IMPROVEMENTS IN THE MANUFACTURE OF EARTHENWARE DRAIN AND OTHER PIPES
Year: 1857

page_text: LETTERS PATENT to Henry Doulton, of Lambeth, in the County of
Surrey, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
EARTHENWARE DRAIN AND OTHER PIPES."
Sealed the 17th November 1857, and dated the 22nd July 1857.
PROVISIONAL SPECIFICATION left by the said Henry Doulton at the
Office of the Commissioners of Patents, with his Petition, on the 22nd
July 1857.
I, HENRY DOULTON, of Lambeth, in the County of Surrey, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
EARTHENWARE DRAIN AND OTHER PIPES," to be as follows:-
This Invention has for its object improvements in the manufacture of
earthenware drain and other pipes. For these purposes the dies or orifices
through which the clay is expressed by any suitable expressing machinery are
formed with cutters or parts, in such manner that in making cylindrical pipes
they shall be grooved or cut longitudinally both internally and externally in an
inclined direction to a radial line, so that each pipe may readily be divided
into two parts longitudinally.
It is preferred to give additional thickness on the sides of the pipe where
such inclined grooves or cuts are produced, so as to obtain additional strength
at those parts; and such grooves or inclined cuts are made both when pro-
ducing cylindrical pipes with sockets or part sockets, and also when producing
plain cylindrical pipes; the sockets as well as the other parts of the pipes being
made with such inclined cuts both inside and outside. When the longitudinal
cuts or grooves are made with a view to separate a cylindrical pipe into two
parts longitudinally, one part being greater and the other less than half, then

page_text: the cuts or grooves interior and exterior may be made in radial lines or
inclined thereto, and where such cuts or grooves are made, the thickness or
substance of the pipe is increased as before mentioned.
By thus making earthenware drain and other pipes, they can be dried
and burned without being divided, and they may, if desired, be laid without
being divided, and the dividing may be delayed till it is desired to remove
the upper part of any such pipes for the purpose of examination and cleansing
of the interior thereof; and by reason of the inclined directions of the
divided surfaces produced, the parts when combined will not be liable to shift
laterally, as the parts fit one into the other.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Doulton in the Great Seal Patent Office on the
22nd January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
DOULTON, of Lambeth, in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of July, in the year of our Lord
One thousand eight hundred and fifty-seven, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Henry Doulton, Her special licence that I, the said Henry Doulton,
my exccutors, 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
mako, 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 THE MANUFACTURE OF EARTHENWARE DRAIN AND OTHER PIPES,"
upon the condition (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
unture of the said Invention, and in what manner the same is to be performed,

page_text: 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 the manufacture of
earthenware drain and other pipes. For these purposes the dies or orifices
through which the clay is expressed by any suitable expressing machinery, aro
formed with cutters or parts, in such manner that in making cylindrical pipes
they shall be grooved or cut longitudinally both internally and externally in an
inclined direction to a radial line, so that each pipe may readily be divided
into two parts longitudinally. It is preferred to give additional thickness on
the sides of the pipe where such inclined, grooves or cuts are produced, so as
to obtain additional strength at those parts; and such grooves or inclined
cuts are made both when producing cylindrical pipes with sockets or part
sockets, and also when producing plain cylindrical pipes, the sockets as well
as the other parts of the pipes being made with such inclined cuts both inside
and outside. When the longitudinal cuts or grooves are made with a view to
separate a cylindrical pipe into two parts longitudinally, one part being greater
and the other less than half, then the cuts or grooves interior and exterior
may be made in radial lines or inclined thereto, and where such cuts or
grooves are made, the thickness or substance of the pipe is encreased, as
before mentioned.
By thus making earthenware drain and other pipes, they can be dried and
burned without being divided, and they may, if desired, he laid without being
divided, and the dividing may be delayed till it is desired to remove the upper
part of
any of such pipes for the purpose of examination and cleansing of the
interior thereof; and by reason of the inclined directions of the divided
surfaces produced, the parts when combined will not be liable to shift laterally
as the parts fit one into the other.
Having thus stated the nature of my said Invention (which is more parti-
cularly applicable for the larger class of drain pipes, such as nine inches in
diameter and upwards, yet, when desired, earthenware pipes for drains and
other purposes of smaller section may be made according to my improve-
ments), I will proceed more fully to describe the manner of performing
Figure 1 shews the section of a drain pipe of earthenware, constructed
according to my Invention when it is desired to have a pipe divisable into
two parts longitudinally, of about equal dimensions. a, a, are grooves or cuts
made before burning, and longitudinally on the outer and opposite surfaces

page_text: where the material or substance of the pipe is thickened, to give additional
strength to the pipe. Each of these cuts or grooves, it will be seen, is not
radial, but is inclined to a radius, and this is important, as it prevents the
upper half shifting transversely when it has been separated after burning,
whether such separation is accomplished before or after laying. b, b, arc
internal longitudinal cuts or grooves, hence when the pipe is dried and
formed, the two parts of which it is composed will be held together by the
remaining portion between the terminations of the outer and inner cuts or
grooves a, b.
Figure 2 shews a perspective view of a complete pipe with a socket, but I
would state that this part of my Invention is applicable to earthenware drain
and other pipes made with or without sockets. It should here be remarked,
that I am aware that earthenware pipes have before been made without
sockets, each divisable into two parts longitudinally, of about equal dimen-.
sions, and such pipes have been made with exterior grooves or cuts, such as is
shown in section at Figure 3; but in such case the grooves or cuts on the
two opposite sides of a pipe were in the same plane and radial, hence when
divided after burning, the two halves were, when in use, liable to be shifted
sideways in respect to each other and separated, whereas by making the
grooves or cuts on the opposite sides of an earthenware pipe, at an angle to
each other, the upper part is retained from lateral shifting; and by making
the longitudinal grooves both inside and outside, the division after burning is
more certain, and a pipe is less liable to be injured on the interior surface
when dividing the two parts, than when the grooves or cuts are made only on
the outside.
Figure 4 shews the section of another earthenware pipe with a socket,
suitable for drains and other purposes; Figure 5 is a perspective view thereof.
In this construction the upper part only of cach pipe, which is comparatively
small, is made divisable from the lower and larger part of the pipe. In this
pipe the grooves are each made slightly inclined to a radius, but this is not
essential, as the longitudinal grooves or cuts in an earthenware pipe may
(when the pipe is divided longitudinally into two parts, one larger than the
other) be radial, as shewn in section, Figure 6. According to either of these
forms, the lateral or sideway shifting of the upper part in respect to the lower
part will be prevented.
The pipes shown by Figures 4, 5, and 6 are made with internal as well as
external grooves or cuts, and the parts of the pipes where they are grooved or
cut are made of greater thickness or substance than the other parts; they may
be also made plain or with sockets, as desired.

page_text: The modes of manufacturing earthenware pipes by expressing the same
through moulding orifices or dics, whether plain or with sockets, being well
understood, it will not be necessary to describe the same here, as it will only
be necessary to vary the moulding orifices or dies in a manner suitable for
producing the additional substance where the cuts or grooves are made, which
a workman will readily do. The longitudinal cuts or grooves may be made in
the act of moulding the pipes or afterwards. I prefer, however, to have fixed
cutters or instruments in the dies or moulding orifices, so as to produce the
longitudinal grooves as the clay is expressed through the orifices or dies; and
where the sockets are moulded by suitable apparatus applied to moulding
orifices or dies, as is well understood, then in making the grooves or cuts in
the sockets I prefer to have moveable cutters, which I pass through slits or
narrow openings, made through the apparatus used for producing the sockets,
and I introduce such moveable cutters into the socket immediately the clay
has been forced into the mould and before commencing to complete the
remainder of the pipe, by forcing the clay through the moulding orifice; but
this may be varied, and I prefer only to groove or cut the socket on the
outside.
Some pipes are made of an egg shape section, that is, cylindrical at the
upper part and not so at the lower part, or invert, as shewn in section,
Figure 7, in which case the upper cylindrical part is similarly formed to those
above described, and by preference with cuts, or grooved longitudinally both
inside and outside.
The above described earthenware pipes may be made with branches or
junctions, and it is preferred to form or apply such branche or junction to the
lower part of a pipe, but when required, such junctions or branches may be
applied to the upper or moveable parts.
In witness whereof, I, the said Henry Doulton, have hereunto set my
hand and seal, this Twenty-first day of January, in the year of our
Lord One thousand eight hundred and fifty-eight.
Witness,
GEO. HASELDEN.
HENRY DOULTON. (L.S.)