Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates generally to the erection or
stringing of a plurality of high voltage conductors simultaneous-
ly and~ more particularly, to bundle blocks or that purpose adap-
ted to receive the pilot or pulling line from a helicopter. -
Helicopter stringing blocks having a single sheave for
receiving a transmission or pulling line have been in use for
some time. United States Letters Patent No. 3,195,862, for exam-
ple, discloses a simple helicopter stringing block, a modification
of which for mounting on a support tower crossarm employs two an~
gularly disposed guides for receiving a single pulling or trans-
mission line, with each guide attached to a latch and~pivota~ly
mounted with it on the associated side frame of a single grooved
sheave. When a line or conductor is deposited on either guide,
it slides down onto the associated latch and its weight pivots
the guide upwardly and the latch downwardly to deposit the line
on the single grooved sheave, with the guide then returning by
gravity to normal position. The other embodiment therein which
is mounted on an open-side~ sheave fr~me does not employ a pivo^~
tally mo~u~t~dtgu~de, which also is true of the modification of
Figl 3Yof NoO 3,479,014. None of the prior structures known are
usable for helicopter stringing~of a pilot or pulling line into
a bundle block to be used for simultaneously stringing two or more
conductors~ This is because they have only a single sheave, and ;~
the multiple sheaves of a bundle block present the problem of
accurately depositing a pilot or pulling line from a helicopter
only onto the center or pulling line sheave and preventing it
from engaging the cond~or: sheaves on either side thereof, which
problem is not solved by the guide means of the prior single
sheave helicopter blocks. The importance of placing the pilot
;3U or pulling line in the groove of the center or pulling line sheave
is that the runningboard interconnecting it and the conductors,
as the latter are pulled in, will thereby be properly guided into
the bundle block whereas if the pulling line is not in its sheave
groove~ the bundle block may be seriously dc~maged and t~e pulling
operation halted with possible attendant and ~rreparable damage
to, or even destruction of, the conductors~
This invention provides a bundle block having a plura-
lity of axially aligned sheaves for simultaneously stringing two
or more conductors with means for receiving a pilot or pulling
line from a helicopter and guiding it over the outside conductor
sheave or sheaves, into the groove of a center or pulling line
sheave, and a guard assembl-y for preventing further axially in~
ward movement of the line therefrom onto the conductor sheave
or sheaves mounted inwardly thereof.
More specificallyg such pilot or pulling line guide
means comprises an outrigger arm for receiving the line as it
is payed out from a helicopter and a guide arm spring-urged up-
wardly and pivoted at its lower, outer end for downward swinging
under the weight of the line to bridge the outer conductor sheave `
or sheaves and direct the line therepast and into the groove of
the center pulling line sheave~ and the guard assembly comprises
a guard arm pivotally mounted at its upper end on the trailing
side of the bundle block frame and a spring interconnecting the
frame and the lower end of the guard arm to normally maintain it
- in a lower position to block movement of the pilot or pulllng line
axially inwardly from its center she~ve, the spring functioning `
to hold the guard arm up in an inoperative position when the arm ~
is struck and swung by a runningboard passing through the bundle ~ ;
block.
The present invention will be further illustrated by
way of the accompanying drawings in which:
Figure 1 is a rear elevation, with parts broken away
and parts in section~ of a helicopter bundle block embodying the
invention showing the line guide arm in its upper position in
full lines and in broken lines in its lower position for guiding ;
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a line onto the center sheave; and
Fig. 2 is an end elevationg as seen from the right of
Fig. 1, with the guard arm shown in full lines in its lower ope-
rative position and in broken lines in its upper inoperative po-
sition.
Referring to the drawings, a bundle block embodying the
features of the invention is illustrated as comprising a frame?
indicated generally by reference numeral 11, coaxially rotatably
supporting a central pulling line sheave 12 and conductor string-
ing sheave means 13 and 14 disposed ax1ally outwardly and inward~
ly thereof, respectively. To this endg the frame ll is attached
in well-known manner at its upper end to laterally extending pa~
rallel head bars 15 and 16, the fro~ head bar 15 being at the
right side as seen from the outer end of the block in Figo 29
which may be supported by clevis means 17, or the likeg (Fig~
~rom the usual insulator means secured to a tower or supporting
ground structure~ Adjasent its lower end, the frame 11 is provi~
ded with a bore supporting the inner end of a laterally extending
shaft 18 which is secured to it by means of a suitable cap screw
19, or the l1ke. It is on this shaEt 18 that the sheaves 12-14
~re rotatably mounted3 as by ball bearing races 21. An outer
~ide frame member 22 is secured at its lower end by means of a
cap screw 23, or the like~ to the outer end of the shaft 18. And
` a stabilizer bar 24 preferably is attached to the lower end of
i' the frame 11 by nut and bolt means Z5.
As best seen in Fig. 1, the front and rear surfaces of
the upper end of the side frame member 22 have vertically extend-
i~g grooves or pockets 26 for receiving the lower ends of a ge- ~ ;
nerally U-shaped outrigger arm 27, with those grooves having in-
ward extensions housing the terminal portions of the arm (Fig.2)
that may be secured to the side frame by pins 28. The main body
of the outrigger arm 27, as best seen in Fig. 1, extends upwardly
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and outwardly Eram the bundle block for receiving a line (not
shown~ payed out from a helicopter which by gravity will slide
down the outrigger arm.
At its upper outer end3 the side frame member 22 (Fig.2) ~-
is shaped to form spaced ears 29 apertured to receive and support
a pivot pin 31 on which is mounted the lower end of a guide arm
32 and spring means 33 having one end engaging the side frame and
the other the guide arm to urge the latter upwa~d or in a clock-
wise direction viewing Fig. l. The guide arm 32 is disposed bet~
ween the spaced legs of the outrigger arm 27, as best seen in Fig. ~;
2~ and its upper end normally is held by the spring means 33 against
a horizontal detent pin 34 mounted in the frame 11.
Secured in any suitable manner to the rear side of the
frame ll near its upper end is a guard bracket 35 having lateral~
ly spaced legs terminating at their lower in a horizontal shelf
portion 36 (Fig. 2) and provided adjacent thereto wi~h aligned
aperturesfor receiving a pivot pin 37O The upper end of a guard
arm 38 is rotatably mounted by the pin 37 and is formed with pa- ~ ?
rallel sides spaced laterally from each other and terminating in
upper ends 39. A coil spring 41 is connected at its upper end
to the upper end portion of the bracket 35~ extends downwardly
between the sides of the guard arm 389 and is secured at its lower
end to the latter by a pin 42. The mounting of the guard arm 38
is somewhat similar to the mounting of the holddown device and `~
its springs disclosed in U.S. Letters Patent No. 3,5843837, but
that patented structure could not be employed in lieu of the ins- -~
tant guard arm 38 because it would p~event lateral movement of
a pulling line into the central sheave groove when in lower ope~
rative position.
The operation of the structure heretofore described is
as follows. With the bundle block 11 hanging from insultators --~
secured to a tower or other ground support as notedg a helicopter
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is employed to lay a pilot or pulling line (not shown) onto the
outrigger arm 27, and the Eorces oE gravity will cause that line
to slide downwardly on the arm into contact with the guide arm
32 which is normally held in its upper full line position of Fig.
1 by the spring means 33.
The weight of the line will swing the guide arm 32 down-
wardly about its shaft 31 (in a counterclockwise direction view
ing Fig. 1) to define a continuing downward and inward path of
movement of the line over and beyond the outer conductor sheave
13 to cause the line to be deposited in the groove oE the central
puLling line sheave 12. This is the lowermost position of the
guide arm 32 illustrated in broken lines in Fig. 1. It will thus
be seen that the guide arm 32 is sufficiently long to extend past
the outwardly disposed conductor stringing sheave means, when
swung downwardly by the deposited line against the action of the
spring means 33, to direct the line onto the central pulling line
sheave 12 and prevent its becoming engaged with or falling upon ~-
the outer conductor stringing sheave means 13. It will be appre-
ciated, of course, that the guide arm 32 will be returned to its
upper full line position of Fig. 1 by the spring means 33 as soon
as the line being laid is deposited in the central pulling line i~
sheave.
In view of the downward and inward sliding movement
of the line into the bundle block as just described, it will be
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~nderstood that there is a very good possibility that such move-
ment could result in the deposited line rebounding or continuing
its inward movement out of the central sheave 12 and onto the in- -
ner conductor stringing sheave means 14. The present invention -
prevents such undesirable action of the deposited line by means
of the guard arm 38. This arm normally is in its downward opera~
tive position shown in full lines in Figo 2 wherein its lower end
is disposed adjacent the inner side of the central pul~ing line
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sheave 12 to prevent movement of a deposited line laterally in-
wardly from the sheave 12. The spring 41 resiliently retain~
the guard arm 38 in such lower operative position, because the
pin 42 securing the lower end of the spring to the guard arm is
then disposed forwardly of the guard arm pivot pin 379 as is the
upper end o-E the spring. During a conductor pulling operation
following such deposit of a pilot or pulling line in the central
sheave 12 of the bundle block 11~ a runningboard interconnecting
the pulling line and the conductors being strung (not shown) will
~ be drawn through the bundle block in well-known manner to depo-
sit the conductors on their respective sheave means. During such
movement of the runningboard through the bundle block, which is
in the direction from right to left viewing Fig~ 2, the running- ;-
board strikes against the lower port~on of the guard arm 38 and -~
swings it rearwardly about its pivot 37. The initial portion of
such swinging movement of the guard arm 38 is resisted by the -
spring 41, but as soon as the spring attaching pin 4~ is thus swung ~ ;
above the extension of a line passing through the centers of the
upper end of the spring and the pivot pin 37, spring 41 will func~
tion to continue that upward swinging of the guard arm 38. This
movement of the guard arm is stopped by the contact of the upper
ends 39 thereof with the shelf portion 36 of the guard bracket 35,
as illustrated in broken lines in Fig. 2, and the guard arm, hav-
ing served its intended purpose, will be maintained in that up-
per inoperative position by the spring 410
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