AN IMPROVEMENT IN THE MANUFACTURE OF INFLATES AND TERNE OR LEADED PLATES.
Year: 1858

page_text: LETTERS PATENT to James Spence, of Liverpool, in the County of Lan-
cashire. Iron Merchant for the Invention of “AN IMPROVEMENT IN THE
MANUFACTURE OF INFLATES AND TERNE OR LEADED PLATES.
Sealed the 14th January 1859, in pursuance of an Order of the Lord Chan-
11
PROVISIONAL SPECIFICATION left by the said James Spence at the
Office of the Commissioners of Patents, with his Petition, on the 17th
July 1858.
I, JAMES SPENCE, of Liverpool, in the County of Lancashire, Iron Merchant,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT
IN THE MANUFACTURE OF TIN PLATES AND TERNE OR LEADED PLATES," to be as
follows:-
Tin plates and terne or leaded plates have hitherto invariably been made of
sheet iron dipped into or otherwise coated with tin, or an alloy of tin, and
afterwards cleaned and polished, or otherwise finished.
My Invention consists in manufacturing such plates from sheets of steel iron
or puddled steel, instead of from sheets of iron, such sheets being then coated
with tin or alloy, cleaned, polished, and finished in the ordinary manner, and I
roll the said sheets of steel iron or puddled steel, cither from a finished piece
or bar, as now practised in iron, or from a piece of the puddled bar of such
steel iron or steel in its first stage of manufacture.
The substitution of steel iron or puddled steel, in place of the iron now
and heretofore used in the manufacture of tin and terne or leaded plates, will
be found to effect a great improvement in such manufacture, as the plates so
made will be lighter, more durable, and can be made soft and pliable, or hard

page_text: SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said James Spence
in the Great Seal Patent Office on the 16th February 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
SPENCE, of Liverpool, in the County of Lancashire, Iron Merchant, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of July, in the year of our Lord
one thousand eight hundred and fifty-eight, in the twenty-second year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said James Spence, Her special licence that I, the said James Spence, my
executors, administrators, and assigns, or such others as I, the said James
Spence, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVEMENT IN THE
MANUFACTURE OF TIN PLATES AND TERNE OR LEADED PLATES," upon the condition
(amongst others) that I, the said James Spence, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and seals, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed,
and cause the same to be filed in the Great Seal Patent Office within seven
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Spence, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement in writing (that is to say):-
Tin plates and terne or leaded plates have hitherto been generally made of
sheet iron, dipped into or otherwise coated or combined with tin, or an alloy
of tin, and afterwards cleaned and polished, or otherwise finished. Now, I
have discovered that by the use of a certain description of steel, known as
"puddled steel," I can produce such tin and terne plates of superior quality
and with great economy of cost. This "puddled steel" is sometimes called

page_text: "steel iron," and sometimes "natural steel," and I define it to be steel made
immediately from pig or cast iron, by or with the process of puddling, and
without any process of cementation or conversion.
By the employment of this "puddled steel" or "steel iron," in place of
the charcoal iron now and heretofore employed in the manufacture of tin
plates, I have been able to effect a great improvement in the manufacture of
such plates, as when so made they are superior in appearance, more durable,
and capable of being made at will soft and pliable, or hard and rigid, and
also more or less elastic, to suit the several purposes for which they are to be
used. I manufacture these tin plates in the following manner:-
I make the steel puddled bar with great attention in the puddling of it, so
as to obtain a regular degree of uniform hardness or quality, and as I find it
difficult to obtain sufficient uniformity in this the crude puddled bar, I prefer
not to make the tin plates from this bar in its first stage of manufacture, when
plates of the best quality are required, but to roll them from a finished bar
made as follows:-I take the puddled bars and sort them into classes accord-
ing to the proportion of carbon they contain, cutting them as usual to the
lengths required for piling. For this pile I make top and bottom bars of the
hardest steel, and between them I pile the layers of puddled bar, the softest in
the middle of the pile. Thus, the outsides of the pile being highly carbonized
will endure the reduction of carbon which takes place in the subsequent heat-
ing, and a medium proportion of carbon will remain in the whole, which
I find to be the condition best suited to this purpose. The pile so formed I
heat and roll out into a finished bar as usual. Where the mode of working
in use is to make the finished bar from "stamps," the foregoing rule will
hold good as to the sorting and piling of such "stamps," so as to keep the
hardest or most highly carbonized at the top and bottom of the pile.
I proceed to roll the bar into sheets of the thickness required, and if the
medium quality aforesaid be obtained in the bar, it may be rolled in the same
manner as iron, using greater care, however, to avoid over heating it. When
the bar is too hard to roll in the usual manner, I treat it thus:-I construct a
smaller furnace or stove beside and in addition to the ordinary furnace; so
soon as the sheets become thin and require to be doubled, instead of continuing
to pass them many times through the rolls in succession, I pass them but
twice or thrice, and return them to the stove, constantly opening the pack to
prevent adhesion of the surfaces. In this way the sheets or black plate can be
rolled at a more moderate and uniform heat than is obtained in the ordinary
method, and a quality of steel can be used which produces highly superior tin
plates, but which is too hard to be rolled in the usual way.

page_text: 66
I
After the black plate is rolled, I remove the oxide by the usual method of
pickling," but allow a third more time than is required in the use of iron, as
the carbon of the steel renders the action of the acid on its surface slower.
anneal the plates as usual, but special care is required to prevent too rapid
cooling when the plates are drawn out of the annealing furnace. I proceed
to tin these plates in the usual manner, but with this difference, that I use ten
per cent. less tin than is required when charcoal iron is used, notwithstanding
which, the appearance of the finished plate will be found superior. Care
should be taken to allow time for the tin to enter into chemical combination
with the steel surfaces and not form a mere coating, which would break off in
working the plates to the detriment of their value. The plates are then
cleaned, polished, and finished in the usual manner.
When it is desired to render the plates elastic, I construct in the tinning
house a refrigerator, and maintain therein extreme cold by any of the ordinary
chemical means, avoiding such as would cause dampness. I pass the rack in
which the hot plates are collected rapidly into this refrigerator, and they will
thus be tempered and made elastic without injury to the surfaces of tin. If it
be desired to render the edges soft, whilst the rest of the plate is elastic, I dip
the edges into a shallow bath of molten tin, which will remove the temper and
soften them to the depth to which they are dipped.
Having thus described the nature and object of my said Invention for
"An Improvement in the Manufacture of Tin Plates and Terne or Leaded
Plates," together with the manner of carrying the same into practical effect, I
wish it to be distinctly understood that I do not claim the above process or
treatment, or any part thereof separately and apart from the combination of
tin or alloy of tin with puddled steel, nor do I claim such combination of tin
or alloy of tin with cast steel, or with the ordinary converted steel of com-
merce; but what I do claim as my Invention is the manufacture of tin and
terne or leaded plates by the combination of tin or alloy of tin with "puddled
steel," as above described.
In witness whereof, I, the said James Spence, have hereunto set my
hand and seal, this Ninth day of February, in the year of our Lord
One thousand eight hundred and fifty-nine.
JAMES SPENCE. (L.S.)