Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to pipe couplings and in particular to pipe
collars of the
clamp-on type. ,
BACKGROUND
Pipe couplings are required for a broad range of applications and many
different
designs are known. Non-welded joints for pipes include many clamp-on type
joints.
These clamp-on joints are used in a wide range of industries including the
mining,
manufacturing and building services industries.
Two types of clamp-on coupling systems that both mechanically and
hydraulically
join pipes together are commonly used. These types are shouldered and grooved
pipe coupling systems. With the shouldered system, shoulders are provided on
each
of the two pipe ends to be joined (either integrally formed or added by
welding a
ring onto the pipe ends). With the groove system, the pipe ends to be joined
are
grooved (grooves can be either rolled or machined). In either case the
shouldered or
grooved pipe ends are held together by a clamp-on coupling.
One form of clamp-on coupling is a two-piece sleeve, split into two semi-
circular
parts, shaped such that it has a pair of spaced apart annuluses sized to
engage the
pipe shoulders/ grooves to which it is to be applied. The clamp-on coupling
typically
includes a flexible seal that is retained over the joint between the pipes.
The
assembled clamp therefore provides both a fluid and a mechanical joint between
the
two pipes (shouldered or grooved).
2~ The above described couplings are usually held together with bolts and nuts
which
need to be installed and tijhtened. In many installations it is difficult for
a single
operator to install the couplings without dropping the bolts and nuts
required.
It is an object of the invention to provide a simple pipe coupling of few
parts that is
easily assembled quickly by a single person.
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SUMMARY OF THE INVENTION
Broadly according to the invention, there is provided a pipe collar for
attachment to
the ends of two adjacent pipes that forms a seal and connection between said
pipes
comprising:
a pair of arcuate sections that connect to form said pipe collar,
a projection on a first end of one of said arcuate sections,
a bearing surface on a first end of the other of said axcuate sections that
can be
engaged by said projection to hold said first ends together while also
allowing said
arcuate sections to hinge from an open position where the second ends of each
arcuate section are spaced to a closed position where said second ends are
moved
together, and
connection means between each said second end that allow said second ends
to be secured together and said arcuate sections to be clamped to said ends of
said
pipes.
Preferably said pipe collar is adapted to retain a seal over said join between
said two
pipes to thereby provide an assembled collax that both mechanically joins said
two
pipes and provides a fluid-tight seal bekween said two pipes.
The adaptation of said arcuate sections to form a said second connection means
may
be a pair of tabs, one extending radially from each of said halves, said tabs
being
adapted to receive a bolt to clamp them together. Alternatively, a quick
release
clamping means, such as a toggle, may be mounted on one of said halves, with
the
other of said halves having a projection engageable by said quick release
clamping
means.
Specific embodiments of the invention will now be described in some further
detail
with reference to and as illustrated by the accompanying Figures. These
embodiments are illustrative and are not meant to be restrictive of the scope
of the
invention.
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
The embodiments are illustrated in the accompanying representations in which:
Fig 1 shows a perspective view of an pipe coupling collar installed over a
pipe
joint.
Fig 2 shows a side view of a partially assembled pipe coupling collar for use
with pipes having shouldered ends.
Fig 3 shows a side view of an assembled pipe coupling collar for use with
pipes having shouldered ends.
Fig 4 shows a perspective view of the two halves of the pipe collar shown in
Figs 2 and 3 prior to assembly.
Fig 5 shows a longitudinal cross-sectional view of a pipe coupling collar
installed over the shouldered ends of two pipes.
Fig 6 shows a side view of a partially assembled pipe coupling collar for use
with pipes having grooved ends.
Fig 7 shows a side view of an assembled pipe coupling collar for use with
pipes having grooved ends.
Fig 8 shows a longitudinal cross-sectional view of a pipe coupling collar
installed over the grooved ends of two pipes.
In a first embodiment of the invention, shown in Figs 1 to 4, there is
provided a pipe
coupling in the form of a pipe collar 10 for coaxially joining two pipes 8 and
9
comprising two semi-circular arcuate halves 15 and 20. When assembled, the
pipe
coupling 10 forms a sleeve over the join 11 between pipe 8 and pipe 9. As
shown in
Figs 2 and 3, the arcuate halves 15 and 20 have interlocking projections 16
and 21
which form a connection means and the halves 15 and 20 have tabs 17 and 26
which
are adapted to receive a bolt and nut combination 25 and 24. Optionally, bolt
25 may
be held in position by a retaining means such as a washer 27 (or a rubber
ring).
The arcuate half 15 has a finger-like projection 16 which extends radially
from one of
its ends as shown in Figs 1 and 2. In Fig 4 shoulder 16a on finger-like
projection 16 is
shown. The other half 20 has a bearing surface (in the form of an edge 22) on
the end
of arm 21 adapted to receive the finger-like radial projection 16 to form an
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interlocking hinge. In use, this edge 22 bears against the radially extending
projection 16 within shoulder 16a thereby providing a hinge joint having an
axis
parallel to the pipes' common axes.
A seal 30 shown in Figs 3 and 5 is contained within the assembled pipe
coupling 10.
When installed over a joint between two pipes as shown in Fig 5, seal 30
provides a
flexible fluid seal between two pipes 8 and 9.
While the preferred embodiment of the invention has a single finger-like
projection
16, other embodiments of the invention may have a plurality of such
projections.
Assembly of pipe coupling collar 10 over two coaxial pipe ends to provide a
fluid
and a mechanical seal between them will now be described. Pipes 8 and 9 having
shoulders 8' and 9' are first aligned coaxially with their ends abutting as
shown in
Fig 1. ?he two arcuate halves 15 and 20 are interlocked by insertion of radial
projection (finger) 16 through the gap between arms 21 and edge 22, until
shoulder
16a abuts edge 22, to form a partially assembled pipe coupling 10 as shown in
Fig 2.
The now partially assembled pipe coupling 10 is placed over the two adjacent
pipe
shoulders 8' and 9' as shown in Fig 1. Bolt 25 projects through flange 26 and
flange
17 and nut 24 can now be tightened to secure the pipe coupling in place. An
alternative way of assembling pipe coupling 10 over pipes 8 and 9 is to first
position
arcuate half 20 over seal 30 and shoulders 8' and 9' and then to bring arcuate
half 15
into interlocking engagement with arcuate half 20 by insertion of projection
16 into
the gap between arms 21 and edge 22. Once this has been done, arcuate half 15
can
be pivoted about its radial projection 16, shoulder 16a bearing against edge
22 until
flange I7 is positioned adjacent flange 26 thereby allowing bolt 25 to secure
flanges
17 and 26 together using nut 24.
The assembled pipe coupling is shown in cross-section in Fig 5. From this
Figure it
can be seen that the pipe coupling 10 provides a fluid seal by enclosing seal
30 over
the join between pipes 8 and 9, and a mechanical seal by the positioning of
annuluses
18 over shoulders 8' and 9' to thereby prevent substantial axial movement of
pipes 8
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and 9 away from each other. Arcuate halves 15 and 20 are sized so that their
respective pairs' of annulus 18 and 23 are sufficiently axially spaced to
allow pipes 8
and 9 a small degree of axial movement within the assembled pipe coupling
collar 10
as shown in Figs 1 and 4. This small degree of movement allows for some
deflection
at the joints which assist in pipe laying where levels vary or where
settlement occurs.
This degree of axial freedom also allows the couplings to accept some linear
expansion and contraction thereby relieving limited pipe line stresses without
costly
expansion joints.
Where a locking action is required (and where the joint is not required to
allow
relative movement of the pipes being joined), gripping lugs can be cast into
the
coupling halves. Such lugs 40 are shown in Fig. 4. These gripping lugs 40 fill
out the
engagement areas within the grooves or shoulders on the pipes thereby
providing a
lucking action and eliminating flexing at the joint. By having pointed ends;
the
gripping lugs 40 grip the pipes and thereby prevent their relative rotation.
The pipe couplings collars 10 described above are easily assembled by one
person.
The pipe couplings 10 are also easily removed and can be reused.
In an alternative embodiment of the invention the pipe coupling collar 10 has
annulus pairs 18 and 23 of a smaller diameter to engage grooved pipes. In this
embodiment grooves 8" and 9" are provided close to the ends of pipes 8 and 9
respectively as shown most clearly in the sectional view shown in Fig 8. The
grooves
8" and 9" need not be as deep as comparable threaded pipe and therefore the
pressure rating of the pipe is largely retained.
The bolted connection, which provides the second connection means between the
two arcuate halves 15 and 20, may be replaced by a quick-release type clamping
means such as a toggle coupling as shown in Figs 5 and 6. The quick-release
toggle
replaces bolt 25, nut 24 and their respective flanges 26 and 17, with lever
arm 35,
pivot arm 36, mounting upstand 37 and recess 38. The lcng lever arm 35 allows
a
large clamping force to be generated by hand and the over-centre geometry of
the
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pivot arm and recess positioning provides a positive locking position as shown
in Fig
6. A safety pin 39 is provided to ensure that the toggle is not inadvertently
released.
The above-described pipe couplings may be made in a variety of sizes being
particularly suitable for pipes of nominal diameters 1 inch to 14 inches.
While the present invention has been described in terms of preferred
embodiments in
order to facilitate better understanding of the invention, it should be
appreciated that
various modifications can be made without departing from the principles of the
invention. Therefore the invention should be understood to include all such
modifications within its scope.
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