Note: Descriptions are shown in the official language in which they were submitted.
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INVENTOR: Danny R. Williams
Robert J. Morris
Charles E. Tucker
Ronald J. Finke
Victor J. Mullen
TITLE: POWER LINE WORKING APPARATUS
BACKGR_UND OF INVENTION
1. FIELD OF INVENTION: The present invention --
relates to apparatus for working on line electrical power
lines.
2. DESCRIPTION OF PRIOR ART: In the electrical
power industry, it is o~ten necessary to cut or interrupt
a live high power line for service or other purposes.
These lines usually carry high voltage electrical power,
often w.ith voltages of thirty kilovolts or higher.
Further, it was usually required to cut the line at a
position located away from any support pole or tower.
U.S. Patent No. 3,205,330 related to an electrical
circuit .interrupter switch for interrupting high power
electrical circuits. However, so far as is known, this
type of interrupter switch was apparently limited to use
in areas where it could be suspended or supported beneath
poles or towers.
Prior practice in other areas was to simply cut the
live line using a cutter at the end of a long insulatin~
rod. This was undesirable, in that hazardous arcs
occurred, often following the cut end of the line to the
ground.
SUMMA~Y OF IMVENTION
Briefly, the present invention provides a new and
improved power line workinq appaxatus and method for
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permitting a live electrical power line to be cut.
Mounting grips are connected to the line at ~irst and
second positions adjacent a section of the line to be cut.
The mounting grips are connected at opposite ends of an
elongate support rod, which is preferably formed from a
highly insulative material. The mounting grips are then
moved closer to each other by a movement mechanism
associated with the support rod to increase tension in the
section of the line to be cut. Conductive stirrups and a
conductive bar are mounted with the support rod to form,
when connected by cables to the line, a parallel
electrical circuit with the portion of the line to be cut.
Once the line has been cut, and preferably after at least
one end has been tied back, the parallel electrical
circuit is broken or interrupted by moving the position of
the conductive bar with respect to the stirrups. An arc
interrupter is engaged as the conductive bar moves to
suppress any arc formed as the parallel electrical circuit
i;~ broken.
B~IEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an elevation view of an apparatus according
to the presen-t inventioni
Fig. 2 is a view taken along the lines 2-2 of Fig. 1;
Figs. 3, 4, 5 and 6 are elevation views of por-tions
o;E the apparatus of Fig. 1 in different positions during
power line working operations; and
Fig. 7 is an elevation view of a spliced power line
aEter power line working operations according to the
piesent invention are completed.
DESCRIPTION OE' PREFERRED EMBODIMF.NT
In the drawings, the letter A designates generally an
apparatus according to the present invention for working
on a power line L, permitting the line L to be cut at
locations away from poles, towers or other support
structures while line L is live or carrying electrical
power therethrough. The line L with which the apparatus A
is used typically carries substantially high levels of
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electrical power, such as at voltages exceedlng thirty
kilovolts.
The apparatus A is mounted to the line L at a first
position 10 and a second position 12 adjacent a section S
5 of the line L to be cu-t by line grips 14 and 16. Line
grips 14 and 16 are of the conventional type and are of
like construction. The position of line grip 14 on the
line L is reversed from that of line grip 16. Each of
line grips 14 and 16 has a generall~ U-shaped mounting
saddle 18 which fits over the line L for support purposes.
An eyelet 20 is formed at an upper end of a mounting arm
22 to receive manipulating hooks of the conventional type
which are mounted at the end of extended insulated
operator poles. A jaw arm 24 of the conventional type
having a gripper jaw formed at an upper portion thereof
for gripping the line L is pivotally mounted at a pivot
point 26 to the arm 22. An arm 28 is formed extending
downwardlv from the saddle 18 and has a pivoted connection
30 with a lever arm 32. The lever arm 32 is further
pivotally connected at a pivot point 34 to the jaw arm 2~.
An eyelet 36 is formed on the lever arm 32 at an opposite
end from the pivot 34 to permit a manipulator hook to be
inserked and move the lever arm 32 to move the jaw on the
jaw arm 24 into firm engagement with the line L beneath
the saddle 18.
Swiveled connector hooks 38 are mounted in the
eyelets 36 of the line grips 14 and 16 to connect the
apparatus A to the line r. adjacent positions 12 and 14.
:~n one embodiment of the present inven-tion, a first of the
connector hooks 3~ is mounted in a swivel housing 40 to a
mounting yoke 42 of a line tensioning mechanism M of the
apparatus A. The other of the connector swivel hooks 38
is mounted in a swivel housing 43 to an end socket member
44 at one end of an elongate insulative support rod 46.
It should be understood, however, that movement mechanisms
M may be mounted according to the present invention at
each end of the support rod 46, if desired. The rod 46 is
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formed from a sui-table insulative material, such as
fiberglass, and is hollow along at least a portion
adjacent movement mechanism or mechanisms M, for reasons
to be set forth. The rod 46 may be tubular in form, if
desired.
A mounting nut 48 at an end of a threaded rod 49 of
the mechanism M mounts the mechanism M to the yoke 42. A
ratchet mechanism 50 is mounted with the yoke 42 and
receives the threaded rod 49 therein. The ratchet
mechanism 50 is driven by a ratchet arm 51 which is
manipulated by means of manipulator hooks inserted into a
swivel eyelet 52 at a lower end of the ratchet arm 51. As
the ratchet arm 51 is moved, ratchet mechanism 50 causes
t:he threaded rod 49 to move inwardly or ou~wardly,
clepending upon the setting of the ratchet mechanism 50,
into a threaded end socket 53 at an end of the rod 46.
l'he rod 46 is hollow in its int~rior portions at such end,
.~orming a tubular receiving member for receiving the
advancing end of the threaded rod 49 as it is moved by the
ratchet mechanism 50. A stop nut 54 is mounted on the
Lhreaded rod 49 to limit the inward advance of the
threaded rod 49 into the end socket 53 of the rod 46.
A connector mounting bracket 55 (Fig. 2) is mounted
with the yoke 42 adjacent the mechanism M and has fixedly
l~ounted therein a first end 56a of a connector rod 56.
The connector rod 56 moves in correspondence with the
threaded rod 49 and a second end 56b of connector rod 56
slides within a mountin~ bracket 57 which is ~ixedly
mounted to the end socket 53 of the rod 46.
Tubular mounting collars 62 are formed extending
upwardly from a channel member 64 to receive the rod 46
therein. The channel member 64 is ormed from a suitably
conductive material, such as aluminum or the like, and has
outwardly extending conductive stirrups 66 ormed thereon.
The conductive stirrups 66 extend sidewardly rom a
conductive plate or bracket member 68. Downwardly
extending conductive spaced side jaws or lugs 70 formed
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beneath the plate 68. The space~ jaws 70 have a pivotal
connection 72 to receive a mov~ble conductive bar 74,
formed from copper or other suitable conductive material,
therebetween. A support latch spring member 76 is mounted
beneath the plate 68 to support the bar 74, as will be set
forth.
Cylindrical mounting collars 78 are formed at each
end of a channel member 80 and receive the rod 46 therein.
Condu~tive stirrups 82 are formed extending sidewardly
from a conductive bracket 84 beneath the channel 80. An
arm 86 is formed extending downwardly from the bracket 84
and has a mounting sleeve 88 formed thereon fox receiving
an interrupter I (Fig. 3). Resilient conductive switch
jaws 90 are formed extending downwardly on each side of
the bar 74 from the bracket 84 to firmly hold the bar 74
in place. A releasable latch mechanism 92 is mounted with
the bracket 84 to engage a lug 98 mounted extending above
a side portion of the bar 74. The lug 98 engages the
releasable latch mechanism 92 to hold the bar 74 in place
connectiny -the conductive stirrups 66 and 82. The lug 98
forms an upper portion of an arm member 100 which has a
pull grip 102 formed at a lower portion thereof.
A generally U-shaped contact yoke 104 is formed at an
end 74a of the bar 74. The yoke 104 has a rod 104a ~Fig.
:3) formed extending across an upper portion which is
adapted to engage a hook 106 formed at an upper end of a
:Latch lever 108 of the interrupter I (Fig. 3). A
~lielectric plate 110 is formed extending upwardly from the
yoke 104, having a suitably shaped center notch at its
upper surface for engaging the channel member 80 (Fig. 3).
The interrupter I is of a conventional type, such as
of the type disclosed in United States Patent No.
3,205,330. The interrupter I is connected by a connector
mechanism 110 to the mounting sleeve 88 beneath the
bracket 84. The latch lever 108 of the interrupter I is
pivotally mounted at a pivot mechanism 112 to a latch
ferrule 114 mounted about an interrupter body 116.
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Contained within the interrupter body 116 is structure,
includlng arc extinguishing material, of the type
~isclosed in UniCed States Patent Number
3,205,330. ~n ~yel.et llR is forme~l
on a member extending outwardly from the ferrule 114 to
permit manipulation of the interrupter I by manipulator
mechanisms. A connector rod 120 is pivotally mo~nted at
an upper end to the latch lever 108 and at a lower end to
a piv~t joint 122 mounted beneath the interrupter body
116.
Jumper cables 124 extend between line clamps 126 and
128 at each end of the apparatus A. The line clamps 126
and 128 are conventional, gripping the line L with
increased force at an eyelet 130 formed therewith is
tightened by a manipulating rod. The line clamps 128 at a
second end of the jumper cables 124 are adapted to be
tightened in a like manner onto the stirrups 66 and 8~ of
the appara-tus A, permitting a parallel electrical circuit
to be formed through the apparatus A from the line clamps
126 through the jumper cables 124, line clamps 128,
stirrups 66 and 82 and the brackets 68 and 84 through the
conductive bar 74 with the apparatus A in the position
shown in Fig. 1.
In the operation of the present invention, the line
grips 14 and 16 (Figs. 1 and 2) are hung on the line L at
the positions 10 and 12 adjacent the section S of the line
L to be cut. The apparatus A is then attached to the
connector eyelets 36 of the line grips 14 and 16 by
connector hooks 38. The ratchet mechanism M is then
operated, by movement of the ratchet arm 56 to drive the
threaded rod 49 inwardly into the threaded end sleeve 58
of the rod 46, bringing the line grips 14 and 16 closer
towards each other, easing tension and placing slack in
the section S of the line to be cut. Jumper cables 124
are thPn attached between the line L and the stirrups 66
and 82, forming a parallel electrical circuit arrangement
through the apparatus A with the line L.
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The interrupter I is then installed (Fig. 3) in the
sleeve 88 of the apparatus A. At this time, it i5 often
desirable to test open the interrupter I with the section
S of the line L still intact as a safety check to insure
that the apparatus A is operating satisfactorily. If the
apparatus A tests satisfactorily, the section S of the
line L is then cut by a conventional line cutting tool.
An end 131 of the cut line is then brought backwards and
tied back so that it is maintained out of proximity with
an opposite end 132 of the cut line Lo
The pull grip 102 of the apparatus A is then pulled
~ownwardly (Figs. 3 and 4), moving the bar 74 out of
l_ontact with the switch jaws 90. However, a conductive
path still exists as the bar 74 moves downwardly due to
the contact between the rod 104a of the yoke 104 with the .
hook 106 of the latch lever 108. This electrical
connection is maintained during downward movement of the
bar 74 until a point is reached (Fig. 4) wherein the
anterrupter I internally breaks electrical connection
~)etween the end portions 131 and 132 of the line L, with
1:he cont~nts of the interrupter body 116 suppressing any
clrc which might tend to be formed on breaking of the
~lectrical connection.
The bar 74 swin~s downwardly of its own weight until
.25 i.t reaches a nearly vertically extending position ~Fig.
r;). At this time, it may again be engaged at pull grip
102 and moved upwardly mtil it is contacted with support
latch spring 76 (Fig. 6) to hold the conductive rod 74 at
a. spaced position from the cut end portion 132 of the line
.. 30 1,. The interrupter I ma~ at this time also be removed to
gain space for working operations.
After the working operations on the cut line L have
been completed, the conductive rod 74 is removed from
enyagement with the support latch spring 76 and pivoted by
means of pull grip 102 back into contact with the switch
jaws ~0. This can usually be done fairly ~uickly and
there is little, if any,.risk of an arc being formed at
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this time. For additional arc suppression protection, the
interrupter I may be reinserted in the sleeve 88 of the
apparatus A prior to this time and used to suppress any
arc which might possibly be formed. At this time, with
the bar 74 engaged between the switch jaws 90, the flow of
electrical current through the line L resumes. The end
portion 131 of the cut line L is then released from its
tied back position and brought into position near the
other cut end portion 132 and a conventional electrical
cable splicing sleeve 140 (Fig. 7) inserted over the end
portions 131 and 132. The splicing sleeve 140 is then
crimped down to electrically connect the end portions 131
and 132 of the apparatus A to each other. The jumper
c:ables 128 are then removed, electrically disconnecting
t:he appara-tus A from the line L. The apparatus A is then
mechanically disconnected from the line L by disengaging
swivel hooks 38 from the eyelets 36 of the line grips 14
and 16, and then removing the line grips 14 and 16.
The foregoing disclosure and description of the
invention are illustrative and explanatory thereof, and
various changes in the size, shape and materials, as well
as in the details of the illustrated construction may be
made without departing from the spirit of the invention.
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