Improvements in Presses for the Production of Tiles and other Ceramic Ware.
Year: 1894

page_text: Date of Application, 1st Nov., 1394-Accepted, 1st Dec., 1894
COMPLETE SPECIFICATION.
Improvements in Presses for the Production of Tiles and other
Ceramic Ware.
I, FRANZ VON HARDTMUTH, carrying on business as L. and C. Hardtmuth, of
Budweis, in the Empire of Austria, 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 improvements in the mould whereby to produce perfect
ceramic wares from very wet clay, and likewise to enable the finished goods to bo
removed from the moulds without damage. It also relates to a particular con-
struction of the mould and pressing die or plunger whereby the water expressed
from the clay during the pressing operation may be extracted and the atmospheric
ir exhausted.
In order to attain these results the mould is constructed of two parts,
namely:-
(a) A lower part in which is inserted a sort of hollow core-like piece made of
metal and enveloped at its sides by a hygroscopic material (ie. a material
able to absorb water) the top being covered with porous material by which
to prevent the adherence of the clay to the mould, and holes being provided
in the hollow core to allow the water and air to escape during the operation
of pressing;
(6) An upper part which may either consist entirely of hygroscopic material
or of which the inner walls alone are liued therewith; or this part may
be made in the form of a removable metal frame to be placed on the
lower part.
For the purpose of extracting the water and air which are expressed from the
clay, pockets or chambers are provided in the mould and in the plunger or die,
with which an air-pump may be put into communication.
The accompanying drawing illustrates an example of a mould and plunger for
the production of Dutch tiles and provided with the new improvements. Figure 1
8 a central vertical section of the press, and Figure 2 shews the top view of the
ress mould.
The press mould comprises a base plate A preferably made of cast iron recessed
to receive a hollow core-like piece B3 of iron or brass forming a pocket or chamber
which is screwed to the base plate. The piece B is provided with outwardly
projecting flanges 6, has holes b', in the top and sides, aud is surrounded by a
nass B of hygroscopic material, such as gypsum, (plaster of Paris,) for example,
which is held in place by the flanges 6. On the top face of said piece B a sheet 6
of felt is laid to prevent the moulded article from adhering to piece B but which at
he same time allows the water and air to pass to the holes b'.
The upper part of the press mould consists of an open frame C removably seated
u the base plate A. Its walls are lined with hygroscopic material c, as shown at
he left side of Figure 1, or it may be constructed entirely of such material, aª
hewn at the right side of same figure, or it may be entirely of metal without
uy coating.
The base plate A has longitudinal grooves in its under surface to slide on
ails e to ensure the exact position of the press mould under the dic or plunger.
The plunger or die consists of an inner casing F filled with hygroscopic
naterial and having holes in its top and sides.
When the stamper descends it enters slightly the upper part of the press
nould, as shewn in Figure 1, and pressing on the clay mass causes it to take the

page_text: shape of the mould, the air contained in the mould escaping partly through the
drains on the top surface of the base plate A and partly through the felt
and the holes in the hollow core-like piece B. Through these holes b' also
passes the water expressed from the clay if it is not already absorbed by the
hygroscopic material of piece B, of frame C, and of the case F.
When the pressing operation is finished, the die or stamper may easily be lifted
and removed, when the air can then enter the holes of the inserted piece B.
The upper part C of the press mould with the ware produced, may also easily be
lifted off after which the mider part of the press mould is to be removed along the
rails e.
In the same manner the Dutch tiles after being properly cut off, may be
removed from the upper part C of the press mould, the shrinking of the dried clay
favouring its taking off and the adherence of the Dutch tile to the piece B being
prevented by the admittance of air through said holes b'.
For the purpose of extracting both the air and the water pressed out of the clay
into the press mould or into the hygroscopic material therein, chambers or pockets 6*
and y are provided, the chamber within the piece 13 being closed by a plato 6º
and the chamber being formed by an outer casing G which envelopes the
perforated casing Eas shewn in Figure 1. The chambers & and g may be put in
communication with an air pomp by pipes d and connected to nozzles 6 on
plate and g' on easing G.
During the operation of pressing or moulding the clay, the air will be exhausted
by the air pump from the pockets & and 9 and by the suction thereby produced the
water contained in the press mould or in the hygroscopic material will also be
removed. Before the die or stamper is again raised, the cocks h, h³, must be
opened in order to allow air to enter the chambers and y.
By means of press moulds thus constructed, either plain goods or goods moulded
in relief may be produced from clay which is mixed with a great deal of water, in
a perfect and undamaged condition.
Having now particularly described and ascertained the nature of the said inveu-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. In apparatus for the production of tiles and other ceramic ware from
very moist clay, a press mould consisting of two parts, namely, a lower part
comprising the base plate A and the inserted piece B provided with holes covered
with felt and cased at its sides in hygroscopic material and a removable upper
part C in the form of an open frame or ring lined with or cousisting of hygroscopic
material, substantially as specified.
2. In apparatus for the production of tiles and other ceramic ware from very
moist clay, the mould constructed as herein specified with a chambered core
piece B apertured and surrounded with hygroscopic material, as specified, the die or
plunger F, G, constructed of a mass of hygroscopic material contained in an
apertured casing enclosed in a chamber 9, both chambers being connected
with an air pump for the extraction of air and water therefrom, substantially as
specified.
3. The improved apparatus for the production of tiles and other ceramic ware
from very moist clay, constructed and operating substantially as specified.
--...נית
AT
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.