IMPROVEMENTS IN THE MANUFACTURE OF THAT DESCRIPTION OF GLASS TERMED PLATE GLASS
Year: 1860

page_text: Sealed' the 18th June 1861, and dated the 19th December 1860.
PROVISIONAL SPECIFICATION left by the said Obed Blake at the
Office of the Commissioners of Patents, with his Petition, on the
19th December 1860,
I, OBED BLAKE, of Southampton Street, Strand, in the County of Middle-
sex, Plate Glass Manufacturer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF THAT DESCRIPTION OF
GLASS TERMED PLATE GLASS," to be as follows:-
My improvements commence with the casting of the melted metal or glass,
and proceed through the annealing, grinding, and smoothing to the final pro-
cess of polishing plates or sheets of glass. In casting I propose to use two
rollers, one of which is to be so fixed that its only motion can be on its axis;
the other to be so arranged that while moving on its axis it will also move
over or round the circumference of the roller first mentioned. These rollers,
previous to casting, are to be so adjusted that space be left between them
equal to the thickness of the plate about to be cast. The casting will be
effected by pouring the molten glass on the fixed roller, in such wise that it

page_text: may pass or flow to the moveable roller, which is made to travel so as to
spread out the glass on the surface of the roller beneath, the which slowly
turning on its axis will serve to bring the sheet of glass (now in process of
casting) spread out as aforesaid into position, so as to be received on a table
which is to be placed under the before-mentioned rollers; said table may be
made or partly made of iron or other metal, and covered with plaster of Paris
or other suitable non-conducting or partially non-conducting material. The
table is to receive the end of the sheet of glass in process of casting, and to be
so arranged that it may travel forward at a speed regulated with respect to the
rollers, in such manner that the surface of the glass, when received on the
table, shall not be rubbed or abraded by the contact with its surface. This
operation being effected, I propose to pass the table with the glass upon it into
the annealing kilu, which I propose so to build and arrange that several tables
with their respective cast plates may be received seriatim, and the plates be
annealed at one operation. And for this purpose
I propose to prepare ledges
or grooves on or in the walls of the kiln to receive and support the tables, or
when the tables are not quite wide enough to fill the breadth of the kiln, and
therefore do not admit of being so placed, I propose to fix iron-bars-on-the-
ledges or in the grooves, so that they may form open shelves and not obstruct
atmospheric contact, or in other words, permit the whole cubic contents of the
kiln to be heated from one fire. I expect that plates of glass so cast and
annealed will, in their rough state, be more transparent and possess a fairer
surface than those made by the present process.
In the further operations of grinding, smoothing, and polishing these plates
(or plates cast by any process) so as to fit them for use for looking glass or
polished window glass, I propose to erect over a lap or circular table (which
will be made to turn round on its vertical axis) a travelling beam, extending
over the diameter of the said lap or table; the ends of this beam are to
rest on slides or carriages. I propose to impart by mechanical means a
to-and-fro movement to this beam, which is to travel in a straight line and
only in one direction. The lap or table being covered with plates of glass
fixed or bedded thereon in the usual manner with plaster of Paris and a
number of small rubbers of iron or other metal or stone (or faced with either
material) being fixed to the travelling beam aforesaid. I proceed to give by
mechanical means circular motion to the table, and to-and-fro motion to the
beam, using for grinding material, firstly, sand, and subsequently emery. Thus
the rubbers will move to and fro across the glass on the table, while the table
revolves horizontally under them. The glass plates being sufficiently ground,
I propose to reduce the speed at which the machinery causes the table. and

page_text: beam to travel, and to smooth the plates (without removing them from the
table) by using finer emery. This process completed, I propose to remove the
rubbers hitherto used from the travelling beam, and to substitute others
covered with felt in the usual manner, set the machinery again in motion, and
polish with crocus or other polishing powder.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Obed Blake in the Great Seal Patent Office on the
19th June 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, OBED
BLAKE, of Southampton Street, Strand, in the County of Middlesex, Plate
Glass Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of December, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Obed Blake, Her special licence that I, the said Obed
Blake, my executors, administrators, and assigns, or such others as I, the
said Obed Blake, iny executors, administrators, 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 THAT DESCRIPTION OF GLASS TERMED PLATE GLASS,"
upon the condition (amongst others) that I, the said Obed Blake, my
executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, 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.
NOW KNOW YE, that I, the said Obed Blake, do hereby declare
the nature of, my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-.
The results produced by bringing my improvements in the manufacture
of plate glass into operation are, obtaining in the first instance (that is, in

page_text: the casting) a better surface on the sheet of glass as cast; in the second,
by annealing, grinding, smoothing, and polishing plates of glass. By my
method they are manufactured well finished for either silvering or glazing. I
have not succeeded, nor did I propose in recording my Invention, to produce
a better finish or polish on plates of glass than is produced by the means ordi-
narily employed for that purpose when such means are used with proper care;
but I obtain the polished surfaces with greater celerity and with considerable
economy of labor and material. One result, that of obtaining in or by the first
process a better surface on the plate (commonly termed rough plate) I attain
by casting the metal (molten glass.) in a novel manner. I am aware that
attempts have been made to cast plates of glass by the use of rollers or cylin-
ders, but such attempts have hitherto failed, unless where a mode of roughing
or toothing the surfaces of the rollers was practised; but by this process the
surface of the plate was destroyed.
For my process I use two rollers of unequal dimensions; the larger (which
I term the receiving roller) which may be from four to ten or more feet in
diameter, according to the size of the plates intended to be manufactured; the
smaller or spreading roller need not exceed eigliteen inches in diameter, and
may be made smaller. The larger roller is a fixed roller, having but one
motion, that rotative and upon its own axis. The smaller not only rotates on
its axis but runs up a portion of the outer periphery of the larger roller;
arrangements being made that the two rollers work at a distance from each
other equal to the intended thickness, of the plate of glass to be cast.
In casting, I pour the metal upon the larger roller, over the face of which
it runs until it meets the small roller, which is then made to rotate and travel
upwards over the larger roller, pressing the metal to the thickness of the space
adjusted between the two rollers. When the small roller attains the apex of
the larger one (which has also been made to rotate, but more slowly, say, at
half speed), the plate is formed upon the large roller (care having been had
that no more metal be poured than is required for this purpose) and the lower
edge of the plate which has been spread or pressed out between. the rollers is
received upon, and a small portion of the glass turned over the end of the
receiving table, forming a welt, which aids in steadying and holding firmly the
plate as the table moves onward with it. The table with the plate of glass
upon it is, then removed to the annealing kiln, and the small roller is then
brought down to its original position for the next operation. The large or
receiving roller is made either of iron turned and polished, or of metal coated
with a non-conducting or partially non-conducting material, such plaster of
Paris, and the material is made to adhere to the surface either by perforating

page_text: the metal and forming key, or by any other contrivance. The smaller or
spreading roller is of metal, and serves as aforesaid (in conjunction with the
receiving roller) to flatten and spread out the glass before it reaches the table.
The table is moveable, and is either acted upon by the larger roller direct or
made to slide on its bed by any of the well-known mechanical contrivances; it
keeps time with the slow motion of the large roller, and receives the plate in
such wise that the surface of the glass is not scratched or abraded in its con-
tact with the surface of the table. I make the framework of the receiving
table of iron, but fix thereupon some substance that shall be a slow conductor
of heat, such as stone, slate, clay slabs, or tiles formed of clay,. pieces of rough.
glass, prepared wood or other fibrous substance, and over this I spread a coat-
ing of plaster of Paris, which I make even and smooth; and such table before
being used for the first time must be thoroughly dried in the annealing kiln..
The operation of casting being completed by the delivery of the roller or flat-
tened plate upon the table, I remove the table with the plate thereon. into the
annealing kiln hereafter described..
The working of the rollers may be effected in various ways, one of which I
will proceed to describe, but as the mechanical arrangements for working my
rollers and moveable table do not form an essential part of my Invention, I
would observe, that those to be described may be modified as circumstances.
arise to render alterations desirable.. The whole of my apparatus is supported.
upon a framing of cast iron or other material. In.bearings on the upper part
of this framing is supported. a large roller carrying at each end a tootheds
wheel. These wheels gear into racks on a moveable frame-beneath the roller,.
which frame, when in motion, is. carried over rollers on spindles crossing
beneath the frame: This moveable frame with longitudinal racks at each side
supports the table on which the glass is received from the rollers. The large
roller is set in motion by two pinions on a spindle crossing the framing on the
side of the roller facing the delivery end of the table, and resting in bearings.
On the opposite side of the
on the same level with those of the large roller.
large roller is a smaller one, also having cog wheels.at either end, which tooth.
into the whole of the large roller, and on the spindle of this roller at both:
ends is attached an elbow-jointed lever, the longer or horizontal arm of which:
has its fulcrum on a spindle crossing the framing beneath the table. The hori-
zontal arm of both these levers has at its extremity a toothed sector, which gears.
into a pinion on a spindle crossing the framing, and near the end of the hori--
zontal arm (immediately behind the sector and on both sides of the machine)
will be fixed a weight, to act as counterpoise to the weight of the-small rollér.
The spindles of the large and small roller are connected at both ends by an

page_text: arm, which can be elongated or shortened by means of a wedge and screw, the
object being to regulate the space between the large and small roller, and thus
the thickness of the glass to be cast. The whole being in position, the metal
is poured on to the large roller, and the pinions gearing into the sectors con-
, nected with the levers which lift the small roller are set in motion, and also
the pinions gearing into the wheel of the large roller, which will be made to
rotate at less speed than the small one, and the wheels of which gearing into
the racks beneath will bring forward the table to receive and carry onward the
glass as formed upon the large roller.
My improved kilu is so arranged that several tables with their respective
load of plates of glass may be received therein, and be annealed at the same
time and by one furnace. And the better to effect this operation, I either
have ledges on the walls of the kiln or construct grooves therein, such ledges
or grooves serving to support the tables, or when the tables are not sufficiently
large to fill the breadth of the. kiln, and therefore do not admit of being so
placed and supported, I cause a support to be made of iron bars, placed cross-
ways and resting on the said ledges or in the said grooves; and on these bars
I-place-the-tables as on a gridiron or openwork support, thus securing a free
circulation or impermeation of the hot air, or in other words, permit the entire
cubic area of the kiln to be heated from one fire. I so construct the front of
my kiln that there shall be a flap or door corresponding with each ledge or
grating intended for reception of the table carrying the glass, in order that
cach plate may be introduced through a separate opening, to prevent the cool-
ing of the kiln, which would result from having too large an aperture opened
at one time, and to prevent the fall of any dirt or foreign substance upon the
plate it is advisable to commence stowing the kiln from the top ledges or
gratings.
The next operations in the manufacture of plate glass are, grinding and
smoothing, and finally polishing. These operations 1 perform without re-
moving the glass, from the time it is imbedded on the disc or table until it is
finally polished on one side thereof. Whether the plates have been cast and
annealed by my process or by any other, I first erect a lap or circular table by
any of the mechanical means now well known and understood, making the
apparatus of such strength in all its parts as to secure the lap turning horizon-
tally on its vertical shaft as nearly as possible without oscillation. Over this
lap or table I extend a travelling beam (worked by cranks or pullies), so as
to cover its entire diameter; the ends of this beam rest on slides or carriages,
so that when motion is imparted to the mechanism setting in motion the
cranks, the beam traverses the entire plane of the disc in one direction with a

page_text: to-and-fro movement (the disc revolving under the beam and on its own ver-
tical axis, the one independant of the other). I cover the lap or table with
plates of glass fixed or bedded thereon in the usual manner with plaster of
Paris. For the travelling beam I fit or fix, in the manner in which polishing
blocks are usually attached, a number of small rubbers, are made either of
iron or other metal, or stone, or wood faced with iron, or faced with stone, or
made of any metal or material suitable to the purpose. The disc' and beam
being both in motion, the one circularly and horizontally, and in a straight
direction, and with a come-and-go or to-and-fro motion, I use sand and water
for grinding as is ordinarily practised.
It will be easily understood that with the same mechanical means as regards
the beam, I double my work, where I desire to do so, by placing the crank and
spindle between two tables, and attaching to the one crank two separate
beams (one to each table), which will work simultaneously; and I
vary this
plan by building up the disc or table on a shaft, having on a portion thereof
of (say, about three-fourths its height) a beveled wheel or pinion working into
two other beveled wheels (one on each side); from each of these passes a shaft
supported by bearings in a framing, which also supports and ties together all
the parts, and at each of the other ends of these shafts is another bevel wheel
gearing into beveled pinions on two upright shafts equidistant from the centre
shaft which supports the lap or disc. On the top of each of these shafts is
fitted the broad end of a crank or arm piece, the other end of the crank being
keyed into or on to the end of a travelling beam. Motion being given to the
apparatus, the centre vertical shaft revolves, carrying with it the disc or table,
and the pinion fixed on itself (the shaft); this pinion sets in motion the two
beveled wheels into which it gears, and those at the other ends of the hori
zontal shafts before-mentioned, causing the pinions on the outer vertical shafts
to rotate, and consequently the shafts themselves; these in their turn impart
movement to the cranks on their tops, and so to the travelling beam which
crosses the disc or table, and moves, when impelled, partly in a come-and-go
motion and partly diagonally. On the lap or disc I place the plates of glass
to be ground, smoothed and polished, and on the travelling beam the small
rubbers before described, to operate on the said plates of glass in the said pro-
cesses. As before said, I use sand for grinding, and subsequently emery. The
glass plates being sufficiently ground, I either do or do not reduce the speed at
which the machinery causes the beam and table to travel. I say, I do or do not,
because, although it is usual to smooth at a greatly reduced rate of speed than
is given in the grinding process, I find it answers very well to grind at a some-
what reduced speed, and smooth at an advanced rate; or, if desirable to alter

page_text: speed, it may be done as directed in my Patent, No. 469, dated the Twenty-
first day of February 1859. In either case I smooth without removing the
plates from the disc, or table, or the rubbers from the beam; but for polish-
ing, although I do not remove the plates from the disc, I remove the rubbers
hitherto used from the travelling beam, and substitute others covered with felt,
such as are ordinarily used for polishing; this being done, the machinery is
again set in motion and continued till the polishing is complete, the substances
used being crocus or other polishing powder. I use for the purposes of grind-
ing and smoothing small detached rubbers separately fixed to the travelling
beam, in such wise that one rubber shall overlap the stroke of the other.
These rubbers are similar both in size and mode of attachment to the ordinary
polishing block, but instead of being faced with felt they are faced with stone,
iron, or other hard substance, the effect of which system of small rubbers is to
grind and smooth the glass in less time than those processes can be accom-
plished by the large rubbing surfaces at present in use.
The operation of grinding, smoothing, and polishing being now finished as
regards one surface of the plate or plates of glass, they are taken off the
table or disc, re-imbedded with the ruff surface upwards, the operation just
described repeated, and then the plates are ready for use either as plates for
looking-glasses, or for glazing into window frames, or other purposes for which
plate glass polished on both surfaces is applicable.
Having now described the nature of my "Improvements in the Manufacture
of that Description of Glass termed Plate Glass," and ways and means by which
I carry them into practical effect, I would here observe that I do not confine
myself to the precise details herein-before given or set forth, nor to any par-
ticular or precise means by which motion is given to the mechanism, or the
precise mechanism by or with which the rollers and table in casting, or the lap
or disc and travelling beam in grinding, smoothing, and polishing are worked.
Nor do I claim. the exclusive use of any of the parts of mechanism or fittings
for kilns herein mentioned or referred to taken as parts or fittings and not used
in combination or for the purposes of my Invention, which I declare to be and
I claim,
Firstly, the exclusive use of the fixed and travelling rollers and moveable
table used in the casting of plates.
Secondly, the exclusive use of the improved annealing kiln, as described for
annealing the plates so cast.
Thirdly, the exclusive use of the travelling beam working with the lap or
disc, whether such beam be working to and fro, on, or over one or more laps
or. discs, or whether such. beam works supported with and by two vertical

page_text: shafts and their cranks for grinding, smoothing, and polishing one surface of a
sheet (or one surface of several sheets) of plate glass in one operation without
removal of the glass from the disc or lap. The whole essentially as set forth
and herein directed.
DU
shafts and their cranks for grinding, smoothing, and polishing one surface of a
sheet (or one surface of several sheets) of plate glass in one operation without
removal of the glass from the disc or lap. The whole essentially as set forth
and herein directed.
In witness whereof, I, the said Obed Blake, have hereunto set my hand
and seal, this Nineteenth day of June, in the year of our Lord One
thousand eight hundred and sixty-one.
Witness,
W. E. GEDGE,
Patent Agent,
OBED BLAKE. (L.S.)
11, Wellington Street, Strand.