IMPROVED PROCESSES FOR COATING METALS
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, wc, EDMUND
MOREWOOD, of Thornbridge, in the County of Derby, Merchant, and GEORGE
ROGERS; of Chelsea, in the County of Middlesex, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain bearing date at West-
minster, the Fourth day of May, in the sixth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto us, the said Edmund
Morewood and George Rogers, Her especial licence, full power, sole privi-
lege and authority, that we, the said Edmund Morewood and George Rogers,
our exors, admors, and assigns, or such others as we, the said Edmund More-
wood and George Rogers, our exors, admors,, or assigns, should at any time
agree with, and no others, from time to time and at all times during the term
of years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, and
also in all Her said Majesty's Colonies and Plantations abroad, our
Invention of "IMPROVED PROCESSES FOR COATING METALS;" in which said Letters
Patent is contained a proviso that we, the said Edmund Morewood and
George Rogers, or one of us, shall cause a particular description of the nature
of our said Invention, and in what manner the same is to be performed,
to be inrolled in Her said Majesty's High Court of Chancery within six
calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto bad,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, we, the said
Edmund Morewood and George Rogers, do hereby declare that the nature
of our said Invention, and the manner-in-which-the-same is to be performed,
are fully described and ascertained in and by the following statement thereof,
reference being had to the Drawings hereunto annexed, and to the figures and
letters marked thereon (that is to say) :-
Having perfectly cleaned and freed the surfaces of the iron or other metal
from oxide or dirt by any of the well-known modes (if the plates are not to be
used at once we put them into a tank containing water slightly acidulated
with muriatic or sulphuric acid) when we wish to give to the iron or other
metal to be coated a first coating of tin, we proceed in the following manner :-
We first prepare a soluble salt of tin, we prefer the chloride, which may be
made by pouring muriatic acid upon as much tin as can conveniently be held
in a suitable earthenware vessel. When the tin and the acid have remained
together about two days the solution is ready for use. Of this solution we put
two or three quarts to cach one hundred gallons of water, contained in a tank,
which we prefer being made of wood; we then sprinkle granulated or small
pieces of zinc over the bottom of the tank, and place upon them under the
surface of the solution the pieces of iron or other metal intended to be tinned,
throwing also upon and amongst them small pieces of zinc in such a manner that
there shall be contact in several places between the metal to be coated and the
pieces of zinc, taking care also that the iron or metal to be coated shall be as
much exposed to the solution as possible. If plates have to be tinned we
sprinkle small pieces of zinc over the bottom as before, and then on the top of
the zinc we lay a layer of plates, then another of zinc, and afterwards another
of plates, and so on until the tank is sufficiently full; the upper plate must be
entirely under the surface of the solution. When the charge has remained in
the tank from one to four hours, according to the strength and temperature of
the solution, a high temperature and a strong solution acting most rapidly, the
plates have usually received a sufficient coating of tin. If, however, in con-
sequence of neglect or mismanagement, they should not at the time be sufficient-
ly coated, they are to be taken out of the tank, and to be either at once trans-
ferred to another, where they are to be heated as before, or to be put into a tub
of clean water, and when another dose of the salt of tin has been added to the
water in the tank they are to be returned thereto, having zinc in small pieces
sprinkled amongst them as before. In case the process is thus repeated, that
side which before was upward should the second time be downwards. Pieces
of metal thus tinned, are then ready for the after process, to which they may
cither be taken directly from the tank, or be put into a wooden vessel contain

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 shews a plan of the pot with the machinery applied thereto;
Figure 2 shews a longitudinal section thereof; Figure 3 shows a transverse
-section thereof; Figure 4 shews two end views of the rollers, by which the
mode of giving motion thereto will readily be traced. A, A, are screws
working up and down, and thereby elevating or depressing the sockets in which
the axles of the upper and back rollers work; B is the socket in which the
lower roller works, and which is detached from the screw and fastened in the
bottom of the frame; C is the socket of the axle of the upper roller, attached
to the screw, and is raised or depressed by it, thereby making the opening
between the upper and lower roller wider or narrower, according to the thick-
ness of the sheets or other pieces of metal to be introduced; D, the socket of
the axle of the back roller, also attached to the screw, and by it raised and
depressed, so as to give the plates, which strike against it after leaving the
front rollers, more or less curve; E, E, cog wheels of the upper and lower
rollers, the motion of the lower roller being communicated to the upper one of
these cog wheels by the teeth of the lower one working in the teeth of the
upper one; G, a cog wheel on the driving axle; H, an intermediate cog
wheel, the object of which is to communicate the motion of the driving shaft
or axle to the lower cog wheel; I, wheel, which is attached to the lower
roller, and communicates to it the revolving motion which the wheel I receives
from the middle cog K. The driving axis K receives motion from a steam
engine or other power by a strap acting on the drum L, which drives the
axis M, which has affixed thereon the screw N, which takes into and drives
the screw wheel O, which is affixed to the driving shaft or axis K, the driving
axis K being in two parts, coupled by an universal joint to allow of variation
of the position of the cog wheel fixed thereon for giving motion to the rollers.
In place of using two rollers, as above explained, one roller or simply a-bar
may be used for causing the plates as they are introduced below the metal to
be insured descending to the same extent below the molten metal. Figure 5
shews a pot with apparatus suitable for that purpose; Figure 6 shews a longi-
tudinal section, and Figure 7 shews a transverse section thereof. P is a roller,
or it might be simply a bar, under which the sheets of metal are introduced;
and Q, Q, are guides for causing the plates of metal to rise upwards and pass
out of the pot, a workman taking hold of the plates with tongs as they rise
above the molten metal in the pot when being pushed forward by the workman
who puts them in. In coating with tin or an alloy of tin and lead, we some-

page_text: ing water slightly acidulated with sulphuric or muriatic acid, where they may
be kept for several days before being subjected to any other process, or they
may be dried over a coke fire without rusting. In coating surfaces of metal
with other metal in a molten state, we prefer doing it, if the surfaces be iron, by
introducing them previously coated, as above explained; or the surfaces of
metal may be only cleansed, and the coating is performed by passing plates or
other suitable pieces of metal between the rollers of a machine working in
contact with molten metal kept melted in a suitable vessel. The machine
used by us consists of a pair of rollers, together with a back roller, which are
placed in a frame, as shewn in the annexed Drawing. The pair of rollers are
made to revolve in opposite directions, so that when a plate is introduced
between the roller it is carried forward by their revolution, and falling upon
the back roller (which is situated as near as possible to the revolving pair) is
so far curved that its end finds its way out at the surface of the molten meta'.
Directly the end makes its appearance it should be taken hold of with a pair of
tongs, so that when the plate leaves the rollers its onward motion may be
kept up by the person whose duty it is to take them from the machine. If
the rollers are placed too near the side of the pot on which, the plates are
introduced, the plates will be so much curved that they cannot be taken out
with ease. This inconvenience may be overcome by diminishing the angle
formed by the plate with the horizontal plane when entering the opening
between the rollers, which may be done by elevating the side ends of the roller
frame, which are on the side of the pot at which the plates are immersed, to
such an angle or degree as may be found most convenient, or it may be done
by removing the rollers to a greater distance from that side of the pot on
which the plates are introduced. There is also to be a sufficient space
between the sides of the rollers at which the plates come out and the back
edge of the pot, or the plates will come out too much curved, or scratch
against the back of the pot. The rollers and other parts are to be so made
that there shall be ample room for every part to work easily, particularly in
the bearings of the axles of the rollers, and also in the cog wheels; and if
working in molten zinc the rollers should never be allowed to stand still in
the fluid metal. We therefore take them out whenever we cease working, and
whilst removing them continue to turn them so long as the metal adhering
remains tolerably fluid. We make the rollers of wrought iron, particularly if
used in molten zinc, as that metal has much less action upon wrought iron
than upon cast iron. When working, we keep the surface of the fluid metal
covered with a flux suitable to the molten metal used, as is well understood.

page_text: AND BE IT REMEMBERED, that on the Fourth day of November, in the
year of our Lord 1843, the aforesaid Edmund Morewood and George Rogers
came before our said Lady the Queen in Her Chancery, and acknowledged
the Specification aforesaid, and all and every thing therein contained and
specified, in form above written. And also the Specification aforesaid was
stamped according to the tenor of the Statute made for that purpose.
Enrolled the Fourth day of November, in the year of our Lord One
thousand eight hundred and forty-three.

page_text: times cover the surface of the molten metal with oil or fatty matter suitable for
being used when making tin plates, but combined with chloride of zinc and sal-
ammoniac, or one of those matters; and we prefer to use this combination of
matters when coating plates to the use of any other flux, and we use about
two parts oil or tallow by weight to two parts chloride of zinc and one part
salammoniac. We do not, however, claim the using of chloride of zinc and
salammoniac, separately or combined, for such process, unless they be one or
both combined with oil or fatty matter. Before passing plates of iron through
the fluid metal to be coated thereby, we have discovered that having the clean
plates dipped in clear water, and put into molten metal whilst still rather
damp, a considerable advantage is obtained. The water may be very slightly
acidulated with muriatic acid. Attention, however, is necessary to avoid
putting the plates into the molten metal too wet, and to avoid suffering them
to remain exposed to the air sufficiently long to cause oxydation or rust.
Having thus described the nature of our Invention, and the best means we
are acquainted with for performing the same, we would have it understood that
we do not confine ourselves to the precise details as herein given, provided
either part of our Invention be retained, but what we claim is,-
First. The mode of coating iron or other metal by causing it to be first
submitted to a precipitation of tin, and then submitting the same to molten
metal.
Secondly. We claim the mode of coating iron and other metal by causing
sheets or other suitable surfaces thereof to pass between rollers in contact
with metal kept molten in a suitable pot or vessel; and we also claim the
causing sheets of metal to be passed under a bar placed below the surface of
molten metal, as above described.
And, thirdly. We claim the application of oil or fatty matter in combination
with chloride of zinc and salammoniac, or either of them, as a flux on the
surface of molten metal when coating with molten metal, as tin or an alloy of
tin and lead.
'
In witness whereof, we, the said Edmund Morewood and George Rogers,
have hereunto set our hands and seals, this Fourth day of November,
in the year of our Lord One thousand eight hundred and forty-three.