Improvements in the Apparatus and Process for Coating Sheets, Plates, and Pieces of Iron and Steel or other Metal with Tin, Terne, and other Metals.
Year: 1887

page_text: Improvements in the Apparatus and Process for Coating Sheets,
Plates, and Pieces of Iron and Steel or other Metal with Tin,
Terne, and other Metals.
I HAMILTON HALL of 118 Bishopsgate Street Within London E.C. in the county
of Middlesex, Gentleman, do hereby declare the nature of this invention to be as
follows:-
:-
The object of my invention is to effect a saving of time labour and material in the
process of coating inetals, and also to improve the quality and appearance of tho
articles coated.
Hitherto great difficulty has been experienced in removing or keeping from the
surface of the coated metal the scruff, impurities, or oxides, which form and accumulato
in the metal bath.
No effectual attempts have yet been made to overcome the difficulty, by removing
the cause and source of this continuous formation of oxides and impurities, which T
shall hereafter designate as scruff.
In the old method of coating Tin and Terne plates, the sheets after having been
pickled in the usual manner, are swilled in water and then passed singly and in a
wet state into a preparing flux, consisting of either grease, oil or acid fluxes such as
chlorides, etc.
These fluxes or greases become consequently charged with a very large percentage
of water, and are allowed to boil on the surface of the coating metal. This together
with the continued introduction of wet plates causes a constant decomposition of
water on or near the surface of the molten metal, and thus communicates to it the
oxygen which coupled with the exposure to atmospheric air, is the principal cause of
scruff.
To overcome these difficulties, I employ means to prevent all air and moisture from
coming in contact with the molten nietal, and under certain conditions I find it
advisable further to protect its surface, with a substance which excludes and absorbs
all free oxygen which may chance to be present. .

page_text: By thus minimizing the seruff, the operation of coating is much simplified and
improve l, enabling me to dispense with some of the labour, and considerably to reduce
the quantity of coating metal and grease, employed in the operation.
I find it necessary to vary the mode of operation, to suit the different qualities and
descriptions of plates and coating.
For certain classes of work, I sometimes employ part of the ordinary "sets" as
at present in use, performing the work by hand, though applying the principles
already mentioned for the reduction of labour and scruff.
At other times I employ in preference, the apparatus or machine hereinafter
described.
In coating plates or sheets of iron or steel, with tin or terno metal, I find it some-
times preferable, to employ for the preparation of the plates, the patent oil or grease,
described in Patent No. 5328 of the year 1886, as being more rapid and effective in
its action, than the ordinary grease or Palm Oil.
When using a grease flux, I find it important, after the plates or sheets etc. have
been thoroughly pickled and swilled in water, in the usual way, to boil all the moisture
from their surface, in a separate vessel or pot, containing the grease, prior to their
immersion in the coating metal.
To accomplish this, I find it well to employ a pot, in which the oil or grease can
be heated to the required temperature above 212 degrees Fahr. either by means of a
steam coil or other suitable appliance.
By the side of this pot, I place another one, in such a position as to receive any
frothing, which may overflow from the hot grease.
This second pot should be kept cooler.
Into the hot grease, I place a number of wet plates, preferably in a bundle or pack,
without previously separating them. As soon as the water is entirely boiled from
their surface, they will ho found to be thoroughly prepared, and in a condition to
receive their coating almost instantaneously. They can then be removed from the oil,
and passed singly into the bath of molten metal, which should always be kept
covered with oil or grease.
It will be observed, that by this method, the body of oil, in which the wet plates
are immersed, is never allowed to come in contact with the molten metal, also that
the plates are freed from moisture before entering the oil, which is floating on the
surface of the metal bath.
The length of time the plate must remain in the coating metal, and its subsequent
manipulation, must necessarily depend on the quality and class of plate required.
I find it greatly facilitates the work, to place what is commonly called a grate, or
rack in the pots of coating metal, in order to keep the sheets separate and in a
perpendicular position. This grate or rack consists of one or more upright bars or
fingers with or without a small projection or catch just below the surface of the metal,
beneath which the plate can be placed, in order to prevent its upper edge from rising
above the metal.
In coating some qualities of plates, tho brush can be entirely dispensed with, the
amount of scruff being insufficient to require its use.
Sometimes, I employ only one pot, containing coating metal, in which case the
plate after being allowed to remain a sufficient time in the metal, is passed on to the
grease pot, and rolled up between the ordinary coated rolls to give it a finish and
regulate the amount of metal.
For other descriptions of work, I have found it advantageous to dip the plate in a
pot of cooler oil after the first coating of metal, then into a second pot of clean metal
before passing it on to the rolls.
In order further to protect the surface of the coating metal from moisture air or
free oxygen, it is important to cover it with a layer of some substance which has the
property of absorbing oxygen, and will not be effected by heat at the temperatures
employed, such as small pieces of carbon or compressed carbon.
It has also the advantage of preventing contact between the metal and grease or
flux, keeping the latter cooler and wiping the plate on its passage through it. This

page_text: method is of great advantage in working with acid .fluxes,,or. chlorides, when I am
unable to dry the plate by boiling it in oil.
.}
It is sometimes necessary to dry the plates, before passing them into the preparing
grease bath. To accomplish this, I pass the sheets between rolls covered with:
rubber, felt, or some suitable substance or allow them to dry. In both cases I prefer
swilling them first in a weak alkaline solution.
In order to keep the preparing grease in an effective state, I find it well,
occasionally, to separate the metal, which gradually enters into combination with the
oil. To effect this I wash the grease with some dilute acid.
In order that my invention may be more fully understood I will now describe the
same with reference to the accompanying sheet of drawings.
Figure I is a vertical cross section of an apparatus constructed according to my
invention. Figure II is a longitudinal cross, section of the same, the double apparatus
working in one,pot.p
a, is a pot or vessel containing the coating metal. 6, a hopper or pot open at the
top and bottom, which fits into pot a, and has a partition c, across the centre. The
lower portion of this hopper or pot is inserted below the surface of the coating metal,
thus forming two distinct chambers, the one containing the preparing grease or flux,
and the other the coated rolls revolving in grease.
d, is a crank worked either by hand, steam power or other suitable appliance.
c. is a bar attached to the crank which acts partly as a lever working on the
fulcrums k. k.
The cross bar h, on the bar e, works in a slot in the arrangement l, m, n.
By means of the projection g. the plates are pressed downwards into pot a. This
projection also acts as a stop to keep the next plate from descending, until the
proper moment.
When the bar e, has reached the limit of its downward stroke, it causes the
piece 1. m. n. to assume an upright position, thus placing the plate in readiness to be
raised into the nip of the rolls, by the finger i, when the bar €, is raised by the
circular motion of the crank.
It will be observed that the plate by this means is inserted at one side of the
partition c. and brought up at the other.
1. m. n. consists of a horizontal bar n. working in the bearings o. 0-1, l, are two or
more bars fixed at right angles in the bar o, having a slot p, in which the cross bar h,
travels, the projection m, prevents the plate from descending into the pot a, until the
preceding plate is caught in the nip of the rolls s. s.
The upright bars Q. Q. serve to guide the plates into the nip of the rolls, and the
projecting bars r. r. sustain the lower edge of the plates until the fingers i. i. pass
beneath to raise them.
3. s. are one or more pair of rolls revolving in the finishing grease bath similar to
those now in common use.
In order to wipe the plates and improve their appearance, I find it advantageous
for certain descriptions of work, to place a box t containing small pellets or pieces of
metal or other substance preferably of a circular form, over, between, or under the
rolls according to circumstances.
This box has a narrow slot or opening underneath running parallel with the nip of
the rolls. This slot should havo sufficient length and width, to allow of the passage
of a plate. The pellets or small pieces of metal, should be of such a size, as to prevent
the possibility of their falling through the slot. The box can be either open at the
top or have an opening above to correspond with the slot below.
u. is a shoot or guide into which the plate is dropped.
The metal and grease pots are heated to the required temperature by a suitable
arrangement of furnace and flues.
I find a further economy of labour and material is effected by placing two or more
of the above described apparatus' in one pot, side by side the rolls being of sufficient
length to admit of two or, more plates being passed between them at one time or
alternately..

page_text: This apparatus or machine is equally applicable to the process of coating through
grease, mineral acid fluxes, or chlorides etc.
Sometimes I boil the water from the surface of the plates, as before described prior
to passing them through the machine.
For coating the better qualities of plates, I find it well after having passed the
plates through the machine, to give it a dip in a pot of cooler metal and afterwards
finish it in the ordinary grease pot, through one or more pairs of rolls.
The action of the machine is automatic.
When the crank and rolls are in motion, the plates after being dropped into the
shoot or guide u are passed through the machine and rolls without further manipu-
lation.
Dated: 11 1 T 1007

page_text: Improvements in the Apparatus and Process for Coating Sheets,
Plates, and Pieces of Iron and Steel or other Metal with Tin,
Terne, and other Metals:
I HAMILTON HALL of 118 Bishopsgate Street Within London E.C. in the county
of Middlesex Gentleman do hereby declare the nature of my invention for IMPROVE-
MENTS IN THE APPARATUS AND PROCESS FOR COATING SHEETS, PLATES, AND PIECES OF
IRON AND STEEL OR OTHER METAL, WITH TIN, TERNE AND OTHER METALS, and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement :-
The object of my invention is to effect a saving of time labour and material in the
process of coating metals, and also to improve the quality and appearance of the
articles coated.
Hitherto great difficulty has been experienced in removing or keeping from the
surface of the coated metal the scruff, impurities or oxides which formn and accumulate
in the metal bath.
1.
No effectual attempts have yet been made to overcome the difficulty, by removing
the cause and source of this continuous formation of oxides & impurities, which I
shall hereafter designate as scruff.
In the old method of coating Tin and Terne plates, the sheets, after having been
pickled in the usual manner, are swilled in water and then passed singly, and in a
wet state into a preparing flux, consisting of either grease, oil, or acid fluxes such as
chlorides etc. These fluxes or greases become consequently charged with a very
largo percentage of water, and are allowed to boil on the surface of the coating metal.
This together with the continued introduction of wet plates, causes a constant
decomposition of water, on or near the surface of the metal, and thus communicates
to it the oxygen, which coupled with the exposure to atmospheric air is the principal
cause of scruff.
To overcome these difficulties I employ means to prevent all air and moisture from
coming in contact with the molten metal, and under certain conditions, I find it
advisable further to protect its surface with a substance, which excludes and absorbs
all free oxygen which may chance to be present.
By thus minimizing the scruff, the operation of coating is much simplified and
improved, enabling me to dispence with some of the labour, and considerably to
reduce the quantity of coating metal and grease employed in the operation.
I find it necessary to vary the mode of operation, to suit the different qualities and
descriptions of plates and coating. For certain classes of work, I sometimes employ
part of the ordinary "sets" as at present in use, performing the work by hand,
though applying the principles already mentioned for the reduction of labour and
scruff.
At other times, I employ in preference, the apparatus, or machine hereinafter
described.
In coating plates or sheets of iron or steel with Tin or Terne metal, I find it sometimes

page_text: preferable, to employ for the preparation of the plates, the patent oil or grease,
described in Patent No. 5328 of the year 1880, as being more rapid and effective in
its action, than the ordinary grease or palm oil.
When using a grease flux, I find it important, after the plates or sheets etc. have
been thoroughly pickled and swilled in water, in the usual way, to boil all moisture
from their surface, in a separate vessel or pot, containing the grease, prior to their
immersion in the coating metal.
To accomplish this. I find it well to employ a pot in which the oil or grease can be
heated to the required temperature, above 212 degrees Fahr. either by means of a
steam coil or other suitable appliance.
By the side of this pot, I place another one, in such a position, as to receive any
frothing which may overflow from the hot grease.
This second pot should be kept cooler. Into the hot grease, I place a number of
wet plates, preferably in a bundle or pack, without previously separating them.
As soon as the water is entirely boiled from their surface, they will be found to
be thoroughly prepared and in a condition to receive their coating almost instan-
taneously.
They can then be removed from the oil, and passed singly into the bath of molten
metal which should always be kept covered with oil or grease.
It will be observed, that by this method, the body of oil in which the wet plates are
immersed is never allowed to come in contact with the Molten Metal, also, that the
plates are freed from moisture before entering the oil, which is floating on the surfaco
of the metal bath.
The length of time that the plate must remain in the coating metal and its subse-
sequent manipulation must necessarily depend on the quality and class of plato
required.
I find it greatly facilitates the work to place what is commonly called a grate or rack,
in the pots of coating metal, in order to keep the sheets separate and in a per-
pendicular position. This grate or rack consists of one or more upright bars or
fingers with or without a small projection or catch, just below the surface of the
metal, beneath which, the plate can be placed, in order to prevent its upper edge
from rising above the metal.
In coating some qualities of plates, the brush can be entirely dispensed with, the
amount of scruff being insufficient to require its use.
Sometimes I only employ one pot of coating metal, in which case the plate after
being allowed to remain a sufficient time in the metal, is passed on to the grease pot,
and rolled up between the ordinary rolls to give it a finish, and regulate the amount of
metal.
For other descriptions of work, I have found it advantageous, to dip the plate into
a pot of cooler grease, after the first coating of metal, then into a second pot of clean
metal, before passing it on to the rolls.
In order further to protect the surface of the coating metal from moisture air or
free oxygen, it is important to cover it with a layer of some substance which has the
property of absorbing oxygen and will not be effected by heat at the temperatures
employed, such as small pieces of carbon or compressed carbon.
It has also the advantage of preventing contact between the metal and grease or
flux, keeping the latter cooler and wiping the plate on on its passage through it. This
method is of great advantage in working with acid fluxes or chlorides, when I am
unable to dry the plate by boiling it in oil.
It is sometimes necessary to dry the plates before passing them into the preparing
grease bath. To accomplish this, 1 pass the sheet between rolls covered with
rubber felt or some suitable substance, or allow them to dry. In both cases I prefer
swilling them first in a weak alkaline solution.
In order to keep the preparing grease in an effective state, I find it well occasionally,
to separate the metal which gradually enters into combination with the oil. To effect
this I wash the grease with some dilute acid.
In order that the mechanical part of my invention may be fully understood, I will

page_text: now describe the same with reference to the accompanying sheet of drawings, which
were filed with the provisional specification.
Figure I is a vertical cross section of an apparatus constructed according to my
invention.
A is a pot or vessel containing the coating metal, b, a hopper or pot open at the
top and bottom, which fits into pot a, and has a partition c, across the centre. The
lower portion of this hopper or pot is inserted below the surface of the coating inetal,
thus forming two distinct chambers, the one containing the preparing grease or flux,
and the other the coated rolls, revolving in grease.
d, is a crank worked either by hand steam power or other suitable appliance. E is
a bar attached to the crank which acts partly as a lever working on the ful-
crums K. K.
The cross bar H, on the bar E, works in a slot in the arrangement L. M. N. By
means of the fingers G, the plates are pressed downwards into pot a. By this
arrangement the surface of the plates are not dented or injured as is the case when
tongs or nipping appliances are employed. These fingers also serve as a stop to keep
the next sheet from descending until the proper moment. The fingers I serve to raise
the sheet into the nip of the lower pair of rolls.
The projections E' E' assist in raising the sheets into the nip of the rolls when
brought in contact with the fulcrums K. K.
When the bar E has reached the limit of its downward stroke it causes the cradle
or piece L. M. N to assume an upright position thus placing the plate in readiness
to be raised into the nip of the rolls by the fingers I, when the bar E is raised by the
circular motion of the crank.
It will be observed that the plate by this means is inserted at one side of the
partition C and brought up at the other.
L. M. N consists of a horizontal bar N working in the bearings O. ().-L. L. are
two or more bars fixed at right angles in the bar N having a slot P, in which the
cross bar H, travels. The projection M prevents the plate from descending into the
pot A until the preceding plate is caught in the nip of the lower rolls S. S.
The projections I serve to support the lower edg of the plates, until the fingers I. I.
pass beneath, to raise them.
The upright bars QQ serve to guide the plates into the nip of the rolls.
S. S. are one or more pair of rolls revolving in the finishing grease bath similar
to those now in use.
In order to wipe the plates, and improve their appearance, I find it advantageous
for certain class of work, to place a box T, containing small pellets or pieces of metal
or other suitable substance, preferably of a circular form, over between or under the
rolls according to circumstances.
This box has a narrow slot or opening underneath, running parallel with the nip of
the rolls. This slot should have sufficient length and width to allow of the passage of
a plate. The pellets or small pieces of metal, should be of such a size as to prevent
the possibility of their falling through the slot. The box can be either open at tho
top or have an opening above to correspond with the slot below.
U. is a shoot or guides into which the plate is dropped.
V1, V2, V3 is an arrangement of cog, or other wheels, by which the crank d, is set
in motion. The wheel V, is fixed on the driving shaft of the rolls S. S. V³, is an
intermediate wheel. V³, is fixed on the driving shaft of the crank d. Thus when
the rolls S. S. (which are now in common use) are caused to revolve in the customary
manner, motion is communicated to the crank d. By this contrivanco I am enabled to
regulate the speed of the crank in proportion to that of the rolls, and thus cause the
sheets to follow each other in close succession through the rolls, leaving little or no
space between the sheets. I find this of great importance, as the rolls by this means
are kept in better condition & little or no list remains on the edge of the sheet.
The metal & grease pots are heated to the required temperature by a suitable
arrangement of furnace and flues.
I find a further economy of material and labour, by placing two or more of the

page_text: above described apparatas's in one pot, side by side, the rolls being of suicient
length to admit of two or more plates being passed between them at one time, or
alternately.
This apparatus or machine is equally applicable to the process of coating through
grease, mineral acid fluxes, or chlorides etc.
Sometimes boil the water from the surface of the plates, as before described, prior
to passing them through the machine.
For coating the better quality of plates, I find it well, after having passed them
through the machine to give them a dip in a pot of cooler metal and afterwards finish
them in the ordinary grease pot through one or more pair of rolls.
The action of the machine is automatic.
When the crank and rolls are in motion the plates after being dropped singly into
the shoot or guides U are pressed downwards by the fingers G below the surface of
the metal they are then canted over & raised into the nip of the lower pair of rolls by
which they are caught & rolled upwards out of the grease bath.
It will be seen by this description that the machine is entirely automatic even to
regulating the time at which the sheet enters the metal.-This enables one man to
attend to the machine with ease.
Having now particularly described, and ascertained the nature of my said
invention, and in what manner the same is to be performed I declare that what I
claim is
1st. The circular crank movement automatically working the general combination
of parts forming the apparatus, thereby enabling one man to perform the entire labour
required with the machine substantially as described.
2nd. The lever bar E with its projection E', cross bar H, and fingers I. for raising
the sheets to the nip of the rolls working in combination with the two fulcrums K. K.
and cradle L. M. N substantially as described.
3rd. The fingers G on lever bar E which force the sheet downward through the
flux into the coating metal without damaging or marking the surfaces of the plate,
which is often the case when tongs or other nipping appliances are used for the
purpose.
4th. The slotted cradlo L. M. N. with it projections R and M. working in com-
bination with the lever crank and fulcrums substantially as described.
5th. The projection M on cradlo L. N. automatically regulating the service of the
sheets into the metal bath, and enabling the workman to select his own time for placing
the sheet in the guides U substantially as described.
6th. The box containing pellets to wipe the sheet and regulate the amount of meta!
substantially as described.
7th. The arrangement of cog or other wheels to communicate motion to the crank
from the driving shaft of the rolls, thus regulating the travel of the sheets in such
a way as to pass them through the rolls in close succession almost touching one
another, by which means the list on the edge of the plate is almost entirely removed,
and the rolls are kept in better condition, substantially as described.
Sth. Boiling the water from the sheets in a separate pot of grease prior to its
immersion in the coating metal, substantially as described.
T: 1 Jave af Naxambo- 1907
HAMILTON HALL,
Applicant.