Note: Descriptions are shown in the official language in which they were submitted.
CA 02558681 2006-08-30
A METHOD AND APPARATUS FOR PROVISION OF TEMPORARY CONDUCTOR
TENSION SUPPORT IN TRANSMISSION OR DISTRIBUTION CIRCUITS
Field of the Invention
This invention relates to the field of repair and service to power
transmission
conductors and in particular to a method and apparatus for provision of
temporary conductor
tension support in transmission or distribution circuits.
Background of the Invention
The replacement of sleeves, dead end insulators, and conductor repair require
that
conductor tension be maintained or altered so that these processes can be
safely applied.
Often circumstances require the process to be done while the conductors are
energized and remain in service.
Present methods require use of conventional chain jacks, or rope blocks to
support
tension. These devices are heavy, cumbersome, difficult to install, and
because they are
conductive present a hazard in their application and use.
SummM of the Invention
In summary, the conductor supporting assembly according to the present
invention
may be characterized in one aspect as including an opposed-facing pair of
first and second tension
supports such as yokes having a parallel pair of flexible first and second
elongate members such as
cables extending therebetween in spaced parallel array, and a means such as
actuators for
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CA 02558681 2006-08-30
tensioning the first and second elongate members so as to selectively draw the
first and second
tension supports toward each other. First and second conductor mounts such as
grips, cooperate
with the first and second tension supports for mounting the first and second
tension supports in
spaced apart array to and along a conductor segment of a conductor to be
serviced so as to extend
the conductor segment along and substantially medially between the first and
second elongate
members. At least one insulator is advantageously mounted in cooperation with
and between the
elongate members and the tension supports. The drawing of the first and second
tension supports
toward each other thereby de-tensions the conductor segment to allow for the
service.
In one embodiment the tension supports are yoke assemblies. The yoke
assemblies
may be substantially planar and may include a rigid spreader element extending
orthogonally
between the elongate members. Each yoke assembly may be a rigid yoke, or may
include a
flexible sling extending from a corresponding spreader element. The spreader
element may be
adjustable along its length so as to selectively adjust a spacing between the
elongate members.
At least one elongate insulated tool may be provided which is mountable to a.
corresponding tension support, for example a yoke, so as to depend downwardly
therefrom and
stabilize the mounting of the corresponding tension support onto the conductor
segment.
Advantageously, the tool mounts underneath, in cooperation with, the spreader
element.
The present invention also expressly includes within its ambit the
corresponding
method of producing, mounting or employing the conductor supporting assembly
described
sumrnarily above and in greater detail below. In particular the method
includes:
a) providing an opposed-facing pair_ of first and second tension supports such
as
yokes having a parallel pair of flexible first and second elongate members
such as
cables extending therebetween in spaced parallel array, and a means such as
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actuators for tensioning the first and second elongate members so as to
selectively
draw the first and second tension supports toward each other,
b) providing first and second conductor mounts such as grips, which cooperate
with
the first and second tension supports and mounting the first and second
tension
supports in spaced apart array to and along a conductor segment of a conductor
to
be serviced so as to extend the conductor segment along and substantially
medially
between the first and second elongate members,
c) drawing the first and second tension supports toward each other to thereby
de-
tension the conductor segment to allow for the service.
In a further embodiment of the method, providing at least one elongate
insulated
tool and mounting the tool to a corresponding tension support, fqr example a
yoke, so as to depend
downwardly therefrom to stabilize the mounting of the corresponding tension
support onto the
conductor segment.
Brief DescritYtion of the DrawinLs
Figure 1 is, in plan view, the conductor supporting assembly according to one
embodiment of the present invention.
Figure 2 is, in front elevation view, the conductor supporting assembly
ofFigure 1.
Figure 3 is, in plan view, the conductor supporting assembly of Figure 1
mounted to
a conductor.
Figure 4 is, in front elevation view, the conductor supporting assembly of
Figure 3.
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Figure 5 is, in front elevation view, the conductor supporting assembly of
Figure 4
tensioned so as to slacken the conductor between the opposed-facing pair of
yokes.
Figure 6 is, in front. elevation view, the conductor supporting assembly of
Figure 4
with an insulated tool mounted to, so as to depend downwardly from, the
corresponding yoke.
Figure 7 is, in plan view, the conductor supporting assembly of Figure 1 with
the
cable slings adjusted inwardly relative to the opposed-facing pair of yokes so
as to decrease the
spacing between the pair of parallel cable slings.
Figure 8 is, in front elevation view, the conductor supporting assembly
ofFigure 7.
Figure 9 is, in plan view, a further embodiment of the conductor supporting
assembly according to the present invention wherein the rigid triangular yoke
of the embodiment
of Figure 1 is replaced with a rigid spreader eleinent supported on a V-shape
cable sling.
Figure 10 is, in plan view, a further embodiment of the cable supporting
assembly
according to the present invention wherein the opposed-facing pair of rigid
yokes of Figure 1 are
replaced with a rigid spreader element of adjustable length supported by a V-
shape cable sling.
Figure 11 is, in side elevation view, a conductor hook assembly for use with
an
insulated tool for mounting under a yoke plate according to one embodiment of
the present
invention.
Figure 12 is, in front elevation view, the conductor hook assembly of Figure
11.
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Figure 13 is, in side elevation view, the conductor hook assembly of Figure 11
mounted to the underside of the yoke plate of Figure 1.
Figure 14 is, in front elevation view, the conductor hook assembly of Figure
13
mounted onto a conductor.
Figure 15 is, in plan view, a further alternative embodiment according to the
present invention wherein the conductor supporting assembly is mounted to a
support slructure so
as to relieve the tension on a dead end insulator.
Figure 16 is, in front elevation view, the conductor supporting assembly of
Figure
16.
Figure 17 is, in front elevation view, the conductor supporting assembly of
Figure
17, tensioned so as to provide slack in the conductor mounted adjacent the
dead end insulator.
Detailed Description of Embodiments of the Invention
Conductor 10 is gripped or. secured by a single grip such as a conventional
conductor clamp 12 on each end 14a and 14b of the conductor support 14 so that
tension support
14 is in contact with conductor 10 throughout the length of the repair
operation Yokes 16 provide
an appropriate space di between the two points of attachment I6a and 16b to,
as tension is
established on, two cable slings 18. Conductor 10 is slackened between yokes
16 as slings 18 are
tensioned in directions A, that is to allow conductor 10 to lower in direction
B the cable slings 18,
thus providing a safe and convenient portion of conductor 10, now relieved
from tension, for what
ever repair or installation is required.
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Thus tension support 14 consists of two yokes 16, whether they be the plates
illustrated in Figure 1 or the flexible cable and rigid spreader bar yokes of
Figure 9 or adjustable or
telescopic spreader bar and cable arrangements of Figure 10. One yoke 16 is
mounted at each end
of the length of conductor 10 to be supported, attached to the conductor with
an appropriate grip
12 through a shackle 20. Two hydraulic cylinders 22, or other mechanical
tensioning devices
tension cable slings 18 between the yokes 16. Cylinders 22 draw the two yokes
16 towards each
other, thus relieving tension on the conductor between the two yokes. The
cylinders or other
tension providing devices can be for example hydraulically, electrically, or
manually powered.
Cylinders 22 are mounted to a first yoke 16. The other, second yoke has two
insulators 24 mounted to ensure that no current flows through cable slings 18,
cylinders 22 or
other tension providing mechanism between yokes 16. The cable slings between
the two yoke
plates can be made as long or as short as the particular job requires, and
must have sufficient rated
strength to support the known tension that they will be subject to.
Both yokes 16and their corresponding assemblies can be applied or installed
using
an insulated tool 26 such as for example the wire tong illustrated. Tool 26 is
of sufficient length to
isolate the installer (not shown) from any electrical hazard. Once a yoke 16
is applied by for
example hooking conductor hook 28 over conductor 10 with yoke 16 mounted atop
the conductor
2 0 hook, this insulated tool 26 is left attached and acts as a pendulum so as
to keep the yoke 16
properly oriented, for example horizontal, to the conductor segment being
repaired or serviced. A
yoke 16 may be mounted atop conductor hook 28 by means of, for example, nut
and studs 30 and
32 respectively. Conductor hook 28 maybe mounted at the tong end of a work
pole 26aby means
of a bai134.
In order to provide a current path adequate to the applied load on the subject
conductor, a conventional parallel conductor (not shown) must be installed
around any intended
opening prior to interruption of the normal current path.
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This apparatus can be installed on single or bundled conductors by means of
appropriate grips and clevises of adequate strength to support tension of all
sub conductors within
the bundle. Depending on the width of the conductor bundle (not shown) the
spacing d1 may be
increased to the full width allowed by the width of yoke 16 (or to which
spacing the yoke mav be
adjusted for the adjustable width yokes of Figure 10), or reduced such as seen
in Figure 7. For
example, a yoke width may be in the order of eighteen to twenty-four inches,
which is not intended
to be limiting. Sling assemblies including insulators 24 and cylinders 22 are
mounted by means of
adapter links 36 for example to a hole 16c in the corresponding array of holes
16c in spreader
element 16d of yokes 16.
The changing of dead end insulators 38 or dead end assemblies (not shown) can
be
achieved by the installation of yoke 16 containing the tensioning devices such
as cylinders 24 with
cable slings 18 providing support from support tower 40 or structure through
appropriate
insulating devices 42 applied in series with cable slings 18 and/or tensioning
devices 22.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is to be
construed in accordance with the substance defined by the following claims.
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