US3837623A

US3837623A - Helicopter bundle block

Info

Publication number: US3837623A
Application number: US00420953A
Authority: US
Inventors: W Chadwick
Original assignee: Sherman and Reilly Inc
Current assignee: Sherman and Reilly Inc
Priority date: 1973-12-03
Filing date: 1973-12-03
Publication date: 1974-09-24
Anticipated expiration: 1991-09-24
Also published as: CA1057274A

Abstract

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 guiding 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

United States Patent [1 1 Chadwick, Jr.

[451 Sept. 24, 1974 1 HELICOPTER BUNDLE BLOCK [75] Inventor: William H. Chadwick, Jr., Rossville,

[73] Assignee: Sherman & Reilly, Inc.,

Chattanooga, Tenn.

[22] Filed: Dec. 3, 1973 [21] Appl. No.: 420,953

[52] US. Cl.. 254/134.3 PA, 242/157 R, 244/1711, 254/ 193 [51] Int. Cl. E21c 29/16 [58] Field of Search 244/17.11, 1 TD; 254/134.3 R, 134.3 PA, 192, 193, 194, 197; 242/157 R [56] References Cited UNITED STATES PATENTS 516,268 3/1894 Hartz 254/197 3,010,700 11/1961 Petersen 254/193 3,077,337 2/1963 Cronkright 254/197 3,195,862 7/1965 Sherman 254/197 3,199,840 8/1965 Lindsey 254/193 3,584,837 6/1971 Reilly et al. 254/l34.3 PA

Primary Examiner-Trygve M. Blix Assistant ExaminerGalen L. Barefoot Attorney, Agent, or Firm-Davis, McCaleb & Lucas [5 7 ABSTRACT 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 guiding 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.

3 Claims, 2 Drawing Figures VIM A HELICOPTER BUNDLE BLOCK BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to the erection or stringing of a plurality of high voltage conductors stimultaneously and, more particularly, to bundle blocks for that purpose adapted to receive the pilot or pulling line from a helicopter.

2. Description of the Prior Art Helicopter stringing blocks having a single sheave for receiving a transmission or pulling line have been in use for some time. US. Letters Pat. No. 3,195,862, for example, discloses a simple helicopter stringing block, a modification of which for mounting on a support tower crossarm employs two angularly disposed guides for receiving a single pulling or transmission line, with each guide attached to a latch and pivotally 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-sided sheave frame does not employ a pivotally mounted guide, which also is true of the modification of FIG. 3 of U.S. Pat. No. 3,479,0l4. 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 conductor 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 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 damaged and the pulling operation halted with possible attendant and irreparable damage to, or even destruction of, the conductors.

SUMMARY OF THE INVENTION This invention provides a bundle block having a 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 guiding it over the outside conductor sheave or sheaves, into the groove of a center or pulling line sheave, and a guard assembly for preventing further axially inward movement of the line therefrom onto the conductor sheave or sheaves mounted inwardly thereof.

More specifically, 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 upwardly 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 directthe 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 pulling line axially inwardly from its center sheave, 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.

In the drawings FIG. 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 a line onto the center sheave; and

FIG. 2 is an end elevation, as seen from the right of FIG. 1, with the guard arm shown in full lines in its lower operative position and in broken lines in its upper inoperative position.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly 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 stringing sheave means 13 and 14 disposed axially outwardly and inwardly thereof, respectively. To this end, the frame 11 is attached in well-known manner at its upper end to laterally extending parallel head bars 15 and 1,6, the front head bar 15 being at the right side as seen from the outer end of the block in FIG. 2, which may be supported by clevis means 17, or the like, (FIG. 1) from the usual insulator means secured to a tower or supporting ground structure. Adjacent its lower end, the frame 11 is provided 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 like. It is on this shaft 18 that the sheaves 12-14 are rotatably mounted, as by ball bearing races 21. An outer side 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 the frame 11 by nut and bolt means 25.

As best seen in FIG. 1, the front and rear surfaces of the upper end of the side frame member 22 have vertically extending grooves or pockets 26 for receiving the lower ends of a generally U-shaped outrigger arm 27, with those grooves having inward 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 and outwardly from 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 end, the side frame member 22 (FIG. 2) is shaped to form spaced ears 29 apertured to receive and support a pivot pin 31 on whichis 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 upward or in a clockwise direction viewing FIG. 1. The guidearm 32 isdisposed betweenthe 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 11 near its upper end is a guard bracket 35 having laterally spaced legs terminating at their lower ends in a horizontal shelf portion 36 (FIG. 2) and provided adjacent thereto with aligned apertures for receiving a pivot pin 37. Theupper end of a guard arm 38 is rotatably mounted by the pin 37 and is formed with parallel 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 38, 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 Pat. No. 3,584,837, but that patented structure could not be employed in lieu of the instant guard arm 38 because it would prevent lateral movement of a pulling line into the central sheave groove when in lower operative position.

The operation of the structure heretofore described is as follows. With the bundle block 11 hanging from insulators secured to a tower or other ground support as noted, a helicopter is employed to lay a pilot or pulling line (not shown) onto the outrigger arm 27, and the forces of 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 downwardly about its shaft 31 (in a counterclockwise direction viewing 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 of 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 appreciated, 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 sheave.

In view of the downward and inward sliding movement of the line into the bundle block as just described, it will be understood that there is a very good possibility that such movement could result in the deposited line rebounding or continuing its inward movement out of the central sheave 12 and onto the inner 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 operative position shown in full lines in FIG. 2 wherein its lower end is disposed adjacent the inner side of the central pulling line sheave 12 to prevent movement of a deposited line laterally inwardly from the sheave 12. The spring 41 resiliently retains 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 37, as is the upper end of 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 wellknown manner to deposit 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 runningboard strikes against the lower portion 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 42 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 function 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 racket 35, as illustrated in broken lines in FIG. 2, and the guard arm, having served its intended purpose, will be maintained in that upper inoperative positive by the spring 41.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a helicopter bundle block having a frame coaxially rotatably supporting a central pulling line sheave and conductor stringing sheave means disposed axially inwardly and outwardly thereof, and an outrigger arm extending upwardly and outwardly from said frame for receiving a line payed out from a helicopter; guide means for directing said line downwardly and inwardly from said outrigger arm, past said outwardly disposed conductor 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 maintaining 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 runningboard interconnecting said line and a plurality of conductors being strung simultaneously, wherein said guard arm is pivotally fmounted on the rearside of said frame to be struck by said runningboard and swung upwardly from operative position, and said second spring means then functions to retain said guard arm in an upper inoperative position.

Claims

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