An Improved Method of Manufacturing Plates, Slabs, or the like for Building Purposes.
Year: 1897

page_text: COMPLETE SPECIFICATION.
An Improved Method of Manufacturing Plates, Slabs, or the like
for Building Purposes.
I, WENZL VLCEK, of Oberbris (Bohemia), in the Empire of Austria-Hungary, Factory-
manager, 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 a method of manufacturing a special kind of clay plate for
covering masonry, flooring and the like, and in which plates the bottom surface is
'provided with recesses or projections.
By forming the plates in this manner the mortar after having properly dried, is
retained in the dove-tail recesses whereby an absolutely reliable adhesion of the plate
to the masonry or flooring is ensured.
The present invention relates to a method of dry-pressing, in which india-rubber
plates are employed, which are provided with projections and which are inserted into
the pressure mould. The ground material or clay substance to be compressed, is then
placed upon these india-rubber plates, or the india-rubber plate, after the filling of the
mould with the material to be pressed, is placed upon the latter and compressed
therewith. During the pressing operation the projections formed assume a suitable
position by extending from the centre toward all sides so that the central projections
are placed in a more or less straight direction, whilst the projections lying nearer to
the edges are inclined more outwardly. The consequence naturally is, that the
recesses formed in the pressed clay plate are inclined in different directions. A further
advantage resulting from the use of the indi-rubber plate as a matrix is, that as the
compression of the ground clay or similar substance is effected under an enormous
pressure the projections become thickened and contracted so that the recesses in the
clay plate are wider than the projections of the india-rubber plate in reality are before
the pressing operation, whereby the clay plate after having been pressed, can be
easily removed from the inatrix as soon as the same is withdrawn from the mould.
In the accompanying drawing I have shown clay plates produced in conformity
with the present invention.
Figure 1 represents a section of the plate.
Figure 2 shews in plan an india-rubber plate serving as a matrix.
Figure 3 is a side elevation of the same, and Figures 4, 5, 6 and 7 shew modifications
hereinafter referred to.
The india-rubber plate a is provided all over its surface with projections b, which
may be either of circular or square shape in cross section and which are of a conical,
prismatic or cylindrical form. On inserting this india-rubber plate as a matrix into
the pressing mould and on subsequently pouring the ground clay on top of it, the
projections b, during the pressing operation, will assume a position inclined from the
centre toward the exterior or toward the interior, the degree of inclination increasing
from the centre toward the sides. It is thus rendered possible to press a clay plate d,
such as shewn in Figure 1, the recesses of which are inclined outwardly, so that the
cement or mortar is dove-tailed and thus retained in the plate.
.
As illustrated in Figures 4 to 7, plates or slabs of clay may be obtained by this
process, on the under-side of which ribs R undercut at an angle are provided. The

page_text: ribs are produced in the same manner as the inclined perforations of the plate shewn
in Figure 2, namely by using an india-rubber plate as a matrix or die the rib-shaped
projections m of which are pressed into the clay, or inversely the clay may be applied
under pressure, when-as above described-owing to the high pressure the ribs formed
in the die will be somewhat inclined to one side, increasing in volume at the same
time, so that they form obliquely undercut ribs in the slab of clay the distances
between which are wider than the india-rubber ribs so that the finished slab may be
readily lifted or removed off the die.
Where such slabs or tiles are embedded in mortar or putty they may be very
readily secured in the supporting material by placing the slab from the first in an
inclined position in the same direction in which its ribs are turned, as is indicated by
the arrows in Figure 4. The plate is by such a method of operation screwed into the
supporting material as it were so that the inortar completely fills the inclined recesses S
which it cannot be exactly relied upon to do where the slab is simply forced into the
supporting material. Experiment has shewn that owing to this method of attachment
the power of adhesion of the slabs or tiles is increased five-fold as compared to similar
articles merely pressed in. The employment of india-rubber dies offers this additional
advantage, moreover, that the lower sides or surfaces of the slabs or plates appear to be
perfectly coarse-grained which again considerably adds to the strength of the joint or
attachment.
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
claim is
1. A method of manufacturing clay plates for covering floorings and wall surfaces,
the bottom surface of which plates is provided with recesses or projections passing in
various directions, and between which the cement or mortar is dove-tailed and thus
retained, the characteristic feature of the process being that, as the ground clay or
other material is dry-pressed in the pressing mould, an india-rubber plate provided
with circular or angular projections is either placed on top of the mould containing
the ground material, or that the india-rubber plate itself is used as a matrix, in which
latter case the clay or like material is placed on top of said plate, whereupon the mould
and matrix are subjected to a high pressure, for the purpose of producing upon the
clay plates recesses or projections in various directions and so that the finished plates
may be easily detached from the mould.
2. A form or modification of the method referred to in the first claim, characterised
by the employment of india-rubber dies provided with ribs (Figures 6 and 7) whereby
they form on the undersides of the clay plates, slabs or tiles, undercut ribs such as are
shewn in Figures 4 and 5.
3. A method of attachment of the clay plates, slabs or tiles, such as are referred to
in the first and second claim, its main feature being that the plates in being embedded
in mortar or cement receive a turn or twist in the direction of inclination of their ribs
for the purpose of pressing the fixing material into the spaces between the ribs by
that screw-like motion.
Dinded th
114L
D
1007
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.