IMPROVEMENTS IN THE MANUFACTURE OF GLASS
Year: 1853

page_text: LETTERS PATENT to George Mackay, of Buckingham Street,
Strand, Gentleman, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF GLASS."-A coinniunication.
Sealed the 23rd August 1853, and dated the 5th July 1853.
PROVISIONAL SPECIFICATION left by the said George Mackay
at the Office of the Commissioners of Patents, with his Petition,
on the 5th July 1853.
I, GEORGE MACKAY, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE MANUFACTURE OF GLASS" to be as
follows:-
This Invention relates, firstly, to the melting of glass. To this end
a reverberatory furnace is employed, having a crown or arch formed
of hollow bricks or even of metal. Above the under surface of the
arched roof of the furnace a winding flue or a series of flues is con-
structed. Into these flues, which are pierced with small holes, air
sufficient for a blast is forced by means of any well-known blowing
apparatus. These holes are arranged so as to direct the flame and
gases of combustion downward upon the glass and pots containing the

page_text: same, and thus, while a powerful blast is directed to the glass, the arch
of the furnace will be in a great measure protected from the action of
the fire.
This Invention relates, secondly, to the forming of plates of glass by
causing the melted material to pass between two or more pairs of
rollers set at different distances apart and having different surface
speeds. These plates, when formed, are retained between the rollers
until cool enough to hang without stretching in a vertical position, and
they are then suspended by their upper edges in an annealing chamber.
Both the rolling and annealing processes may be used in conjunction,
or either may be employed where the old modes are in part resorted to.
In a carriage which runs on a railway placed above the annealing
chamber, two or more pairs of pressing rollers are mounted.
A hopper or reservoir containing the melted glass from the furnace
is set above the upper rollers, so that by opening the bottom of the
reservoir the glass can be precipitated directly between them; or the
hopper is hung in a frame, so that it can be turned up to pour the glass
on to the rollers, the revolution of which causes it to pass down between
them. The second pair, which are closer together than the first pair,
should have a greater surface speed than the latter, in order to draw
the glass to a reduced thickness..
In introducing the glass into the annealing chamber the lower series
of rollers are holding rollers simply. If the rollers are found to becoine
too highly heated their temperature is to be reduced by a current of
steam or water introduced into their interior through their journals.
One or more of the rollers can be embossed in any desired pattern,
which will be transferred to the glass, either for ornament or strength;
or the rollers may all be perfectly plain, making smooth surfaces.
The annealing chamber (which is rectangular and may be of any
dimensions) is provided at top with a series of long narrow fissures
extending the whole breadth of the chamber, which is equal to the
length of the rollers. Each of these openings is furnished with a clamp,
which may be formed like a parallel ruler or in any other way found
most convenient; it may be set up by a screw at the end, or other well-
known device, so as to gripe the glass it is to sustain: The chamber is

page_text: beated by air pipes connected with the furnace. After the glass has
passed down through a sufficient number of holding rollers to attain a
proper consistency to sustain its own weight it may be polished by one
or more sets of polishing rollers formed of wood or metal and covered
with
emery, pulverized charcoal, or other polishing substance used for
polishing glass. These rollers are to receive a rapid rotary motion,
and also have an end chase, and they are to be kept pressed against
the surface of the glass.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Mackay in the Great Seal Patent Office,
on the 5th January 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME,. I,
GEORGE MACKAY, of Buckingham Street, Strand, Gentleman, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of July, in the year of our
Lord One thousand eight hundred and fifty-three, in the seventeenth
year .of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Mackay, Her special license that I,
the said George Mackay, my executors, administrators, and assigns,
and such others as I, the said George Mackay, my executors, admi-
nistrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
MANUFACTURE OF GLASS," being a communication from abroad, upon the
condition (amongst others) that I, the said George Mackay, by an
instrument in writing under my hand and seal, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.

page_text: NOW KNOW YE, that I, the said George Mackay, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
unto annexed, and to the letters and figures marked thereon (that is
to say):
This Invention of "Improvements in the Manufacture of Glass"
relates, firstly, to the melting of glass. For this purpose a reverberatory
furnace of peculiar construction is employed. This furnace is provided
with a crown or arch formed either of hollow bricks or of metal.
Above the under surface of the arched roof of the furnace a winding
flue or a series of flues is constructed, and into these flues (which are
pierced with small holes) air sufficient for a blast is forced by means
of any well-known blowing apparatus. These holes are constructed and
arranged in such a manner as to direct the flame and gases of com-
bustion downward upon the glass or the pots containing the same; and
thus, while a powerful blast is directed to the glass, the arch of the
furnace will be in a great measure protected from the action of the fire.
This Invention relates, secondly, to the forming of plates of glass by
causing the melted material to pass between two or more pairs of rollers
set at different distances apart and having different surface speeds.
These plates, when formed, are retained between the rollers until cool
enough to hang in a vertical position without stretching, and they are
then suspended by their upper edges in an annealing chamber.
In order, however, that this Invention may be clearly understood I
have shewn in the accompanying Drawings the machinery and ap-
paratus which I propose to employ to carry out the objects of the
Invention.
Fig. 1, is a longitudinal vertical section of a reverberatory furnace
constructed according to the first part of the improvements.
Any of the usual pots for making plate glass may be used, and I.
prefer to construct the reverberatory furnace in the following manner :-
I turn the arch m, of the furnace as low as is 'consistent, and form it of
hollow bricks or even of metal, so as to form a kind of hollow roof. I
make above this metal plate, or by means of the hollow bricks above

page_text: the under surface of the arched roof of the furnace, a winding fluc
n, n, m, n, or a series of flues, occupying a part or the whole surface of
the arch; into these flues I force air sufficient for a blast by means of
any well-known blowing apparatus, and along the surface of the arch I
pierce the flues with small openings 0, 0, 0, 0, so arranged as to cause
the air from the flucs to be forced downwards; by this means a stratum
of air is brought between the roof of the furnace and the heated gases,
and these gases and the heat therefrom are driven downward upon the
glass and the pots containing the same. This blast has a twofold effect,
as it supplies heated atmospheric air to produce the most perfect com-
bustion of the gases, and forces the heat evolved therefrom downwards.
to the point upon which it is desirable to concentrate it, and it shields
at the same time the roof of the furnace from the excessive heat and
prevents the vaporized fluxes and other material from attacking the
roof and destroying it, as they are well known to do in many glass
furnaces, to the great annoyance of the workmen and injury to the
melting glass. This device, it is obvious, is applicable to other glass
furnaces. In the Drawing this device is shewn in one form merely, as
an example, which may be modified as occasion may require.
.
The apparatus for forming plates of glass, as shewn at Figs. 2, 3,
and 4, consists of a carriage composed of two side pieces a, properly
connected and placed on trucks, wheels, or rollers b, on which it moves.
This carriage a, supports two or more pairs of rollers e, (scen best in the
ectional view Fig. 3). The second pair may be placed nearer than those
above them, so as gradually to reduce the thickness of the glass as it
passes between them.
#
A hopper or receiver d, called a cuvette," containing the melted
glass from the furnace, is located above the upper rollers, so that by
opening its bottom the glass can be precipitated directly between the
first pair of rollers; or the vessel containing the glass may be hung in
a frame, so that it can be turned up to pour the glass on to the rollers,
which by their revolution causes it to pass down between them, as in
Fig. 3. The second pair can be made to move faster at their surface
than the first pair, and the glass may thereby be drawn to any thickness.
It is necessary for the glass to be cool enough to sustain itself before it

page_text: enters the annealing chamber, which forms the third improvement,
therefore the lower series of rollers are holding rollers simply. If
the rollers are found to become too highly heated they can be cooled
to any degree by a current of steam or water introduced into their
interior through their journals, as is done in paper-drying machines
and many others.. One or more of the rollers can be embossed in any
desired pattern, which will be transferred to the glass, either for orna-
ment or strength; or the cylinders may all be perfectly plain, in order
to produce smooth surfaces.
The annealing chamber C, is rectangular and may be of any
dimensions; in the top of this chamber are a series of long narrow
fissures f, extending the whole breadth of the chamber, which is equal
to the length of, the rollers. Each of these openings is furnished with
a clamp i, which may be formed like. a parallel ruler, as shewn in the
Drawing, or in any other way found most convenient: it may be set
up by a screw k, at the end, or other well-known device, so as to gripe
the glass it is intended to sustain. The annealing chamber is heated
by air pipes connected with the furnace; by which a proper supply of
heat is kept up in the annealing chamber. After the glass has passed
down through a sufficient number of holding rollers to obtain a proper
consistency to sustain its own weight it may be polished by one or
more sets of polishing rollers; these rollers a, Fig. 3*, and Figs. 4, and 4*,
can be formed of wood or metal, and their outer surface covered with
emery, pulverized charcoal, crocus, or other polishing substance used
for polishing glass. The rollers receive a rapid rotary motion, and an
endway motion is also given to them by means of the crank z. They
are kept pressed against the glass by springs, weights, or other con-
trivances, or they may, in certain cases, have no endway motion; there
may or may not be other holding rollers below the polishers, but if
there are such rollers interposed between the polishers and the an-
nealing oven they must be highly finished and perfectly smooth on
their surface.
To enable persons skilled in the art of manufacturing plate glass to
use the present improvements I will describe the process of manufacture
thereby The glass is made and prepared in the usual way, and then

page_text: transferred to the hopper or reservoir, which is placed in a heating arch,
where it is brought to the necessary temperature; when the glass is in
a proper state the hopper is removed, and by means of cranes or other
devices it is transferred to the carriage, which runs along a railway
over the annealing chamber with its rollers parallel with the fissures
therein. When directly over one of these openings the metal is caused
to run between the rollers, as before named, and thence down into the
annealing chamber. When a sufficient length has been run off into
the chamber the clamp is closed upon it and the glass is broken off*
above; the carriage then passes on to the next opening and the same
process is repeated. It is obvious that the carriage may be stationary,
and the clamps made to move along the annealing chamber. The
glass thus suspended maintains a perfectly straight position till annealed,
and much labor is saved in the after process of grinding and polishing.
Both sides can, if desired, be embossed and not be injured, as would be
the case if they were made to lay on a bed or table. The glass manu-
factured by any known process can be suspended in the annealing
furnace to be kept straight while cooling by this Invention.
Having thus fully described the improved process of making plate
glass and annealing the same, what I claim as this Invention, and which
I desire to secure by Letters Patent, is-
First, manufacturing plates of glass by causing the glass, after having
been formed by rolling or otherwise while in a plastic state, to pass
between two or more pairs of rollers for drawing and holding the glass
till cool enough to support itself.
I also claim embossing the surfaces of plate glass by passing it
between embossing rollers, as above described.
I also claim the polishing rollers for polishing the glass before an-
nealing, as herein specified.
I also claim the construction of the crown of the arch of a rever-
beratory glass furnace with an air chamber or chambers having,
downward openings to throw down the heat and vaporized materials,
and thereby preserve the top of the arch and increase the effect of the
fires.

page_text: And, lastly, I claim suspending plates of glass by their upper edges,
after they have been formed, while annealing, so as to keep them in a
perfect plane without resting on a bed:...
In witness whereof, I, the said George Mackay, have hereunto
set my hand and seal, the Eleventh day of October, in the year
of our Lord One thousand eight hundred and fifty-three.."
Witness,
J. T. LIDIARD,
50, Carey Street,
Law Stationer.
GEORGE MACKAY. (L.S.)