Improvements in the Method of and Apparatus for Manufacturing Glass Plates, Sheets, and Films.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Manufacturing
Glass Plates, Sheets, and Films.
A communication by ROGER SHERMAN PEASE, of Minneapolis, in the County of
Hennepin and State of Minnesota, United States of America, Glass Maker.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool and 6, Bank Street,
Manchester both in the County of Lancaster and 323 High Holborn, in the
County of Middlesex, Civil Engineer do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention relates to the manufacture of glass plates, sheets and films, and
contemplates the making thereof in dfferent colours or combinations of colours.
In a previous invention, the slide or plunger was arranged to move upward
through the molten metal contained within a tank or receptacle, and to carry
upward on its exterior a film or films of glass which was severed from the metal
in the tank or receptacle and removed from the plunger, and subsequently
annealed.
This feature is retained under the present plan, but the capacity of the apparatus
is doubled by arranging the plunger to draw down with it, in passing downward,
two additional films or sheets which are acted upon by rollers and rolled to the
proper thickness and made uniform, the rollers being made to serve also to chill
or set the glass, if found necessary, as may be the slide where the sheets are of
considerable thickness.
It is also proposed, in some cases, to figure the rollers so as to produce figured
or roughened glass.
In the accompanying drawings:-
Figure 1 represents, in vertical section, so much of a glass making apparatus as
is necessary to a thorough comprehension of the present invention;
Figure 2 a transverse sectional view of the same ;
Figure 3, a horizontal sectional view showing the manner in which the plunger
passes upward through the glass-containing receptacle, and is guided in its
movements;
Figure 4, an outline view or diagram illustrating the arrangement for elevating
the plunger by means of fluid pressure, or elevating and heating the plunger by
steam or other heated fluid.
In said drawings, A, indicates a plunger adapted and arranged to move vertically,
its edges being provided with guiding ribs a which move and are guided in grooved
blocks or brackets & projecting from a framework B of metal or other suitable
material, which serves the double purpose of carrying the guides and of sustaining
or partially sustaining the metal-containing receptacle C through which the
plunger moves.
The vertical movements of the plunger may be effected by any suitable hoisting
apparatus; but it is preferred to employ a hydraulic lifting apparatus consisting
simply of a pipe or pipes D, connected with a suitable elevated tank or receptacle
as shown in Figure 4, which is supplied by pumps or a natural head in the ordinary
manner, and which pipe, being carried upward into the hollow plunger A, delivers
the water thereto with sufficient head or pressure to cause the rise of the plunger.
The delivery of water to the plunger and the discharge thereof through the
pipes D are controlled by a three-way valve E, or in any other convenient manner,
the rate of rise and fall of the plunger being controlled by the extent to which said
valve is opened to the receiving or discharging port.

page_text: The water thus introduced into the plunger serves the double purpose of
controlling its movements and cooling the plunger, so that no other or special
provision for the latter purpose is necessary..
The pipe or pipes D' will be surrounded by a suitable packing gland or glands
to prevent leakage.
Ĉ indicates a receptacle for molten metal, which is preferably delivered thereto
from pots or crucibles F contained in a chamber or chambers G, at the side or
sides of the said receptacle C.
In practice, the receptacle C may be supplied from a tank or tanks, or from
melting furnaces entirely separate from the apparatus herein represented, but it
is preferred to make use of the pots or crucibles here indicated, because the
molten metal can thereby be delivered directly from the pots without removing
the pots from the furnace, and thereby the difficulties, which attend the use of
tanks or the employment of removable pots which require to be taken from the
heating or melting chamber and carried to the receptacle in which the glass is
to be used, can be avoided.
In Figure 1, the pots F are represented as arranged in chambers G located on
opposite sides of the receptacle C, it being the intention to heat the chambers G
by mingled air and gas from regenerative furnaces of the Siemens type by
preference, though other provision may be made for heating them if desired.
Except when the pots are being emptied, the openings c through the walls of
the chambers G are closed by blocks H of fire clay, or by any other convenient
means.
The bottom of the receptacle formed by hinged gates or sections I, which
are counterweighted as shown, to hold them normally closed against the face of
the plunger A, the gates or sections I being backed with iron or other suitable
metal, and said backings being brought to a sharp annular edge where they bear
against the plunger A, for a purpose hereinafter explained.
The counterweights I may be made as heavy as desired, and should, in any
case, be sufficient to hold the gates in contact with the plunger A, notwith-
standing a full charge or supply of molten metal being contained within the
receptacle C.
The metal in the receptacle C is to be permitted to cool therein sufficiently
to bring it to the proper consistency for advantageous working, the consistency
being determined in some degree by the thickness of the sheet or film desired,
but the condition of the surrounding atmosphere and the degree to which the
plunger A is cooled are circumstances which are also to be taken into consideration
in determining this point.
While pots F are represented for supplying molten metal to the receptacle C,
and. while the pots are preferred because of the difficulty of delivering molten
metal to such a receptacle from a tank, and properly closing the passages through
which the molten metal flows, and because of the opportunity afforded of supplying
glass to receptacle C in different conditions, qualities, or colours, it is to be
understood that tanks may be used instead of the pots F.
KK indicate two rollers which are carried by hangers or pendulous bars LL
suspended from studs or pivots d which it is preferred to arrange in line with the
axis of the plunger A, but which will be located at such point or points as to cause
the rollers to bear with proper force against the side faces of the plunger A, as
indicated in Figures 1 and 2.
If desired, the pivots may be made adjustable with reference to the plane of
movement of the plunger so as to vary the force or pressure with which they
bear against the roller or against the films or layers of glass which are brought
down by the plunger, as hereinafter explained.
In order that the rollers may be prevented from shifting longitudinally, and
to ensure the retention of the glass films or layers, within the proper limits
laterally the rollers K are provided with flanges e at their ends, which flanges
work in close contact with or proximity to the edges of the plunger. A.

page_text: The upright framing B is provided with two openings fat each side, which are
designed to receive rods of bass wood or other suitable material, and to hold the
same in close contact with the faces of the plunger A. for the purpose of stripping
therefrom the layers or sheets of glass brought down thereby.
The apparatus being thus constructed, the operation is as follows
The plunger A is drawn downward until its upper end is below the upper surface
or level of the molten metal within the receptacle C, its motion being then reversed
so that a body of metal is carried upward across its top, resting in the semicircular
or depressed seat therein, as shown in Figure 1, and extending downward on the
sides of the plunger to the molten metal.
The thickness of the sheet, film or body lying upon the face of the plunger will
depend upon the extent to which the plunger is cooled, the condition of the
surrounding atmosphere and the consistency of the metal in the receptacle C,
these matters being subject to the control, and in some measure depending upon
the judgment, of the attendant.
When the plunger is carried as high as is necessary to produce sheets or films
of the desired length, its motion is stopped, or is suddenly accelerated for a short
distance to permit the cutting or to cause the severance of the film or sheet
produced.
The sheets or films being properly removed from the elevated plunger, the
motion of said plunger is reversed, and a slight opening of the gates I is permitted,
which may be regulated and determined in any convenient manner, the plunger
carrying downward with it, on its face, sheets or films of the molten metal, which,
following the plunger, pass between said plunger and the rollers KK which roll
out the metal to a proper and uniform thickness, and may, if desired, impart any
suitable figuring or marking to the plates so produced.
To permit the plates thus formed to properly cool and on both faces, it is deemed
desirable to strip them from the face of the plunger A, and it is for this purpose
that the bass wood strips are inserted into the openings f
The receptacles C may be provided with adjustable or removable covers M, by
which to retain the heat therein or determine the rate or degree of cooling of
the molten metal.
Cutting plates N may be arranged upon these covers for cutting the glass films
or plates and severing them from the molten metal or from that portion of the film
connecting them with the molten metal.
It is of course to be understood that the receptacle C is intended to contain only
a limited quantity of glass, and that it is made of comparatively small capacity,
the intention being to pour from the pots or to run a fresh supply from the tanks
into the receptacle at each drawing, or after a few drawings.
As above mentioned, the metal backings of the gates I are brought to a sharp
edge where they bear against the plunger A. This construction causes them to
make a close joint with the plunger, preventing the escape of molten metal as the
plunger rises, and to scrape off any adhering matter that may lie upon the face of
the plunger as the latter ascends.
When opened to permit the flow of metal downward with the plunger, these
edges serve as gauges to determine the thickness of the body flowing from the
receptacle, and to render the surface even and uniform.
When the sheets or films have been drawn downward to the proper length, the
gates I are thrown upward and against the plunger I, so as to sever the sheets or
films and prevent the further escape of the molten metal.
In this way the sheets are manufactured with great rapidity, two being
formed on each upward stroke, and two others on each downward stroke of the
plunger.
The plunger or slide is arranged to travel clear of the walls of receptacle C, and
the molten or plastic glass is scraped from the edges of the plunger by scrapers O,
as the plunger rises, and by the metal backing of the oven bottom or floor as the
plunger descends.

page_text: The plunger will be formed with longitudinal side ribs f, to gauge and determine
the thickness of the glass formed on the downstroke, or the rollers K K may be
formed with narrow bearing collars at or near their ends for a like purpose.
When the side ribs are employed, the bottom of the chamber C and its
backing will be of a width or length to enter between the side ribs, and, con-
sequently, to come into contact with the faces of the slide or plunger.
While it is proposed to introduce water into the plunger and to cool the same,
steam may be introduced instead, which may be utilised to heat and to clevate the
plunger. So too, the rollers K K may be heated or cooled, as required.
cross section of the plunger may be varied as desired.
The
The plunger, by reason of its movement through the molten metal, becomes in a
short time highly heated, and, in fact, so much so as to cause the glass to adhere
and be taken up in too thick a body, and it is to guard against this contingency
that Mr. Pease arranges in the present instance, to cool the plunger; but, in
starting the apparatus, the plunger being cold, the film drawn up is liable to be
quite thin, and, to avoid its being made too thin, he provides for heating the
plunger, for which purpose the same pipes or apparatus provided for cooling may
be made use of, but merely connected with a different source of supply, as, for
instance, the steam generator, indicated in Figure 4.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. The herein described method of producing glass films or sheets, which consists
in causing a plunger to move upward through a body of molten metal, and
thereby to carry upward upon its surface a film or layer, removing the same, then
reversing the movement of the plunger and causing a second film or layer to
be carried downward through the bottom of the receptacle by said plunger,
substantially as set forth.
2. The herein described method of producing sheets or films of glass, which
consists in moving a plunger downward through an opening in a receptacle
containing molten metal and thereby drawing from the molten metal a film or
sheet upon the surface of the plunger.
3. The herein described method of making films and sheets of glass, which
consists in moving a plunger downward through an opening in the bottom of a
receptacle containing molten metal, and thence between rollers, whereby a film
or sheet of glass is formed upon and carried downward by the plunger and reduced
to the proper thickness between the rollers and plunger, substantially as set forth.
4. In combination with a receptacle adapted to contain molten metal, a plunger
movable upward and downward through the same, and gates or sections con-
stituting the bottom of said receptacle, and adapted to bear against the sides of
the plunger or to be moved outward therefrom at will.
5. In combination with a receptacle adapted to contain molten metal, a plunger
movable upward and downward through the same, gates or sections constituting
the bottom of said receptacle, and adapted to be thrown into and out of contact
with the plunger at will, and rollers located below said receptacle and adapted to
be moved into and out of contact with the face of the plunger, substantially as and
for the purpose explained.
6. In combination with receptacle C adapted to contain molten metal, plunger A
movable through said chamber, and counterweighted gates I bearing against the
faces of the plunger and constituting the bottom of the receptacle, substantially as
shown and described.
7. In combination with a receptacle adapted to contain molten metal, and with a
plunger movable vertically through the same, a pipe or pipes extending upward
within the plunger and connected with a supply of fluid under pressure, the plunger
being closed against the escape of fluid, substantially as described, whereby the
inlet and exit of fluid through the pipe are caused to raise and lower the plunger.

page_text: 8. In combination with receptacle C and plunger A movable through the same,
pipe D connected with a pressure tank or supply, a three-way valve E, adapted to
permit and control the inlet and exit of water or fluid.
Dated this 23rd day of November 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.