IMPROVEMENTS IN THE MANUFACTURE OF ENCAUSTIC TILES AND OTHER SIMILAR ARTICLES
Year: 1878

page_text: LETTERS PATENT to Leonard Broughton Wood, of Stoke-upon-Trent, in the
County of Stafford, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF ENCAUSTIC TILES AND OTHER SIMILAR ARTICLES."
21
PROVISIONAL SPECIFICATION left by the said Leonard Broughton Wood at
the Office of the Commissioners of Patents on the 6th September 1878.
LEONARD BROUGHTON WOOD, of Stoke-upon-Trent, in the County of Stafford.
IMPROVEMENTS IN THE MANUFACTURE OF ENCAUSTIC TILES AND OTHER SIMILAR
ARTICLES."
The principal object of my Invention is to enable encaustic tiles and other similar
articles of earthenware, such as ornamental slabs, finger plates, and so forth, to be
made from a combination of clay and dust, that is to say, to form the pattern in
clay and the body of the tile in dust. Hitherto this has been found impracticable
in consequence of the unequal contraction of the two materials, and of the liability
of the clay to stick to the steel surface of the mould.
I first cut out or perforate the pattern in sheet brass or other metal or suitable
hard material, taking care that the edges are slightly bevilled, so as to draw off the
clay when moulded. I then place this perforated pattern plate upon a piece of
cardboard or other suitable absorbent material the size of the bottom of the mould,
and fill in with clay. I then lift off the perforated pattern plate, leaving the clay
pattern adhering to the cardboard. I now place the latter with the clay pattern
thereon in the ordinary mould, fill in the back with dust to the required thickness,
and press the whole as usual.
In some cases I reverse this operation, namely, I first fill in the mould with dust
to the requisite depth, and then place the cardboard (with the clay pattern adhering
thereto) face downwards on the top of the same, and then apply the pressure as
before.

page_text: In either case upon withdrawing the pressed tile from the mould the cardboard
can easily be removed from the face thereof, and the tile is then dried, burnt, and
finished in the usual manner.
Instead of using the perforated metal plates to form the clay patterns, the latter
may be cut or stamped out from a thin sheet of clay of the required thickness, or
clay patterns may be formed in any other manner and laid on the cardboard or
other absorbent surface before filling in the body of the tile with dust, the object
being to absorb the moisture to a certain extent so as to prevent the unequal
contraction of the two materials (clay and dust), which would either crack the
pattern or leave a space between the junction of the pattern and the ground, and
thus make an imperfect tile.
Instead of using the cardboard or other absorbent material the stamped or
moulded clay patterns may be slightly dried and then placed directly upon the steel
plate of the mould before filling in the body of the tile with dust.
The pattern may (if preferred) be made from dust by the aid of the perforated
pattern plate, and then slightly solidified by pressure of an india-rubber pad or
other similarly soft surface, after which the plate can be removed and the body
of the tile filled in with dust, and pressed and finished as before. In this case also
the cardboard may be dispensed with.
For making raised or embossed patterns similar to majolica ware the intaglio is
laid in the mould, and the various colours are filled in by means of the perforated
pattern plates or otherwise, after which the body is filled in with dust and pressed,
dried, and finished, as before.
In cases where it is required to perforate the tile or other article the pegs or pins
for making the said perforations are attached to the lower part of the sides of the
mould, and project upwards through corresponding holes in the bottom of the
mould, so that after the tile has been pressed and the sides of the mould are lowered,
leaving the tile on the bottom, the pegs are drawn downwards at the same time, so
as to be clear of the holes in the tile.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Leonard Broughton Wood in the Great Seal Patent Office on the 6th
March 1879.
LEONARD BROUGHTON WOOD, of Stoke-upon-Trent, in the County of Stafford.
"IMPROVEMENTS IN THE MANUFACTURE OF ENCAUSTIC TILES AND OTHER SIMILAR
ARTICLES."
The principal object of my said Invention is to enable encaustic tiles and other
similar articles of earthenware, such as ornamental slabs, finger plates, and so forth,
to be made from a combination of clay and dust, that is to say, to form the pattern
in clay and the body of the tile of dust. Hitherto this has been found impracticable
in consequence of the unequal contraction of the two materials, and of the liability
of the clay to stick to the steel surface of the mould.

page_text: I first cut out or perforate the pattern in sheet brass or other metal or suitable
hard material, taking care that the edges are slightly bevilled so as to draw off the
clay when moulded. I then place this perforated pattern plate upon a piece of
cardboard or other suitable absorbent material the size of the bottom of the mould,
and fill in with clay. I then lift off the perforated pattern plate, leaving the clay
pattern adhering to the cardboard. In case that owing to the dampness of the clay
or dust (or from any other reason) the pattern should not readily leave the perforated
plate, I use a die or stamper corresponding with the perforated plate, and when the
fatter is filled and pressed raise it up and insert beneath each end or side a slip of
metal (or other material) rather thicker than the thickness of the "inlay," and
placing the die or stamper above the latter I press the clay pattern out on to the
cardboard or other absorbent material beneath, or on to the bottom of the mould
itself. I would bere remark that this part of the process is also applicable for
removing the clay patterns from the ordinary perforated plates with vertical or not
bevilled edges, the advantage being that the detached pieces of the pattern fall out
exactly in their desired position and require no adjustment before filling in the
back. This also obviates the necessity for holding up the plates and fingering or
It is much cleaner, saves
pushing the patterns through in the ordinary manner.
time, and enables larger patterns to be worked than could be done under the old
process. In some cases where there is a considerable quantity of moisture I apply.
pressure or some absorbent material to the clay, so as to press out the moisture
before removing the perforated plate. I now place the latter with the clay pattern
thereon in the ordinary mould, fill in the back with dust to the required thickness,
and press the whole as usual.
In some cases I reverse this operation, namely, I first fill in the mould with dust
to the requisite depth, and then place the cardboard (with the clay pattern adhering
thereto) face downwards on the top of the same, and then apply the pressure as
before.
In either case upon withdrawing the pressed tile from the mould the cardboard
can easily be removed from the face thereof, and the tile is then dried, burnt, and
finished in the usual manner.
Instead of using the perforated metal plates to form the clay patterns the latter
may be cut or stamped out from a thin sheet of clay of the required thickness, or
clay patterns may be formed in any other manner and laid on the cardboard or
other absorbent surface before filling in the body of the tile with dust, the object
being to absorb the moisture to a certain extent so as to prevent the unequal
contraction of the two materials (clay and dust), which would either crack the
pattern or leave a space between the junction of the pattern and the ground, and
thus make an imperfect tile.
Instead of using the cardboard or other absorbent material the clay pattern may
be slightly dried and then placed direct upon the steel plate of the mould before
filling in the body of the tile with dust.
The pattern may (if preferred) be made from dust by the aid of the perforated
pattern plate, and then slightly solidified by pressure, after which the plate can be
removed and the body of the tile filled in with dust, and pressed and finished as
before. In this case also the cardboard may be dispensed with.
In making dust or clay patterns I also propose to use a perforated or partially
perforated plate or mould of india-rubber or other compressible material, I fill in
the dust or clay (in the former case from the back, and in the latter case from the
front), and when pressure is applied to the mould and the clay or dust are both
compressed at the same time, the upper part of the compressible mould collapsing
with the pressure and acting as a stamper to compress the clay or dust into the
lower part thereof. If required, the lower part of the plate or mould may be made
of a harder material than the upper portions. When the clay or dust is sufficiently
solidified the compressible plate or mould can be readily removed. These perforated
or semi-perforated india-rubber plates or moulds may also be used for making
embossed tiles.

page_text: For making raised or embossed patterns similar to majolica ware the intaglio is
laid in the mould, and the various colors are filled in by means of the bevilled
perforated pattern plates, after which the body is filled in with dust and pressed,
dried, and finished, as before.
In some cases I cover the intaglio to a certain thickness with dust of the required
color for the pattern, and then with a stamper cut and embossed to the exact pattern
I apply pressure which forces the dust into the depressions of the mould and
consolidates it; after which I remove the loose dust which has not been compressed,
and then fill in with dust of the ground color, and press the whole as before.
When making ornament of embossed tiles from clay I use the absorbent pad to
give the pressure, and to remove the excess of moisture from the clay before filling
in the back with dust.
In cases where it is required to perforate the tile or other article in moulds
having the bottom fixed and the sides movable, the pegs or pins for making the said
perforations are fixed to a bar attached to the lower part of the sides of the mould,
and project upwards through corresponding holes in the fixed bottom of the mould,
so that after the tile has been pressed and the sides of the mould are lowered,
leaving the tile at the bottom, the pegs are drawn downwards at the same time, so
as to be clear of the holes in the tile; or the pegs may be fixed to a separate bar
actuated by a lever.
When the perforations are not required to extend through the whole thickness of
the tile the pegs are to be made proportionately shorter.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I wish it to be understood that I claim as my Invention,―
First. The use of perforated metal or other plates, the edges of such perforations
being bevilled (instead of parallel, as heretofore) for the purpose of facilitating the
delivery of the clay or dust patterns therefrom.
Secondly. I claim in combination with the above the use of a piece of cardboard
or other absorbent material for the purpose of getting rid of the excess of moisture.
Thirdly. I claim the use of the perforated or partially perforated plates or moulds.
(composed wholly or in part) of india-rubber or other compressible material,
Bubstantially in the manner and for the purposes above described.
Fourthly. In making embossed tiles I claim the use of a stamper cut and
I embossed to the exact pattern required.
Fifthly. In making the perforated tiles in moulds with a fixed bottom and
movable sides I claim the pegs or pins projecting upwards through holes in the
fixed bottom, and capable of being withdrawn, substantially as described.
And, Sixthly. I claim generally the various novel processes or methods of manu-
facturing encaustic tiles or other similar articles, substantially as herein-before
particularly described.
In witness whereof, I, the said Leonard Broughton Wood, have hereunto set
my hand and seal, this Fourth day of March, in the year of our Lord One
thousand eight hundred and seventy-nine.
LEONARD BROUGHTON WOOD. (L.S.)