AN IMPROVED METHOD OF AND APPARATUS FOR APPLYING A GELATINOUS, RESINOUS, OR SIMILAR COATING OR COVERING TO PHOTOGRAPHIC PLATES AND OTHER ARTICLES
Year: 1879

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"AN IMPROVED METHOD OF AND APPARATUS FOR APPLYING A GELATINOUS,
RESINOUS, OR SIMILAR COATING OR COVERING TO PHOTOGRAPHIC PLATES
AND OTHER ARTICLES." A communication from abroad by George Eastman,
of Rochester. New York, United States of America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at
the Office of the Commissioners of Patents on the 22nd July 1879.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED METHOD OF AND APPARATUS
FOR APPLYING A GELATINOUS, RESINOUS, OR SIMILAR COATING OR COVERING TO
PHOTOGRAPHIC PLATES AND OTHER ARTICLES." [A communication from abroad
by George Eastman, of Rochester, New York, United States of America.]
This Invention relates to an improved method of and apparatus for expeditiously
applying an even layer of gelatine, albumen, gum, dextrine, varnish, or similar
substance to surfaces of glass, metal, wood, papier-maché, or other rigid material,
and is chiefly designed to be employed in the preparation of photographic dry plates.
by the gelatino-bromide emulsion process, and of the gelatine-plates used in collotype'
printing. The said Invention may however be advantageously employed for
coating any surfaces with a uniform layer of any of the above named or similar
substances.
In carrying the said Invention into practice I provide a trough or receptacle to
hold the gelatine emulsion or other coating liquid to be employed, also a roller
working on bearings, and by means of which the liquid is distributed equally upon
the surface of the plate to be coated, and an outer casing or jacket surrounding the
trough for the purpose of containing hot water in cases where the coating liquid
employed may require the application of heat in order to retain it in a state fit for
use, as for instance gelatino-bromide emulsion or other solutions containing
gelatine.

page_text: The liquid coating to be applied is placed in the said trough, and if it be a
gelatinous solution the outer jacket is also filled with water of a sufficiently high
temperature to prevent the solution-in-the-trough-solidifying. The roller_having
been placed-in-position-and partially immersed in the solution in the trough is set
in motion by hand_or_by_any_convenient mechanical means, the object being to
secure a steady regular motion. As the roller revolves a portion of the solution in
the trough is carried round with it, adhering to the surface. The glass plate or other
surface-to-be-coated is.now taken up by means of a suitable holder applied to its
back, and passes across the roller in a direction opposite to that in which the-latter
--revolves. The consequence of this is that as the plate of glass (or other material)
comes in contact with the roller the liquid adhering to the surface of the roller is
arrested and forms a wave on the surface of the glass, and as the glass is drawn
with a regular motion across the roller a uniform layer of the solution is left thereon.
So soon as the glass or other plate has passed the roller (the coated side being now
underneath) it is turned over by the operator and laid with its coated side upper-
most upon a level table to "set" or dry. .
In this manner gelatino-bromide dry plates, collotype plates, or other articles.
which are required in large numbers may be prepared with the greatest rapidity,
and of a better quality than is possible by hand work.
By causing the glass or other plate or object to be coated to pass across the roller
in a direction contrary to the revolution of the latter the coating is applied to the
plate after the latter has passed the roller. This renders the coating more uniform,
as it is not influenced by varying pressure of the plate upon the roller. Moreover
it enables the operator, by altering the speed of the roller or of the passage of the
plate across it, to vary and control the thickness of the layer of gelatine or other
matter left on the plate.
I construct the trough of silver (or other metal electro-plated with silver),
porcelain, glass, or other suitable material, which shall have no chemical action
upon the solutions contained therein, and it is to be of such size and shape as may
best suit the purpose to which the apparatus is to be applied, but preferably of a
semi-cylindrical form, and provided with a flange or rim to enable it to be fitted
into the aforesaid outer jacket. The said roller is constructed of india-rubber, glass,
hard wood, or other material capable of being turned to a true surface, but I prefer
india-rubber. It is fitted with a stock or spindle of steel, iron, or other suitable
metal, which may be silver plated on that portion of its length which projects
outside the body of the roller; or such a stock or spindle may be passed through an
accurately turned wooden roller, which in turn is covered with an outer casing or
tube of soft india rubber prepared for that purpose. The roller is mounted between
centres so that it will revolve within the trough, the stock or spindle passing
through apertures or slots provided in the ends of the trough and of the outer jacket
for that purpose. When in position the body of the roller occupies the whole length
of the trough, and must be of a diameter suitable to the-dimensions-of-the-trough;
but it is important that the respective dimensions be so arranged that the roller
may be immersed to the depth of one third of its diameter in the liquid contained
in the trough.
It inay
The outer casing or jacket should be of such form and dimensions as will be most
suitable, and it may be constructed of zinc, iron, copper, or other material.
be supported on feet, by means of which it can be screwed or otherwise fastened to
a table or bench, and if necessary arrangements may be made by means of which
the heat of a spirit lamp or Bunsen's burner may be applied to it in order to keep
up a uniform temperature while the apparatus is at work.
I do not confine myself to the precise details of construction above described, as
the said apparatus may be made in somewhat different form without departing
from the principle of the said Invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Robert Lake in the Great Seal Patent Office on the
22nd January 1880.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED METHOD OF AND APPARATUS
FOR APPLYING A GELATINOUS, RESINOUS, OR SIMILAR COATING OR COVERING TO
PHOTOGRAPHIC PLATES AND OTHER ARTICLES." A communication from abroad
by George Eastman, of Rochester, New York, United States of America.
This Invention relates to a method and apparatus by which an even layer of
gelatine, albumen, gum, dextrine, varnish, or any similar substance may be applied
expeditiously to surfaces of glass, metal, wood, papier-maché, or other material,
and is specially intended for use in the preparation of photographic dryplates
by the gelatino-bromide emulsion process, or of gelatine plates employed in collotype
printing, or of other surfaces which require the application of a uniform layer of either
of the abovementioned or similar substances.
The said apparatus is illustrated in the accompanying Drawing, in which,―
Figure 1 is a plan or top view.
Figure 2 is a longitudinal section on the line x, x; and
Figure 3 is a transverse section on the line y, y, Figure 1.
Like letters indicate the same parts throughout the Drawing.
The said apparatus is constructed with a trough a to hold the gelatine emulsion
or other liquid to be employed; b is a roller working in bearings, by means of
which the said liquid is distributed equally upon the surface of the plate to be
coated; and c is an outer casing or jacket surrounding the trough a for containing
hot water when the liquid employed may require the application of heat to keep
it in a state fit for use, as when gelatino-bromide emulsion or other solution con-
taining gelatine is used.
The trough a is constructed of silver or other metal electro-plated with silver,
porcelain, glass, or other suitable material, which has no chemical action upon, and
is not affected by the liquid or solution contained therein. The size and shape of
the said trough may be such as will best adapt it to the specific purpose for which
the said apparatus is to be applied. I prefer in ordinary cases that it should have
a semi-cylindrical form, and should be provided with a flange or rim to enable it to
be fitted into the outer jacket c.
The roller bis constructed of india-rubber, glass, hard wood, or other material
capable of being turned to a true surface, and is fitted with a shaft or spindle d of
steel, iron, or other suitable metal, which may be silver plated on its portion which
projects beyond the body of the roller b. I may modify the construction of the
said roller by passing such a shaft or spindle through an accurately turned wooden
roller covered with an outer casing or tube of soft india-rubber prepared for this
purpose. The roller b is mounted in suitable bearings so arranged that it will
revolve within the trough a. The shaft or spindle extends through apertures or
slots provided in the ends of the trough a and of the outer jacket c. When in its
proper position the body of the roller 6 occupies the entire length of the trough a,
as shewn in Figures 1 and 2. The said roller must be of a diameter suitable to the
dimensions of the trough a, and it is important that the dimensions of the parts
should be such that the roller 6 may be immersed to the depth of about one third
of its diameter in the liquid contained in the trough.
The outer casing or jacket c may be of any suitable form and dimensions, and
nay be constructed of zinc, iron, copper, or other material. It is so constructed
that it may be screwed or otherwise fastened to a table or bench, and if necessary
arrangements may be made by means of which the heat of a spirit lamp e, a
Bunsen's burner, or the like may be applied to it to maintain a uniform temperature

page_text: shewn at j. g is a tube for ruling the said casing; 18 the discharge tube for
emptying the trough-a.
To-use-the-said: apparatus a quantity of the liquid to be applied to the plates
or other articles is placed in the trough a; if it be a gelatinous solution the outer
jacket c is supplied with water at a sufficiently high temperature to prevent the
solidifying of the solution in the trough. The roller b having been placed in position
-in-its-bearings, and partially immersed in the solution in the trough a, is set in
motion by any convenient means, care being taken to ensure a steady regular
movement of the same. As the roller revolves a portion of the solution in the
trough is carried around with it, adhering to its surface. The glass plate or other
surface to be coated is now taken up by means of a suitable holder applied to its
back, and passed. across the roller b in a direction opposite to that in which the
latter revolves. The consequence of this operation is that as the surface of glass or
other material to be coated comes in contact with the roller b, the liquid adhering
to the surface of the said roller is arrested and forms a wave on the surface to be
coated, and as the glass or other material is drawn with a regular motion across the
roller a uniform layer of the solution is left thereon. So soon as the glass or other
plate has passed the roller (the coated side being now underneath) it must be turned
over by the operator, and laid with its coated side uppermost upon a level table to
"set" or dry.
In this manner gelatino-bromide dry-plates, collotype-plates, or other plates, or
the like which are required in large numbers may be prepared with great rapidity
and of better quality than is practicable by handwork.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I am aware of the use of an apparatus somewhat similar to that herein
described having been used for applying gum to postage stamps; I therefore do not
claim a process or apparatus for applying gum or mucilage to stamps, or labels
for postal or similar purposes, but I claim,-
First. The herein-described method or process of coating by the aid of a roller
the surface of glass or other material with gelatine or other emulsion or the like
for the purposes specified.
Second. In an apparatus for coating glass or other plates with gelatine or other
emulsion or the like the combination of the revolving roller and the stationary
trough, composed of materials that will not be affected by the emulsion or substance
with or without the other parts shewn in the Drawing, all constructed substantially
as and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Twenty second day of January, in the year of our
Lord-One-thousand eight hundred and eighty.