
remove the same we employ a bath containing a dilute solution of fluo-silicic acid
when fluoric acid has not been used, or we may employ for this purpose a dilute
solution of any other suitable acid.
The composition is made by mixing the soluble with the insoluble silicate, and
the proportions may be equal in ordinary cases, but they may be varied according
to the consistency required for the work to be performed, this being a matter
which will be readily understood by the workman. The plates are coated or
covered with this composition or mixture by means of a brush, or they may be
coated by being dipped into a bath thereof, or in any manner-most-convenient.
After the conting has been effected the plates are dried in stoves or otherwise, and
are then ready to be made up-into-boxes-or-cases-in-any-ordinary_inanner.
By means-of-our-Invention we furnish_the_tin or other metal plate with a surface
which somewhat resembles glass, but without the aid of fusion, and this coating-
material adheres so firmly to the metal that it cannot be separated therefrom, and
the metal so coated may be bent or worked in any manner desired. It will
therefore be seen that we provide boxes, cases, or vessels made of plates which are
covered or faced with a material which interposes a protective film between the
surface of the metal and the fruit, vegetables, or other contents, thereby supplying
a want which has long been felt in the trade.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Parry and Thomas Henry Cobley in the Great Seal Patent
Office on the 4th March 1881.
15
EDWARD PARRY, of New Bridge Street, in the City of London, Iron Merchant,
and THOMAS HENRY COBLEY, of Dunstable, in the County of Bedford.
IMPROVE-
MENTS IN AND RELATING TO THE MANUFACTURE OF TIN AND OTHER PLATES,
LINED OR COATED WITH VITREOUS OR SIMILAR MATERIAL, AND IN VESSELS OR
ARTICLES MADE THEREOF FOR THE PRESERVATION OF FOOD AND FOR OTHER
PURPOSES."
Our Invention relates to improvements in the manufacture of tin, zinc, or other
plates with a vitreous or similar coating; also to boxes, cases, cans, or other vessels
or articles made from such coated plate, and to a composition or compound which
forms the said coating.
The said Invention is designed to provide such plates or articles with a special
surface or coating above or upon the tin, zine, or other metal, which surface or
coating is applied in the form of a paste or solution without the aid of fusion. .
This coating will protect the metal from the injurious effects due to the chemical
action of the acids or salts contained in some kinds of materials or merchandize
packed or put up in boxes or cases made of tin or similar plates, and will thus
prevent the deterioration of such materials and their becoming unwholesome and
unfit for food or unpalatable.
It is well known that when preserved fruit, vegetables, or other substances
containing acids or salts are packed in boxes or cans made of ordinary tin plate,
the acids or salts by their chemical action frequently affect the metal in such a
manner that the contents of such boxes or cans are so damaged in many instances
as to be totally unfit for use.. Many attempts have heretofore been made to render
the tin or other plate impervious to the action of these acids and salts, but such
attempts have either failed entirely, or have been only partially successful. By
means of our said Invention, however, the metal is thoroughly and effectually
protected against the injurious action of such acids or salts. It is therefore
particularly applicable for the above named purposes, although the said Invention
may obviously be applied to the coating of metal plates designed for other purposes
in which special protection of the surface is desired.
In carrying the said Invention into practice we take greaseless tin or other plates
and coat or cover the same with a soluble silicate, such, for instance, as silicate of soda
or potash, to which we add an insoluble silicate, preferably silicate of lime or of
baryta, and to render the mixture sufficiently adherent it is desirable to add a small
proportion of serum of blood, gluten, waste starch liquor, or vegetable or animal
albumen. To facilitate the mixing or combining of these ingredients we prefer to
use silicate of lime which has been obtained by double decomposition from
polysulphide of calcium, and in which a small quantity of the latter remains. If
the silicate of lime is obtained from other sources than polysulphide of calcium we
add to the same a small quantity of a soluble sulphide, such, for instance, as
sulphide of sodium, the object in both cases being to prevent coagulation of the
albumen and to facilitate its combination with the other materials forming the
silicious compound. The proportions of the compound which we have found most
suitable for coating such tin or other plates are the following, namely:-
100 parts
Silicate of soda (60° Twaddell)
Silicate of lime containing 90 per cent. of moisture,
and with a slight excess of polysulphide of calcium
in a wet gelatinous state, as precipitated
-
100 parts

page_text: The plates when coated with this compound are dried in a stove or otherwise,
and in order to remove or fix any excess of alkali in the silicious coating we employ
a bath containing a dilute solution of fluo-silicic acid, or we may employ for this
purpose a dilute solution of other acid, such as fluoric, carbonic, or boracic acid. The
Bilicious compound is placed in a suitable bath or vessel and the plates to be coated
or covered are dipped therein; or, if desired, the compound may be applied with a
brush, roller, or other suitable device. After the application of the coating to the
plates, the drying of the same in stoves or otherwise, and their washing in a bath
containing a weak solution of suitable acid, such as fluo-silicic, carbonic, or boracic
acid, as above described, the said plates are ready to be made up into boxes or
cases in any suitable manner, and may be varnished or decorated as desired.
By means of our Invention we furnish the tinned or other metal plates treated
thereby with a surface which somewhat resembles glass, but without the aid of
fusion, and this coating material adheres so firmly to the metal that it cannot
readily be separated therefrom, and the metal so coated may be bent or worked in
any manner desired without danger of the silicious coating cracking or separating.
It will, therefore, be seen that we may provide boxes, cases, or vessels of any form
made of plates covered or lined with a material which interposes a protective film
between the surface of the metal and the fruit, vegetables, or other contents,
and we-thereby supply-a-want which has long been felt by those engaged in
the trade of preserving food.
-
Having thus fully described our said Invention, and the manner of performing
the same, we wish it understood that we claim,=-
First. The silicious compound-or-solution_consisting of the above specified
ingredients mixed or combined, substantially in the proportions and in the manner
described for the purpose set forth.
Second. The manufacture of metal plates with a coating or covering of silicious
material applied without the aid of fusion, as and for the purposes above set forth.
Third. A box. case, can, or other vessel formed of a tin, zinc, or other metal plate
THOMAS HENRY COBLEY. (L.S.)
3