Improvements in the Manufacture of Sheets, Cylinders, and other Forms of Glass.
Year: 1896

page_text: Date of Application, 6th Aug., 1896
Complete Specification Left. 26th Feb., 1897-Accepted, 10th Apr., 1897
STERILTIVATION.
Improvements in the Manufacture of Sheets, Cylinders, and other
Forms of Glass.
I, PAUL THEODOR SIEVERT of Lindenaustrasse, 32, Dresden, Saxony,
Germany, Glass Manufacturer, do hereby declare the nature of this invention to
be as follows :--
This invention relates to the manufacture of glass sheets, glass cylinders, and
other glass bodies, by the process of drawing the molten glass issuing from a
properly shaped slit or opening in a holder or vessel.
The present invention refers more particularly to a system of combining the
glass-holding vessel or vessels, provided with a properly shaped slit or opening,
with the glass melting furnace, in such a manner, that the molten glass proceeds
directly or underneath bridges, or over partition walls from the furnace into the
vessels, so that a continuous working of glass articles, such as above referred to,
may take place, while the molten glass, on its way from the furnace to the receiving
vessel or vessels, and while in the vessel or vessels, is under the influence of the
heat radiating from the melting furnace, which heat may, by proper means, be
regulated. The glass, at its issue from the slit or opening of the vessel or vessels,
is also brought under the influence of heat conducted thereto by separate flues, to
which also devices for regulating such heat may be applied. In the process of
manufacturing glass articles by drawing the molten glass, issuing from the slit of
a vessel, it was originally designed to transfer the molten glass by ladles out of the
furnace or glass pots to the receiving vessel or vessels. This method, however,
involves much labour and expense, and has the disadvantage of introducing bubbles,
and retaining impurities in the glass. Again, in other cases, the molten glass was
caused to run in gutters or their equivalent from the melting vessel into the place
where the shaping of the glass commences, by metal rollers or other devices.
I now remove the difficulties referred to by combining my vessel or vessels, (out
of which I allow the molten glass to issue) directly with the glass melting furnace,
in such a manner that the molten glass always, and at the ratio of its being drawn
away from the receiving vessel or vessels, flows from the furnace directly without
ladling, and without any extra guiter, into said vessel or vessels.
By this system I avoid all impurities and bubbles which the handling of the
molten glass by ladles or other implements may incorporate in the molten glass.
I furthermore have, by my system, the molten glass, in its course from the furnace
into the receiving vessel or vessels, under the direct influence of the heat radiating
from the glass-melting furnace, which heat I am enabled to regulate by dampers
or such-like devices, so that the molten glass is always in the proper state of semi-
fluidness or toughness in the receiving vessel or vessels for my purposes. In the
way from the furnace to the vessel or vessels, I may arrange all the constructions
well known to, glass manufacturers and constructors of melting glass furnaces,
which constructions serve to keep within the furnace such impurities which form
on the top of the inolteu glass, or which form the bottom of the molten glass; such
constructions consisting of bridges for keeping the molten glass surface back from
leaving the furnace, or they consist in separation walls fixed on the bottom of the
furnace, or of the channel for the running glass, such walls being of the proper

page_text: height, to allow the surface of the molten glass to run over such walls, while such
wall or walls keep back the impurities at the bottom of the glass.
At the end of such channel, I arrange my vessel or vessels in such level, that
they will always be kept filled with molten glass of the proper semifluidness or
toughness, which glass runs out by its own weight, or by additional pressure,
through the opening at bottom of the vessel.
I may arrange, in direct connection with the glass melting furnace, or interrupted
by bridges and walls, as aforesaid, an annex of the furnace, such as will allow of
the arrangement of a number of vessels in a semi-circular manner, which are all
simultaneously, or part of them, filled with molten glass in proper condition
running from the furnace. These vessels, will be provided with proper discharge
openings of straight, curved, or circular shape, so that from them the molten glass,
as it is discharged, will take one or other of the forms desired. The drawing out
of the molten glass, may be done by hand or by mechanical means, in order not
only to give the proper shape and length to the bodies to, be produced, but mainly
to give to these bodies the proper thickness of skin required.
In order to maintain the issuing glass in that condition which is necessary for its
being drawn to the desired thickness, it is necessary to subject the glass in the
vessel, as well as on its point of issue, to proper. heat, and I therefore construct, in
the glass melting furnace in which the vessel or vessels are arranged, or in the
annex of the glass-melting furnace in which the vessel or vessels are arrangel,
proper ilues, which conduct the necessary heat to the outer surface of the vesicl,
and to the, point of issue where the molten glass leaves said vessel or vessels.
Dated this 6th day of August 1896
NEWTON & SON,
Agents for the Applicant.
Improvements in the Manufacture of Sheets, Cylinders, and other
Forms of Glass.
I, PAUL THEODOR SIEVERT of Lindenaustrasse, 32, Dresden, Saxony, Germany,
Glass Manufacturer, do hereby declare the nature of this invention 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 sheets, glass cylinders, and
other glass, bodies, by the process of drawing the molten glass issuing from a
suitably shaped slit or opening in a holder or vessel.
The present invention refers, more particularly to a system of combining the
glass holding vessel or vessels provided with a suitably shaped slit or opening with
the glass melting furnace, in such manuer that the molten glass proceeds directly,
or underneath bridges, or over partition. walls, from the furnace, into the receiving
vessel or vessels, so that a continuous. working. of glass articles, such as above
referred to, may take place, while the. molten glass, on its way from the furnace to
the receiving vessel or vessels, and while. in the vessel or vessels, is under the
influence of the heat radiating from the melting furnace, which heat may, by proper
means be regulated. The glass, at its issue from the slit or opening of the vessel
or vessels, is also brought under the influence of heat conducted thereto by separate
I flues, to which, also, devices for regulating such heat may be applied. In the
process, of manufacturing glass articles by drawing. the molten glass issuing from
the slit of a vessel, it was originally designed to transfer the molten glass by
ladles out of the furnace or glass pots to the receiving vessel or vessels.
This

page_text: method, however, involves much labour and expense, and has the disadvantage of
introducing bubbles, and retaining impurities in the glass. Again, in other cases,
the molten glass was caused to run in gutters or their equivalent from the melting
vessel into the place where the shaping of the glass commences, by metal rollers or
other devices.
I now remove the difficulties referred to, by combining my vessel or vessels (out
of which I allow the molten glass to issue) directly with the glass melting furnace,
in such a manner that the molten glass always, and at the ratio of its being drawn.
away from the receiving vessel or vessels, flows from the furnace directly, without
ladling, and without any extra gutter, into said vessel or vessels..
By this system, I avoid all impurities and bubbles which the handling of, the
molten glass by ladles or other implements may incorporate in the molten glass.
I furthermore have, by my system, the molten glass, in its course from the furnace
into the receiving vessel or vessels, under the direct influence of the heat radiating
from the glass melting furnace, which heät I am enabled to regulate by dampers or
such like devices, so that the molten glass is always in the proper state of semi-
fluidness or toughness in the receiving vessel or vessels for my purpose.
In the way from the furnace to the vessel or vessels, I may apply the means
well known to glass manufacturers and constructors of melting glass furnaces, for
retaining, within the furnace, the impurities which form on the top of the molten
glass, or which fall to the bottom of the molten glass, such constructions consisting
of bridges for keeping the molten glass surface back from leaving the furnace, or
of separation walls fixed on the bottom of the furnace, or in the channel for the
running glass, such walls being of the proper height to allow the surface of the
molten glass to run over such walls, while such wall or walls keep back
the impurities at the bottom of the glass.
At the end of such channel, I arrange my vessel or vessels in such level, that
they will always be kept filled with molten glass of the proper semifluidness or
toughness, which glass runs out by its own weight, or by additional pressure,
through the opening at the bottom of the vessel.
In some cases, I arrange, in direct connection with the glass melting furnace, or
interrupted by bridges and walls, as aforesaid, an annex of the furnace, such as
will allow of the arrangement of a number of vessels in a semi-circular manner,
which are all simultaneously, or part of them, filled with molten glass in proper
condition running from the furnace. Each vessel is provided with proper discharge
openings of straight, curved, or circular shape, so that from them the molten glass,
as it is discharged, will take one or other of the forms desired. The drawing out
of the molten glass may be done by hand, or by mechanical means, in order not
only to give the proper shape and length to the bodies to be produced, but mainly.
to give to these bodies the proper thickness of skin required..
In order to maintain the issuing glass in a suitable condition for drawing to the
desired thickness, it is necessary to subject the glass in the vessel, as well as at its
point of issue, to proper heat. For this purpose I may construct in the glass
melting furnace in which the vessel or vessels are arranged, or in the annex of the
glass nielting furnace in which the vessel or vessels are arranged, proper flues,
which conduct the necessary heat to the outer surface of the vessel, and to the
point of issue where the molten glass leaves said vessel or, vessels.
In order that the invention may be fully understood, I refer to the annexed
sheet of drawings, in which
Fig. 1 is a vertical section, on line A-B of Fig. 2, and the latter a horizontal
section on line CD of Fig. 1, of a glass melting furnace b, in combination with
one or more glass holding vessels a arranged in an annex c to the said furnace b.
Fig. 1 sliews the arrangement of but one such holder vessel a, while Fig. 2 shews
a number of such holders or vessels à situated in a semicircular position in the
annex c. The vessel or vessels a, of preferably a truncated shape, are provided at
their lower and smaller end with a ring or other shaped opening for the issue of
the molten glass in circular, oval, or polygonal form; in order that, in issuing, the

page_text: glass may take a corresponding form. The molten glass in the furnace 6 flows in
known manner, and under the influence of the radiating heat of the furnace, into
the annex c, and enters into and fills the vessel or vessels a. The glass is kept
here in its semifluid state by the heat of the furnace. When the temperature is
unduly raised, and the glass is thereby made too fluid for the purpose in view, the
heat may be regulated by the damper o to any required degree, or the damper may
be fully closed. As the mass of molten glass enters into the vessel or vessels a at
a speed or ratio determined by the rise of level in the furnace, it will be obvious
that a quiet flow of the glass may be obtained at will, so that the formation of
bubbles is entirely prevented. The entering of any impurities in the glass into the
vessel or vessels a, is also, prevented by the course. which said glass takes from the
furnace into the annex.
The exterior of the vessel or vessels a is heated by flames 'issuing from the
channels m. This heating prevents the choking of the slit or opening at a by
the solidification of the glass during the drawing operation, and consequently the
glass, at its point of exit or initial formation, is kept in the requisite state of
semifluidity or temperature for the completion of the drawing process. According
to the increase or decrease of the flame or flames issuing from m, the molten glass
inside and outside of said opening may be kept in either a tougher or more liquid
state, as required. The process of drawing the glass may therefore be influenced
partly by regulating the flame or flames of the channel or channels m, and partly
by regulating the heat radiating from the furnace into the annex.
When the drawing process interrupted or stopped, the issue of the flames must
be arrested. This will cause such a cooling down of the glass at the slit or
opening, that further issue is prevented. If the drawing process is to be continued,
the flame is again applied to the vessel, in order to make the glass flow again out
of the slit or opening. According to the size of the melting furnace, the number of
exits for the glass (which is to be subjected to the drawing process) arranged in the
annex of the furnace, will be determined.
Fig. 3 is a vertical section through centre of Fig. 4, the latter being a horizontal
section taken above the vessel a of Fig. 3.
In this instance, the annex for the openings or slits is dispensed with, the holder
or vessel a being arranged in immediate connection with or within the glass
melting furnace b. The admission of glass from the furnace into the vessel, the
regulation of heat radiating from the furnace or issuing from the flues or
channels m, for keeping the molten glass in proper condition, and for influencing
the drawing process, may be the same as in the description with reference to
Figs. 1 and 2. The molten glass may enter from the furnace below bridges,
such as e, or above partition walls, such as f, into the holder or vessel a, furnished
with a proper slit or opening for the glass to issue in the form of a sheet or sheet.
mm are flues or channels for conveying heat to the exit opening or openings for the
purpose above stated.
I have spoken above (with reference to Figs. 1 to 4) of a holder or vessel a
provided with a straight or ring shaped slit or opening; but I wish it to be under-
stood that I do not coufine myself to the arrangement of extra vessels or vessels
in the annex c, or immediately within the melting furnace, for the purpose
aforesaid. A chamber or chambers, or space or spaces, arranged in the annex,
or immediately within the melting furnace, and provided at bottom with a slit or
opening, or slits or openings, may be suitable for the purpose in view; thus,
in Fig. 5, I have shewn the end of a melting furnace (if necessary, provided with
bridges e and partition wall f) with a chamber, space, or room g, such chamber,
space, or room, having a slit or opening at the bottom for the glass to issue by its
own gravity. The slit or opening may be formed as shewn, for example, in
Fig. 5, by iron bars or tubes h, which, to withstand the heat to which they are
exposed, may be made hollow, for water to circulate through them. In this
instance, I preferably arrange nozzles to pipes i for gas, or for a mixture of gas
and air, to issue below slit or opening, the flames of which are directed as near as

page_text: possible to the centre of the flowing glass; such glass, by the regulation of the
flames, may be kept in the necessary state of semi-fluidity, in order that it may
issue in proper condition for the drawing.
In the arrangements Figs. 1 to 5, I reserve to myself the right to provide
extra flues or channels or jets of gas above the vessels, holders, or chambers,.
in order to influence the surface of the molten glass by extra heat, in addition to
the heat radiating from the furrace, or without such radiating heat, as the case
may require.
It will be understood, that I may arrange the vessels, holders, or chambers,.
either with straight, or with ring-shaped slots or openings, in all the different.
cases, whether the molten glass is to issue from the annex of the melting
furnace, as in Figs. 1 and 2, or immediately from the melting furnace, as in.
Figs. 3, 4, and 5.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. For the purpose of drawing molten glass into the form of sheets or hollow
bodies, when the same flows by its own gravity through slits or openings of
suitable configuration, the arrangement of such slits or openings in combination
with a glass melting furnace, said slits or openings being situated either in an
annex of the furnace, or directly within said furnace, and, in combination therewith,.
means for subjecting the molten glass, in its flow, to heat under the control of an.
attendant, for the purpose set forth.
2. The employinent of a glass melting furnace 6 provided with an annex c, in..
which latter a slit or opening, or slits or openings, of the required shape, are
arranged for the molten glass of the furnace to pass through by its own gravity,
in order to be drawn into a form corresponding to said slits or openings, substantially
as specified above with reference to Figs. 1 and 2.
3. The employment of a glass melting furnace 6 with a slit or opening, or slits.
or openings, of the required shape for the molten glass to pass through by its own
gravity, in order to be drawn into a form corresponding to said slits or openings,.
in combination with the means for heating the glass at its exit, as described with
reference to Figs. 3, 4, and 5.
1 C1007
NEWTON & SON,
Agents for the Applicant.