Improvements in the Manufacture of Glass Articles, both Plain and Ornamental, and in Apparatus to be used therefor.
Year: 1899

page_text: Date of Application, 30th Jan.. 1899
500
100 1812 ‘paid2004-6691 das What WONBOWLOADS AĴajowod
Date of Application, 30th Jan.. 1899
Improvements in the Manufacture of Glass Articles, both Plain and
Ornamental, and in Apparatus to be used therefor.
I, PAUL THEODOR SIEVERT, of No. 43, Eisenstuck Strasse, Dresden, in the
Empire of Germany, Glass Manufacturer, do hereby declare the nature of this
invention to be as follows:-
This invention has for its object the manufacture of articles of blown glass, as,
for instance, cylinders (for conversion into plate glass) balls, accumulator cells,
lamp globes, bottles, goblets, etc.; especially the manufacture of blown glass
articles of extraordinary dimensions.
The articles may be manufactured in one operation, but two operations may be
recommended in the case of such articles as bottles with small mouths, where
the body, with the neck and mouth, can be made in one operation, and the bottom
made and joined, thereto in a second one.
The invention relates further to means for decorating blown glass articles
made by the herein-described process, during their manufacture, and in many
ways; and, finally, it affords a method of cooling the blown glass articles
immediately after their manufacture, by the introduction of air thereto.
The manufacture of blown glass articles according to the herein-described
process is distinguished by the following three immediately consecutive
operations;-
-
1. The spreading out of a flat liquid glass layer on a perforated plate. pre-
ferably with the aid of "slicking or smoothing the upper surface thereof.
"
2. In the holding or confining of this liquid glass layer on the exterior ground
or plan lines of the objects to be manufactured, by frames giving shape, or by the
edges of hollow forms or moulds placed on the plastic glass layer.
3. In the blowing up of the still plastic glass layer within the fast-held
exterior lines of the objects to be manufactured, such lines being determined
by the frames giving shape, or by the edges of the hollow forms or moulds
placed upon the plastic glass layer.
In the carrying out of this process, the following method is observed:-
On a hollow slab, which has, on its upper surface, narrow slits, holes, or
various openings, a plastic glass mass is so spread that it covers these openings.
These openings must be as fine as feasible, in order that the glass mass may
not penetrate into them. Upon the smooth glass mass, one or more hollow
formers (preferably with cutting edges), or one or more frames corresponding to
the principal lines of the blown glass articles which are to be made, are firmly
pressed. As soon as this is done. steam, compressed air, or other expansive
medium, is admitted into the hollow pierced slab, whereby the glass layer is
blown up in uniform thickness, and with great speed, while at the same time it
is held fast by the frames, or the lower edges of the moulds, on the exterior
principal outlines of the desired objects.
When the blown-up glass mass is made to take shape by the outline frames or
inverted covering moulds, the glass articles will take the desired form.

page_text: The expansive medium can be let out through special outlets in the hollow
slab, or, in some cases, disposed of by leaving an opening in the upper part of
the moulds, at which opening the molten glass will be burst through by the
expansive medium, which thus escapes.
This secures, at the same time, immunity from too great pressure. The
determination of the thickness of the glass walls of the moulded objects can be
regulated by applying to the slab a more or less thick glass layer, and by main-
taining, for a longer or shorter time, elastic pressure on the glass. The slicking
or smoothing of the glass mass, prior to blowing, in order to get even thickness
of wall, is of special importance, although in some cases the slicking or smooth-
ing of the glass would be unnecessary.
For producing ornamented articles, the molten glass may be coated with a
layer of colored glass immediately before the moulding into shape commences,
and the article, when formed, may be subjected to the action of the sand-blast,
or to acid, for removing the colored layer in parts, thus producing the effect of
flashed glass, as well known in the glass manufacture.
Or the molten glass may be strewed with grains of plain or colored glass,
or other suitable material, which will adhere to the molten glass, when pressure
is applied thereto. This form of decorating moulded articles lends itself to the
production of ornamental devices, not only on the surface, but in the walls of the
moulded article.
It will be understood that when flat glass is required, moulds with flat surfaces
may used, the glass when cooled, being severed at the angles, to convert the
moulded article into flat plates.
The carrying out of the process of moulding under elastic pressure, with
the aid of suitable apparatus, lends itself to the cooling of the glass by the
admission thereto of air while the glass is contained in the moulds.
This cooling action takes place in such a way that the air introduced into the
hollow slab is first heated in the narrow slits, holes, or openings of the slabs,
whereupon it cools down continuously in the same proportion as the surface of
the slab cools down; hereby the temperature within the glass body decreases
gradually.
By making the cooling a part of the process, the annealing furnace is rendered
unnecessary, and a great economy in labour is effected.
ונ.י.ת
2011
T
1000
NEWTON & SON,
Agents for the Applicant.
Improvements in the Manufacture of Glass Articles, both Plain and
Ornamental, and in Apparatus to be used therefor.
I, PAUL THEODOR SIEVERT, of No. 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:-
This invention has for its object the manufacture of hollow articles of blown
glass. as, for instance, boxes, chests, goblets, tumblers, lamp-shades, bottles, &c.;
also hollow forms, with large, flat, smooth, thin walls, which, when properly
cut up, yield, for each side, one or more sheets of plate glass.
The articles may be manufactured in one operation, but two operations may be

page_text: recommended in the case of such articles as bottles with small mouths, where
the body, with the neck and mouth, can be made in one operation, and the bottom
made and joined thereto in a second operation.
The invention relates, further, to means for producing blown glass articles,
with coloured and opaque ornamentation; and, finally, it includes a method of
cooling the blown glass articles immediately after their manufacture, by the
introduction of cooling air thereto.
The manufacture of blown glass articles according to the herein-described
process, 'is distinguished by the following three immediately consecutive
operations.
1. The spreading out of a flat liquid glass layer on a perforated plate, pre-
ferably with the aid of "slicking" or smoothing the upper surface thereof.
2. In the holding or confining of this molten glass layer on the exterior
ground or plan line of the objects to be manufactured, by frames giving shape,
or by the edges of hollow forms or moulds placed on the plastic glass layer.
3. In the blowing up of the still plastic glass layer within the fast-held exterior
lines of the objects to be manufactured, such lines being determined by the shape
of the retaining frames or edges of the hollow forms or moulds placed upon
the plastic glass layer.
In carrying out this process, the following method is observed:
On a hollow slab, which, on its upper surface, is pierced with narrow slits, or
other openings, a plastic glass mass is so spread that it covers the openings,
which are as fine as feasible, in order that the glass may not penetrate into them.
Upon the smooth glass mass, one or more hollow formers (preferably with cutting
edges), or one or more frames corresponding to the principal lines of the
blown glass articles which are to be made, are firmly pressed. As soon as this
is done, steam, compressed air, or other expansive medium, is admitted into the
hollow pierced slab, whereby the glass layer is blown up in uniform thickness,
and with great speed, while at the same time it is held fast by the frames, or
the lower edges of the moulds, on the exterior principal outlines of the desired
objects.
The expansive medium can be let out through special outlets in the hollow
slab, or, in some cases, disposed of by leaving an opening in the upper part of the
moulds, at which opening the molten glass will be burst through by the expan-
sive medium, which thus escapes.
This secures, at the same time, immunity from too great pressure.
I will now describe the appliances necessary for carrying out the process.
In the accompanying drawings:
Fig. 1 is a vertical longitudinal central section of the apparatus with a simple
perforated plate or slab, for the purpose of expanding or inflating the molten
glass which has been spread out thereupon.
Fig. 2 shows the same apparatus during the blowing up into the open air, of
the previously spread-out molten glass.
Figs. 3, 4, and 5, are vertical longitudinal central sections of the same
apparatus, in combination with a mould (each of different shapes), into which
the spread-out layers of molten glass are severally blown or inflated.
Fig. 6 is a vertical longitudinal central section of the same apparatus, in com-
bination with several hollow moulds, for the simultaneous blowing up of the
spread-out molten glass layer into several articles.
Fig. 7 is a plan of the latter apparatus.
Fig. 8 shows the apparatus according to Fig. 1, with an appliance for spread-
ing out the molten glass layer.
Fig. 9 shows in central vertical longitudinal section, several hollow moulds
for tumblers suspended over the apparatus.
Fig. 10 shows the apparatus according to Fig. 1, with moulds according to
Fig. 9 upon the glass layer; and
Fig. 11 is a plan thereof.

page_text: mouius.
and
Fig. 13 shows the apparatus according to Fig. 1, with hollow bottle moulds;
Fig. 14 is a plan thereof.
Fig. 15 shows, the form of glass casting for a finished bottle, produced in one
of the moulds.
Fig. 16 shows the apparatus according to Fig. 1, with hollow moulds for the
production of bottomless bottles.
Fig. 17 shows such a bottle in section.
Fig. 18 shows the apparatus according to Fig. 1 for the production of bottoms
for the bottles Fig. 17; and the attachment of the same in place.
Fig. 19 shows, in section, a completed bottle.
In Fig. 1, a is a hollow slab, into which open an inlet pipe b and an outlet
pipe c, each provided, for the regulation of the pressure, with a cock or valve.
The upper surface of this hollow slab a is perforated with holes or slots a¹.
This slab a, in connection with the frame d, forms a flat receptacle for the molten
glass layer e, which, by means of the platen shown by dotted lines, or by means
of a roller, can be smoothed or slicked on its upper surface. On the slab frame d,
a second frame f is applied, the lower edges of which, cut or press into the glass
layer, and serve to confine or hold down the glass within the boundary lines of
the article to be formed. The medium used for expanding the glass will be
either air, steam, or gas. It is admitted into the hollow of the slab, and, issuing
from the perforations, blows up the glass mass into and through the frame f, and
thereby makes a blown-glass body, its base form taking its shape from the
moulding frame f, while the height of this body depends on the duration of the
blast or pressure, which can be continued as long as the molten glass suffices to
form a hollow glass body.
In Fig. 2 is shown how a hollow body e¹ has been formed from the glass layer e.
Thorough experiments have shown that the wall-thickness of the hollow glass
objects is the same all over, and that this thickness depends on that of the glass
layer and on the amount of pressure employed.
'
Experience will soon show each workman how thick the glass layer, and how
high the pressure, must be, to produce the desired wall-thickness; and he can
easily shut off the pressure when the desired height has been attained, in order
to terminate the operation. In the before-mentioned sample operation, the
blowing up of the plastic glass layer takes place in the open air (i.c., without
the use of a confining chamber), but, for obtaining hollow glass objects of
special form, a mould g, Fig. 3, may be employed, inverted, and applied to the
glass layer, whereby the lower edge of the mould replaces the holding-frame f
of Fig: 1. The lower edge h of the mould holds the glass layer firmly in the
outlines of the required objects, when they are formed by the blowing up of the
glass layer. The mould g can, of course, have any desired forin. It can be
supplied with vertical partition walls, which reach to or under the surface of the
glass layer, so that the blown-out body is practically a box with one or more
partition walls. The blowing up process is shown in Fig. 3 in dotted lines, i,
in an incomplete, and in full lines, k, in a completed state. Here the pipe 6 for
the expansive medium is shown in connection with a compressing pump 7.
Fig. 4 shows the blowing up of the glass layer into a mould with narrow mouth-
piece. In order to get enough of the material of the glass layer for the expan-
sive medium to work on, the glass mould of the object to be made (in this case,
for example a bottle a) is provided with a funnel-shaped mouth-piece y, the
larger diameter of which rests on the glass layer, and holds the latter firmly
with its margin or border. The form of casting produced is best shown at
Fig. 15. After separation at the line --z, the finished bottle is obtained.
Fig. 5 shows an arrangement similar to that in Figs. 1 and 3, only here
another form of mould is selected, in which the glass layer is blown by pressure,

page_text: and in which there is, above, an opening m in the mould g. This opening is
intended to let the pressure in the mould be relieved by a bursting through of
the glass at the place provided therefor, when the mould has been filled by the
blowing out of the material into a hollow article.
In Figs. 6 and 7 is shown how, according to the process described, the simul-
taneous manufacture of several objects is accomplished. The mould which is
applied to the glass contains a number of moulds g (for example; for the manu-
facture of tumblers), the lower edges, h, of which, hold the glass layer down in
circular lines, and those portions of the glass layer which lie within these circles
are blown up, and fill the separate tumbler moulds. Naturally; after the manu-
facture of the various objects here given as examples, the separation of the
remaining firmly-held glass mass is best effected by breakage at the point where
the blowing of the thin walls begins. To facilitate the removal of the superfluous
glass mass from the manufactured articles, the confining frame f, or the lower
edges of the moulds g, Figs. 1, 2, 3, 5, 6, can be sharp-edged or bevelled. The
sharp edges penetrate the glass layer, but hold it sufficiently firmly, and facilitate
the removal of the superfluous glass mass.
•
In order to effect economy in glass between the moulds the entire glass-layer
can be covered with single, or with connected moulds, of three, four, or six sides,
each mould covering enough of the glass mass as suffices for the manufacture
of one hollow article.
An example of this is shown in Figs. 8 to 15, inclusive.
In Fig. 8, there is shown the glass layer e on the perforated upper surface of
the hollow slab a, spread out and slicked on its upper surface by means of a
roller ea.
Over the glass layer hangs the vertically-movable mould g, Fig. 9, which is
held by the stems v, and which is formed of 'a number of moulds (here, for
example, for tumblers). The lower edge of each tumbler mould terminates in
a sharp square g°, and all these squares touch each other, so that when, as in
Fig. 10, the mould g is lowered upon the thoroughly plastic glass layer e, the
latter is perfectly covered, as shown in plan in Fig. 11. Each square covers
enough glass for the manufacture of the tumbler corresponding to its mould.
In the two moulds at the right hand side of Fig. 10, there is shown, in one, g³,
the commencement of the blowing out process; "in the other, 'g, the completion
thereof. After the manufacture, each tumbler can be taken out of its own mould,
and, on the removal of the superfluous glass at the line, Fig. 12, by grinding
away or by melting of its rim; the tumbler will be completed.
A similar arrangement is shown by Figs. 13 and 14, in which the compound
mould g is formed by a number of single moulds 'g', 9; g; g','g, etc., for the
manufacture of bottles. The separate moulds can be arranged in rows and each
row consists of two parts, hinged together. Here, also, the glass-layer is com-
pletely covered by the four sided lower edges of each mould. Each square covers
enough glass material for the manufacture of a bottle, and after the formation
in each mould, liy blowing, of a glass skin in the shape of a bottle, the hinged
moulds are removed, a row at a time, and opened for the removal of the manu-
factured hollow-glass articles.
1
The manufacture of hollow glass articles according to this invention may,
however, as above indicated, also take place in two successive operations; in the
first operation one part of the farticle, and in the second; another part thereof,
being made; the uniting of the two parts taking place during the second
operation.....
:
The manufacture of bottles as illustrated in Figs. 16 to 19, inclusive, suffi-
ciently explains this part of the invention.
The herein before often-mentioned preparatory spreading of the glass layer
on the hollow slab a, with perforated upper surface a, confining or gripping
the glass layer by moulds g set thereon in the outline of the objects to be formed,
and the blowing up of the glass layer in the moulds, is, in Figs. 16 and 18, the

page_text: same, with only the difference, that in the preparatory stage, in Fig. 16, the
bottle is made without bottom (Fig. 17), and in the same preparatory process,
in Fig. 18, the moulds, with the bottomless bottles, are applied to the glass layer e,
the divided-up portions of which are respectively united with the bottom edges
of the bottles during the manufacture of the bottoms, so that the complete
bottle, Fig. 19, results.
The process just described and illustrated in Figs. 10 to 19, inclusive, is
specially adapted to the manufacture of all such hollow glass articles as, by
reason of a narrow mouth and long neck, are more difficult to blow. The uniting
of the bottom with the body of the bottle will take place in a reliable manner,
if both operations (Figs. 16 and 18) take place without undue delay.
The process described with reference to Fig. 3, is well adapted to the manufac-
ture of plate-glass or sheet glass, by blowing the material in moulds which give
hollow forms with flat sides which, after blowing, may be separated from each
other.
"
Fig. 20 shows an arrangement with an open box or case, consisting of four
surrounding flat sides and a top surface. By separation of the moulded article
at the angles, there are yielded five glass sheets or plates. In the same way, a
mould can be made of roof shape. The blown glass form which corresponds to
the sloping surface, yields, after cutting apart at the ridge, large plates suitable
for pier glasses, etc.
It is especially to be noticed that, by the process according to this invention,
there result hollow or flat articles which retain the "fire polish," as in the blowing
up process (Fig. 2), without iron moulds. This advantage may also be secured
by the use of wooden moulds, or moulds faced with asbestos sheets.
The principal feature of the process is the spreading out of a layer of molten
glass, but it does not exclude the use of already prepared glass plates, reduced
by heat to the plastic condition, laid upon the perforated plate, held down at
the outline basis of the article to be produced, and blown up as above specified.
The immediate product of the process is a hollow body. As, however, this
may be obtained of any desired shape and size, so as to be available for plates,
the process, to state it in a few words, embraces the whole field of glass manu-
facture, with the exception of artistic glass work.
In the examples thus far brought forward, of the manufacture of hollow glass,
the articles prepared were described irrespective of their further development or
manufacture, but it will be understood that the separation of box-shaped or roof-
shaped articles is intended to convert them into plates or sheets.
The operation of spreading out a layer of glass on the perforated upper surface
of a hollow slab, and, by means of confining the glass layer at the outer boundaries
of the article to be manufactured, the blowing up of the glass layer, either with
or without the use of moulds, offers at the same time the possibility of decorating
the hollow glass bodies in the most widely different manner, while receiving
their shape.
For producing ornamented articles, the molten glass may be coated with a
layer of coloured glass, immediately before the moulding into shape commences,
and subsequently, after the formation of the articles, the coating may be partially
removed, to produce ornamental designs.
Or the molten glass may be strewed with grains of plain or coloured glass, or
other suitable material, which will adhere to the molten glass when pressure
is applied thereto. This form of decorating moulded articles lends itself to the
production of ornamental devices, not only on the surface, but in the walls of the
moulded article.
The following examples of the application of this decorative process may be
adduced.
When the molten glass mass is spread and slicked out on the slab a, Fig. 21,
the surface of the layer e can be strewed with coloured glass powder or grains e.
The pressure which comes up through the apertures a¹ of the slab, blows up the

page_text: plastic glass, either with or without the use of moulds, the glass layer being
held firmly on the slab. The glass grains or powder will adhere to the glass layer,
and will cover the outer surface of the manufactured blown glass article, as
Fig. 22 shews.
At the time of applying the glass grains or powder, stencils or patterns can be
employed to give the decorative material the previously desired figures or lines,
so that the decorative material will appear on the blown glass articles in such
figures or lines as shewn at Fig. 23.
If, instead of glass grains or powder, a glass sheet which is coloured, opal, or
otherwise distinguished from the plastic glass layer, be used, there will result
what is known as "flashed" glass, which, by means of the sand-blast or an
etching process, can be decorated with any desired pattern or device. Instead of
an entire glass sheet, sections of that sheet, or pieces of monotone or parti-
coloured glass can be laid on the plastic glass layer, and will then appear in the
undisturbed arrangement on the blown glass articles. Such an arrangement,
made up of coloured pieces set together, is shewn in Fig. 24, as laid on the plastic
layer, while Fig. 25 shews the same as they appear on the blown-glass article.
It goes without saying, that in the decoration of a blown or other glass article,
there may be employed at the same time various different decorative objects,
as, for instance, glass rods and glass grains, by which a great number and variety
of novel effects can be obtained. In the same manner that these decorative
materials are strewed on, or applied to, the plastic glass layer, a molten glass
layer of less thickness can be poured or slicked" on the plate a; then the
powder, the grains, or the entire or sectional glass sheet, can be laid on, and
these decorative materials covered with a further liquid glass overlay, which,
in its turn, can be slicked or smoothed on its upper surface. If the blow be now
made, the decorative material will appear in the body of the glass walls, as
Fig. 26 shews.
The decorative materials, which may be varied in form, color, and disposition,
are not confined to glass; other materials may be employed which are suitable for
the purpose, by reason of their resistance to high temperatures, their adhesive-
ness, and extensibility or ductility, in the manufacture of hollow-glass articles,
according to the present invention.
In many cases, it is to be recommended that the decorative materials, imme-
diately previous to their application, be heated to such a degree that they will
not chill the plastic glass, or will themselves be liquefied.
The carrying out of the process illustrated in the accompanying drawings, and
the installation of the appliances therefor, offers a means of cooling the blown
glass articles immediately after their manufacture, and before they are removed
from the slab or plate a. By means of this cooling, immediately after the forma-
tion of the hollow articles, the necessity for an annealing oven, with the neces-
sary preparations and precautions, the outlays for wages in this connection, and
for fuel, and the loss of breakage in the usual cooling process, are done away with.
If the article is manufactured by the here-mentioned process, it is held on its
outlines by means of a frame, or by the lower edges of the mould, fast to the
slab a, the openings of which afford inlet to the expansive medium, which blows
up the glass layer and gives form to the manufactured object.
These openings, in connection with the proper conduits for inlet and outlet
of the expansive medium, can be used to admit the cooling medium to the blown
glass articles.
The simplest method is by atmospheric air, which is forced through the slab
by a pump or an accumulator, and then reaches the hollows of the blown-glass
articles. The perforated metal slab becomes, of course, heated by the layer
of molten glass, so that when the article has been given its form by the blowing,
and air is now let in to cool it, this air is, in its passage through the perforations
in the slab, warmed, so that it does not exert its cooling action too suddenly.
After continued admission and circulation of the air, the air reaches the blown

page_text: glass articles in a cooler and cooler state, until thorough cooling is effected. By
this method of cooling the glass articles by gradual lowering of the temperature
of the admitted air, the annealing operation is attained comparatively rapidly
requiring no special transportation of the glass articles, and no further apparatus
or appliances, heating, or special precautions, than the already provided com-
pressed-air apparatus.
If the blown article is broken through in any place during its manufacture, by
the pressure from within, as was above described with reference to Fig! 5 the air
which is driven through the slab will be sufficiently heated, and will flow through
the hollow glass article, and gradually, according to its rate of inlet, cool it,
with a gradually cooler and cooler air.
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:
M'
1. Manufacturing from a layer of molten glass held down upon a pierced
hollow slab, by a shaping frame, mould, or moulds, hollow articles by the aid
of compressed air or other elastic medium, as and for the purpose set forth.
2. The means above described for applying elastic pressure to the underside
of layers of molten glass, held down on a pierced supporting slab by the retaining
edges of shaping-frames or moulds.
3. The means for producing flat plates from layers of molten glass by the aid
of retaining moulds, as above set forth.
4. The manufacture of bottles from layers of inolten glass in two operations,
as described, with reference to Figs. 16 to 19, inclusive.
5. The mode of manufacturing ornamented articles of glass, as described with
reference to Figs. 21 to 26, inclusive.
6. The application to glass articles moulded as explained with reference to
Claim 1, of a gradually cooling medium, for the purpose of annealing such
articles, as set forth.
Dated this 7th day of September 1899