IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF EARTHENWARE PIPES."
Year: 1875

page_text: LETTERS PATENT to Henry Doulton, of High Street, Lambeth,
in the County of Surrey, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR THE MANUFACTURE OF EARTHENWARE PIPES."
PROVISIONAL SPECIFICATION left by the said Henry Doulton at the
Office of the Commissioners of Patents, with his Petition, on the
19th May 1875.
I, HENRY DOULTON, of High Street, Lambeth, in the County of
Surrey, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF EARTHENWARE PIPES,” to
be as follows:-

page_text: 1
To form the socket at the lower end of the pipe I proceed as follows:-
I provide around the annular orifice of the die a flange, the interior of
which corresponds in form with the exterior of the socket. At the base
of the flange around the die I form slits for the admission of air, and I
provide plugs to close the slits at pleasure. Beneath the die is a table |
which carries a 66 socket head" or form on which to mould the interior
of the socket; this table can be raised and lowered at pleasure.
In the process of moulding a socket pipe the table is raised by
ordinary means until the "socket head" or form to mould the interior
of the socket is in contact with the flange, which is provided for
moulding the exterior of the socket. The table being firmly supported
in this position pressure is applied to the clay, and it is forced through
the die into the socket mould, formed as already described, until the
socket mould is full; or the socket head or mould may be held up from
above independently of the table. Up to this time the slits in the 1
flange forming part of the socket mould have been closed by the plugs,
but these are now withdrawn, and the table is released so that it is free
to descend. More clay is now pressed through the die, and air being
able to enter behind the socket, the socket leaves the mould freely and
the table descends whilst the barrel of the pipe is formed and issues 2
from the die.
When I am making pipes, such as are described in the Specification
of a Patent granted to Walter Halstead Cortis Stanford, No. 4039, in the
year 1873, where the sockets and ends of the pipes are, after the pipe has
been burned, lined and tipped with a composition accurately moulded, 2
so that the pipes may fit together with greater truth, I proceed as
follows: I make the pipe in the first instance thicker both in the
socket and at the end than is required in the finished form, and before
burning the pipe I cut away the superfluous material from the interior
of the socket and from the end of the end of the pipe, but without 3
removing the portions of clay so cut off. On the contrary I take care
to cause them to adhere to the pipe and remain in their original places
whilst the pipe is being burned, and afterwards they are easily broken
away. By resorting to this method I obtain two advantages; first,
these surplus pieces add greatly to the strength of the pipe at the parts 3
where it is most liable to injury during manufacture, and consequently
fewer imperfect pipes are made; and, second, the surplus pieces protect
from the action of the glaze the parts of the earthenware which it is

page_text: necessary to leave rough in order that the composition with which the
sockets are to be lined and the ends of the pipes tipped may adhere
firmly.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Doulton in the Great Seal Patent Office
on the 18th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DOULTON, of High Street, Lambeth, in the County of Surrey, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Nineteenth day of May, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Henry Doulton, Her special
license that I, the said Henry Doulton, my executors, administrators,
and assigns, or such others as I, the said Henry Doulton, 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
APPARATUS FOR THE MANUFACTURE OF EARTHENWARE PIPES," upon the con-
dition (amongst others) that I, the said Henry Doulton, 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 Henry Doulton, 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 :—
-
This Invention has for its object improvements in apparatus for the
Contura of northan

page_text: In order to form the barrel or straight portion of the pipe I cause clay
to be pressed down through a die in the usual manner.
To form the socket at the lower end of the pipe I proceed as follows:-
I provide around the annular orifice of the die a flange, the interior of
which corresponds in form with the exterior of the socket. At the base
of the flange around the die I form a slit or slits for the admission of
air, and I provide plugs to close these slits at pleasure. Beneath the
die is a table which carries a "socket head" or form on which to mould
the interior of the socket; this table can be raised and lowered at
pleasure.
In the process of moulding a socket pipe the table is raised by
ordinary means until the "socket head" or form to mould the interior
of the socket is in contact with the flange which is provided for moulding
the exterior of the socket. The table being firmly supported in this
position pressure is applied to the clay, and it is forced through the die
into the socket mould; formed as already described, until the socket
mould is full; or the socket head or mould may be held up from above
independently of the table. Up to this time the slits in the flange
forming part of the socket mould have been closed by the plugs, but
these are now withdrawn and the table is released so that it is free to
descend. More clay is now pressed through the die, and air being able
to enter behind the socket the socket leaves the mould freely and the
table descends, whilst the barrel of the pipe is formed and issues from
the die.
When I am making pipes, such as are described in the Specification
of a Patent granted to Walter Halstead Cortis Stanford, No. 4039; in
the year One thousand eight hundred and seventy-three, where the
sockets and ends of the pipes are, after the pipe has been burned,
lined and tipped with a composition accurately moulded so that
the pipes may fit together with greater truth, I proceed as follows :-
I make the pipe in the first instance thicker both in the socket and
at the end than is required in the finished form, and before burning
the pipe I cut away the superfluous material. from the interior of
the socket and from the end of the pipe, but without removing
the portions of clay so cut off; on the contrary I take care to cause
them to adhere to the pipe and remain in their original places whilst the
pipe is being burned, and afterwards they are easily broken away. By

page_text: resorting to this method of forming and burning with the pipe rings of
surplus material which are removed before the pipe is finished, I obtain
two advantages; first, these surplus pieces add greatly to the strength
of the pipe at the parts where it is most liable to injury during manu-
facture, and consequently fewer imperfect pipes are made; and, second,
the surplus pieces protect from the action of the glaze the parts of the
earthenware which it is necessary to leave rough, in order that the com-
position with which the sockets are to be lined, and the ends of the
pipes tipped may adhere firmly. Or in place of cutting away and
replacing the surplus material before burning the pipe, as above
described, I simply nick the surplus material before burning in such a
manner that after burning it may be readily broken away with hammer
and chisel.
In order that my said Invention be most fully understood and readily
T
411
י
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical section of the apparatus I employ for making
socket pipes.
a is the clay cylinder from which, in the usual way, the clay is forced
through the orifice in the dic plate b. ' is a flange formed around the
orifice, it is turned on its inner side to correspond accurately in form to
the exterior of the socket to be produced. Just at the point where the
orifice of the die enlarges into the socket mould I form a slit, into which
I fit a plug c (it may be square or oblong in section), and I provide a
screw d to hold the plug firmly in its place whilst the socket is being
moulded; but afterwards the plug is drawn back to allow air to enter
by the slit in order that the socket may be free to leave the mould.
For pipes of the smaller sizes one slit is sufficient, but for large pipes
two slits on opposite sides should be employed. In some cases it may
even be desirable to employ more than two slits. e is the core of the
die; and, the socket head or form to mould the interior of the socket;
it is fixed upon a table g. This table is supported upon a plate h, and
whilst the socket is being moulded the plate is secured to the under side
of the die by three strong lugs 6², more clearly seen in Figure 2, which
is a plan of the table with the lugs in section. The plate / can be turned
partly round by means of the lever handle /¹ fixed upon it, and it is

page_text: provided with three wedge-shape projections h³, which entering notches
in the lugs wedge the table up to its place at the mouth of the socket
mould. The table g is carried upon a base i, with which it is connected
by a pin; at the centre k, k, are counterpoises of sufficient weight to
raise the table to the die, but they allow it to descend as a pipe is formed.
¿¹ is a stem in connection with the base i, it works through guides.
The operation of moulding a pipe is as follows:-The table having
been raised and locked in position the pressure is applied to the clay in
the cylinder, and so the socket is moulded, then the pressure having
been taken of the plug c is withdrawn so as to admit air, and the plate h
is turned so as to release the table 9. The pressure is then again
applied to the clay, when the socket leaves the mould and the barrel of
the pipe is produced. When the barrel is of the proper length the
pressure is again taken off, the clay is cut through close up to the die,
and the pipe is carried away upon the table.
When I wish to make pipes to be lined and tipped at the joints, as is
described in the Specification of Stanford's Patent, I form the socket
mould so as to make a much thicker socket than is required for the
finished pipe, as is shown at Figure 3, then after the pipe is moulded,
by means of a ring cutter, the portion which is shaded is cut out, and
the interior of the socket is grooved or roughened; then the surplus
piece previously removed is replaced and pressed firmly into its original
position to make it adhere so that it will not separate in the burning,
but on the contrary hold the socket in shape; it is readily broken away
afterwards with hammer and chisel. Figure 4 shows the spigot end of
the pipe, the shaded portion is the surplus piece which is cut away and
afterwards replaced. Or in place of removing and replacing the surplus
pieces I can groove them, as is indicated by the Figures 5 and 6, so that
although they serve to strengthen and support the pipe before and
during the burning they are easily broken away and removed afterwards,
leaving rough surfaces very convenient to receive the lining and
tipping.
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 confine myself to the exact details described; but I claim,-
First. The means for the manufacture of socket pipes, and especially
for causing the socket to be delivered from the socket mould, sub-
stantially as described.

page_text: Second. The means for the manufacture of socket pipes, which after
burning are to be lined and tipped, such means consisting in forming
upon the pipe "surplus pieces" to strengthen the pipe during manu-
manufacture, and to protect portions of the surface from the action of
the glaze, substantially as described.
In witness whereof, I, the said Henry Doulton, have hereunto set
my hand and scal, this Eighteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-
five.