IMPROVEMENTS RELATING TO THE JOINTS OR CONNECTIONS OF EARTHENWARE PIPES
Year: 1880

page_text: LETTERS PATENT to Henry Doulton, of High Street, Lambeth, in the County
of Surrey, for an Invention of "IMPROVEMENTS RELATING TO THE JOINTS OR
CONNECTIONS OF EARTHENWARE PIPES."
PROVISIONAL SPECIFICATION left by the said Henry Doulton at the Office
of the Commissioners of Patents on the 2nd September 1880.
HENRY DOULTON, of High Street, Lambeth, in the County of Surrey.
"IMPROVEMENTS RELATING TO THE JOINTS OR CONNECTIONS OF EARTHENWARE
PIPES."
This Invention has for its object improvements relating to the joints or connections
of earthenware pipes.
In the Provisional Specification of a former application filed by me, No. 2057 in
the present year, I have described means for connecting pipes by means of clips;
the pipes are made without sockets, and on the interior are cylindrical throughout.
The ends are ground, so that butted together they form a tight joint, and a collar
or ring of increased thickness is formed near each end to receive the clips which
hold the pipes together.
According to my present Invention also 1 grind the pipes at the end, and whilst
they are butted and held together, I form a ring of cement around them.
I prefer still to employ cylindrical socketless pipes with external collars near the
ends, I lay them with chains and make the joints by means of a suitable cement,
generally employing clips temporarily until the cement is set.
The chairs (which may be made in terra-cotta or other material) are laid at the
joints, and the collars lie within them. The chairs serve both to support the pipes
and to retain the cement which is run in in a semi-fluid state to form the joint.
The operation in laying the pipes is as follows:-The chairs are first accurately
placed, the pipes are laid upon them, and clips are applied to hold the ends in
contact. Cement mixed or rendered sufficiently thin to flow is then poured into
the chair and made to fill the space between the collars on the underside of the
pipes, and all crevices as far up as the chair extends on either side. Cement in a
somewhat thicker state is also applied to fill the space between the collars on the
upper side of the pipes, and so as to connect with the cement in the chair, forming
[Price 6d1

page_text: thus a connecting ring of cement all around. The projecting ends of the pipes
between the collars are corrugated or roughened, in order that the cement may
obtain a firmer hold, and precautions are taken to prevent this portion of the pipe
from becoming glazed; this may be effected by causing the part to be covered
whilst burning with a ring of the same material, which is afterwards removed.
I prefer to employ chairs as above described, but their use may in some cases be
dispensed with, other means being resorted to to retain the cement to the under
side of the pipes whilst making the joints.
The chairs should have side flanges upon them to aid in holding the ends of the
pipes together, but even if there be no flanges on the chair, the strength of the
cement ring will be found to be considerable and sufficient to resist a certain
amount of internal pressure. Similarly if the pipes be made without external
collars, the adhesion of the cement to the rough and unglazed ends will be sufficient
where but a moderate strength is required.
In some cases the grinding of the ends of the pipes may be omitted, the cement i
alone being then relied upon to ensure a water tight joint.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Doulton in the Great Seal Patent Office on the 2nd March
1881.
HENRY DOULTON, of High Street, Lambeth, in the County of Surrey.
"IMPROVEMENTS RELATING TO THE JOINTS OR CONNECTIONS OF EARTHENWARE
PIPES."
This Invention has for its object improvements relating to the joints or connections
of earthenware pipes.
In the Provisional Specification of a former application filed by me, No. 2057 in
the present year, and also in the Specification filed in accordance with the con-
ditions of the Patent granted to me thereon and bearing the same number, I have
described means for connecting pipes by means of clips; the pipes are made without
sockets, and on the interior are cylindrical throughout. The ends are ground so
that butted together they form a tight joint, and a collar or ring of increased
thickness is formed near each end to receive the clips which hold the pipes
together.
According to my present Invention also, I grind the pipes at the ends, and
whilst they are butted and held together, I form a ring of cement around them.
I prefer still to employ cylindrical socketless pipes with external collars near the
ends. I lay them with chairs and make the joints by means of a suitable cement,
generally employing clips temporarily until the cement is set.
The chairs (which may be made in terra-cotta or other material) are laid at the
joints, and the collars lie within them. The chairs serve both to support the pipes
and to retain the cement which is run in in a semi-fluid state to form the joint.
The operation in laying the pipes is as follows:-The chairs are first accurately
placed, the pipes are laid upon them, and clips are applied to hold the ends in
contact. Cement mixed or rendered sufficiently thin to flow is then poured into
the chair, and made to fill the space between the collars on the underside of the
Cement in a
pipes and all crevices as far up as the chair extends on either side.
somewhat thicker state is also applied to fill the space between the collars on the
upper side of the pipes, and so as to connect with the cement in the chair, forming
thus a connecting ring of cement all around. The projecting ends of the pipes
between the collars are corrugated or roughened, in order that the cement may
obtain a firmer hold, and precautions are taken to prevent this portion of the pipe
from becoming glazed; this may be effected by causing the part to be covered
whilst burning with a ring of the same material, which is afterwards removed.
I prefer to employ chairs as above described, but their use may in some cases be
dispensed with, other means being resorted to to. retain the cement to the under
side of the pipes whilst making the joints.
The chairs should have side flanges upon them to aid in holding the ends of the
pipes together, but even if there be no flanges on the chair, the strength of the
cement ring will be found to be considerable and sufficient to resist a certain
amount of internal pressure. Similarly if the pipes be made without external
collars, the adhesion of the cement to the rough and unglazed ends will be sufficient
where but a moderate strength is required.
In some cases the grinding of the ends of the pipes may be omitted, the cement
alone being then relied upon to ensure a water tight joint.
In order that ny said Invention may be most fully understood and readily
carried into effect, I will proceed to describe the Drawings hereunto annexed.

page_text: chairs; these latter may be made of a rougher material than that which is used for
the manufacture of sanitary pipes. In order that the pipes may be rough at the
ends, that the cement may adhere well to them, I make them first with a ring of
surplus material surrounding the end in the manner represented at Figure 1*,
where a represents the surplus ring. The material is cut through as the Drawing
indicates, so as nearly to detach the ring from the pipe and flange, but it is not
removed until after the burning. The ring is useful in preserving the end of the
pipe from injury, and in preventing warping in the kiln, as well as for the purpose
for which it is primarily employed. The ends of the pipes are ground smooth and
true after the rings a have been broken away. The chairs having been properly
laid on concrete or otherwise, the pipes are laid upon them, and the ground ends
are drawn into close contact by driving in wooden wedges c, c, between the flanges
of the pipes and of the chairs. The joints have then to be made good with cement;
I employ Portland cement, one of cement to three of sand, and mixed so that it
will flow pretty freely. This I cause to be poured into the chairs so as to fill up
all the space left in their trough like cavities between and around the flanges of
the pipes. Before the cement in the chair is quite set, cement mixed to a mortar
like consistency is pressed in with a trawel between the flanges on the upper side
of the pipes, and so a complete and continuous ring of cement is formed enveloping
the ends of the pipes. Before wedging up the pipes in the chairs, it is very
convenient to insert into the pipes where the ends meet, a block which can be
expanded after the manner of a boot-tree. The block when inserted is able to enter
the pipes freely, and when having been brought to its place it is expanded, it
causes the bores of the two lengths to correspond accurately. By driving in the
wedges the pipes are then locked together, and the block is contracted and
withdrawn.
Figures 3 and 4 are respectively an elevation and a section representing flanged
pipes laid without chairs. In lieu of the chairs a bed of concrete is laid, and upon
this the pipes are bedded. Beneath the ends of the pipes trough like cavities,
corresponding to those of the chairs in Figures 1 and 2, are cut or formed in the
concrete. The ground ends of the pipes are clamped together by means of iron
clamps & and wooden wedges d' driven in, as the Drawing shows. These clamps
may also be used when chairs are employed, their use will permit of smaller chairs
being employed than are shown in Figures 1 and 2. The clamps & may be removed
after the joints have been made, or if the pipes are likely to be exposed to con-
siderable pressure, they may advantageously be left on. It is advisable to employ
the expanding block within the pipes, to set their ends truly together, as already
described; the joint shown in Figures 3 and 4 is made good with cement run into
the trough like cavities of the bed, and laid on between the flanges on the upper
side of the pipes in the manner already described.
Figures 5 and 6 differ from Figures 1 and 2, only in that the chairs are of
sinaller size, and are made without side flanges. Clamps, such as that shown in
Figure 3, are employed in forming these joints.
Figures 7 and 8 are respectively an elevation and a section representing
flangeless pipes laid in chairs. The omission of the flanges upon the pipes
materially cheapens the construction, but the pipes thus made are more liable to
warp in the burning. The ends of these pipes are made rough (to give a better
hold to the cement) by combing them so as to form screw like grooves, as the
Drawing indicates. In the absence of the flanges on the pipes, the upper part of
the joint is made by plastering on a band of cement, as is seen in Figure 7, so as
together with the thinner cement in the chair, to form a complete ring around the
ends of the pipes.
Figures 9 and 10 represent a cheap, and for some purposes an efficient, method of
construction; the pipes are laid upon concrete, and trough like cavities are formed
beneath the ends in the manner already described in respect to Figures 3 and 4.
These cavities are run full of cement, and the ring around the joint is completed by
laying thicker cement on with a trowel, as described in respect to Figures 7 and 8.

page_text: If the ends of these pipes be ground, the ground ends should be made to buti
together by an endway pressure whilst the joint is being made, but for work
requiring ground joints, it is better to employ flanged pipes.
Where the pipes are intended for the conveyance of pure water for domestic
consumption, grinding of the ends of the pipes is a matter of much importance, as
by this means a practically continuous pipe of earthenware is obtained, and the
water comes into contact with no other material. Ground joints are also desirable
where it is important that leakage should be avoided. Nevertheless, tight joints
can be made in the manner which I have described without grinding.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim,―
First. The method of forming the joints or connections of earthenware pipes,
illustrated by Figures 1 and 2, where flanged pipes with ground ends are laid end
to end in trough like chairs, and the joints made good with cement, for which the
chairs serve as moulds.
Second. The method of forming the joints or connections of earthenware pipes,
illustrated by Figures 3 and 4, where flanged pipes with ground ends are laid end
to end on a suitable bed, having mould like cavities beneath the ends of the pipes
receiving cement by which the joint is made good.
Third. The method of forming the joints or connections of earthenware pipes,
illustrated by Figures 5 and 6, which is similar to that described in reference to
Figures 1 and 2, except that the side flanges of the chairs which give to it its
trough like form are dispensed with.
Fourth. The method of forming the joints or connections of earthenware pipes,
illustrated by Figures 7 and 8, which is similar to that described in reference to
Figures 1 and 2, except that the collars upon the pipes are dispensed with.
Fifth. The method of forming the joints or connections of earthenware pipes,
illustrated by Figures 9 and 10, which is similar to that described in reference to
Figures 3 and 4, except that the collars on the pipes are dispensed with.
Sixth. The methods of forming the joints or connections of earthenware pipos,
referred to in the preceding claiming clauses, but dispensing with the grinding the
ends of the pipes.
In witness whereof, I, the said Henry Doulton, have hereunto set my hand
and seal, this Second day of March, in the year of our Lord One thousand
eight hundred and eighty one.
HENRY DOULTON. (L.S.)