An Improvement in the Manufacture of Glass.
Year: 1890

page_text: PROVISIONAL SPECIFICATION.
An Improvement in the Manufacture of Glass. .
I, JOHN GEORGE SOWERBY, of Sowerby's Ellison Glass Works, Limited,
Gateshead-on-Tyne, in the County of Durham, Glass Manufacturer, do hereby
declare the nature of this invention to be as follows:-
This invention relates to an improvement in the manufacture of hollow glass-
ware and it consists essentially in blowing the article in process of manufacture into
any required shape by means of a current of compressed air forced into inside of
glass whilst in the mould; the processes of pressing and blowing being thus carried
on at one time.
I first press the article and as the plunger is withdrawn I allow a current of
compressed air to be forced through the plunger ring or any suitable method by
which the air can be forced inside of the glass whilst in a hot state and the glass be
thus blown into the desired shape.
I may introduce the compressed air into the mould through a longitudinal conduit
in the plunger or in any convenient manner and I may use spring packing or other
suitable means of keeping the plug and ring air tight.
COMPLETE SPECIFICATION.
An Improvement in the 'Manufacture of Glass.
I. JOHN GEORGE SOWERBY, of Sowerby's Ellison Glass Works, Limited,
Gateshead-on-Tyne, in the County of Durham, 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 relates to an improvement in the manufacture of hollow glassware
by blowing the article in process of manufacture into any required shape by means
of a current of air steam or gas forced into the glass while in the mould and it
consists in the introduction of compressed air into the glass contained in the
mould through the ring fitting around the plunger in combination with a solid
plunger having a packing preventing escape of compressed air from the mould
during the operation.
On the accompanying sheet of drawings I have shown a mould suitable for the
manufacture of a glass jug according to my invention; I desire it however to be
understood that this mould may be easily adapted for making gas globes or moons
or other articles of glassware..
Figure 1 represents a longitudinal section through the mould with the charge of
metal or glass shown in the bottom mould.
Figure 2 is a similar section with the plunger shown in act of pressing or
forcing the metal up into the neck or upper portion of the mould.
Figure 3 shows the mould pushed back and the plunger partly withdrawn the
arrows indicating the entrance of the compressed air.
Similar letters of reference indicate similar parts in each of the figures
respectively.

page_text: E the plunger,
F metallic packing,
G step or bottom piece,
Hair inlet,
I annular passage or ring,
K base plate,
L handles for operating top moulds,
M handles for operating bottom moulds,
N studs secured in underside of bottom mould.
O slots or grooves formed in base plate for studs N to traverse.
The plunger E being lifted and the mould closed as at Figure 1; the molten
metal or glass A is dropped into the bottom mould B, the plunger E is then forced
into the glass driving it into the upper mould C, as shown Figure 2, thereby
forming the neck and handle of the jug. The mould B is then opened, pushed
back, as at Figure 3, the finishing mould D takes its place and the mould is again
closed. Compressed air is then sent by the inlet H through the ring I and passing
down into the glass contained in D, in the manner indicated by the arrows, blows
this glass out to the required size and shape; the metallic packing F preventing
escape of air from the mould, and the downward taper of the solid plunger
facilitating the passage of the air into the glass.
To withdraw the jug thus made, the ring and plunger are bodily lifted, the mould
is opened and the jug removed.
I thus obtain a jug formed at once in every part and of any desired shape,
whereas by the ordinary method of manufacture, the handle, top and lip are
separately made and the former attached to the body; my improvement in the
manufacture therefore gives a great saving of time and labour and considerably
increased production.
I have not deemed it necessary to describe or show any means of lifting the
plunger automatically as I may use any well known means, and this observation
applies equally to the air compressing machine, which may be of any kind.
I now give preference to a metal spring or springs as packing on the plunger but
may use other suitable packing to prevent escape of air.
In the manufacture of some articles I may find it desirable to modify the
arrangement of the mould as above described so that I may press upward instead
of downward.
I may use in connection with my improved mould a lining of carbon, or other
suitable material, which being made to revolve while blowing the glass will prevent
any appearance of mould joint on the finished article.
I have found the use of a solid plunger in combination with the introduction of
compressed air into the mould imperative; the introduction of the air through a
hollow plunger is practically useless for my purposes; a hollow plunger is very
rapidly heated and the delays necessary for cooling and clearing it render such
mode of manufacture commercially unprofitable; I therefore disclaim the use of
any such method.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
:-
1. The improvement in the manufacture of glassware consisting in the intro-
duction of compressed air. gas or steam into the mould through the ring around
the plunger in combination with a solid plunger in the manner substantially as
hereinbefore described.

page_text: 2. The use of a mould constructed, combined and arranged to operate sub-
stantially as hereinbefore described and shown on the accompanying drawing for
the purpose specified.
Dated this Twenty-eighth day of November 1800.