Retaining plate for a reinforcing strip
Technical field
5 The present invention relates to the repair of pipes
used for carrying fluid such as oil and relates in
particular to a retaining plate •for a strip of
reinforcing tape used in the repair of the fluid
carrying pipes.
10
Prior art
Repairing a pipe that carries fluid such as a pipeline
for carrying oil, when it is damaged, always involves
15 bandaging a reinforcing tape around the damaged part of
the pipe. This reinforcing tape is generally made of a
flexible material having very good tensile mechanical
properties such as a high breaking strength. Such a
material is preferably Kevlar (registered trade name)
20 from the aramid family, or fiberglass.
Figure 1 shows a pipe 10 comprising a damaged portion
14 at its periphery. For the repair, the first thing is
to plug the damaged part using a polymer resin. Next, a
25 bandage 16 is fitted over the damaged part. Such a
bandage is made up of a reinforcing tape surrounding
the pipe and covered with a crosslinking resin as the
reinforcing tape is gradually wound.
30 Note that a bandage may also be installed on the part
of a pipe that has become thinner as a result of damage
to the inside of the pipe.
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Figure 2 shows how the reinforcing tape is fitted. The
start of the tape 20 is first of all fixed to the pipe
by any suitable means. Next, the reinforcing tape is
wound under tension around the pipe, each turn of the
5 winding overlapping part of the previous winding,
generally half the width of the reinforcing tape.
However, because a reinforcing tape has to have a
finite length, this length may be insufficient to
10 bandage the damaged part of the pipe and it is often
necessary to wind at least one other reinforcing tape
at the end of the first reinforcing tape. Because the
reinforcing tape is wound under tension, it is
unfortunately difficult to hold it in place and prevent
15 it from slipping at least during the initial stages of
winding.
Summary of the invention
20 This is why the object of the invention is to provide a
means that prevents a new reinforcing tape from
slipping when it is being wound under tension.
Another Object of the invention is to provide a means
25 that allows a new reinforcing tape to be secured while
it is being wound at the end of another reinforcing
tape that has already been wound around a pipe.
The main subject of the invention is therefore a
30 retaining plate made of rigid material comprising
spikes on each of its two faces, the spikes on each of
the faces, of a length of between 1 and 3 mm, making an
angle of between 30° and 60° with the base of the face
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on which they lie, the plate being, on the one hand,
secured by the spikes of one of its faces to a first
reinforcing tape already placed on the damaged portion
of a pipe, said spikes being inclined toward the tail
5 end of the first reinforcing tape and, on the other
hand, secured to a second reinforcing tape that is to
be wound on after the first reinforcing tape by the
spikes of the other face, said spikes being inclined
toward the starting end of the second reinforcing tape.
10
Another subject of the invention is a method of
installing a new reinforcing tape after a first
reinforcing tape wound around a damaged part of a pipe,
consisting in placing a retaining plate according to
15 the invention on the tail end of said first reinforcing
tape so as to secure the plate to the first reinforcing
tape using the spikes on the underside face of the
plate, then in placing the starting end of the new
reinforcing tape on the plate so as to secure the new
20 tape to the plate using the spikes on the top face of
the plate.
Brief description of the figures
25 The objects, subjects and features of the invention
will become more clearly apparent from reading the
following description given with reference to the
drawings in which:
30 figure 1 depicts a damaged external part of a pipe
which has been repaired by fitting a bandage;
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figure 2 depicts a damaged internal part of a pipe
which has been repaired by fitting a bandage;
figure 3 is a view in cross section of a retaining
5 plate according to the invention; and
figure 4 depicts the fitting of a new reinforcing tape
using a retaining plate according to the invention.
10 Detailed description of the invention
Figures 1 and 2 which relate to a pipe that has a
damaged portion for which the repair consists in
fitting a bandage have already been described in the
15 prior art-
Figure 3 depicts a retaining plate according to the
invention, viewed in section. The actual plate 30 is
made of a rigid material which can be any suitable
20 substance such as very hard plastic or preferably metal
such as steel, aluminum, etc. The plate is generally of
rectangular shape with the width less than or equal to
the width of the reinforcing tape.
25 The retaining plate 30 has spikes 22 on one face and
spikes 24 on the other face. These spikes, which are
betvjeen 1 and 3 mm long, are inclined with respect to
the face of the plate. This inclination corresponds to
an acute angle of between 30° and 60°, preferably of
30 45°, in the direct direction with respect to the face
on which they lie. Note that, in this last instance,
the spikes on the two faces of the plate are parallel.
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One embodiment of the plate involves using a metal
mesh. The spikes are formed by cutting the sides of the
grid cells of the mesh at regular intervals and bending
them up with respect to the mesh by a determined angle
5 of between 30° and 60° in the direct direction with
respect to the face,
Figure 4 shows how the retaining plate 30 with its
spikes 22 and 24 depicted in figure 3 is used. The
10 first reinforcing tape 26 is wound around the damaged
part of the pipe 10 as explained with reference to
figure 3, as far as its tail portion 28. A retaining
plate 30 according to the invention is then placed over
the end of this tail portion so as to be secured to the
15 reinforcing tape using the spikes on the underside face
of the plate which bite into the reinforcing tape. Note
that the plate is placed on the reinforcing tape in
such a way that the spikes on the underside face are
inclined toward the tail end of the tape 26 already
20 wound so that, when tension is applied to the retaining
plate toward the end of the tape, the plate is held
firmly in place.
Next, the starting end 32 of the new reinforcing tape
25 is placed on the retaining plate in such a way as to be
secured to the retaining plate using the spikes thereof
which bite into this tape. Note that the spikes on the
top face of the plate are inclined toward the starting
end 32 of the new tape so that tension applied to the
30 new reinforcing tape as it is wound holds the tape
firmly in place, whereas if the spikes faced in the
other direction, the tape would detach from the plate
under the effect of the tension.
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Thus, because the spikes on the top face of the plate
make an acute angle of between 30° and 60° with the
reinforcing tape, which means to say because they are
5 substantially in the same direction as the spikes on
the underside face, the new reinforcing tape is held
firmly .to. the plate and the latter to the first
reinforcing tape and is therefore secured to the first
reinforcing tape. It is therefore easy to proceed with
10 winding the new reinforcing tape under tension without
the risk of this tape slipping as a result of the
tension.
In a preferred embodiment described in Monaco patent
15 application No. 2593, each reinforcing tape comprises
at least one conducting wire incorporated in the
longitudinal direction, the electrical properties of
the wire (or wires) being used for the operations
including the crosslinking of the resin, detecting the
20 bandaged portion of the pipe or detecting repaired
portions of pipe that have experienced an increase in
diameter caused by a thinning of the wall. The
integrated conducting wire is preferably an integrated
metal wire. ' •
25
As mentioned previously, the retaining plate is
preferably made of metal. Using this preferred
embodiment, the two metal edges of the plate are
therefore in contact with the end of the {or of the
30 wires) integrated into each of the reinforcing tapes
connected by the retaining plate. Thus, the retaining
plate ensures the physical continuity of the set of reinforcing tapes and also ensures the electrical
continuity thereof.

CLAIMS
1. A retaining plate made of rigid material (30)
comprising spikes (22, 24) on each of its two faces,
5 the spikes on each of the faces, of a length of between
1 and 3 mm, making an angle of between 30° and 60° with
the base of the face on which they lie, said plate
being, on the one hand, secured by the spikes of one of
its faces to a first reinforcing tape (26) already
10 placed on the damaged portion of a pipe, said spikes
being inclined toward the tail end of said first
reinforcing tape and, on the other hand, secured to a
second reinforcing tape that is to be wound on after
the first reinforcing tape by the spikes of the other
15 face, said spikes being inclined toward the starting
end (32) of said second reinforcing tape.
2. The retaining plate (30) as claimed in claim 1, in
which said spikes (22, 24) make an angle of 45° in the
20 direct direction with the face on which they lie.
3. The retaining plate (30) as claimed in claim 1 or 2,
in which said rigid material is metal such as steel.
25 4. The retaining plate (30) as claimed in claim 3, said
plate being a metal mesh and said spikes being formed
by cutting the sides of the grid cells of the mesh at
regular intervals and bending them up with respect to
the mesh by a determined angle of between 30° and 60°.
30
5. The retaining plate (30) as claimed in one of claims
1 to 4, made of metal so that said plate is in contact
at its two ends with a conducting wire incorporated
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into each of said first and second reinforcing tapes so
as to ensure electrical continuity between said
reinforcing tapes,
5 6. A method of installing a second reinforcing tape
after a first reinforcing tape wound around a damaged
part of a pipe, consisting in placing a retaining plate
(30) as claimed in one of claims 1 to 4 on the tail end
of said first reinforcing tape so as to secure said
10 plate to the first reinforcing tape using the spikes on
the underside face of the plate, then in placing the
•starting end (32) of the new reinforcing tape on said
plate so as to secure said tape to said plate using the
spikes on the top face of the plate.