Improvements in the Construction of the Joints of Drain and other Pipes.
Year: 1891

page_text: Date of Application, 15th Dec., 1891
Complete Specification Left, 15th Sept., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
Improvements in the Construction of the Joints of Drain and
other Pipes.
I, FREDERICK CHARLES LYNDE of 25 Cross Street Manchester, Civil and
Sanitary Engineer do hereby declare the nature of this invention to be as
follows:-
'
My invention consists in forming the sockets and spigots of drain and other
pipes in such a manner that the cement or jointing material is held firmly in position
by reason of the undercut form of the spigot and socket or of either. The outer.
end of the socket is made of smaller internal diameter than the inner end and the
former diameter is considerably larger than the exterior diameter of the spigot end
of the pipe. The interior of the socket and exterior of the spigot may be provided
with rings which may be undercut or with helices or they may be provided with a
guide or guides so as to maintain them in a concentric position. The main objects
of my invention are, the retention of the luting material in its place, the facilitating
of luting the joints, the prevention of the luting material being washed away or
falling off and injury by frost.
· Dated this 14th dox of December 1891
FREDERICK CHARLES LYNDE.
COMPLETE SPECIFICATION.
Improvements in the Construction of the Joints of Drain and
other Pipes.
I FREDERICK CHARLES LYNDE of 25 Cross Street Manchester in the County of
Lancaster Civil and Sanitary Engineer do hereby declare the nature of this invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
My invention consists principally in forming the sockets and spigots of drain
and other pipes in such a manner that the cement or jointing material is held
firmly in position by reason of the undercut form of the interior portion of the
socket.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference
to the sheet of drawings hereunto annexed and the following explanation thereof.
Fig. 1 is a section showing the simplest form of my invention, and Figs. 14, 23
and 4 are similar views illustrating modifications thereof.
(A in all the figures being the socket end of one pipe and B the spigot end of
another.)
According to my invention the outer end or mouth a of the socket (see Fig. 1) is
made of smaller internal diameter than the inner part thereof, and the diameter
at a is considerably larger than the exterior diameter of the spigot end of the
pipe at c.
The interior of the socket A may be made plain as shown at Figs. 1 and 1 and
the exterior of the spigot B may also be made plain as shown in dotted lines at
Fig. 14, or one or both of them may be provided with rings or annular steps as
shown at Figs. 2 3 and 4 which may be undercut, or, they may be formed with
helices or spiral grooves (preferably undercut) and they may be provided with ribs
or projections so as to guide the spigot end into the socket and maintain it in a
concentric position therein.

page_text: The main objects of the invention are the retention of the luting or jointing
material in its place, the facilitating of luting the joints, the prevention of the
luting material d from being washed away or talling off, and injury by frost.
In carrying out my invention I preferably obtain the undercut form of the interior
of the sockets in the following manner.
It will be understood by any practical person that an undercut socket smaller at
the month a than at the inner portion as shown at Fig. 1 could not be made in
the ordinary manner as it would not "draw" out of the mould, and to obviate
this difficulty I mould the socket in an approximately cylindrical form or with
almost parallel sides in the first place as shown by the dotted lines on Fig. 1 in.
which form it will easily draw from the mould, and afterwards whilst it is still in
a plastic state, and revolving I apply pressure to the outside edge thereof and
thereby bend the same over until it assumes the undercut form required, as drawn
in full lines at Fig. 1, or as an alternative I make the end of the pipe A, conical
as shown at Fig. 1 and mould the socket separately, the same being joined on
whilst in a plastic state as shown.by the line a*.
In the modification shown at Fig. 4, the exterior of the spigot end B and
the interior of the socket A (instead of being plain as at Fig. 14) are formed with
rings or annular indentations which assist in retaining the luting material d.
Fig. 2 shows the form in which the socket is first moulded the rings or steps
being cylindrical so as to draw readily from the mould. Fig. 3 shows by the dotted
lines the process of bending in or compressing the outer edge to obtain the undercnt
effect and Fig. 4 shows the ultimate form of the joint. The requisite pressure may
be produced by a conical roller or rollers applied outside whilst revolving or by an
india rubber, or other flexible cap or ring contracted by hydraulic or pneumatic
pressure.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The improvements in the construction of the joints of drain and other pipes
by making the .socket ends thereof of an undercut form that is, with the outer
extremity or mouth of a smaller diameter than the interior portion thereof.so
as to retain the cement, luting, or jointing material firmly in position, substantially
as hereinbefore described and illustrated by the drawings annexed whether the
interior be made with a plain surface (as shown at Fig. 1 and Fig. 1 on the
drawings) or with rings or annular steps (as shown at Figs: 2, 3 and 4).
Dated this 14th day of September 1892.
FREDERICK CHARLES LYNDE.