IMPROVEMENTS IN METAL MOULDS OR DIES USED IN THE MANU- FACTURE OF EARTHENWARE OR CHINA FROM CLAY IN THE POWDERED STATE BY MEANS OF COMPRESSION, WHICH IMPROVEMENTS ARE SPECIALLY APPLICABLE TO THE MANUFACTURE OF POTS AND JARS
Year: 1874

page_text: LETTERS PATENT to Arthur Maw, of Benthall Works, near Broseley,
in the County of Salop, Encaustic Tile Manufacturer, for the Inven-
tion of "IMPROVEMENTS IN METAL MOULDS OR DIES USED IN THE MANU-
FACTURE OF EARTHENWARE OR CHINA FROM CLAY IN THE POWDERED STATE BY
MEANS OF COMPRESSION, WHICH IMPROVEMENTS ARE SPECIALLY APPLICABLE TO
THE MANUFACTURE OF POTS AND JARS."
Sealed the 2nd April 1874, and dated the 21st January 1874.
PROVISIONAL SPECIFICATION left by the said Arthur Maw at the
Office of the Commissioners of Patents, with his Petition, on the
21st January 1874.
I, ARTHUR Maw, of Benthall Works, near Broseley, in the County of
Salop, Encaustic Tile Manufacturer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN METAL MOULDS OR DIES USED IN THE
MANUFACTURE OF EARTHENWARE OR CHINA PROLI CLAY IN THE POWDERED STATE BY
MEANS OF COMPRESSION, WHICH IMPROVEMENTS ARE SPECIALLY APPLICABLE TO THE
MANUFACTURE OF POTS AND JARS," to be as follows:―
My Invention consists in the construction and operation of metal
moulds or dies so formed as to give a vertical compression to the

page_text: powdered clay in proportion to the depth or thickness of the various
parts of the object to be moulded, as shewn in Figures 1, 2, (the mould
for covered pot) and 3, the cover to the same.
Also in a plan for applying pressure by hydraulic power from within,
both vertically and laterally, or where necessary in every direction at
the same time, as shewn in Figure 4, the object being in each case to
compress and consolidate powdered clay instead of the usual process of
moulding such articles out of plastic clay.
Figure 1 refers to my first method of procedure, and is a vertical
section of mould for making covered pots by vertical pressure with the
parts in position ready to be filled with powder previous to compression,
the pot being moulded bottom upwards. A, A, is the circular box or
mould forming the outside of the pot; B, B, is a cylindrical cup with
flat bottom (the top edge of which moulds the flanged edge of pot)
working up and down in A, and connected by means of the tubular
shaft E to a discharging treadle not shewn. C is a plug or core which
moulds the inside of the pot working up and down in B and connected
with a hand lever by the rod F which moves inside the tubular shaft E;
D is the die which forms the bottom surface of the pot, and is attached
to a scrow press not shewn.
In commencing to mould a pot the plug C is lifted by means of the
hand lever acting on the rod F to the position shewn at Figure 1, the
box is then filled with powder up to the top and struck off level. The
die D is then brought down by means of the screw press, and having
first partially compressed the powder forming the bottom of the pot it
commences to force down the plug C, by which means the sides of the
pot are also compressed (until (when the compression of the whole is
completed) the positions of the various parts of the mould are as shewn
at Figure 2. The pot is then discharged from the mould by means of
the treadle acting on the cup B by means of the tubular shaft E, and
the process is repeated.
Figure 3 shows section of mould for making the lids of the pots
referred to above, and is constructed and worked precisely on the same
principle as the pot mould.
Figure 4 refers to another method of procedure, and is a vertical
section of a mould for making galleypots. A, A, is the circular box or
mould forming the outside of the pot; B, B, is a hollow india-rubber

page_text: core or centre mould filled with water or other fluid firmly attached to
the collar or cylinder D by means of a circular washer and screws; C is
the bottom die connected by a rod to the discharging lever not shewn;
E is a plug or piston correctly fitted in the cylinder D, and so attached
as to prevent its Drawing quite out, but after being nearly withdrawn it
lifts the cylinder D up with it by means of the guides I, I, attached to D,
and working through holes in the cross head on the piston E. F, F, are
two bolts to hold the cylinder D in its place whilst the mould is under
pressure; G is a cup for keeping the core B filled with water so as to
make good any leakage which may occur during the action of the
hydraulic pressure.
In commencing to mould a gallypot or other vessel by this process,
the piston E with the cylinder D having the india-rubber core B
attached to it is raised by the screw press (not shewn) out of the box A.
The bottom die C is then raised to within a given distance of the top of
the box A, when the required quantity of powder to form the bottom of
the pot is put in and struck off level; the bottom die C is then dropped
to within a sufficient distance of the bottom of the box A, so that the
top edge of the pot about to be moulded would be level with the top of
the box A. A cylindrical block of the proper size to allow round its
outer circumference a sufficient space between it and the box A for the
powder required to mould the sides of the pot is then placed in the
centre of the mould, and the space round it is filled with powder after
which it is removed. The screw press is then lowered, bringing with it
the piston E with the cylinder D, and the india-rubber core B attached
to it until the projecting flange on D rests on the top of A, and the
bottom of B at the same time rests on the powder intended to form the
bottom of the pot. The action of the press being then continued the
piston E is forced down, displacing the water in the core B and dis-
tributing the pressure equally over its whole surface until the powder is
sufficiently solidified, when the press is again raised, first lifting up the
piston E, and afterwards with it removing the cylinder D with the core B
which is colapsed to its original dimensions; the pot is then discharged
by means of the treadle and shaft (not shown) acting on the bottom
die C; should any leakage of water occur between the piston E and
cylinder D it is at once on the withdrawl of E supplied from the
cup
G
through the pipe H, the mouth of which is closed by the piston E imme-
diately on its being again forced down.

page_text: Articles of almost any form can be moulded from powder by this
process providing the openings in them are large enough to enable the
india-rubber core to be withdrawn when in its collapsed state, but where
an article with a contracted top has to be produced it is of course
necessary to make the outer mould in sections.
Referring to my process Figures 1, 2, and 3, in which vertical screw
pressure is applied directly, I do not bind myself to the arrangement by
which the plug or core C is made movable as I may prefer to have this
part of the mould fixed, and to force the cup B upwards into the same
relative position to the plug C, as shewn at Figure 2, nor do I bind
myself to any particular form in the articles manufactured, which may
be square or of any other shape. They may either have continuous
raised sides or have only two raised sides as in the case of a half round
tile, or they may be flat or curved articles supported on legs.
Referring to my process, Figure 4, I do not bind myself to the exact
means by which the pressure is to be obtained, which may be either by
the piston and cylinder above described, or by water conveyed through a
pipe from an ordinary hydraulic pump, nor do I bind myself to the use
of water only for this purpose, but may employ mercury or other
fluid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur Maw in the Great Seal Patent Office on
the 21st July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
MAW, of Benthall Works, near Broseley, in the County of Salop,
Encaustic Tile Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-first day of January, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors give and grant unto me, the said Arthur Maw, Her special
license that I, the said Arthur Maw, my executors, administrators, and
assigns, or such others as I, the said Arthur Maw, my executors,
administrators, and assigns, should at any time agree with, and no

page_text: 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
METAL MOULDS OR DIES USED IN THE MANUFACTURE OF EARTHENWARE OR CHINA
FROM CLAY IN THE POWDERED STATE BY MEANS OF COMPRESSION, WHICH IMPROVE-
MENTS ARE SPECIALLY APPLICABLE TO THE MANUFACTURE OF POTS AND JARS," upon
the condition (amongst others) that I, the said Arthur Maw, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 Letters Patent.
NOW KNOW YE, that I, the said Arthur Maw, do hereby declare the
nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
My Invention consists firstly in the construction and operation as
herein-after described of metal moulds or dies formed to give a vertical
compression to the powdered clay in proportion to the depth or thick-
ness of the various parts of the object to be moulded. When moulding
powdered clay in this manner I have found it necessary that a
movement should be given to the outer mould during the time that the
clay is being compressed within it, so that when the article has been".
moulded it shall be at the top of the mould, and therefore shall not have
to be forced up through a considerable length of such mould to be dis-
charged therefrom.
The Invention also consists in a plan for applying pressure by
hydraulic power from within, both vertically and laterally, or where
necessary in every direction at the same time, the object being in each
case to provide a means whereby powdered clay may effectually be com-
pressed and consolidated instead of the more usual process of moulding
such articles out of plastic clay.
Figure 1 is a vertical section of a mould for making covered pots
according to the first-mentioned method of precedure; this Figure also
shews parts of the press by which it is operated, Figure 2 is a front

page_text: view of the same also shewing the arrangements for placing the plug
or core C in position, and for discharging the pot when pressed up;
Figure 3 is a side view of the same.
A, A, is the circular box or mould forming the outside of the pot;
B, B, is a cylindrical cup with flat bottom (fixed to and resting on a
cylindrical block attached to the bed of the press) the top edge of which
moulds the flanged edge of the pot; C is a plug or core which moulds
the inside of the pot, working up and down in the cup B, and connected
by the vertical shaft F, and the horizontal rod G, to the hand lever H
by which it is placed in the position shewn at Figure 1 (ready for
filling the mould) and is temporarily kept in position by a spring (see
Fig. 2) attached to the hand lever H, which drops into a notch in
the guide J; D is the top die which moulds the bottom of the pot; K is
a vertical shaft (provided with a coupling box to vary its length)
attached by means of the cross bar L to two levers M which work
through slots in the guides N, N, attached to the mould A, and working
on the projecting slide bars O, O, attached to the uprights of the press
P, P; Q is a sheet iron platform attached to and moving with the box A
and the guides N, N; R, R, are two collars or stops fitted to the circular
uprights of the press P, P, &c. (when adjusted in their proper position),
fixed in their place by set screws; S is a treadle operating on the
shaft K.
In commencing to mould a pot by this process the circular box or
mould A with the guides N, N, and the platform Q attached to it is
fifted up by means of the cross bar L, and the levers M, M, until the
platform Q comes in contact with the stops R, R, where it is kept in its
place by the counterbalance weight T. The plug C is then raised by
means of the hand lever H until it is placed in the position shewn at
Figure 1. The mould is then filled with powder and the top die D
brought down by means of the screw. When its outer edge comes in
contact with the mould A and the platform Q it presses it down, also
carrying with it the plug C, until the latter rests on the bottom of the
cup B when the bottom and sides of the pot have received a pro-
portionate degree of pressure. The top plate D is then raised, after
which the pot is discharged by means of the treadle S, which acting on
the shaft K and the levers M, M, draws the mould A down on to the
bed of the press, leaving the finished pot resting on the plug C from
which it is removed by the hand.

page_text: The peculiarity of this part of my Invention consists in the mould A
being made to move on the fixed cup or cylinder B, by which means the
pot is moulded at the top of the mould, and has not therefore to be dis-
charged by forcing it through a considerable length of the mould.
This improved plan of operating the mould also has the advantage of
enabling a projecting rim or moulding to be made on the bottom edge of
the pot and on the top edge of the lid (which is moulded in a precisely
similar manner to the pot), as the projecting rim being moulded at the
top edge of the mould A the pot can be discharged without breaking it
off, which would be the case if it had to be forced through the mould.
I would here remark that although I have shewn and described one
construction of press, by which the various parts of the mould may have
the motion above described imparted to them, I do not confine myself to
the use of this particular description of press as other means may be
adopted for imparting the same motions to the mould, but what I claim
as respects this part of my Invention is, the combined arrangement of
moulds or dies substantially as herein-before described for the manu-
facture of earthenware or china from clay in the powdered state by
means of compression, the mould A being made to move on the fixed
cup or cylinder B during the time of compressing the clay.
Figure 4 shews a vertical section of a mould for making gallipots
according to the second method above mentioned. A, A, is the circular
box or mould forming the outside of the pot; B, B, is a hollow india-
rubber core or centre mould (filled with water or other fluid) firmly
attached to the collar or cylinder D by means of a circular washer and
screws; C is the bottom dic connected by a rod to the discharging lever
not shewn; E is a plug or piston correctly fitted in the cylinder D, and
so attached as to prevent its drawing quite out, but after being nearly
withdrawn it lifts the cylinder D up with it by means of the guides I, I,
attached to D, and working through holes in the cross head on the
piston E; F, F, are two bolts to hold the cylinder D in its place whilst
the mould is under pressure; G is a cup for keeping the core B filled
with water so as to make good any leakage which may occur during the
action of the hydraulic pressure.
I commonaing to mould
collinato athon vol be this uni
11

page_text: it is raised by the screw press (not shewn) out of the box A. The
bottom die C is then raised to within a given distance of the top of the
box A, when the required quantity of powder to form the bottom of the
pot is put in and struck off level. The bottom die C is then dropped to
within a sufficient distance of the bottom of the box A, so that the top
edge of the pot about to be moulded would be level with the top of the
box A. A cylindrical block of the proper size to allow round its outer
circumference a sufficient space between it and the box A for the
powder required to mould the sides of the pot is then placed in the
centre of the mould, and the space round it is filled with powder, after
which it is removed. The screw press is then lowered, bringing with it
the piston E with the cylinder D, and the india-rubber core B attached
to it until the projecting flange on D rests on the top of A, and the
bottom of B at the same time rests on the powder intended to form the
bottom of the pot. The action of the press being then continued the
piston E is forced down, displacing the water in the core B and
distributing the pressure equally over its whole surface until the powder
is sufficiently solidified, when the press is again raised, first lifting up
the piston E, &c., afterwards with it removing the cylinder D with the
core B, which is collapsed to its original dimensions. The pot is then
discharged by means of the treadle and shaft (not shown) acting on the
bottom die C. Should any leakage of water occur between the piston E
and cylinder D it is at once on the withdrawal of E supplied from the
cup G through the pipe H, the mouth of which is closed by the piston E
immediately on its being again forced down.
Articles of almost any form can be moulded from powder by this
process, providing the openings in them are large enough to enable the
india-rubber core to be withdrawn when in its collapsed state, but where
an article with a contracted top has to be produced it is of course
necessary to make the outer mould in sections.
I would state that I do not bind myself to the exact means by which
the fluid pressure is to be obtained, which may be either by the piston
and cylinder above described or by water conveyed through a pipe from
an ordinary hydraulic pump, nor do I bind myself to the use of water
only for this purpose, but may employ mercury or other fluid, but what
I claim as respects this part of my Invention is, the combined arrange-
ment of moulds or dies, substantially as above described, whereby the

page_text: compression and moulding of clay in the powdered state is effected by
fluid pressure.
In witness whereof, I, the said Arthur Maw, have hereunto set my
hand and seal, this Eleventh day of July, in the year of our
Lord One thousand eight hundred and seventy-four.
ARTHUR MAW. (L.S.)