An Improved Process for the Manufacture of Decorated Glass.
Year: 1898

page_text: Date of Application, 8th Aug., 1898-Accepted, 22nd Apr., 1899
COMPLETE SPECIFICATION.
An Improved Process for the Manufacture of Decorated Glass.
I, EMIL OFFENBACHER, of Markt-Redwitz, Bavaria, in the Empire of Germany,
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:-
For some time past glass decorated by rolling has been greatly employed
because whilst it is not very expensive to make, it is an advantageous substitute
for the decorated glass plates produced by engraving or etching with strong acids
or by means of the sand blast. This glass decorated by rolling as hitherto pro-
duced has the disadvantage that it is only smooth on the decorated side, whilst
the rear side of it is rough and dull. The result is that the transparency of this
glass is lessened and the cutting of the same is also rendered very difficult
because the glass-cutting diamond slips along the rough back and does not there-
fore cut the glass uniformly, although it wears away very rapidly. The reason
for which the decorated glass heretofore manufactured is rough at the back, is due
to the fact that the design is engraved in the cylinder and that the table for
spreading the glass is smooth. The cylinder provided with the design is moved
over the mass of liquid glass and the plate thus formed by spreading comes with
the whole of its lower surface in contact with the table in such a manner that it
cools and becomes rough, the more so that the table itself cannot be made abso-
lutely smooth as otherwise the mass of glass would slide along the table and would
not allow itself to be spread out. This process has also to be employed for the
reason that after the spreading out, the decorated side of the glass plate, (namely
its face) is turned upward, whilst the smooth side (namely the back) of the glass
plate is turned downward. Thus the glass plate could be removed directly from
the iron table and be placed upon the plaster table arranged at the side whence
it is slidden into the straightening or annealing furnace. During this operation
the face of the glass plate always remains uppermost, and is therefore not damaged
and this is a circumstance of great importance. Now all these drawbacks are
obviated by the cylinder-apparatus hereinafter described by means of which
decorated glass having a perfectly polished back can be produced.
As shown in the accompanying drawings this new cylinder-apparatus consists
of a frame a with spindles b and c in which is fixed, the plate of iron or steel
engraved, or decorated in any other manner, with the designs d so as to be capable
of being changed. With the object of more perfectly utilising the material, this
plate is decorated on the upper side, and also on the lower side, so that it can be
used on both sides. It is even advantageous to use: the two sides alternately
because by this means it is possible to obviate the warping of the plate which is
of frequent occurrence in the old process which only knows smooth plates that
can be used only on one side. Over the plate there is or are moved one or more
smooth rollers ef by means of metallic ropes and crank handles ghjk or similar
mechanism. In this manner it is therefore possible in contradistinction to the
process heretofore employed, to produce decorated glass by rolling, with a per-

page_text: fectly smooth back because the design is not engraved in the roller as heretofore
but is engraved in the plate whereby there is also produced a uniform spreading
of the glass due to the fact that the glass cannot slip. Upon the crank axle 7
there is also mounted a third drum m which serves to disengage by means of a
cord n the forked lever o from a recess or its equivalent provided in the worm-
wheel at the moment at which the cylinders ef have moved over the plate a
and have spread the glass. At this moment the casting device ad makes by the
action of the drum q and of the counter-weight r half a revolution and deposits
the glass with its smooth side downwards and with its face uppermost on to the
plaster tables by means of which it is then brought in front of the straightening
or annealing oven in which it is cooled in the usual way. This operation is
effected in such a short time which is necessary besides and without the interven-
tion of the workman so that all solidification is avoided. In order to recommence
the operation the worm-wheel is moved along the spindle b until it again
becomes connected with the clutch secured thereon, and then the plate a is moved
together with the endless screw u secured on the shaft and the crank winto the
initial position, which is also the case with the cylinders ef which are brought
back towards x.
The operation of the above named parts is as follows:-
The frame a in which is fixed the plate of iron or steel engraved or decorated
in any other manner with the designs d so as to be capable of being changed, has
spindles b and c, carried on suitable supports whilst the frame a with the meta!
plate is perfectly free and adapted to be rotated. In order to produce the latter
movement automatically, I have provided the following arrangement:-The
clutch t engages worm-wheel 2 which is prevented from being rotated by the
endless screw u. Now as the cylinders ef are completely moved over the plate a
and spread the glass, said cord n which has been rolled upon drum m, will draw
lever o and worm-wheel p towards the left whereby the latter will be disengaged
from screw u and clutch t. Thus the frame a will be rotated by the action of
drum and balance-weight r.
By rotating axle in reversed direction, the tension of cord n will be removed
and lever o and worm-wheel p may be easily pushed towards the right, until the
latter re-engages screw u and clutch t.
Then by rotating crank w the frame a will be brought again in its initial
position for spreading glass. In order that the glass, when the table a is inverted;
shall not fall from too great a height on to the plaster tables the following
arrangement has been adopted. On the table a there are provided rollers 1, 2, 3,
which at the moment when the table a has commenced to turn, carry the table s
which is situated on the platform 4 top side downwards (Figure 2) but as soon
as the table a has been inverted, the platform 4 and the tables are turned by the
action of a lever 5 with counterweight 6, top side up again and as near to a
as the adjustable shoulder 7 will allow. In turning a over, the plaster table is
returned by the rollers 1, 2, 3, into the position shown. In order to heat the
casting table which is necessary to obtain very clear designs, the frame a as well
as the plate d are provided with passages 8 and 9 as required. In these passages
there may circulate hot water, steam, hot air, &c., which is supplied thereto and
is discharged therefrom by means of the hollow spindles be without interfering
with the tipping movement of the table a. By the fact that the casting plate
is engraved, the said plate offers the requisite resistance to the glass to be spread
out, so that very fluid glass can be used and very clear designs can be produced.
This new arrangement has also the advantage of allowing the raw glass to be
spread in several colours. For this purpose the roller e moves directly over the
engraved plate d and presses, for example the blue glass, into the cavities of the
plate. But at the same time white glass for example, is poured in front of the
roller which has two rollers e¹ (Figure 4) which give a thickness of glass of
about 3 mm. This white glass is spread out at the same time as the blue orna-
mentations, and it combines therefore with the latter, whilst the plate of two

page_text: colours which can be made as rapidly as a plate of one colour is consequently not
more brittle than the latter and is then treated exactly as above described.
It is also possible in order to imitate leaded glass, to pour in front of the
cylinder e, fluid lead or any other metal, instead of glass. Also the ornamenta-
tions or incrustations can equally well be made by means of other machines and
be placed into the recesses of the plate d and be then fixed by the spreading of the
glass by means of the cylinder e in the glass plate which is thus produced. In
order that these metal ornamentations shall not be displaced by the mass of the
glass, the casting table d may be permanently or temporarily magnetised. As the
manufacture of plates ornamented by hand is relatively expensive, and is more
expensive than the manufacture of the ornamented cylinders by means of which
glass plates of indefinite length can be spread the following process is employed
for the manufacture of ornamented plates.
The design which is repeated at certain intervals is engraved only once by hand
on the periphery of a small auxiliary cylinder of steel which may be hardened,
and is fixed in the support or holder of a planing machine. The plate to be
ornamented is passed under the auxiliary cylinder whereby the latter is caused to
rotate and to automatically impress the design over a certain length. When a
strip of the plate has been thus ornamented, the auxiliary cylinder is shifted
laterally in a corresponding manner, and a second, third, etc., strip is then
ornamented in the same way until the whole of the plate has been uniformly
provided with the desired design over its length and its width. By employing
machines of great power the design may be directly engraved in the steel. But
in many cases it is preferable to impress the design by means of the auxiliary
cylinder or by means of any other device (such as a press, a punching machine) or
it may be by hand, in a flexible material, such as papier-mache, plaster, wax, etc.
This material may also be worked in a cylindrical form which is then spread out
to form a plate. This plate which contains the positive design and therefore
exactly resembles the glass to be produced, is introduced with a plate of iron or
steel into a solution of copper in such a manner that the iron plate shall be about
2 mm. from the positive. By the action of an electric current the negative will
then be deposited in the necessary thickness of 2 mm. on to the iron plate, and
it will adhere sufficiently thereto. It is to be understood that in the same way
the two sides or all the sides of the plate may be provided simultaneously with
designs in such a manner that there will be produced a plate of copper or bronze
having an iron core which may be dispensed with if desired.
said
Having now particularly described and ascertained the nature of my
invention and in what manner the same is to be performed, I declare that what
I claim is
(1) A process for the manufacture of decorated glass, according to which the
mass of liquid glass is poured on to the surface of the plate that is provided with
the design, so that said glass is consequently decorated on its lower side, which
cools first, whilst the side of the glass which is uppermost that is to say the back,
is rolled and perfectly polished.
(2) An apparatus for carrying out the process specified in Claim 1, characterised
by a combination of a casting table a adapted to rotate about a horizontal axle c
and containing the ornamented plate d, with a plaster table s that is movable on
a platform 4 and is arranged below the casting table in such a manner that after
the glass is spread, the casting table is tipped by the action of a counterweight r,
that is to say is turned through 180 degrees so that it deposits the glass with its
smooth side underneath and with its decorated face uppermost upon the plaster
table.
(3) A form of construction of the apparatus specified in Claim 2, characterised
by the fact that the spreading plate d is provided on its two sides, with designs,
which serve alternately for spreading the glass, with the object of equalising the
warping which is produced in plates that are employed on one side only.

page_text: (4) A form of construction of the apparatus specified in Claim 2, characterised
by the fact that for the purpose of making glass decorated in several colours or
provided with incrustations of a different material, two movable cylinders ef are
arranged one behind the other above the casting table, and of which one rests
directly upon the ornamented plate d, whilst the other is kept by means of rollers el
etc. at a distance from the plate d, corresponding to the thickness of the glass
plate, the arrangement being such that on moving the cylinder along the plate d,
the first cylinder presses the coloured glass or the material which is to constitute
the ornament and which is situated in front of the said cylinder, into the recesses
of the plate d, whilst the following cylinder spreads out and flattens in the usual
'manner the glass which is poured in front of it and causes it to combine the
incrustation which may if desired be kept in place by means of magnetisation.
(5) A form of construction of the apparatus specified in Claim 2, characterised
by the fact that the casting table a is provided with channels and hollow spindles
through which there is supplied and discharged steam, hot-water, hot-air, etc., for
the purpose of heating the casting table, and the ornamented plate with the object
of facilitating the production of very clear designs in the spread glass.
(6) An apparatus for carrying out the process specified in Claim 1, characterised
by the fact that ornamented plates or cylinders are produced mechanically by
means of an engraved auxiliary cylinder or similar device, which said plates or
cylinders may serve directly for spreading the glass or from which the plates or
cylinders serving to spread the glass, are produced by galvano-plastic processes..
Dated this 8th day of August 1898
ROBERT E. PHILLIPS, Assoc.M. Inst. C.E., M.I.Mech.E.,
Chartered Patent Agent, 70, Chancery Lane, London, W.C.,
Associate Agent.