IMPROVEMENTS IN THE MANUFACTURE OF CRUCIBLES AND OTHER ARTICLES OF POTTERY WARE
Year: 1883

page_text: LETTERS PATENT to Henry Lewis Doulton of the firm of Doulton and
Company Albert Embankment Lambeth for an Invention of "IMPROVEMENTS
PROVISIONAL SPECIFICATION left by the said Henry Lewis Doulton at
the Office of the Commissioners of Patents on the 2nd February 1883.
HENRY LEWIS DOULTON of the Firm of Doulton and Company Albert
Embankment Lambeth " IMPROVEMENTS IN THE MANUFACTURE OF CRUCIBLES
AND OTHER ARTICLES OF POTTERY WARE
"
This Invention has for its object improvements in the manufacture of crucibles
and other articles of pottery ware.
According to any invention I make the crucible or other article of pottery ware
by the use of a "Jolly" or similar machine which forms the piece of ware within
a rotating mould by means of a shaping lever or tool.
I make a bag of woven fabric to the shape of the interior of the mould I provide
the bag with a stiff bottom of sheet metal and also with a rim or flange of the
same material at the top
To prevent the flange cutting the fabric I make the flange of two thicknesses of
metal and interpose india rubber between the metal and the fabric where the fabric
is likely to be chafed
I place the bag in the mould before cominencing to fashion the article and I put
in the clay or material.
I spread it by means of the lever whilst the mould revolves against the sides of
the mould but within the bag.
When the moulding is complete I withdraw the mould from the machine with
the bag and the article within it-the mould being then removed I at once strip
off the bag and place the article aside to dry.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry Lewis Doulton in the Great Seal Patent Office on the
2nd August 1883.
HENRY LEWIS DOULTON of the firm of Doulton and Company Albert
Embankment Lambeth " IMPROVEMENTS IN THE MANUFACTURE OF CRUCIBLES
AND OTHER ARTICLES OF POTTERY WARE
"
This invention has for its object improvements in the manufacture of crucibles
and other articles of pottery ware.
According to my invention I make the crucible or other article of pottery ware
by the use of a "Jolly" or similar machine which forms the piece of ware within
a rotating mould by means of a shaping lever or tool.
I make a bag of woven fabric to the shape of the interior of the mould I provide
the bag with a stiff bottom of sheet metal and also with a rim or flange of the
same material at the top.
To prevent the flange cutting the fabric I make the flange of two thicknesses of
metal and interpose india rubber between the metal and the fabric where the fabric
is likely to be chafed.
I place the bag in the mould before commencing to fashion the article and I put
in the clay or material.
I spread it by means of the lever whilst the mould revolves against the sides of
the mould but within the bag.
When the moulding is complete I withdraw the mould from the machine with
the bag and the article within it the mould being then removed I at once strip off
the bag and place the article aside to dry.
In the annexed drawings Figure 1 is a vertical section of the machine. a is an
upright axis which is rotated in any convenient manner it has mounted upon its
upper end a cup b into which the mould c is inserted. d is the shaping lever and
the tool d' is fixed upon it. In working with this machine a lump of clay or
material of the proper size is thrown into the mould and whilst the axis rotates
the tool d is brought down upon the material and forms it against the sides of the
mould.
In working with a Jolly or similar machine it is usual to employ plaster moulds
and to allow the moulded article to remain in the mould until it has shrunk
sufficiently to admit of its being turned out. When working in this way a large
stock of moulds is required. My invention allows me to dispense with this stock
of moulds to employ only one mould and to deliver the moulded article from the
mould immediately it is formed. By preference I make the mould in wood (and
sometimes I make them in parts hinged together so that the mould may open for
the ready discharge of the moulded articles). I line this mould with textile fabric.
Figure 2 shows the lining made in the form of a bag. I employ by preference a
fine closely woven fabric sewn or glued together to the proper shape. The upper
edge of this bag I clamp between two metal plates or rings as is shown in section
to an enlarged scale at Figure 3. I lay also a ring or washer of india rubber
beneath the fabric and by screws or rivets passing through the metal plates I clamp
the whole together. The bottom of the bag or mould lining is also a plate of metal
and the edges of the fabric are glued to it.
When in use this lining is placed within the wooden mould the metal rings
resting upon the top thereof as is seen in Figure 1. The lump of clay or material
is thrown in to the bag within the mould and the tool being brought down shapes
it in the usual way. Immediately afterwards the wooden mould is lifted out of the
cup b on to a table the bag with the crucible or article within it is removed and

page_text: then the bag is stript away leaving the article ready to be placed aside to dry.
The crucible or article is afterwards finished and fired in the usual way. When
the lining is made in the way above described it is necessary that the moulded
article should be larger at the top than in any other place otherwise the bag lining
cannot be stript from it. But a fabric lining may be applied to the mould in such
manner as to admit of the largest diameter of the moulded article being in the
middle or at any distance from the top; one way of doing this is illustrated by
Figures 4 and 5, Figure 4 shows a perspective view of a crucible mould and
crucible of which the largest diameter is at a distance down from the top.
Figure 5 shows in section to a larger scale the way in which a lining is applied to
this mould. Each part of the mould is covered separately with the lining fabric
so that the fabric overlaps the edges of the parts and it is fastened with pins or
otherwise. In the figure the overlap of the lining at the top and bottom is clearly
seen. At the top and bottom of the mould also where the fabric would be exposed
to wear semicircular pieces of india rubber are fastened on to protect it. The
bottom of the mould is a separate piece it is dropped first into the cup 6 of the
machine and afterwards the side pieces are put in upon it. The moulding then
takes place; this having been done the mould is removed from the machine and
taken apart the lining of fabric causing the mould to deliver freely and it is not
necessary to wait for shrinkage to take place.
Having thus described the nature of my said invention and the manner of
performing the same I would have it understood that I do not claim generally
lining with fabric moulds in which plastic materials are moulded But what I
claim is :-
First Moulding crucibles and other articles of pottery ware in a revolving
mould lined with fabric by spreading the clay or plastic material with a shaping
tool within such lined mould substantially as described.
Second-The combination of apparatus for the manufacture of crucibles and
other articles of pottery ware consisting of a rotating mould a bag lining and a
forming tool arranged and operating together substantially as described.
In witness whereof I the said Henry Lewis Doulton have hereunto set my
hand and seal this twenty seventh day of July in the year of our Lord One thousand
eight hundred and eighty three.
HL DOULTON (ra)