IM- PROVEMENTS IN THE MANUFACTURE OF TIN AND TERNE PLATES,
Year: 1870

page_text: LETTERS PATENT to Edmund Morewood, of Rock Cottage, Britton
Ferry, in the County of Glamorgan, for the Invention of "IM-
PROVEMENTS IN THE MANUFACTURE OF TIN AND TERNE PLATES,'
PROVEMENTS IN THE MANUFACTURE OF TIN AND TERNE PLATES,
Sealed the 29th November 1870, and dated the 22nd June 1870.
PROVISIONAL SPECIFICATION left by the said Edmund Morewood
at the Office of the Commissioners of Patents, with his Petition,
on the 22nd June 1870.
I, EDMUND MOREWOOD, of Rock Cottage, Britton Ferry, in the
County of Glamorgan, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF Tin and Terne PLATES," to
be as follows:-
: -
Hitherto in the process of coating sheets or plates of iron with tin or
terne metal it has been customary to immerse several together in the
first tinning or coating pot; and in consequence those parts of the iron
plates which are fully exposed to the action of the melted coating metal
are longer in contact with it than is necessary or desirable, and other
parts which press more or less against the surfaces of other plates have

page_text: only just, or perhaps scarcely sufficient time to acquire their coating.
Therefore I find it advantageous to cause every part of the surface of
plates undergoing the process of coating to be in contact with the
coating metal whilst acquiring their coating. In order to accomplish
this, and to give every part of the surface of each plate as short a length
of time under the coating metal as is consistent with giving them a
sound coating, I arrange the framing of a round pot so that each plate
shall fall into its separate and allotted space or division, which travels so
that each plate is carried round to the exit side of the bath, and contact
with any other plate or surface is as much as possible avoided. Further,
by this means any flux or foreign matter has the opportunity of rising
from the surface of the plate to the top of the melted metal. When oil,
grease, or fatty matter is used as a flux on the surface of melted coating
metal, the introduction of damp or wet sheets or plates of iron through
it into the melted coating metal causes it to boil up, and the oil, grease,
or fatty matter becomes for some time afterwards open and spongy,
in this state it does not sufficiently or suitably take hold of and act upon
the surface of the iron plate, so as to fit it for readily and properly
taking or receiving the coating when the plate or sheet of iron becomes
immersed in the melted coating metal.
and
And one of my improvements consists in so arranging the apparatus,
machinery, or pots for coating iron with other melted metal that I am
enabled to pass damp or wet plates or sheets to be coated through a flux
of oil, grease, or fatty matter into the melted coating metal, whilst still
´ maintaining a layer of non-porous, greasy, or oily or fatty matter on the
surface of the melted metal at the point at which the plates enter into
the coating metal. This I do by keeping up a circulation of the grease
by drawing off continually the grease which has become frothy or
'porous, and introducing more solid non-porous grease. The frothy or
porous grease 'is 'allowed to stand for a short time, and is then fit to
return to the surface of the coating metal. I immerse the plates so that
they may lay or travel singly or a few together under the coating metal,
and be removed in rotation out of the melted coating metal, in order
that each plate may be immersed a shorter and more equal length of
time in the melted coating metal than in the old way.
And I so arrange the said machinery, apparatus, or pots, as to enable
the oil, grease, or fatty matter to recover sufficiently from the open
spongy state into which it is thrown by the wet plates or sheets of iron

page_text: being passed into it, so that the metal pot may be fed with a regular and
steady succession of damp plates or sheets, and the oil or fatty matter
on its surface kept in suitable condition; or the damp plates may receive
their coating of grease in a first separate grease pot made in partitions,.
so that the plates may be introduced and removed in succession, and
kept as far as possible from contact with other plates or surfaces whilst
under the grease.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edmund Morewood in the Great Seal Patent
Office on the 22nd December 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDMUND
MOREWOOD, of Rock Cottage, Britton Ferry, in the County of Glamorgan,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date the Twenty-second day of Junc, 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 suc-
cessors, give and grant unto me, the said Edmund Morewood, Her special
licence that I, the said Edmund Morewood, my executors, administrators,
and assigns, or such others as I, the said Edmund Morewood, my exe-
cutors, 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 "IMPROVEMENTS IN
THE MANUFACTURE OF TIN AND TERNE PLATES," upon the condition (amongst
others) that I, the said Edmund Morewood, 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 per-
formed, 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 I, the said Edmund Morewood, do hereby
declare the nature of the said Invention, and in what manner the

page_text: same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, that is to say :-
Hitherto in the process of coating sheets or plates of iron with tin or
terne metal it has been customary to immerse several together in the
first tinning or coating pot; and in consequence those parts of the iron
plates which are fully exposed to the action of the melted coating metal
are longer in contact with it than is necessary or desirable, and other
parts which press more or less against the surfaces of other plates have
only just or perhaps scarcely sufficient time to acquire their coating.
Therefore I find it advantageous to cause every part of the surface of
plates undergoing the process of coating to be in contact with the
coating metal whilst acquiring their coating. In order to accomplish
this, and to give every part of the surface of each plate as short a length
of time under the coating metal as is consistent with giving them a
sound coating, I arrange the framing in a round pot so that each plate
shall fall into its separate and allotted space or division, which travels so
that each plate is carried round to the exit side of the bath, and contact
with any other plate or surface is as much as possible avoided.
Further, by this means any flux or foreign matter has the opportunity of
rising from the surface of the plate to the top of the melted metal.
When oil, grease, or fatty matter is used as a flux on the surface of
melted coating metal the introduction of damp or wet sheets or plates of
iron through it into the melted coating metal causes it to boil up, and
the oil, grease, or fatty matter becomes for some time afterwards open
and spongy, and in this state it does not sufficiently or suitably take
hold of and act upon the surface of the iron plate, so as to fit it for
readily and properly taking or receiving the coating when the plate or
sheet of iron becomes immersed in the melted coating metal.
And one of my improvements consists in so arranging the apparatus,
machinery, or pots for coating iron with other melted metal that I am
enabled to pass damp or wet plates or sheets to be coated through a flux.
of oil, grease, or fatty matter into the melted coating metal, whilst still
maintaining sufficiently non-porous, greasy, or oily or fatty matter on
the surface of the melted metal at the point at which the plates enter
into the coating metal. This I do by keeping up a circulation of
the grease by drawing off continually the grease which has become
frothy or porous, and introducing more solid non-porous grease. The
frothy or porous grease is allowed to stand for a short time, and is then

page_text: fit to return to the surface of the coating metal. I immerse the plates
so that they may lay or travel singly or a few together under the coating
metal, and be removed in rotation out of the melted coating metal, in
order that each plate may be immersed a shorter and more equal length
of time in the melted coating metal than in the old way.
And I so arrange the said machinery, apparatus, or pots as to enable
the oil, grease, or fatty matter to recover sufficiently from the open
spongy state into which it is thrown by the wet plates or sheets of iron
being passed into it, so that the metal pot may be fed with a regular and
steady succession of damp plates or sheets, and the oil or fatty matter on
its surface kept in suitable condition; or the damp plates may receive
their coating of grease in a first separate grease pot made in partitions,
so that the plates may be introduced and removed in succession and
kept as far as possible from contact with other plates or surfaces whilst
under the grease.
In order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings
Figure 1 is a plan, and Figure 2 is a transverse section of a first
tinning or coating metal pot with its apparatus arranged according to my
Invention.
a is an annular pot, it is set in brickwork and heated by a furnace;
b is a vertical axis with a worm wheel upon it driven by a worm on an
axis c; d, d, are arms on the axis b, supporting a circular frame
consisting of two sheet iron cylinders e, e, to which are fixed a number
of inclined partitions f,f; one of these partitions is shewn separately at
Figures 3; I prefer to make them in cast iron; the hoops 9, g, are fixed
to the bottom edges of the partitions for the plate to rest upon. In this
way an open frame is constructed passing all round the pot, and divided
over its entire circumference into cells each suitable to receive a single
plate. More than one plate may be put in a cell, but it is not desirable
to do so, for by arranging the apparatus as shewn and described
accommodation is provided for a sufficient number of plates in the pot at
one time, whilst the plates are kept entirely out of contact the one with
the other, and are supported only at a few points by the ridges of the
partitions. g*, g*, are fixed bars which are used when coating with

page_text: terne metal to prevent the plates floating to the surface of the metal.
The axis 6 is driven at a speed of twelve revolutions in the hour, more
or less, depending on the surface and gauge of the iron plates in process
of coating; a thin plate as a rule requiring less time in the coating metal
than a thicker one. Cone pulleys may advantageously be provided for
regulating the speed, so that the plates may be kept in the pot a suitable
time for obtaining a complete coating. The time is best adjusted from
observation of the process as it varies with the heat of the metal and the
surface and thickness of the plate in process of coating. I work with
the melted coating metal in this pot at about or slightly over the usual
heat of the ordinary washman's pot. The sheets wet as they come from
the pickling (or it may be in some cases from a preparatory process of
deposition of metal upon them from a solution, as is well understood,)
are introduced into the metal through a flux. Chloride of zinc may be
used as the flux if care is taken to prevent any trace of it remaining on
the surface of the plate after it is removed from the coating metal.. At
the taking out point the plates are removed with tongs, and the workman
takes care to keep the surface of the metal free from the chloride of zinc
flux at this point. This care however is comparatively unnecessary when
grease, or oily or fatty matter is used as the flux.
When I use grease, or oily or fatty matter, as a flux on the surfaco
of the coating metal it is contained in a flux box fixed to the first coating
or tinning pot, which may be cither such as above described or it may
be conveniently a circular pot such as described in my Patent of the
Ninth March, One thousand eight hundred and sixty-eight, No. 814, or it
may be otherwise constructed. This flux box is of a length to allow the
plates to pass down readily through it, and I make it about twelve
inches wide, if I am coating plates twenty by fourteen inches in size.
The flux box is open at the bottom and dips down into the molten
metal in the pot; its depth is such as to maintain about six inches of
grease over the coating metal. There are guides within the flux box
to direct the plates as they are passed down through the grease into the
cells of the rotating frame beneath, if cells are used in the first tinning
or coating pot as already described, and index points are also in this case
provided on this frame to indicate to the workmen the arrival of each
cell into position to receive a plate. Around the top of the flux box is
a horizontal ledge some inches wide to give room for the froth forming
on the grease to flow freely away. There is a rim around the ledge

page_text: except at one end or side of the flux box where a lip or outlet pipe is
formed for the froth to flow or pass away and escape into a cistern.
This cistern I make about fourteen inches in depth, and about four
times the capacity of the flux box with its froth chamber. It contains
a pump which is driven continuously by power; this pump draws the
grease from the lower part of the cistern and returns it to the flux box
by a perforated pipe passing horizontally along it just over the surface
of the grease which it contains. The quantity of grease raised from the
cistern by the pump is capable of regulation so that it may keep up such
a supply of suitable and sufficiently solid grease in the flux box, as is
desirable, whilst the outflow lip or channel of the flux box carries away
the froth as it is formed into the cistern, thus constantly recovering
and righting the grease in the flux box without unduly cooling it.
Occasionally I add a little fresh grease to that in the cistern to make up
for loss and waste. In place of the froth being mercly allowed to flow away
through a lip or outlet pipe, as above described, it may be drawn or carried
away as it is formed by a revolving endless band with blades or buckets
upon it, or by a revolving screw above the lip, or other suitable arrange-
ments may be adopted for constantly removing the froth and discharging
it into a convenient receiver, and the froth as it becomes sufficiently
solid or righted may be continuously pumped or passed back into the
flux box, and a supply of suitable and sufficiently solid grease in the
flux box thus kept up. When the grease is used in this manner so that
the passage of the sheets to be coated through sufficiently solid or rather
homogenous grease into the molten metal is ensured, the grease will be
found to act upon the surface of the plates passing through it so as to
cause the coating metal to take very freely to the plates. When terne
metal is employed the coating is not quite so readily effected as with tin,
and the coating is facilitated, especially in this case, by passing the plates
into a grease pot before introducing them into the first metal pot. I
construct the grease pot in the manner shewn in the Drawings. The
plates are introduced into the grease through a box corresponding with
the flux box already described, and similarly provided with an overflow
or outlet. The overflow or outlet to carry off the froth is in this case on
a level with or it may be slightly below the grease in the pot, so that
the froth may freely pass out, and the froth is received into a cistern to
recover itself, as already described. The grease is taken continuously
from the bottom of the cistern and returned to the pot by a pump.
The heat of the grease in this pot is that of the grease in the first grease

page_text: pot in the ordinary mode of tinning. The plates as they are taken out
of this pot are passed into the flux box of the first metal pot, they will
carry over with them some of the grease, and to compensate for this the
pump in the receiving cistern is caused to return some or all of the
grease which flows out of this flux box into the preparatory grease pot.
The plates as they are taken out of the first metal pot may be finished
by brushing and dipping them and passing them through rollers
revolving in grease, or by other well-known process.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that what I claim
as my improvements in the manufacture of tin and terne plates is,-
The arrangement of the coating apparatus in such manner that the froth
resulting from the introduction of the moist plates into the grease, or
fatty or oily matter, which is used as a flux, and through which the
plates to be coated are passed into the molten coating metal, may pass
away, or be drawn off, as it is formed, and its place be supplied by
other grease free from froth, and so keep up a circulation, substantially
as described.
I also claim the arrangement of preparatory grease pots which receive
plates in a moist state in a similar manner.
I also claim the arrangement of first metal pots, and preparatory
grease pots, in manner substantially as shewn by the Drawings.
In witness whereof, I, the said Edmund Morewood, have hereunto
set my hand and seal, this Nineteenth day of December, in the
year of our Lord One thousand eight hundred and seventy.