IMPROVEMENTS COATING METALS
Year: 1869

page_text: LETTERS PATENT to Edmund Morewood, of Rock Cottage, Briton
Ferry, Glamorganshire, for the Invention of "IMPROVEMENTS
COATING METALS."
IN
Sealed the 20th July 1869, and dated the 29th March 1869.
PROVISIONAL SPECIFICATION left by the said Edmund Morewood at
the Office of the Commissioners of Patents, with his Petition, ou
the 29th March 1869.
I, EDMUND MOREWOOD, of Rock Cottage, Briton Ferry, Gla-
morganshire, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN COATING METALS," to be as follows:-
This Invention has for its object improvements in coating metals with
other metals..
When coating sheets of iron or other metal with tin or terne metal or
other readily fusible metal I remove the plates from a bath of the coating
metal through a pair of rollers placed in contact with tlie molten coating
metal, but with their nip or line of contact above it. On the outer sides
of the rollers and resting on the molten metal grease or flux is placed so
[Price 8d.]

page_text: as to rise by preference nearly to the top of the rollers, but the grease or
flux is not allowed to pass 'between the rollers, the rollers themselves
stopping it back, and there are suitable guards or partitions at their ends.
The grease or flux serves to keep the rollers hot and their surfaces in
proper working order, and it prevents the formation of a scum on the
surface of the coating metal, which if allowed to form would adhere to
the rollers and spoil the plates passed between them. Little or no grease
or flux is allowed to pass between the rollers, so that the plates rise up
between them in passing out of the molten coating metal in. a finished
state, and they do not require to be rubbed with bran as they do when
they are raised out of grease, as is the usual practice.
In this way a
saving both of grease and of the bran and also in labor is effected. The
rollers may be made hollow and filled with sand or other bad conductor
of heat. Covers may be employed to prevent loss of heat from the
exposed surface of the grease or flux: Sometimes in place of with-
drawing the plates from the molten coating metal through rollers, I do
so between two guard plates placed as closely together as is consistent
with the free passage of the plates between them. At the back of the
guard plates .the surface of the metal is covered with sand; it is banked
up behind the guides, which are thus kept heated.. Sometimes I make
the guards hollow. I fill them with sand the more effectually to retain
the heat. In this way I am able to remove the plates from the molten
coating metal in a finished state, using little or no grease or flux, so that
the plates require no subsequent rubbing. The guards so narrow the
surface of the coating metal exposed at the point of exit that the
amount of scum forming upon it is inappreciable, and they also confine
the heat in the plate as it rises out of the molten metal so as to cause
the excess of coating metal to draw off from it.
Similar arrangements may advantageously be employed for the intro-
duction of the plates into the coating metal.

page_text: WHEREAS Her most Excellent, Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of March, in the year of our
Lord One, thousand eight hundred and sixty-nine, in the thirty-second
year of Her reign, did, for. Herself, Her heirs and successors, 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 executors, adminis
trators, 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 COATING METALS," upon
the condition (amongst others) that I, the said Edmund Morewood, my,
executors or administrators, 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 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 same
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say:
This Invention has for its object improvements in coating metals with
other metals.
When coating sheets of iron or other metal with tin or terne metal or
other readily fusible metal I remove the plates from a bath of the coating
metal through a pair of rollers placed in contact with the molten coating
metal, but with their nip or line of contact above it. On the outer
sides of the rollers and resting on the molten metal grease or flux is placed
so as to rise by preference nearly to the top of the rollers, but the grease
or flux is not allowed to pass between the rollers, the rollers themselves
stopping it back, and there are suitable guards or partitions at their ends.
The grease or flux serves to keep the rollers hot and their surfaces in
proper working order, and it prevents the formation of a scum on the
surface of the coating metal, which if allowed to form would adhere to
the rollers, and spoil the plates passed between them.
Little or no
grease or flux is allowed to pass between the rollers so that the plates

page_text: rise up between them in passing out of the molten coating metal in a
finished state, and they do not require to be rubbed with bran as they
do when they are raised out of grease; as is the usual practice.
In this
way a saving both of grease and of the bran and also in labor is
effected.
In carrying out this part of my Invention I prefer to arrange the
apparatus in the manner illustrated by the annexed Drawing.
Figure 1 is an end, view of the pair of rollers; they are of wrought
iron tinned or coated with the metal of the bath in which they work,
and they are mounted in bearings with springs, and are driven at a
Convenient speed for withdrawing the plates, all which is well under-
stood.
The melted metal in the bath should be about three-quarters of
an inch beneath the nip of the rollers., Near their ends the rollers a, a,
have deep grooves a¹ turned in them, as is seen at Figure 2, which is a
side view. of one of the rollers, and in these grooves the iron guard or
partition b is loosely. supported. The grease or flux on the outer side of
the rollers may be about three-quarters of an inch in depth. The guard
or partition 6 if not perfectly grease or flux tight when commencing to
work soon becomes so by the thickening of the flux around the edges.
The rollers equalize, reduce,, or finish the coating on the sheets or plates,
and assist such sheets in making their exit from the coating metal.
The grease or other flux on the exterior side of the aforesaid rollers
enables me to keep the surface of such rollers clean, hot, and in suitable
order for their work. By this means I am able to cause the plate or
sheet to rise up from between the before-mentioned rollers coated, but
practically free from grease or flux, whilst such rollers in revolving are
constantly presenting their surfaces to be washed, cleaned, and warmed
by the before-mentioned grease or flux on their exterior side, and are
kept in a fit state to finish, reduce, and improve the coating of the
sheets or plates passing up between them. I find it well to make the
rollers hollow, and fill the interior with sand or other material which is
a slow conductor of heat, as such rollers after standing and when they
are again started more, quickly get into a proper working state; and
over the rollers I find it desirable to have a lid or covering of such
material or so arranged as to be calculated to retain the heat about
the rollers, and to check the evaporation of the grease. I make the lid
or covering which I use over the finishing pair of rollers of thin sheet
iron filled with sand or other material which is a slow conductor of heat.

page_text: The lid may be so arranged as to shut down over the rollers when they
are stopped at any time, and during work the lid may be supported.in
an inclined position so as to lessen the radiation from the bath without
interfering with the working.
When coating with tin I consider tallow or palm oil with. 10 to 15
per cent. of rosin to be the best flux on the exterior side of the said
rollers for the purpose of keeping them clean, warm, and in good order,
as described. The grease acts most efficiently when it has been in use
for some time. When coating with terne metal I use clean and
fresh rosin by itself for keeping the said rollers in good working order.
In coating with zinc I use around the rollers what is called old or
spent sal ammoniac flux from the entrance side of the bath mixed with
about 25 per cent. by weight of fresh sal ammoniac, or such quantity as
is required to make, the old flux sufficiently fluid, for good working.
Sometimes in place of withdrawing the plates from the molten coating
metal through rollers I do so between two. guard plates placed as closely
together as is consistent with the free passage of the plates between
them. At the back of the guard plates the surface of the metal is
covered with sand; it is banked up behind the guides, which are thus
kept heated. Sometimes I make the guards hollow.
sand the more effectually to retain the heat.
In this
remove the plates from the molten coating metal in
using little or no grease or flux, so that the plates require no subsequent
rubbing. The guards so narrow the surface of the coating metal exposed.
at the point of exit that the amount of scum forming upon it is
inappreciable, and they also confine the heat in the plate as it rises out
of the molten metal, so as to cause the excess of coating metal to draw
off from it.
!
.
I fill them with
way. I am able to
a finished state,
In carrying out this part of my Invention I prefer to use the apparatus
shown at Figure 3. a, a, is the surface line of the melted metal in the
bath; b, b, are two sheet-iron guards or vessels 'filled with sand or
other slow conductor of heat. These vessels dip down into the metal
for some inches, and they stand above the surface of the metal to a
height of several inches as far as is consistent with the convenient
manipulation of the plates. The faces of the vessels b which are opposed
to each other are convex, and the distance, between them is least at or
about the surface of the melted metal, where it is about three-quarters of

page_text: an inch. The vessels 6 are backed. up with loose sand at c, c. This
arrangement is especially applicable for the purpose of reducing or
equalizing the coating metal on sheets which are afterwards to receive
a further coating of melted metal, the object. being to cause the plate to
pass through a chamber or channel of hot air as it emerges from the
coating metal. In order economically to lessen the radiation of the heat
of these forms of iron I place sand or some material which is a slow con-
ductor of heat on the exterior side of the said forms of iron, and thus I am
enabled to bring out the plates at such a temperature that the coating
metal runs down and from the plate more freely and is reduced to a
greater extent that it would be if such plates in making their exit
from the melted metal were brought immediately into the unconfined
air of the workshop. When coating with more than one bath of melted
coating metal, and when the first bath contains metal of a different kind
or a different alloy or mixture of metals from the after bath, it is
important to bring out only so much coating on the surface of the plate
to the after bath as will not materially add to, or alter the character of
the metal or alloy or mixture of metals in the after or finishing bath.
This would often be the case unless special means such as I have
described were taken to limit the quantity of coating on the surface
before the plate in process of coating is brought to the after or last coat-
ing bath of melted metal. Thus it is sometimes desirable that the coating
metal in the first bath should contain 95 per cent. of lead to 5 per cent. of
tin in order to give a foundation coating almost entirely of lead, and that
the plate should be finished through a bath containing a mixture of 50 per
cent. of lead and 50 per cent. of tin so as to give a bright and useful wash
over the lead foundation. But unless special means are resorted to the plate
brings such a heavy coating of lead on its surface from the first coating
bath that much lead is left behind by each plate as it passes through the
after bath, and the proportions of the alloy therein of 50 per cent. of
tin and 50 per cent. of lead are rapidly changed. The guards or forms
of iron b, b; are eimmersed, as shown in the Drawing, to such a depth in
the coating metal that any portion of the inner surfaces between which
the coating sheet makes its exit and against which it is liable to come in
contact shall be of such temperature that the coating metal is not liable
to chill or set upon it.
I also make these forms descend to such a
depth in the coating metal that any sand on the surface of the coating
metal is prevented from being drawn down or so displaced as to be brought
into contact with the plate while in process of coating or of making its exit

page_text: from the bath of coating metal. Similar arrangements are also according
to my Invention employed for the introduction of the plates into the
coating metal. As the sheets or plates enter the melted métal I cause
them to pass through flux contained in a deep flux box. Such flux
boxes have heretofore been made so as to expose a large surface of the
flux to contact with the melted metal on which it rests. This has been
done in order to maintain the flux at a sufficiently high heat, for when
the sheets of iron forming the flux box are left exposed on the outer
sides as has heretofore been the practise the heat is rapidly radiated off.
In coating with a flux which décomposes or evaporates rapidly it is
especially desirable in order to avoid waste to have a limited breadth of
the coating metal covered. When the plates or sheets which are to be
passed. through such flux into the; melted coating metal are wet or
comparatively cold they also tend to chill or numb the flux or coating
metal as they enter. It is usual to make the surfaces of flux and coating
metal within the flux box of considérable width or breadth in order to
have such a body of hot melted metal or flux that the combined effect of
the radiation from the flux box and the entry of the cold sheets may
not chill, the flux and metal sufficiently to hinder or interfere materially
with the process. A great heat also is. usually applied under, or against
the entrance side of the first pot in order to keep the metal and. flux
sufficiently hot for steady and regular working. This is injurious in
various ways.. To obviate these inconveniences "I employ an improved
flux box: The object of my improved flux box is to lessen the radiation
of heat from its outer surfaces and to enable me by retaining it to have
the space within the flux box inuch more narrow, and thus to avoid.
waste and loss of flux and metal by evaporation or otherwise. Therefore
I make the sides of my flux box. double, and between the pieces which
form the sides of my flux box I place sand or other material which is a
slow conductor of heat. Such flux box may also be used on the
entrance side of the second or after bath of coating metal. I interpose
sand between the air and every part of the ironwork of such flux
box except the two face plates between which the plates pass into the
coating.metal.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that what I
claim as my improvements in coating metals with other metals is,-
First. The withdrawing the sheets of metal which are in process of

page_text: coating from a bath of melted coating metal through a pair of rollers placed
so as to touch the molten coating metal but with their nip or line of
contact above it, such. rollers on their outer, sides being in contact with
grease or flux, which by suitable guards or partitions is prevented from
flowing between the rollers.
Second. The withdrawing the sheets of metal which are in process of
coating from a bath of melted coating metal between metal guard plates
which are heated by being partly immersed in the melted metal, and
which are protected from loss of heat by radiation by means of a backing
of sand or other slow conductor of heat, as herein described, so that
such guard plates serve the double purpose of allowing but a very small
surface of the melted coating metal to be exposed where the sheets
emerge, and of forming a hot-air chamber in which the sheets may,
drain as they rise out of the melted coating metal.
Third. The arranging the flux boxes through which the sheets of
metal which are in process of coating are introduced into the bath of
melted coating metal, as herein described, so that the radiation of heat
from their exterior surfaces may be to a great extent prevented by means
of a backing of sand or other slow conductor of heat.
set
my.
In witness whereof, I, the said Edmund Morewood, have hereunto
hand and seal, this Twenty-fourth day of September,
in the year of our Lord One thousand eight hundred and sixty-
nine.