IMPROVEMENTS IN JOINTS FOR EARTHENWARE PIPES AND IN THE MEANS EMPLOYED FOR PRODUCING THE SAME "
Year: 1883

page_text: LETTERS PATENT to Henry Doulton of Lambeth in the County of Surrey. for
an Invention of "IMPROVEMENTS IN JOINTS FOR EARTHENWARE PIPES AND
IN THE MEANS EMPLOYED FOR PRODUCING THE SAME
"
PROVISIONAL SPECIFICATION left by the said Henry Doulton at the Office
of the Commissioners of Patents on the 1st September 1883.
HENRY DOULTON of. Lambeth in the County of Surrey.
"IMPROVEMENTS IN
JOINTS FOR EARTHENWARE PIPES AND IN THE MEANS EMPLOYED FOR PRODUCING
THE SAME.'
"
This invention has for its object improvements in joints for earthenware pipes
and in the means employed for producing the same.
Heretofore in some cases joints for earthenware pipes have been formed by
casting a ring of a tough cement around the exterior of the spigot ends of the
pipes and the interior of the sockets at the opposite ends.
The interior of the one ring and the exterior of the other have been made taper
so that when the spigot end of one pipe has been inserted into the socket end of
another pipe the tapered surfaces fit together and form a tight joint so long as the
one pipe is pressed firmly up to the other. If however from any cause the pipes
cease to be held firmly the one up to the other the fit of the joint is destroyed and
the joint leaks.
I avoid this by making the interior surface of the one ring and the exterior
surface of the other cylindrical and to fit accurately one within the other so that
even if the pipes separate to some extent the joint will still remain secure.
In order to ensure that the interior or bore of the pipe, and the exterior surface
of the composition band shall be concentric, I form a metallic mould having an
annular groove cut in its face. In the centre of the mould there is a conical
projection. The outer diameter of the groove is cylindrical and of a diameter equal
to the exterior diameter of the ring to be formed. When the ring is to be cast I
insert the spigot end of the pipe into the annular groove, the conical projection
entering the bore of the pipe which at once truly centres it. The base of
the cone is made of slightly (greater diameter than the bore of the pipe Bo

page_text: that the bottom end of the pipe does not reach quite to the bottom of the
groove of the mould-the bore of the pipe is therefore kept concentric with the
mould and in addition when cement is poured into the groove to fill the space
around the exterior of the pipe it also fills the space between the end of the pipe
and the bottom of the groove and forins a true facing to the end of the pipe. In
the same way for casting the ring around the interior of the socket I use a metallic
disc which is dropped into the socket the external diameter of the disc is less
than the interior of the socket leaving an annular space into which the cement is
cast. The disc is formed with a central conical projection passing downwards from
it to enter the bore of the pipe and not only keep the disc concentric with the
bore but also to keep a space between the bottom of the disc and the socket which
gets filled with cement and forms a true facing to the bottom of the socket.
In place also of making a socket at one end of each pipe I make both ends of the
pipe alike and with a ring of cement around their exterior. To form a joint
between the abutting ends of two such pipes I employ an earthenware ring with
a ring of cement around its interior and I insert the ends of the two pipes into
this ring. The earthenware ring I make longer than the ring of cement within it,
in order that when a joint has been formed by inserting the ends of two pipes
into it the spaces left at the ends of the ring between it and the pipes may be
filled in with Portland or such like cement. I also form grooves around the
exterior of the ends of the pipes and the interior of the rings so that the cement
may obtain a firm hold upon them... In the same way when, a socket is used at
one end of each pipe I make the socket longer than the ring cast in it so that
when a number of pipes has been put together the sockets may subsequently be
filled up with Portland cement.
I "rough" the interiors of the sockets, and collars and the spigot ends of the
pipes, and form the band of Portland cement" for the purpose of holding firmly
together the pipes when placed in position; and in addition to binding them
together, the band of cement forms a watertight joint of itself, thus providing a
double security against leakage.
In some cases the collars and sockets are "balf cut" so that if desired the collar
or socket could be split, and a length of pipe withdrawn and again replaced,
without disturbing the pipes on either side.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Doulton in the Patent Office on the 1st March 1884.
HENRY DOULTON of Lambeth in the County of Surrey "IMPROVEMENTS IN
JOINTS FOR EARTHENWARE PIPES AND IN THE MEANS EMPLOYED FOR PRODUCING
THE SAME
"
This invention has for its object improvements in joints for earthenware pipes
and in the means employed for producing the same.
Heretofore in some cases joints for earthenware pipes have been formed by
casting a ring of a tough cement around the exterior of the spigot ends of the pipes
and the interior of the sockets at the opposite ends.
The interior of the one ring and the exterior of the other have been made taper
so that when the spigot end of one pipe has been inserted into the socket end of.
another pipe the tapered surfaces fit together and form a tight joint so long as the
one pipe is pressed firmly up to the other. If however from any cause the pipes
cease to be held firmly the one up to the other the fit of the joint is destroyed and
the joint leaks.
I avoid this by making the interior surface of the one ring and the exterior
surface of the other cylindrical and to fit accurately one within the other so that
even if the pipes separate to some extent the joint will still remain secure.
In order to insure that the interior or bore of the pipe and the exterior surface
of the composition band shall be concentric I form a metallic mould having an.
annular groove cut in its face. In the centre of the mould there is a conical
projection. The outer diameter of the groove is cylindrical and of a diameter equal
to the exterior diameter of the ring to be formed. When the ring is to be cast I.
insert the spigot end of the pipe into the annular groove, the conical projection
The base of the
entering the bore of the pipe which at once truly centres it.
cone is made of slightly greater diameter than the bore of the pipe so that the
bottom end of the pipe does not reach quite to the bottom of the groove of the
mould the bore of the pipe is therefore kept concentric with the mould and in
addition when cement is poured into the groove to till the space around the exterior
of the pipe it also fills the space between the end of the pipe and the bottom of
the groove and forms a true facing to the end of the pipe." In the same way for
casting the ring around the interior of the socket I use a metallic disc which is
dropped into the socket the external diameter of the disc is less than the interior
The disc is
of the socket leaving an annular space into which the cement is cast.
formed with a central conical projection passing downwards from it to enter the
bore of the pipe and not only keep the disc concentric with the bore but also to
keep a space between the bottom of the disc and the socket which gets filled with
cement and forms a true facing to the bottom of the socket..
In place also of making a socket at one end of each pipe I make both ends of
the pipe alike and with a ring of cement around their exterior. To form a joint
between the abutting ends of two such pipes I employ an earthenware ring with
a ring of cement around its interior and I insert the ends of the two pipes into this
ring. The earthenware ring I make longer than the ring of cement within it in
order that when a joint has been formed by inserting the ends of two pipes into
it the spaces left at the ends of the ring between it and the pipes may be filled in
with Portland or such like cement. I also form grooves around the exterior of the
ends of the pipes and the interior of the rings so that the cement may obtain a
firm hold upon them. In the same way when a socket is used at one end of each
pipe I make the socket longer than the ring cast in it so that when a number of
pipes have been put together the sockets may subsequently be filled up with
Portland cement.
:

page_text: I "rough" the interiors of the sockets, and collars and the spigot ends of the
pipes and form the band of Portland cement for the purpose of holding firmly
together the pipes when placed in position; and in addition to binding them
together, the band of cement forms a watertight joint of itself, thus providing a
double security against leakage.
In some cases the collars and sockets are "half cut" so that if desired the collar
or socket could be split and a length of pipe withdrawn and again replaced without
disturbing the pipes on either side.
In order that my said invention may be most fully understood and readily
carried into effect I will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal section through the joint connecting two earthenware
pipes and this joint is made in accordance with my invention.
A is the socket end of one of the pipes. B is the spigot end of the other pipe.
C is a ring of cement lining the socket A; the interior surface of this ring is
cylindrical. D is another ring of cement upon the spigot end B; the exterior of
this ring also is cylindrical and its dimensions are such as to admit of its entering
and fitting the ring with which the socket is lined. E is a ring of Portland
cement with which the outer end of the socket may be filled after the pipes have
been put together in the place they are intended to occupy.
Figure 2 is a mould which I employ in forming the lining ring C within the
socket A; it is a cast iron block with a turned surface.
At F the block is conical and this part is intended to enter the bore of the pipe
and to centre the block truly in relation to the bore. When the mould is so
placed in the socket a void space is left between the cylindrical surface G of the
mould and the inner side of the socket; into this space the cement employed is
poured in a liquid state and after it has set and hardened the mould or block is
removed.
The cement used may be such as has heretofore been used for the purpose of
tipping the spigot ends and lining the sockets of earthenware pipes.
Figure 3 is a section of the mould employed for the purpose of tipping the
spigot ends of pipes.-The end of the pipe is inserted into this mould so that the
conical portion H enters into the bore of the pipe and whilst the pipe is in this
position cement is poured in to fill the space left in the mould, that is to say, the
space between the cylindrical part I of the mould and the side of the pipe.
Figure 4 is a longitudinal section of another pipe joint in which both of the
pipes brought together have spigot ends and the joint is made within a collar K
which serves the purpose of a double socket. The ends of these pipes are tipped
with cement in the manner already described except that the cement is allowed to
extend beyond the end of the pipe. To admit of this the conical portion in the
centre of the mould is of such dimensions that the end of the pipe does not descend
to the bottom of the mould and then when the cement is poured some cement passes
beneath the extremity of the pipe and forms a ring facing the end of the pipe as
indicated in Figure 4.
This however is not essential as the ends of the pipes may be allowed to abut
together in the same way that the end of the pipe abuts directly on the bottom of
the socket in the arrangements shewn in Figure 1.
Figure 5 is a section of the mould employed for lining the collar K. This mould
consists of a divided block of dimensions to fit within the collar and with a groove
turned around the exterior to receive the cement to form the lining. The mould
having been placed within the collar cement is poured in to fill the cavity of the
mould by passages which are not represented in the drawing, but which aie formed
ly removing portions of the upper flange of the mould.
The division in the mould allows of its being withdrawn without difficulty from
the collar after the cement has become hard.

page_text: 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 the tipping
spigot ends of earthenware pipes with cement nor do I claim lining the sockets o 1
such pipes with the same material but what I do claim is forming the joints of
earthenware pipes as herein described, that is to say, with a cement tip having a
cylindrical surface cast upon the spigot end of the pipe and a lining also of cement
cast within the socket or equivalent part receiving the said spigot end such lining
being also cylindrical on its interior surface and of dimensions to receive the tip
upon the spigot end, the whole forming a joint which will remain tight even when
the extremities of the pipes are not closely abutted the one to the other.
I also claim the moulds herein described to be used in tipping the spigot ends
and lining the sockets or equivalent parts of the joints of earthenware pipes.
In witness whereof I the said Henry Doulton have hereunto set my hand and
seal this first day of March in the year of our Lord One thousand eight hundred
and eighty four.
HENRY DOULTON. (L.S.)