IMPROVEMENTS IN THE MANUFACTURE OF TIN PLATES
Year: 1870

page_text: LETTERS PATENT to William Evans and Thomas Price, both of the
Allcastle Tin Works, Llanelly, in the County of Carmarthen, for
the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF TIN PLATES
"
Sealed the 21st March 1871, and dated the 6th October 1870.
PROVISIONAL SPECIFICATION left by the said William Evans and
Thomas Price at the Office of the Commissioners of Patents, with
their Petition, on the 6th October 1870.
We, WILLIAM EVANS and THOMAS PRICE, both of the Allcastle Tin
Works, Llanelly, in the County of Carmarthen, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
TIN PLATES AND OTHER METAL-COATED PLATES," to be as follows:-
This Invention has for its object improvements in the manufacture
of tin plates and other metal-coated plates.
In the manufacture of tin and terne plates in order to finish the
plates we pass them into a rack contained in a bath of tin or terne

page_text: metal, and when the rack is full we force down into the rack bath
over the rack a cover or bell, so as to displace the metal from around
the rack and the plates which it contains. The plates then drain in
the hot enclosure which the cover or bell forms around them, and the
surplus metal runs from them; the rack and the cover or bell are then
raised together out of the metal bath, and the cover or bell is lifted
sufficiently to admit of the finished plates being removed from the rack.
Sometimes after the cover or bell has been put over the rack containing
the plates the rack is lowered for an instant and raised again, so that
the edges of the plates may touch the metal in the bath to melt off and
remove the list or thickened edges at the bottom of the plates, which
forms as the plates drain.
When finishing plates in this manner we work with two metal bars
so connected that the melted metal displaced by the cover or bell from
one bath flows into the other, one cover or bell being raised as the other
is lowered.
We also work in a similar manner when using other metals and
alloys as the coating metal.
The cover or bell is provided at the top with an air tap, so that the
metal in the bath may be admitted in the cover or bell when desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Evans and Thomas Price in the Great
Seal Patent Office on the 5th April 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
EVANS and THOMAS PRICE, both of the Allcastle Tin Works, Llanelly, in 2
the County of Carmarthen, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of October, in the year of our
Lord One thousand eight hundred and seventy, in the thirty-fourth year
of Her reign, did, for Herself, Her heirs and successors, give and grant 3
unto us, the said William Evans, and Thomas Price, Her special license
that we, the said William Evans and Thomas Price, our executors,
administrators, and assigns, or such others as we, the said William Evans
and Thomas Price, our executors, administrators, and assigns, should at

page_text: 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 In-
vention for "IMPROVEMENTS IN THE MANUFACTURE OF TIN PLATES AND OTHER
METAL-COATED PLATES," upon the condition (amongst others) that we, the
said William Evans and Thomas Price, our executors or administrators,
by an instrument in writing under our or their hands and scals, or
under the hand and seal of one of us or them, 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 six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said William Evans and Thomas
Price, do hereby declare the nature of the said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement thereof, that is to
say :-
:-
In order to finish metal-coated plates we place them in a rack which
is immersed in a bath of the coating metal, and we force down into the
bath over the rack a cover or bell, so as to displace the metal from
around the rack and the plates which it contains. The plates then
drain in the hot enclosure which the cover or bell forms around them;.
and the surplus metal runs from them. The rack and the cover or bell
are then raised together out of the metal bath.
When finishing plates in this manner we work with two metal baths
so connected that the melted metal displaced by the cover or bell from
one bath flows into the other, one cover or bell being raised as the other.
is lowered.
In order that our said Invention may be most fully understood and
readily carried into effect we will proceed to describe the manner in-
which we prefer to conduct the manufacture. The plates being.
thoroughly coated with the coating metal by means of the ordinary.
processes are placed in a rack so constructed as to hold a number of
plates, touching them only at their edges and. keeping them out of
contact the one with the other.
The annexed Drawings show this rack, together with other apparatus,
which we employ.

page_text: Figure 1 is a plan of the apparatus, and Figures 2 and 3 are sections
taken on the lines P, Q, and R, S, in Figure 1 respectively.
Figure 4 shews a plan of the rack separately. The rack is marked a,
it consists of a frame carrying the serrated bars a¹, between the teeth of
which the coated plates A rest. A hinged flap a³ with similar teeth is
turned over on to the plates when the rack is full, and this flap is of
such a weight as to prevent the plates floating in the coating metal if
they tend so to do. The rack thus filled with plates is put into one of
the compartments of the double pot 6 which contains the coating metal.
The pot is set in a furnace and the coating metal is thus kept melted
and the plates are completely immersed in it. One of the bells c is now
forced down so as to cover the rack and the plates within it; the level
of the coating metal is thus depressed, so that it leaves the plates, and
they drain in the hot enclosure which the bell dipping into the molten
metal forms. When the plates have drained for a sufficient time (whilst
another rack is being filled) the bell is lifted, the rack having first been
linked with it by means of the rods a³, which are jointed at their lower
ends to the rack, and at their upper ends drop over studs on the ends of
the bell. At the same time that one bell is lowered the other bell together
with a rack full of plates within it is raised, and the coating metal
flows from one compartment to the other of the pot through the opening
6. The bells are carried by rods c¹ which work in guides and receive
simultaneous but opposite movements from racks gearing into a spur
wheel between them. When the bell is out of the metal bath it is in
any convenient manner lifted off from the rack, which is removed with
the finished plates which it contains.
This method is very suitable for finishing terne metal plates; in this
case the plates are put into the rack as they are delivered from the
washman's pot.
Applied to tin plates the process is worked in a similar manner, and
well-finished plates are obtained, but the plates will not have the
appearance of the plates now in the market, and probably for this
reason the application to tin plates will be limited.
The heat of the coating metal in the pot should not be excessive, but
sufficient to cause it to flow freely from the surface of the plates.
At the top of each bell we provide an air tap, so that the metal can
be allowed to enter the bell when desired. Sometimes, just after removing

page_text: the bell and rack from the pot we lower them again a short distance,
the air tap on the bell being open so as to allow the molten metal to
return and touch the bottom edges of the plates to remove the excess of
metal which will hang to these edges.
Having thus described the nature of our said Invention, and the
manner of performing the same, we would have it understood that we
claim the process of finishing metal-coated plates by placing them in a
pot of coating metal, then displacing the metal from around the plates
by means of a bell and draining them in the hot enclosure so formed,
substantially as described.
In witness whereof, we, the said William Evans and Thomas Price,
have hereunto set our hands and seals, this First day of April,
in the year of our Lord One thousand eight hundred and seventy-
one
W. EVANS. (L.S.)
T. PRICE.
(L.S.)