PIPE COUPLING COMPONENT

MANCHON D'ACCOUPLEMENT POUR TUYAUX

English Abstract

ABSTRACT


An insert for use in a pipe coupling of the type
comprising an insert for insertion into the end of a pipe,
a member having a tubular portion for reception of an end
portion of the pipe containing the insert, and a sleeve
for engagement about the tubular portion thereby to trap
the pipe between the tubular portion and the insert, and
thereby connect the member to the pipe, the insert comp-
rising a cylindrical cross-section tubular member the
outer surface of which comprises a first portion extending
from one end of the insert and having a uniform diameter;
a second, intermediate portion extending from the first
portion and having a plurality of relatively wide, arcuate
cross-section annular grooves therein; and a third portion
extending from the intermediate portion and having a
plurality of relatively narrow straight sided and bottomed
annular grooves therein, the side of each groove in the
third portion facing away from the first and second portions
extending substantially perpendicularly of the longitudinal
axis of the insert.

Claims

The embodiments of the invention for which an exclusive
property or privilege is claimed are as follows:

1. An insert for use in a pipe coupling of the type
comprising an insert for insertion into the end of a pipe, a
member having a tubular portion for reception of an end portion
of the pipe containing the insert, and a sleeve for engagement
about the tubular portion thereby to trap the pipe between the
tubular portion and the insert, and thereby connect the member
of the pipe, the insert comprising a cylindrical cross-section
tubular member the outer surface of which comprises a first
portion extending from one end of the insert and having a uniform
diameter; a second, intermediate portion extending from the first
portion and having a plurality of relatively wide, arcuate cross-
section annular grooves therein; and a third portion extending
from the intermediate portion and having a plurality of relatively
narrow straight sided and bottomed annular grooves therein, the
side of each groove in the third portion facing away from the
first and second portions extending substantially perpendicularly
of the longitudinal axis of the insert.
2. An insert as claimed in Claim 1, in which the side
of each groove in the third portion facing the first and second
portions extends at substantially 45° to the longitudinal axis
of the insert.
3. An insert as claimed in Claim 1 or Claim 2, in which
the outer surface of the insert has a fourth portion extending from
the third portion to the other end of the insert, the fourth
portion having a uniform diameter throughout its lenght, there
being an outwardly directed flange at the other end of the insert.

Description

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This invention relates to a pipe coupling component.
In Canadian Patent Number 875435
(7360) there is described a pipe coupling comprising an
insert for inSertiQn into the end of a pipe, a member having
a tubular portion for reception of an end portion of the
pipe containing the insert, and a sleeve for engagement about
the tubular portion thereby to trap the pipe between the
tubular portion and the insert, and thereby connect the member
to the pipe.
This invention is particularly concerned with an
insert for use in such a pipe coupling.
It is known for such inserts to have a grooved outer
surface, particularly when for use with a plastics material
pipe, thereby to enhance the grip of the insert within the
pipe, and thus help to prevent axial forces applied to the
pipe pulling the pipe out of the coupling.
One known insert has a plurality of identical frusto-
conical ribs extending about its outer periphery with the
bases o the ribs extending perpendicularly to the axis of
the insert and facing away from the end of the insert, which
is to be the leading end when the insert is inserted into a
pipe. The ribs are spaced from each other, the spaces
between adjacent ribs constituting the above mentioned grooves.
A difficulty which arises with this known insert is
that in use under tensile axial load conditions, stress
concentrations occur, which can lead to damage and in
particular, cracking of the pipe connected to the pipe

coupling .
According to this invention an insert for use in a
pipe coupling as described above, comprises a cylindrical





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cross-section tubular member the outer surface of which '
comprises a first portion extending from one end of the
insert and having a uniform diameter; a second, intermediate
portion extending from the first portion and having a
plurality of relatively wide, arcuate cross-section annular
grooves therein; and a third portion extending from the
intermediate portion and having a plurality of relatively
narrow straight sided and bottomed annular grooves therein,
the side of each groove in the third portion facing away
from the first and second portions extending substantially
perpendicularly of the longitudinal axis of the insert.
Preferably the side of each groove in the third
portion facing the first and second portions extends at
substantially 45 to the longitudinal axis of the insert.
It has been found that the use of an insert accord-
ing to this invention in a pipe coupling as described above,
the insert being inserted into a pipe end with the first
portion leading, avoids the above described difficulty of
the pipe cracking, and it is thought that this is because
the insert permits a small amount of axial movement of a
pipe relative to the insert under tensile axial load
conditions. This movement allows the stresses occuring under
such conditions to be spread over a greater length of the
insert, thus avoiding stress concentrations as can occur
with known inserts~
The form of the grooves in the third portion of
the ins,ert ensures satisfactory sealing of the connection
between a pipe and a pipe coupling utilising an insert
according to this invention.
Preferably the outer surface of the insert has a

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fourth portion extending from the third portion to the
other end of the insert, the fourth portion having a uniform
diameter throughout its length there being an outwardly
directed flange at the other end o~ the insert, which flange
will serve in use to locate the insert in a complete pipe
coupling.
An insert according to this invention will now be
described by way of example with reference to the drawing
in which:-

Figure 1 is a side view of the insert;
Figure 2 is an end view of the insert; and
Figure 3 shows a detail from within the ring III
in Figure 1.
The insert 1 is a cylindrical cross-section, tubular
member formed of steel, to have a constant diameter bore 2.
The outer surface of the insert 1 has a first portiGn
3 extending from one end 4 of the insert and having a uniform
diameter. The end 4 of the insert is rounded in order to
facilitate insertion of the insert into a pipe end.
A second, intermediate portion 5 extends from the
first portion 3, and has three relatively wide, arcuate cross-
section annular grooves 6 therein.
A third portion 7 extends from the intermediate
portion 5 and has nine relatively narrow straight-sided and
bottomed annular grooves 8 therein. The side 9 (Figure 3) of
each groove 8 facing away from the first and second portions
3 and 5 extends substantially perpendicularly of the lonq-
itudinal axis of the insert 1, while the other side 10 (Figure
3) of each groove 8 facing the first and second portions 3 and
5 extends at substantially 45 to the longitudinal axis of the


insert 1. lOS~67
A fourth portion 11 extends from the third portion
7 to the other end 12 of the insert 1, the fourth portion
11 having a uniform diameter.
There is an outwardly directed flange 13 at the
other end 12 of the insert 1, which flange 13 will serve in
use to locate the insert 1 in the housing of a complete pipe
coupling assembly.

10 .