IMPROVEMENTS IN COATING THE SURFACE OF TIN-PLATE AND OTHER METAL SHEET, AND OF ARTICLES MADE THEREFROM
Year: 1881

page_text: LETTERS PATENT to Alfred Nind Hopkins, of Birmingham, in the County of
Warwick, Manufacturer, for an Invention of "IMPROVEMENTS IN COATING
THE SURFACE OF TIN-PLATE AND OTHER METAL SHEET, AND OF ARTICLES
MADE THEREFROM."
PROVISIONAL SPECIFICATION left by the said Alfred Nind Hopkins at
the Office of the Commissioners of Patents on the 29th November 1881.
ALFRED NIND HOPKINS, of Birmingham, in the County of Warwick, Manu-
facturer. "IMPROVEMENTS IN COATING THE SURFACE OF TIN-PLATE AND OTHER
METAL SHEET, AND OF ARTICLES MADE THEREFROM."
According to this Invention varnishes, lacquers, and japans (or other similar
coating materials), either alone or mixed with suitable colors or stains as desired,
are laid on to the surface of tin-plates and other sheets of metal, and upon the
surface of articles made from such plates and sheets, by means of rollers which
have their rolling surfaces formed of india-rubber, or of leather, or other suitable
yielding substance. The rollers are formed preferably with a wooden or iron core
covered with the yielding material, and may be used either by hand or in a
machine. When used by hand the core is extended beyond each end of the roller
to form or to receive handles. When the india-rubber surface of a roller is quite
smooth, or when the coating material is mixed up with much varnish, or otherwise
made of a light consistency, and in this latter case whether an india-rubber or a
leather roller is used, the coating material, when laid upon the plate, sheet, or
article aforesaid, has a smooth appearance, but when the coating material has a
greater consistency the surface has a grained appearance, resembling very much the
surface of leather, the degree of roughness or distinctness of the graining depending
on the consistency of the coating material and in some degree also on the extent
of the pitting or roughness of the covering of the roller. The india-rubber yields
best to the unevenness of the surface to be coated, and in using the rollers in a
machine it will be found convenient in cases where the coated surface is to be

page_text: finished with the leather covered roller to lay the coating material on first by
means of an india-rubber roller. When the operation is performed by hand the
coating material is taken up from a plate, stone, or other flat surface, or in other
convenient manner, on to the surface of the roller. The roller is then passed
backwards and forwards under pressure upon the surface of the plate, sheet, or
article, as aforesaid, thus laying on the coating material. When the operation is
performed in a machine the coating material is taken up from a convenient source
of supply on to a roller and conveyed therefrom on to a roller, or series of rollers,
rolling in contact. The tin-plate or metal sheet (or article, as aforesaid, if of
convenient shape and construction therefor) is passed between rollers arranged in a
pair or pairs, which thus put the coating material upon the plate, sheet (or article),
the required pressure being imparted to the rollers by a screw or other mechanical
arrangement. The plate, sheet, or article, after being coated as aforesaid, is
stoved, etc., in the usual manner. The coating material is very evenly and thinly
laid on by this Invention, and shews no liability to peel or crack off, even when
the coated tin-plate or metal sheet is bent about at sharp angles. In the case of
sheet iron of a common quality from which the scale has been removed it is found
that the coating cannot be rolled into the pits left by the removal of the scale, but
this difficulty may be overcome by first coating the sheet by means of a revolving
brush and then employing rollers, as before mentioned.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alfred Nind Hopkins in the Great Seal Patent Office on the
27th May 1882.
ALFRED NIND HOPKINS, of Birmingham, in the County of Warwick, Manu-
facturer. "IMPROVEMENTS IN COATING THE SURFACE OF TIN-PLATE AND Other
METAL SHEET, AND OF ARTICLES MADE THEREFROM.”
According to this Invention varnishes, lacquers, and japans (or other similar
coating materials) either alone or mixed with suitable colours or stains as desired
are laid on to the surfaces of tin-plate and other sheets of metal, and upon the
surfaces of articles made from tin-plates and other sheets of metal by means of
rollers which have their rolling surfaces formed either of vulcanized india-rubber
or of leather or other suitable yielding substance. The rollers are formed preferably
with a wooden or iron core covered with the yielding material, and they may be
used either by hand or (when coating tin-plates and other sheets of metal) in a
machine worked by hand or driven by motive power. When a roller is used by
hand the core is extended beyond each end of the roller to form or to receive
bandles.
When the exterior surface of a roller covered with india-rubber is quite smooth,
or when the coating material is mixed up with much varnish or otherwise made of
a light consistency, and in this latter case whether an india-rubber or a leather
covered roller or a roller covered with similar coating material is used, the coating
material when laid on the tin-plate, sheet, or article as aforesaid has a smooth
appearance; but when the coating material has a greater consistency the surface
of the coating material, when laid on as aforesaid, has a grained appearance
resembling very much the surface of leather, the degree of roughness or distinctness
of the graining depending on the consistency of the coating material, and in some
degree also on the extent of the pitting or roughness of the covering of the roller.
When a roller is used by hand to lay on the coating material, as aforesaid, the
coating material is taken up from a plate, stone, or other Hat surface on to the
surface of the roller, or in other convenient manner; but when the rollers are used
in a machine the coating material may be fed to a roller or rollers from a hopper
or bath or other source of supply, and either direct to the rolier or rollers for laying
on the coating material, or else transmitted by the friction of one roller rolling in
contact with another, and so on from the receiving roller or rollers to the roller or
rollers which lay the coating material on to the surface of the tin-plate or other
metal sheet, or according to both these latter-described methods, as in the machine
hereinafter described with reference to the accompanying Drawings.
The deposition of the coating material is effected as follows:-When a roller is
operated by hand, in the case of coating a tin-plate or other metal sheet, the tin-
plate or other metal sheet is placed on a flat surface, and the roller suitably charged
with the coating material, as before described, is passed under pressure backwards
and forwards over it till the required coating is obtained. In the case of articles
made from tin-plates or other metal sheets the article is held firmly by any con-
venient means, and a roller of suitable size, charged as before described, is passed
backwards and forwards by hand over the surface till the required coating is
obtained.
When a machine is employed for coating tin-plates or other sheets of metal
the same result is obtained as when using a roller operated by hand. The rollers
are carried in the machine so as to work in a pair or pairs (or in a set of three or
more together in the machine illustrated by the accompanying Drawings), the

page_text: proper pressure being put upon the rollers by means of screws or other mechanical
equivalent, and both the rollers of a pair are made to revolve at equal velocities,
and so as to draw the tin-plate or other metal sheet between them. The tin-plate
or other metal sheet may be passed and repassed between a pair of rollers, or
passed between succeeding pairs until the required coating is obtained.
If desired a machine may be employed in which a roller or rollers are made to
roll upon the tin-plate or other metal sheet, or the tin-plate or other metal sheet
passed on a moving table under the roller or rollers instead of the plate or sheet
being passed between the rollers, in which cases the roller or rollers may be charged
by passing over a plate, stone, or other flat surface fed with the coating material;
or the said plate, stone, or other flat surface may be passed under the roller or
rollers.
The tin-plate or other metal sheet or article made therefrom after being coated
as aforesaid is stoved in the usual way, preferably at a high temperature.
The coating material is by this Invention very evenly and thinly laid on, and
shews no liability to peel or crack off even when the coated tin-plate or other
metal sheet is bent about at sharp angles.
In carrying my Invention into practice I do not confine myself to any special
form of machine, when a machine is employed to coat tin-plates and other metal
sheets instead of simply a band roller, or to any special arrangement of rollers in
such machine; but it may be convenient to describe a simple machine I have
devised for the purpose, and in doing so I shall refer to the accompanying Drawings,
and to the letters of reference marked thereon.
The Drawing is to a scale of three inches to a foot, the rollers being two feet
long. Figure 1 is a side elevation and Figure 2 a section taken on line x, x, of
Figure 1. A, A, are housings or frames bolted to a bed-plate A¹. B, B, B, are
rollers formed with wooden or iron cores covered with vulcanized india-rubber of
about three eighths of an inch in thickness. C, C, etc., are chucks (shewn by dotted
lines, Figure 2) carrying the spindles or necks of the rollers and themselves carried
in the housings A, A. The chucks C, C, etc., of the middle and top roller bearings
are capable of sliding vertically in the housings. D, D, are screws passing through
the tops of the housings and bearing upon the chucks of the top roller bearings.
By means of the screws D, D, therefor the rollers can be forced together with any
desired pressure. F is a hopper or open bottomed trough to feed the coating
material to the top roller, and G is a bath or trough to supply the coating material
to the bottom roller which runs with the lower part of its periphery in the said
bath. In the machine illustrated the rollers are intended to revolve in the direction
indicated by the arrows. The machine is driven by the band pulley H on one end
of the bottom roller spindle, and the equal spur wheels I, I, I, one on each roller
spindle. The rollers run about twelve revolutions per minute. K, K, and KI, K¹,
are snugs (shewn by dotted lines, Figure 2) formed out from the ends of the
hopper F. L, L, are bracket pins fixed at their lower ends L', L', to the housings
as shewn, and having their upper ends which are screwed passing up through
vertical holes in the snugs K, K, K¹, K. M, M, are nuts upon the pins L, L, and
between each pair of snugs K, K', as shewn. By means of the nuts M, M, the
hopper F is raised or lowered so as to cause the bottom to bear upon the surface of
the roller with just sufficient pressure to allow of the coating material passing out
on the surface of the roller in an even layer and proper quantity. N is a metal
rubber set up against the surface of the bottom roller, by means of the adjusting
screws 0, 0, to keep back any superfluous coating material raised out of the bath Ğ
and to ensure the remainder passing in an even layer over the surface of the roller.
The rubber N is held firmly to the top of the bath G by means of the pins a, a, a,
when the adjusting screws 0, 0, are not being operated.
The machine may be made with an additional roller placed above the highest
roller shewn or with any desired number of rollers.
The tin-plates or other metal sheets are coated by being passed backwards and
forwards between the rollers, say first between the bottom and middle roller and

page_text: then between the middle and top roller. The middle roller receives its coating
material from running in contact with the other rollers. If only one side of each
tin-plate or other metal sheet is to be coated the tin-plates or other metal sheets
are preferably passed through the rollers in pairs or are each rolled in contact with
a blank or dummy plate or sheet to keep the intended plain side of the tin-plate
or sheet to be coated from coming in contact with the rollers.
Having thus stated the nature of my said Invention, and particularly described
and ascertained the manner of performing the same, I declare that I do not
limit myself to the precise details herein described, nor to the machinery illustrated,
as such may be varied without departing from the nature of my said Invention ;
but what I claim as my Invention and desire to secure by the herein-before in-part-
recited Letters Patent is,-
1st. Coating the surfaces of tin-plates and other metal sheets and of articles made
from tin-plates and other metal sheets, with varnishes, lacquers, and japans (or
other similar coating materials) either alone or mixed with suitable colors or stains,
as desired, previously to stoving the same in the usual manner, and preferably at a
high temperature, by means of rollers which have their rolling surfaces formed
either of india-rubber or of leather or other suitable yielding substance, the said
rollers being operated under pressure either by hand or (in the case of coating
tin-plates and other metal sheets) in a machine, substantially as herein
described.
2nd. Producing the "grained" appearance hereinbefore referred to upon the
coated surface of tin-plates and other metal sheets, and of articles made from tin-
plates and other metal sheets, previously to stoving the same in the usual manner
and preferably at a high temperature, by the use of rollers covered with a yielding
material such as india-rubber or leather or other suitable yielding substance, the
said rollers being operated under pressure either by hand or (in the case of coating
tin plates and other metal sheets) in a machine, substantially as herein
described.
In witness whereof, I, the said Alfred Nind Hopkins, have hereunto set my
hand and seal, this Twenty fifth day of May, in the year of our Lord,
One thousand eight hundred and eighty two.
Witness,
STEPHEN WATKINS,
Assoc. M. Inst. C.E.,
Office for Patents,
Wolverhampton.
ALFRED N. HOPKINS. (L.S.)