IMPROVEMENTS IN COATING TIN AND TERNE PLATES AND IN MACHINERY OR APPARATUS TO BE - EMPLOYED THEREIN
Year: 1882

page_text: LETTERS PATENT to Thomas Henry Johns of The Grove Hackney in the
County of Middlesex for an Invention of "IMPROVEMENTS IN COATING TIN
AND TERNE PLATES AND IN MACHINERY OR APPARATUS TO BE - EMPLOYED
THEREIN
"
PROVISIONAL SPECIFICATION left by the said Thomas Henry Johns at the
Office of the Commissioners of Patents on the 11th October 1882.
THOMAS HENRY JOHNS of The Grove Hackney in the County of Middlesex
"IMPROVEMENTS IN COATING TIN AND TERNE PLATES AND IN MACHINERY OR
APPARATUS TO BE EMPLOYED THEREIN."
The object of this invention is to coat and finish Tin and Terne plates with as
little handling as possible and at the same time to produce a superior finished
plate with less metal thereon than can be produced by the present process.
To accomplish this I prefer the sheets of metal in a peculiarly formed chamber
which contains a solution of metals so that while in preparation the said sheets
are slightly coated with zinc or tin by electric deposition. The bath for treating
the plates by electric deposition may consist of an annular trough with a cylinder
in its centre containing a piston the rod of which piston projects upwards and
carries bars from which cages for containing the plates are suspended. These
suspenders and cages are made of a good conducting metal. On pressure being
withdrawn from beneath the piston it descends in its cylinder and the plates
contained in the cages are lowered into the bath and the current created for
effecting the deposition of the metal.
In coating the plates by electric deposition they are only coated with metal
which leaves a dull unfinished surface and are not in a marketable condition.
According to my Invention they are after deposition either passed through grease
heated so as to remelt the coating and give a finished appearance to the plate or
they are coated with a further coating of metal preferably in a bath constructed as
hereinafter described. Thus a cheaper metal may be deposited for filling the pores
of the iron and a more expensive metal only be used for the finished surface. To
give a second coating of metal I pass them through a bath so arranged as to work.
D

page_text: double or single. This bath contains molten metal and grease. In this bath there
are guides, arranged opposite each other and consisting of tubes or slotted side
pieces with bars or ribs inside them by which the plates are guided by bearing
alternately on opposite sides of the bars or ribs the first plate bearing against the
front side of one bar and the back side of the opposite bar the next plate bearing
on the same sides as did the first and so on alternately. The guide bars
may be double so that two sets of plates are passed into the bath at one
time. In this case the bars terminate before they reach the exit end of the
bath so as to enable certain line of plates to be pushed forward to be gripped
by the follers of the finishing mechanism. The quantity of metal on the sheets
or plates may be governed by a regulator consisting of perforated surfaces
forming the sides of boxes between which surfaces the plates pass any surplus
metal passing through the perforations at the upper part into the boxes and
therefrom through the lower perforations again on to the plate before it enters
this regulator. The surfaces are adjustable to or from each other to suit
different thicknesses of plates and different quantities of metal to be coated thereon.
Large and small sheets may be coated by this process equally well and larger
sheets than hitherto have been made can be coated with ease according to my
Invention. I prefer to give the sheets or black plates their first coating of zinc or
lead or, terne by means of the electric battery by which process the iron is
thoroughly protected and they then receive a second coating of Tin or Terne metal
in the finishing bath thus the sheets are protected by the first coating of Zine or
lead or terne and finislied by the second coating of Tin or terne thereby effecting
a great saving in Tin or terne while a better and cheaper plate is produced.
After the sheets are coated with the zinc lead or terne and before they are
coated with the Tin or Terne they may be sent through a chamber containing
grease below the melting point of Tin Zine or lead which prepares them for taking
the tin to accomplish this I may have a finishing apparatus at the delivering end
of the aforesaid grease and metal bath which works in contact with molten Tin and
grease.
In coating sheets for decorating or japanning purposes I finish their surfaces
between a pair of rollers which work in a grease bath and which run at high speed
the first part of this process is specially suitable for all tinned Iron or steel as it is
well known in the trade that by putting such Iron or steel into a hot chainber or
in contact with fire without their first being protected a mpid oxidation takes place
and that much metal is wasted.
To carry the above into practice I first pickle the sheet in the usual manner with.
sulphuric acid thoroughly swilled in a water bath they are then immersed in the
chamber which contains the sulphate of zine or other metal after which they are
immersed in a Bath of molten metal covered with fatty matter or flux they can
thereafter be immersed in a second bath containing grease sufficiently hot to melt
off the surplus metal. In finishing Tin plates without using grense but using
chemical fluxes I find that the plates before they reach the consumers and especially
before they arrive at Foreign markets and within a short time after being coated
are covered with specks or rust which renders them almost useless and that to
make a good durable and well finished Tin plate it is necessary that they should
be passed through a suitable mixture of grense before they enter the last metal,
bath and that they should' also come out of the finishing end of the machine
through. Rollers and rubbers with chilled faces and coated with metal which work
in contact with grense.
A
All plates or sheets to be coated must first be cleared from oxidation or scales
which are more or less on the surface of Iron or steel sheets or plates. When they
are taken out of the annealing boxes the, sheets are first pickled in the ordinary
way in white pickling baths and swilling baths then I pass them into the electro-
deposition bat: The cages before described are charged with plates and they are.
lowered into the Vat or bath of Sulphate of Zinc which, is connected by a wire.
with the Cathode battery of a dynanio-electric machine. Sheets of Zinc are hung

page_text: in the same solution and connected with the anode of the battery or said dynamo
electric machine or electric battery which is now set to work and immediately the.
Iron sheets receive a coating of Zine:-this coating may be given of any desired
thickness by allowing the sheets to remain for a longer or shorter time in the bath
under the action of the current from the battery or machine. When the iron is
sufficiently coated the sheets are lifted out of the bath and placed in a vat through
which water passes and are taken therefrom as required or remelt the coating or
to receive the second coating in the finishing machine after being prepared therefor
as hereinbefore explained.
It is. well known in the trade that plates coated in a solution bath under
Electric influence will not take a second coating either iu Zinc or Tin nor can they.
be finished by giving them an additional dip or dips and I overcome the difficulty
in the following manner. I thoroughly grease or soak these sheets in a properly
seasoned grease of good quality such as palm oil tallow and resin or other such
flux and thereafter I pass the sheets singly through a bath which contains molten
Tin heated to such a temperature as will keep the grease at both ends of the bath
in a coating and finishing condition but under the temperature of the metal used
for the first coating.
The apparatus.in which the second coating is obtained is preferably constructed
double consisting of two baths formed of wrought iron or steel fixed on either side
of a cast iron piece ontaining the receiving rollers and planishers or other finishing
apparatus and a central grease bath. The passages through which the plates are
fed to the baths are preferably extended to feeding tables on which the plates are
held and these passages may be provided with a passage for the escape of fumes
clear of the workman down which passages plates may be fed into the bath if
desired.. The whole of the baths and pots are enclosed in a casting provided with
means for heating and openings for rapidly cooling when required.
!. The grease bath in which the electro deposition is remelted may be constructed.
in duplicate and be open at the bottoms which dip into a trough of metal kept
liquid by fires inside an enveloping casing provided with openings for rapid-cooling
when required.
To receive the coated plates as they issue from the baths there may be provided
surface rubbers the width of the plates drawn inwards by springs and capable of
being relieved by hand.
The passages which lead to the double baths are preferably formed with a
shallow receptacle for grease the part of the passages between these receptacles and
the bath being kept hot.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Henry Johns in the Great Seal Patent Office on the
11th April 1883.
THOMAS HENRY JOHNS of The Grove Hackney in the County of Middlesex
"IMPROVEMENTS IN COATING TIN AND TERNE PLATES AND IN MACHINERY OR
APPARATUS TO BE EMPLOYED THEREIN "
The object of this Invention is to coat and finish Tin and Terne plates with as
little handling as possible and at the same time to produce a superior finished plate
with less metal thereon than can be produced by the processes hitherto used.
And in order, that my said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
In preparing the Sheets of metal to receive the coating of Tin or Terne I first
remove from their surfaces in the ordinary manner any scale that may be thereon
and then coat the said surface with tin terne zinc or other suitable metal by Electro-
deposition, in a peculiarly formed bath or chamber which is illustrated in figures 1
and 2 of the accompanying drawings, Figure 1, being a longitudinal vertical
Section and figure 2 a plan of the same. A is the bath or chamber containing a
solution of metals or alloys for treating the plates by electro-deposition, which bath
consists of an annular or other suitably shaped trough, with a cylinder B in its
centre containing a piston C the rod D of which projects upwards and carries
bars E from which cages F for containing the plates are suspended. These bars or
suspenders and the cages are made of a good conducting metal. The piston C may
be worked up or down in the cylinder by Steam hydraulic or other power. As
shewn in my drawing the piston is forced and held up by pressure from beneath
so that upon withdrawing the pressure from beneath the piston it descends in its
cylinder whereupon the plates G. contained in the cages are lowered into the bath
and the current for effecting the deposition of the metal is then created.
In coating the plates by electro-deposition they are only coated with metal which
leaves a dull unfinished surface and are not in a marketable condition. According
to my Invention after receiving the electrical deposition the plates are either passed
through grease heated so as to remelt the conting and thereby impart a finished
appearance to the plate or the plates thus coated with an inferior or cheap metal
may be conted with a more expensive metal for the finished surface only. To give
the second coating of metal I pass the plates through a bath which may be
arranged to work either a double or a single set of plates at the same time.
Figures 3 and 4 represent respectively a longitudinal Vertical Section and a plan of
n bath for carrying out this part of my Invention..H is a vessel or bath containing
molten metal and grease. In this bath there are fitted guides 1, arranged on
opposite sides of the bath so as to face each other. These guides consist of slotted
tubes or grooved or slotted side pieces J, with bars or ribs K inside them by which
the plates are guided through the bath. The plates G to be coated are placed in
the guides alternately on opposite sides of the burs or ribs K the first plate bearing
against the front side of one bar and the back, side of the opposite bar, the next
plate bearing on the opposite sides as shewn in figure 4, and so on alternately.
The guide bars K may if desired be doubled so that two sets of plates may be
passed into the bath at one time. In this case, the bars K should terminate before
they reach the exit end of the bath so as to enable either line or set of plates to be
pushed forward to be gripped by the rollers of the finishing mechanism. The

page_text: quantity of metal on the sheets or plates is regulated by means of two perforated
surfaces M, each forming one of the sides of a box N, between which perforated.
surfaces the coated plates pass after leaving the bath so that any surplus metal on
the plates will be removed and -pass through the perforations at the upper part of
the surfaces into the boxes, and therefrom through the lower perforations on to the
next plate, before it enters this regulator. The surfaces M, are adjustable to or
from each other, so as to suit different thicknesses of plates and different quantities
of metal to be coated thereon. Large and small sheets may be, coated by this
process equally well and larger sheets than hitherto have been made can be coated
with ease according to my Invention. I prefer to give the sheets or black plates
their first coating of zinc. or lead or terne by means of an electric battery as herein-
before described (by which process the iron is thoroughly protected) and then give
the second coating of Tin or Terne metal in the finishing bath, thus the sheets are
protected by the first coating of zinc or lead or terne and finished by the second
coating of Tin or Terne thereby effecting a great saving in Tin or Terne while a
better and cheaper plate is produced.
After the Sheets are first coated with the zinc lead or terne and before they receive
the second coating of tin or terne, they may for the purpose of preparing them for
taking the tin, be passed through a chamber containing grease at a temperature
below the melting point of tin zinc or lead. This may be accomplished by means
of a finishing apparatus arranged at one end of the aforesaid grease and metal bath
and working in contact with molten tin and grease.
In coating Sheets for decorating or japanning purposes, I finish their surfaces
between a pair of rollers, running at a high speed in a grease bath-The first part
of this process is specially suitable for all tinned Iron or Steel as it is well known
in the trade that by placing iron or Steel plates into a hot chamber or in contact
with fire without their being first protected a rapid oxidation takes place and that
much metal is wasted.
*
In carrying out this part of my Invention. I first pickle the Sheets in the usual
manner with Sulphuric acid thoroughly swilled in a water bath, then immerse
them in the chamber which contains the Sulphate of Zinc or other metal, after
which they are immersed in a bath of molten metal covered with fatty, matter or
flux, they are then immersed in a second bath containing grease sufficiently hot to
melt off the surplus metal. In finishing Tin plates by using chemical fluxes,
without grease, I have found that the plates within a short time after being coated
are covered with specks of rust which renders them almost useless. In order to
make good durable and well finished tin plates it is necessary that, they should
be passed through a suitable mixture of grease before they enter the last metal
bath and that they should also pass out of the finishing end of the machine through
rollers and rubbers with chilled faces coated with metal which work in contact
with grease.
It is necessary that the plates or Sheets to be coated should be first cleared from,
oxidation or scales, for which purpose when the plates or sheets are taken out of
the annealing boxes, they are pickled in the ordinary way, in white pickling baths.
and swilling baths. When the scale is removed from the plates I place them in..
the cages F, hereinbefore. described with reference. to figures 1 and 2, and lower
them by removing the pressure from beneath the piston C, into the bath of
Sulphate of zinc or other metal or alloy which bath is. connected by a wife with
the Cathode of a battery of a Dynamo-Electric Machine-Sheets of Zinc or other
desired inėtal are hung in the said. solution and are connected with 'the anode of
the battery or said dynamo electric machine or electric Battery which is now set
to work whereupon the Iron sheets or plates receive. a .coating of zinc or other
metal which may be of any desired thickness by allowing the sheets to remain for
a longer or shorter time in the Bath. When the iron is sufficiently coated the
cages with the plates are removed from the Bath by raising the piston C and the
plates placed in a vat through which water is caused to flow and are taken
therefrom as required and if desired the coating which they have received is

page_text: re-melted so as to impart a finish to the plates by subjecting them to a bath of hot
grease as herein before described or they may be subjected to the second coating
process in the finishing machine illustrated by Figures 3 and 4 after being
prepared therefor as hereinbefore explained.
It is well known in the trade that plates coated in a solution Bath under
electric influence will not take a second coating either of zinc or tin nor can they
be finished by giving them an additional dip or dips
In order to overcome this difficulty. I thoroughly grease or soak the slicets or
plates in a properly seasoned grease of good quality such as palm oil tallow and
resin or other such flux and then pass them singly through a Bath containing
molten tin heated to such a temperature as will keep the grease at both ends of
the Bath in a coating and finishing condition but at a lower temperature than that of
the metal used for the first coating.
Figure 5 is a vertical section of the grease bath in which the electro deposition
is remelted-This bath may be constructed in duplicate and be open at the
bottom, P and dip into a trough Q of metal kept in a fluid condition by fires inside
the enveloping casing.
To receive the coated plates as they issue from the baths, surface rubbers the
width of the plates are provided which are drawn inwards so as to grip the plates
by springs and capable of being opened out (so as to release the plates) by hand.
I have not illustrated the means for heating the baths as any convenient means
may be employed for the purpose of maintaining the metal and the grease at the
required temperature and also for rapidly cooling the same when required..
Having now described and particularly ascertained the nature of my said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the herein before in part
recited Letters Patent is:-
"
First Coating metal plates with tin or terne by first depositing the tin or terne
thereon by electro deposition and then subjecting the plates so coated to a bath of
hot grease for the purpose of remelting the coating so as to produce a better finish
substantially as herein before described
Second-Coating metal plates with tin or terne by first depositing thereon by
electro deposition a coating of zinc or other metal and then subjecting the plates
so coated to a batli of grease and finally to a bath of molten tin or terne to receive
a coating thereof substantially as hereinbefore described.
Third In apparatus for coating metal plates by electro deposition the combination
with a bath containing the coating solution of a cylinder B and piston C with
armis or suspenders E and cages F for containing the plates to be coated the whole
being arranged and operated substantially in the manner hereinbefore described
with reference to Figures 1 and 2 of my drawings
Fourth-In apparatus for coating metal plates, with tin or torne the employment
of perforated surfaces M between which the coated plates from the bath are passed
for the purpose of removing superfluous coating metal therefrom and returning the
same to the bath substantially as herein before described with reference to Figures 3
and 4 of my drawings.
In witness whereof I the said Thomas Henry Johns have to this my
Specification set my hand and seal this tenth day of April One thousand
eight hundred and eighty three.