CA1057274A

CA1057274A - Helicopter bundle block

Info

Publication number: CA1057274A
Application number: CA205,141A
Authority: CA
Inventors: William H. Chadwick (Jr.)
Original assignee: Sherman and Reilly Inc
Current assignee: Sherman and Reilly Inc
Priority date: 1973-12-03
Filing date: 1974-07-19
Publication date: 1979-06-26
Also published as: US3837623A

Abstract

ABSTRACT OF THE DISCLOSURE

Bundle block having plurality of axially aligned sheaves for simultaneously stringing two or more conductors, with means for receiving a pilot or pulling line from a helicopter and guid-ing it over the outside conductor sheave or sheaves and onto the center or pulling line sheave and a guard assembly for preventing further axial inward movement of the pilot or pulling line onto the conductor sheave or sheaves mounted inwardly of the center or pulling line sheave.

Description

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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 - 4 ~ ` ~

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7 L~k 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 .~
~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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Claims

THE EMBODIMENT OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a helicopter bundle block having a frame coaxi-ally rotatably supporting a central pulling line sheave and con-ductor stringing sheave means disposed axially inwardly and out-wardly thereof, and an outrigger arm extending upwardly and out-wardly from said frame for receiving a line payed out from a he-licopter; guide means for directing said line downwardly and in-wardly from said outrigger arm, past said outwardly disposed con-ductor stringing sheave means and onto said central pulling line sheave, comprising a guide arm pivotally mounted at its lower end on said frame, and spring means normally maintaining said guide arm in an upper position, said guide arm being sufficiently long to extend past said outwardly disposed conductor stringing sheave means when swung downwardly against the action of said spring means by the weight of said line to direct the latter onto said central pulling line sheave.

2. In a helicopter bundle block according to claim 1, a guard assembly comprising a guard arm pivotally mounted at its upper end on said frame, and a second spring means normally main-taining said arm in a lower operative position to block movement of said line axially inwardly from said central pulling line sheave.

3. A helicopter bundle block according to claim 2 for receiving and passing from front to rear therethrough a running-board interconnecting said line and a plurality of conductors be-ing strung simultaneously, wherein said guard arm is pivotally mounted on the rear side of said frame to be struck by said run-ningboard and swung upwardly from operative position, and said second spring means then functions to retain said guard arm in an upper inoperative position.