IMPROVEMENTS IN MACHINERY OR APPARATUS FOR THE MANUFACTURE OF POTTERY
Year: 1854

page_text: LETTERS PATENT to George Wall, of the City of Manchester, in the
County of Lancaster, for the Invention of "IMPROVEMENTS IN MACHINERY
OR APPARATUS FOR THE MANUFACTURE OF POTTERY."
Sealed the 7th November 1854, and dated the 26th August 1854.
PROVISIONAL SPECIFICATION left by the said George Wall at the Office
of the Commissioners of Patents, with his Petition, on the 26th August
1854.
I, GEORGE WALL, of the City of Manchester, in the County of Lancaster,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
MACHINERY OR APPARATUS FOR THE MANUFACTURE OF POTTERY " to be as follows:-
There have been many difficulties experienced in moulding pottery ware by
pressure, because if the mould is made of iron the clay is apt to stick to it,
and if made of plaister, will crush or break under the pressure. To prevent
which I propose, firstly, to reduce the pressure, by applying it to a small por-
tion of the article at once, and thus make a small or light pressure suffice;
and, secondly, to apply a stretched thin sheet of caoutchouc to deliver the
article from the mould. I reduce the pressure by making a concentric
mould, as shewn in the accompanying outline Drawing, so that the pressure
will be given only to portions of the clay at a time, which will have the double
advantage of lightening the pressure, and preventing confined air fixing itself

page_text: in parts of the clay, and bursting the pottery when made. The application
of stretched caoutchouc to the concentric mould will also have the double
advantage of forcing the article out of the mould by its own contraction, and
giving a finish to the surface of the pottery; or, in other words, it will dispense
with the marks of the folds of the canvass or other similar material on the
surface of the pottery, when used for that purpose.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said George Wall in the Great Seal Patent Office on the
26th February 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
WALL, of the City of Manchester, in the County of Lancaster, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Royal
Letters Patent, bearing date the Twenty-sixth day of August, in the year of
our Lord One thousand eight hundred and fifty-four, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said George Wall, Her special licence that I, the said George Wall, my
executors, administrators, and assigns, or such others as I, the said George
Wall, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN MACHINERY OR
APPARATUS FOR THE MANUFACTURE OF POTTERY," upon the condition (amongst
others) that I, the said George Wall, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Royal Letters Patent.
NOW KNOW YE, that i, the said George Wall, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement (that is to say):-
My Invention relates to machinery or apparatus for moulding or forming
clay into pottery ware by diminishing or reducing the amount of force or
pressure required for that purpose.

page_text: The amount of pressure required to form or mould any article of clay, as a
plate, dish, &c., between dies or moulds in the ordinary way, is
so great that
the common absorbent moulds will not bear it, and if metallic or other non-
absorbent moulds are used, the clay adheres to them. To overcome these
obstacles, I use a concentric mould made in separate parts, so constructed that
the necessary force or pressure is applied to each part successively, beginning
at the centre part, and ending at the last or external part, by which the pres-
sure is so much reduced and gradually applied that the common absorbent
moulds of plaster of Paris will bear it, with the assistance of an iron case or
hoop round them. I therefore employ a mould of this description for one
side of the article, and my said concentric mould made of metal or other hard
substance for the other side; and to prevent the adhesion of the clay to the
non-absorbent material of the concentric mould, I use a sheet of stretched
caoutchouc between it and the clay, which has the double advantage of forcing
the article out of the mould by its own contraction, and giving it a finished
surface.
The nature of my Invention will be clearly understood by reference to the
accompanying Sheet of Drawings, in which the same letters of reference are
used to represent corresponding parts in each view.
Fig. 1 is a front view, in section, of my improved apparatus, as applied to a
small-sized plate, and Fig. 2 is a side view thereof. A represents the concen-
tric mould, consisting of the fixed head a, and the separate concentric rings
a', a², a³, and a. a' is attached by screws to the fixed head a, and a³, a², and
a³ are free to rise in the recess of the fixed head into the position shewn by
the dotted lines, and to fall again by their own gravity into their previous
positions. The mould A may either be fixed rigidly in a frame or attached to
the spring S, but I prefer the latter. B is a counter mould or die, made of
absorbent material, such as is ordinarily used for moulds in making pottery
ware, and is strengthened by the metal enclosing case b, and rests upon the
spindle head c, which has a conical projection C, fitting into a corresponding
recess in the mould B, to chuck it correctly. The spindle c is made to rise
and fall by any suitable means in its bearings, one of which is shewn at 6.
D is an endless band of thin caoutchouc stretched over rollers d. The counter
mould B is represented with a bat of clay E upon it, such as would be made
by my patent batting machine. To mould this clay into a plate, the spindle
c is made to rise vertically by any suitable means, carrying with it the mould B
and the bat of clay E. In its upward motion, the clay first comes in contact
with the stretched caoutchouc, and afterwards successively with the concentric
rings a', a², and a, each by its weight pressing and partially moulding the part

page_text: assigned to it, and being lifted into the position shewn by the dotted lines, at
which point the ring a* comes into operation and finishes the moulding. As
the bat is made a little thicker in the centre than at the edges, each of these
concentric rings comes successively into contact with the fixed head A, where
the final pressure is given; the spindle c then descends, and the rings a', a², and
a³, falling by their gravity, follow it till their progress is arrested by the collars
on their tops, when they resume their original positions. The stretched caout-
chouc having been still further stretched during the operation of moulding,
now releases itself from the. formed plate by its own elasticity, assisted by the
descent of the spindle c, and the plate is left perfectly formed on the absorbent
mould B to be dried, and the same operation repeated with another mould B
and bat E. The concentric mould may be equally well applied to dishes and
other flat articles, as it is not essentially necessary that the concentric parts of
tho mould shall be circular. I prefer the concentric arrangement of the parts
of the mould A as described, because it excludes the air from between the clay
and the mould from the centre outwards. If it should be found more con-
venient, the pressure may be given by the descent of the concentric mould,
instead of the ascent of the counter mould, but I prefer the method I have
herein described. The concentric mould may also be used without the fixed
head A, the weight of the separate parts a', a³, and a³, being so regulated by
encreasing their length as to give the degree of pressure each requires in its
position of the work, or each may have a separate spring; but I prefer tho
arrangement as before described, in which the weight of each concentric part
is sufficient, in combination with the rapid motion of the spindle, to equalize
and partially mould the clay, the moulding being completed by the concentric
parts coming in contact at the end of the stroke with the solid head. The
caoutchouc may also be applied in a hand frame or other convenient manner;
but the endless band will be found preferable, because it can be turned a little
after each operation, and thus present a fresh dry place to the clay.
Having thus fully described the nature and particulars of my said Invention,
and in what manner the same is to be carried into practical effect, I desire it
to be distinctly understood that I do not confine myself to the exact details
herein set forth, as such may be varied or modified without departing from the
principle thereof, neither do I claim the exclusive right of moulding clay by
pressure; but I claim as my Invention, and which, to the best of my knowledge
and belief, has not been hitherto used within this realm,-
Firstly, the construction and use of the concentric mould made in separate
parts, for the purpose of applying the pressure to each part separately, and
afterwards, if necessary, to the whole of them together.

page_text: And, secondly, the use of stretched caoutchouc in the manner and for the
purpose herein specified, as such improvements are herein described and
illustrated in the accompanying Sheet of Drawings.
In witness whereof, I, the said George Wall, have hereunto set my
hand and seal, this Twenty-fourth day of February, Oue thousand
eight hundred and fifty-five.
Signed, sealed, and delivored by the within-
named George Wall, in the presence of
E. J. HUGHES,
Patent Agent,
Manchester.
GEORGE WALL. (L.S.)