Improvements in Apparatus for the Production of Glass Articles.
Year: 1899

page_text: Date of Application, 25th May, 1899
Complete Specification Left, 4th Oct., 1899-Accepted, 9th Dec., 1899
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for the Production of Glass Articles.
I, PAUL THEODOR SIEVERT, of 43, Eisenstuck Strasse, Dresden, in the Empire of
Germany, Glass Manufacturer, do hereby declare the nature of this invention
to be as follows:-
In an application for a patent made by me on the 30th January 1899,
No. 2094, it is stated that, among the devices for carrying out the process for
the production of hollow glass articles, a hollow plate with a multiplicity of
perforations in its thickness, may be employed; and in an application dated
February 6th 1899, No. 2679, it is stated that a solid plate with a perforation
suited to the shape of the glass object to be produced is employed.
It has now been found that the process may be carried out by means of a
solid plate in which a multiplicity of perforations is done away with, and which
also has no large opening corresponding to the shape of the object to be pro-
duced, but which, on the contrary, has only small apertures for the entrance of
the pressure medium,-air, gas, or steam.
By means of a proportionately small perforation, and a proportionately small
quantity of the pressure medium, numerous forms of plastic glass articles may
be symmetrically raised and blown up, either according to the shape imparted
thereto by the frame, or for the purpose of producing a skin, in a hollow mould.
This method of carrying out the invention simplifies and cheapens the
apparatus employed for the process in a material degree, because, firstly, the
hollow plate, with its multiplicity of perforations, and the closing device of the
large openings, are dispensed with, and the small perforations may be directly
connected with the supply pipe of the pressure medium.
It has been found advantageous when the pressure medium is directed against
the centre of the glass layer, to impart a somewhat greater thickness to the
spread-out and smoothed molten glass. This is easily effected by slightly
dishing" the upper surface of the solid plate. The stream of pressure medium
thus impinges upon the thickened portion of the plastic glass layer, lifts it up,
and blows it out, the thickened centre of the glass layer so distributing itself
over the object to be produced, that if a breaking through of the blown-up glass
is not intended, the skin will be formed of equal thickness throughout.
For the simultaneous production of a number of hollow glass bodies from a
spread-out plastic glass layer, this "dishing" of the plate may be as often
repeated as there are objects to be simultaneously produced, and in this case
the plate will be provided with a perforation for each article.
This arrangement is of particular value, when it is desired to produce glass
objects the lower surface of which is of small extent in proportion to their
height, as, for example, lamp chimneys, bottles, etc., or articles thick at the
bottom, as drinking vessels of tumbler form. In the case of the latter articles,
the blowing process is not carried to the point where the glass is blown out to a
niform thickness, but terminates beforehand by striking against the bottom of
he hollow mould, thus producing a tumbler with a thicker bottom and thinner
ide walls.

page_text: The wart-shaped excrescence of the fluid glass which forms in the perforation
of the plate may be disregarded, as may also those arising from a large number
of perforations, seeing that they disappear, as a rule, when thick glass is blown
up, and are not of much consequence in most cases, viz., when they appear on
those parts where the glass skin is broken through during its formation, or
shew themselves, for example, at the four corners of the plate in such portions
of the glass where they either come away when the edge is broken off, or
otherwise.
The weakening of the spread-out glass layer at the edges thereof, which is
caused by the above-mentioned" dishing," necessitates precautions being taken
to prevent this thin edge portion from cooling too rapidly.
Such precautions may consist in thinning the hollow mould at its edge for a
certain height up, that is to say, in a considerably greater measure than is the
case with the sharpened edges described in the applications above referred to,
so that only a very small portion of the metal penetrates the hot glass; or the
precautions may consist in not giving the glass mass the necessary support at
the outlines of the hollow body to be produced by form-giving frames, but by
furrows instead, which are formed in the plate itself, or produced in combina-
tion with a frame enclosing the plate. These furrows may have any convenient
form, and are intended to take the liquid glass mass at the edge of the plate,
and so afford the support to this edge necessary when the pressure medium
raises and blows up the glass surface. The enclosing frame is made to open,
to facilitate the removal of the bead from the furrow, and the filled-up furrows
afford a good means of packing for the pressure medium, which is led beneath
the glass, to raise and blow it up.
The use of such frames to form furrows, lends itself also, it will be under-
stood, for uniformly thick glass sheets; if the furrow be provided with a sharp
projecting edge, the glass surface, under the influence of the pressure medium,
lifts itself against this edge, and is blown up of the required thinness of wall,
which is effected by the constant heat maintained, and the consequent readiness
of the glass to assume the desired shape, while, if the edge of the glass be too
rapidly cooled down by contact with too large a mass of metal, e.g., of frames
or hollow moulds, the glass at the edge is constrained to raise itself in a thicker
wall.
This arrangement of holding and packing the glass sheet at its edges by
furrows filled with glass, does not necessitate placing the form-giving frame,
or the hollow mould or moulds, upon or in the glass mass. They may surround
the glass mass at its edge, or rest upon the frames which confine the edges of
the glass mass, or even be supported a short distance above the glass mass, 80
that the plastic glass sheet is first raised under the influence of the pressure
medium beneath it, then fills up the groove or furrow, and is thereby held and
rendered air-tight, and then enters beneath the lower edge of the hollow mould,
to receive its shape therefrom.
The separation of the hollow mould from the plate upon which the glass layer
is spread out, enables the plate to be turned with the hollow glass article formed
thereon in the divided mould, to prevent the formation of mould seams upon the
outer surface of the hollow glass article.
As is stated in the applications above refered to, the formation of the hollow
glass body may be effected by pressure upwards or downwards upon the spread-
out glass sheet; so may this also be attained by spreading out the glass layer
upon the plate, and placing the mould upon it, then turning the assembled
parts upside down, to apply the pressure from above upon the glass sheet, and
to allow the formation of the hollow body to be completed in the position in
which it is placed during the ordinary glass-blowing process.
The formation in this position is much more advantageous for the production
of many glass articles.
For raising and blowing up the glass layer by means of a small opening, or

page_text: by one or more small perforations in the foundation plate, with or without a
"dished" upper surface, the glass layer may be spread by rolling or pressing.
For the production of fairly large quantities, the plastic glass layer may be
first prepared upon a separate foundation plate, and then transferred to the
plate, whereon the raising and blowing up of the still sufficiently plastic glass
layer takes place.
Improvements in Apparatus for the Production of Glass Articles.
I, PAUL THEODOR SIEVERT, of 43, Eisenstuck Strasse, Dresden, in the Empire of
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:-
In certain applications already made by me for Patents, on the 30th January
1899, No. 2094, and on the 6th February, 1899, No. 2679, it is stated, among the
devices for carrying out the process for the production of hollow glass articles,
that a hollow plate with a multiplicity of perforations in its thickness may be
employed, or a solid plate with a perforation suited to the shape of the glass
object to be produced.
It has now been found that the process of moulding or shaping glass articles
may be carried out by means of a solid plate in which a multiplicity of per-
forations is done away with, and which also has no large opening corresponding
to the shape of the object to be produced, but which, on the contrary, has only
small apertures for the entrance of the pressure medium,--air, gas, or steam.
By means of small perforations, and proportionately small streams of the
pressure medium, numerous forms of plastic glass articles may be simultaneously
raised and blown up, either according to the shape imparted thereto by the
frame, or for the purpose of producing a skin, in a hollow mould.
This method of carrying out the invention simplifies and cheapens the
apparatus employed for the process in a material degree, because, firstly, the
hollow plate, with its multiplicity of perforations, and the closing device of
the large openings, are dispensed with, and the small perforation or perforations
used may be directly connected with the supply pipe or pipes of the pressure
medium.
It has been found advantageous, when the pressure medium is directed against
the centre of the glass layer, or of its sections, if divided up, to impart a some-
what greater thickness to the spread-out and smoothed molten glass at such
the upper
centre or centres. This is easily effected by slightly "dishing
surface of the solid plate at the central point or points thereof. The stream
of pressure medium thus impinges upon the thickened portion of the plastic
glass layer, lifts it up, and blows it out, the thickened centre of the glass layer
so distributing itself that if a breaking through of the blown up glass is not
intended, the skin of the moulded article will be formed of equal thickness
throughout.
For the simultaneous production of a number of hollow glass bodies from a
spread-out plastic glass layer, this "dishing" of the plate may be as often
repeated as there are objects to be simultaneously produced, and, in this case,
the plate will of course be provided with a perforation for each article.

page_text: This arrangement is of particular value, when it is desired to produce glass
objects, the diameter of which is of small extent in proportion to their height,
as, for example, lamp chimneys, bottles, etc., or articles thick at the bottom, as
drinking vessels of tumbler form. In the case of the latter articles, which
are moulded in an inverted position, the blowing process is not carried to the
point where the glass is blown out to a uniform thickness, but terminates before-
hand by striking against the top of the hollow mould, thus producing a tumbler
with a thicker bottom and thinner side walls.
The wart-shaped excrescence of the fluid glass which forms in the perforation
of the plate may be disregarded, as may also those arising from the use of a solid
plate having a large number of perforations, seeing that they disappear when
thick glass is blown up, and are not of much consequence in most cases, viz. :-
when they appear on those parts where the glass skin is broken through during
its formation, or shew themselves, for example, at the four corners of the plate,
in such portions of the glass where they either come away when the edge is
broken off or otherwise.
The weakening of the spread-out glass layer at the edges thereof, which is
caused by the above-mentioned "dishing," necessitates precautions being taken
to prevent this thin edge portion from cooling too rapidly.
Such precautions may consist in thinning the hollow mould at its edge for
a certain height up, that is to say, in a considerably greater measure than is
the case where moulds with sharpened edges are used, so that only a very small
portion of the metal penetrates the hot glass.
In place of this contrivance, the precautions may consist in not giving the
glass mass the necessary support at the outlines of the hollow body to be pro-
duced, by form-giving frames, but by furrows instead, which are formed in the
plate itself, or produced in combination with a frame enclosing the plate. These
furrows may have any convenient form, and are intended to take the liquid
glass mass at the edge of the plate, and so afford the support to this edge neces-
sary when the pressure medium raises and blows up the glass. The enclosing
frame is made to open to facilitate the removal of the bead from the furrow,
and the filled-up furrows afford a good means of packing for the pressure
medium, which is led beneath the glass, to raise and blow it up.
The use of such frames, to form furrows, lends itself also, it will be understood,
to the manufacture of unitormly thick glass sheets; it the furrow be provided
with a sharp projecting edge, the glass surface, under the influence of the pres-
sure medium, litis itself against this edge, and is blown up of the required thin-
ness of wall, which is effected by the constant heat maintained, and the conse-
quent readiness of the glass to assume the desired shape, while if the edge of
the glass be too rapidly cooled down by contact with too large a mass of metal,
c.g.. of frames or hollow moulds, the glass at the edge is constrained to raise
itself in a thicker wall. This arrangement of holding and packing the glass
sheet at its edges by furrows filled with glass does not necessitate placing the
form-giving frame, or the hollow mould or moulds, upon or in contact with the
glass mass. They may surround the glass mass at its edge, or rest upon the
frame, confining the edges of the glass mass, or even be supported a short dis-
tance above the glass mass, so that the plastic glass sheet, raised under the
influence of the pressure medium beneath it, first fills up the groove or furrow,
is thereby held and rendered air-tight, and then enters beneath the lower edge
of the hollow mould, to receive its shape therefrom.
The separation of the hollow mould trom the plate upon which the glass
layer is spread out, enables the plate to be turned axially, with the hollow glass
article formed thereon in the divided mould, to prevent the formation of mould-
seams upon the outer surface of the hollow glass article.
The formation of the hollow glass body may be effected by pressure upwards or
downwards upon the spread-out glass sheet.
This may be attained by spreading out the glass layer upon the plate and

page_text: placing the mould upon it, then turning the assembled parts upside down, and
applying the pressure from above to the glass sheet.
The moulding of many glass articles in the inverted position facilitates their
production.
For the production of fairly large quantities, the plastic glass layer may be
first prepared upon a separate foundation plate, and then transferred to the
plate, whereon the raising and blowing up of the still sufficiently plastic glass
layer takes place.
In the accompanying drawings:
Figs. 1 and 2 shew, in vertical section, the devices for producing the hollow
glass bodies.
Fig. 1 shews a single perforation in the centre of the plate a, while Fig. 2
shews a perforation in each corner of the plate (see also the plan view, Fig. 3).
The pressure medium admitted lifts, in both cases, the plastic glass layer
with a uniform surface pressure, and blows it up. is the inlet valve and c the
outlet valve for the pressure medium.
65
C
In Fig. 1, the pressure is directed against the centre of a plastic glass layer e
spread out on a solid plate a, having a dished" upper surface, while in Fig. 2
the face of the plate is not "dished."
Both figures shew the plate as surrounded by a frame d, which, in combina-
tion with the plate a, forms a furrow m, into which the liquid glass, when spread
out, enters, to resist the upward pressure of the elastic medium, and hold down
the edges of the glass layer in contact with the plate.
The frame, as seen in Figs. 1, 2, 8, 9, 10, 11, and 12, may have various internal
profiles among which those shewn at Figs. 9 and 12 are especially preferable,
because they most readily admit of the separation of the supporting glass bead
formed, when the frame, as shewn in Fig. 13, in plan view, is made to open
out, as is necessary to admit of the removal of the article. Fig. 8 shews, in
addition, a second frame (capable of opening) applied to the surrounding frame d,
by which the height of the glass layer, when being spread out, is regulated.
The profile of the frame shewn in Fig. 9, by means of its sharp edge at the
upper opening of the furrow, has the effect of imparting the particular thick-
ness of wall to the glass object which it is desired that it shall possess, when the
plastic glass sheet is blown up, while in case of a furrow whose mouth has
vertical walls, the glass has a tendency to rise in greater thickness at its lower
edge; the frame shewn in Fig. 9, combined with a plate furnished with an
overlying sharp hot edge, compels the glass to rise immediately in quite a thin
wall.
In Figs. 1, 2, 10, and 12, the moulds 9 are shewn as resting either upon the
glass mass, or upon the frame surrounding the edge of the glass mass. In Figs. 4
and 5, the plate a is shewn with a plurality of depressions in its upper surface
suitable for producing a number of hollow glass articles from a single sheet of
plastic glass; each depression has, therefore, its own pressure medium admission
opening or openings in the plate a.
In Fig. 6, the plate a is shewn with a rolled-out sheet of glass thereon, to
illustrate how the small excrescence n forms in the perforation of the plate a,
which, however, in most cases, does not cause any inconvenience in the produc-
tion of the hollow glass articles. In Fig. 7, the mould g is shewn with weakened
walls at its lower edge, by which a reduced cooling of the glass mass, by reason
of the diminshed mass of metal in the mould, is obtained.
In Figs. 14 and 15 is shewn how, in the application of the dished plates with
the retaining groove between the plate and its enclosing frame, the hollow
mould may be placed over both plate and sheet, for the purpose of first raising
the whole glass sheet till it comes in contact with the edges of the mould, and
then blowing it up by continued pressure into the moulds.
When it is desired to produce a single hollow article by means of a mould or
pattern frame, the bed plate may be made to rotate axially, so that the expanded

page_text: glass will rotate in the mould or pattern frame, and in this way the marking
of the seams of the mould will be avoided. In Fig. 16, the arrangement for
effecting the rotation of the glass is shewn. The bed plate a is carried by a
spindle o, which is hollow; and which, in connection with a fixed pipe p, forms
the pressure medium pipe. The pipe is formed with a flange q, having an
annular groove for the reception of anti-friction balls: upon these balls, the
flanger of the hollow spindle o, provided with a similar groove, bears; and
attached to this flange is a sleeves, which loosely embraces the pipe p. The
plate a, thus mounted, can be easily rotated when the expanded glass has
entered the fixed mould.
The action of this apparatus will be better understood by reference to Fig. 16ª,
where the mould g, for the reception of the expanding glass, rests upon the
floor. is the pipe for leading the pressure-medium into the apparatus.
Fig. 17 shews a hollow bed plate furnished with trunnions tt, to enable the
plate to be turned over, and invert the position of the plastic glass. This will
allow of the formation of the hollow glass body, as by the pendent, and to-and-
fro swung, glass-blower tube.
The action of this apparatus will be better understood by reference to Fig. 17ª,
in which the bed-plate is shewn in the vertical position to receive the plastic
glass e, which is held firmly in place by the frame d. The trunnion t, which is
hollow, has a hose pipe connected with it, for leading the pressure medium to
the under-side of the glass, and a winch handle is connected to the trunnion t¹,
to facilitate the turning over of the bed-plate. When the plate is turned over,
as in Fig. 17, the glass layer e will, by its own weight, begin to bulge, and blow-
ing being immediately commenced, a cylindrical figure with a closed end, as
shewn by dots, may be formed, such cylinder having an equal thickness of wall
throughout its length. For the conversion of this cylinder into a sheet, it is only
necessary to sever it at the cross lines, 1, 1, and longitudinally at the line 2-2,
when, by the application of furnace heat, the cylinder will open, and form a flat
plate of 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 what
I claim is:
1. In the manufacture of glass articles, the use, in combination with an ex-
panding frame d, of a solid or hollow bed plate a, flat, or provided with dished
recesses on its upper surface, to receive the plastic glass layer, and having one,
or only a small number of perforations, for the admission of the elastic pressure
medium, beneath the glass layer; such frame being made to open out, for the
purpose of forming a channel or groove m, which serves to receive molten glass,
and hold and render air-tight the glass layer.
2. In the arrangement described in Claim 1 for holding and rendering air-
tight the plastic glass sheet by the annular groove or channel m, the arrange-
ment of pattern frame, or the hollow mould, a short distance from the glass layer,
for the purpose of rotating the plate a, with the blown up glass mass, indepen-
dently of the pattern frame or the hollow mould, to prevent the formation of
mould-seams.
3. Suspending the bed-plate a, referred to in Claim 1 on trunnions, for the
purpose of turning over the plate with the spread-out glass layer held in the
channel or groove m, and thereby facilitating the moulding of articles of glass.
Dated this 28th day of September 1899.
NEWTON & SON,
Agents for the Applicant.