Improvements in the Manufacture of Plate Glass and in Apparatus therefor.
Year: 1885

page_text: Improvements in the Manufacture of Plate Glass and in
Apparatus therefor.
I, ANTHONY DIXON BROGAN, of Firhill, Glasgow, Lanarkshire, Glass Manu-
facturer, do hereby declare the nature of my invention, to be as follows:—
The object of my invention is to produce plate glass (particularly the rougher
varieties) by rolling molten glass into sheets. The manufacture of plate glass in
this manner has not hitherto been found practicable owing mainly to the tendency
of the glass to adhere to the rolls and to difficulties arising from the liability of the
soft and plastic sheets of hot glass becoming elongated and contorted by their own
gravity; but these difficulties I overcome by the employment of improved apparatus
specially adapted for the purpose in view.
In front of a pair of rolls I fit a hopper whose lower end bears on the under roll,
and this hopper I fill or partially fill with glass in a molten or plastic state. From
a slit in the bottom of the hopper the molten glass passes out by its own gravity or
is pressed out by a plunger in the hopper, and it passes in a thin streain through
the rolls. To prevent adhesion of the glass to the rolls I may polish their surfaces
with graphite or similar lubricant. At the opposite side of the rolls I fit in contact
with the lower roll a block of wood or of metal extending the whole length of the
rolls in the form of a bridge, over which the sheet of glass as it is rolled is carried
Behind this bridge and in contact with it I fit upon rollers a travelling web of
asbestos cloth or of sheet metal, or of any suitable material faced with asbestos or
other non-inflammable substance. This endless web is driven at the same surface
velocity as the rolls and serves to carry off the sheet or plate of glass as it is rolled.
The rolling of the glass into sheets or plates may be finished at a single operation
as above described, but in general it will be found advantageous to provide a series
of rolls and travelling webs in order that the glass sheets may be gradually reduced
in thickness in passing through the successive pairs of rolls while it changes from the
molten to the plastic state. In that case a second pair of rolls is fitted immediately
behind the first travelling web, a bridge piece and a second travelling web behind
the second pair of rolls, and then if desired a third pair of rolls and so on.
last of the series of rolls employed may be suitably formed to impress patterns,
names, numbers, or other impressions on the glass as it passes through the rolls, or
the rolls may be quite smooth to produce plain flat glass.
The

page_text: Apparatus therefor.
I, ANTHONY DIXON BROGAN of Firhill in the County of Lanark, Glass Manu-
facturer, 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:--
The object of my invention is to produce plate glass (particularly the rougher
varieties) by rolling molten glass into sheets by the use of rollers. The manu-
facture of plate glass in this manner has not hitherto been found practicable owing
mainly to difficulties arising from the liability of the soft and plastic sheets of
hot glass becoming elongated and contorted by their own gravity but these
difficulties I overcome by the employment of improved apparatus specially adapted
for such manufacture.
As represented in side elevation at fig. 1, in plan at fig. 2, in end elevation at
fig. 3, and under a modified arrangement in side elevation at fig. 4, of the accom-
panying drawings the improved apparatus which I employ in carrying out my
invention comprises a framing A, supporting a pair of rolls B, B, in front of which
is fitted a hopper C, whose lower end bears on the under roll B, and this hopper is
filled or partially filled with glass in a molten or plastic state. From the lower end
of the hopper the molten glass passes out by its own gravity or if need be is
pressed out by a plunger in the hopper, and it passes in a thin stream through the
rolls B, B. To prevent adhesion of the glass to the rolls their surfaces may be
polished with graphite or similar lubricant. At the side of the rolls beyond the
hopper I fit in contact with the lower roll B, a block of wood or of metal extending
the whole length of the rolls in the form of a bridge D, over which the sheet of
glass as it is rolled is carried. Behind this bridge and in contact with it I fit upon
rollers a travelling web E of asbestos cloth or sheet metal or any suitable material
faced with asbestos or other non-inflammable substance. This endless web is
carried round a set of rollers F by which it is driven at the same surface velocity
as the rolls B, B; and the web serves to carry off the sheet or plate of glass as it
is rolled. Immediately beyond the web E, is fitted a bridge piece D' aud a second
pair of rolls G, G, through which the plate of glass is carried by the movement of
the web or by the draught of these rolls. The travelling web between the pairs
of rolls B, and G, may be dispensed with by carrying the bridge D, across the
intervening space as shown in fig. 4. The bridge should in any case be formed of
wood or similar material which emits vapour on the passage over it of the hot
glass and thereby reduces friction to a minimum. The rolls B, and G and the
rollers F carrying the band are driven by gearing H, from a shaft provided with
fast and loose belt pulleys I.
In some cases it may be found advantageous to provide a series of rolls and
travelling webs or bridges in order that the glass sheets may be gradually reduced
in thickness in passing through the successive pairs of rolls while it changes from
the molten to the plastic state. The last or any pair of the series of rolls employed

page_text: is suitably formed to impress patterns, names, numbers or other impressions on the
glass as it passes through the rolls, or the rolls may be made quite smooth when
used to produce plain flat glass.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that I do
not claim broadly the mode of forming plate glass by the use of rolls but what
I do claim as my invention is: -—
1. The manufacture of plate glass by the use of apparatus adapted to roll out
molten or plastic glass and to impress patterns, designs or the like thereon in the
rolling operation substantially as described.
2. The improved apparatus herein described with reference to the annexed
drawings for use in the manufacture of plate glass substantially as set forth.
Dated this twenty first day of June 1886.
CRUIKSHANK & FAIRWEATHER,
Agents.