US1847461A - Conductor support - Google Patents

Description

March l, 1932. I A, o, AUsTlN 1,847,461

CONDUCTOR SUPPQRT Filed Jan. y31, 1929 13Y%/Wt M ATTORNEY auf claims.

Patented Mar. l, 1932 i 1,841,46iv

. UNITED STATES. PATENT oFFIc-,E

ARTHUR- AUSTIN, 0T NEABBABBERTON, OHIOS` ASSIGNOIB, BY MESNE ASSIGNMENTS,

T0 THE. 01H10 BRASS CGMPANY, 0F MANSFIELD, QEIO, A CORPORATIGN .0T NEW `JERSEY GONDUCTUR SUPPORT Application filed January 31, 1929. Serial No. 336,57,5.

A further object is, to provide a cross arm which will withstand small unbalanced longitudinal stresses in the conductor without displacement lbut which will yield to larger, unbalanced stresses'. f A further object is to provide a cross. arm mounting suitable for a wood cross armgand kwhich will permit maximum utilization of the insulating properties ofthe wood. A furtherobject isto provide a cross arm mounted to' swing upon its support but having vmeans for providing a limited degree of stability for withstanding small unbalanced stresses without moving upon its pivotal support.V A further object is to providelv a cross arm support having spaced pivots which may be selectively disconnected but'which `cannot both be disconi nected simultaneously.` Other objects and advantages will appear from the following description The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawings and described in the following specification, andv it is `.more particularly pointed out vin the appended In the drawings:

Figure 1' is a plan* view showing ,a'conduc-v torsupport embodying one form of the present invention. i

Figure 2 is an elevation with parts in sec-` tion showing the support of'Figure 1.

VFigure 3 is an elevation-looking from the f right' in Figure I with parts in section.

Figure 4 is a fragmentary' plan section showing a modified construction.`

Figure 5 is a. fragmentary' sectionl on line 545of'Fig. 2.-

In electrical transmission lines, it is ad-` visable to4 use high voltageV for the sake of Y economy.` .This requires considerable insula-Y tion. Where the line traverses districts sub*V ]ect tolightning, the transmission' line. may

also besubject to very high potentials produced by the lightning so thatthe transmis- Y sion conductors have to be insulated not only for the voltage used in the transmission of power, but for the abnormal voltage caused by lightning as well. In addition to these disturbances, lines are subject to switching surges. Another source of trouble on'transmission lines is due to birds.

Where the excessive voltages tending to cause liashover occur at a high frequency or with a steep wave front, or where the duration of the stress is exceedingly short, material which will `ordinarily not insulate the line may be quite effective. By using insulators such as `porcelain to carry the` normal voltage, it is possible to support these insulators from wood cross arms so that for abnormal surges or transients theiiashover voltage will be greatly increased. In many cases the flashover voltage of the insulator may be more than doubled by Vmounting it on a wood cross arm.

Where the mechanical Vloads are light-V Wood has been effectively used to afford high flashover voltage so as to'prevent arcs toA ground. Where the mechanical loads are heavy, however, the problem of supplying suiicient mechanical strength in the wood is more diilicult, particularly where clearance is an important factor` Inmy present invention it is possible to take advantage of Y the great increase in ashover voltage due' to theuse of wood and at the same time eliminate to 'a very large degree the mechanical limitations of the wood itself. It is also possible to increase the insulation furnished by the wood members without increasing the mechanical loads upon the towers orV main supporting structure to which the cross arms are attached. l A

A cross arm having wood members lO'is provided with endrfittings Il to which an insulator string 12V is attached.VV The cross -which the wood members rest. Themenliber 16 is provided with pinsl( and 18 which fit into slots 19 and 20 respectively in :plates 21secured'to'one ofthe tower members'22.

varms are attached to a vertical channel 13 by suitable bolts 14. The vertical member 13' -95 The wood members 10 are extended back into the basket of the tower and secured together by a spacer member 23. rlhe member 23 is attached to angle bars 2a, which are connected to the main channel member 13, and to brace 25 the upper end of which is secured to channel member 13.

The object of the several members 24 and 25 together with the member 13 is to form a rigid structure which will support the mechanical load imposed upon the arm b v the insulator string 12. The channel member 13 is secured to and supported by a pin 26 which takes the vertical load produced by the arm and furnishes an axis or rotation. lith this arrangement it is possible to utilize practically the entire lena'th ot' the arm projecting bevond the tace of the tower Ytor insulation as the main bracing; is placed inside the tower, although it is evident that this bracing;l could be applied outside ot' the face of the tower equally as well from a mechanical standpoint which would permit the use of a short-er arm, but would cut down the insulation for a given extension of the arm bevond the face oit the tower. The pin 26 is supported at its upper end by a rounded head 27, the pin being passed through a perforation in a flange 28 secured to the tower and the head being arranged to permit rotation of the pin and also limited transverse swinging in all directions as will be more apparent from Fig. 5.

Vith the arrangement shown in Fing. 1, the small unbalanced longitudinal loa-ds in the conductor will produce no movement o1 the cross arm but it is necessary that the nnbalanced longitudinal stress be sufficient to relieve the horizontal component on one of the pins 17 and 18 before rotation ot the cross arm on its pivot-al support can start. The downward component produced by the weight of the insulator and conductor as well as the arm tends to produce a horizontal component acting inwardly toward the face et' the tower. Since the pins 17 and 18 are spaced well apart, they are capable oi3 setting up a considerable moment which will tend to resist rotation oli the arm. When. however, the unbalanced longitudinal pull ot this conductor becomes sufficient to over come the inward component on one ot the pins 17 or 18, the cross arm will tend to rotate toward the position shownin broken lines in Figs. 1 and 3. Such rotation takes place about an axis extending from theupper end of pin 26 to pin 17 or 18 depending;r on the direction of rotation. Since the line joining the upper end of the pin 26 with the pin 18 is inclined, as will be apparent from Fig. 3, the arm 10 will swing about an inclined axis which willV tip the outer end of the arm upwardly as it swings. The lower end of the supporting' pin 26 is spaced from the lower end 18 of the inclined axis of' rotation so that the lower end ol.l the pin 26 will swing outwardly and laterally toward the position 26, Fig. 1, and the pin 26 will swing toward the position 26, Fig. 3. The upper end of the pin 26, as explained above, is supported in thc liange 28 in a manner to permit the transverse swinging: movement imparted to the pin 2G.

If a very heavy unbalanced load exists. the arm may be rotated entirely into the position shown in broken lines. llc't'orc reachinsr this position however, the thrust on the pin 18 becomes parallel with the face ot the tower. The slot in the lower plate permits the pin to move into the position 18 where it will be arrested by a stop 29. The weight ot the arm and conductor will tend to hold the pin ti nhtlv in this position an d owingV to the shape o'l1 the stop 20. it will not be possible for the pin to jump out and tberebv lose the bene'lit of the lower bearing. This is quite important tor it the cross a m swings against the face ot the tower. the momentum mi vht readily force the pin out of the slot. Il the unbalanced longitudinal stress is relieved. the arm will tend to assume its normal. position. as the relation ot the bearii'lgrs is such that the outer end oiE the arm is raised materially ir beiner thrown out of normal position. Bv properly spacingr the bra einer members in the tower with respect to the location of the cross arm. it is possible to utilize practically the entire portion extending4 from the 'Face ot the tower for insulatinapurposes and. at the sa me time` use a portion extending: into the tower for gripping the wood members. 7h ere the portion inside the tower has the proper relation in renard to the opening.lm in the tace ot the tower. it is possible to permit this portion to swine; ont through the opening without comin;r in contact with any olf' the tower members. It will be seen that with this type of construction it is possible to use long arms and. at the same time. limit the torsional stress imposed upon the tower. As the arm swings. tho tension in the conductor is greatly reduced and the tower relieved ot the stress which may save it from destruction owingr to the breaking' of the conductor or to heavy sleet loads. The construction has the further advantage that the arm does not oscillate with any slight change in load, making it difficult to work upon the arm. The construction is such that it may be applied to many existing structures to improve the ei'iective insulation, particularly from lightning; or to eliminate bird trouble.

The general construction is equally suitable for steel arms as well as wood arms. There are a number of ways of producing the equivalent results embodying the above principles. The invention makes it possible to take advantage of 'tl ne rigid arm and the swine` ti.. arm and also permits utilizing the insulation lut ICL'

lll,

55 of said pivotal connections being spaced from each other in a direction transverse to their to a lmaximum for a given clearance between the conductor and tower body.

In the modification shown inv Figure 4, the plate is usedin place of the plate 21 and is provided with slots 31 having enlarged circular openingsv 32 at the inner ends thereof. Each slot- 31 is arranged in van arc struck about the center of the opposite enlarged will be swung out of, its slot to permitv the cross arm to swing into the direction of the pull on the line. i i

Y Iclaim:

1. In combination a supportingstr'ucture,

a. cross .arm mounted onisaidstructure, ay

' transmission linecarried by said cross arm,

said cross arm beingpivoted tomovefin thel directionof the transmission line under 1inbalancedload and having horizontally spaced.

pivotal points about one of which said cross arm swings when moved Vin the direction of the transmission line. 4 j

2. Aconductor nsupport comprising a supportingstructure'l cross arm mounted on said structure and two f sets of .pivotal connections between said cross arm and said lsupporting structure, said Apivotal connections .provid-` ing different axes of rotation for said cross arm, said cross arm being arranged tofswing in-opposite directions about said different axes in rotationrespectively.

A conductor supportcomprising a, supporting. structure. a cross larm mounted -on said structure and arranged to Swingin op` posite directions from an initial ,position about different axesof rotation, said axes of rotation being inclined to the vertical to cause the supporting end of the cross arm to rise` when rotated in either direction.

4. In combination a supporting structure,

a cross arm mounted on said structure and having a conductor carried at the outerend thereof, said cross arm having three points of pivotal connection with said structure, two

pivotal axes.

5. In combination a supporting structure, a cross arm mounted on said structure, a pair of pivotal connections between said cross arm and the structure, about which said cross arm;

is arranged to swing selectively, depending Vupon the direction .of movement of said cross arm, each coniiection'being arranged to sepag rate kwhen, said cross arm swings aboutthe other connection.

6. In combinationa supporting structure, a cross arm mounted on said structure,a pivotal connection between said cross arm-` an structure and two supplementary, separable,

pivotal connections-between said cross arm and structure, said :supplementary connections being spaced from eachother in a direction transverse to the axis of said first named pivotal connection, each of -said supplementary pivotal connections being arranged to become detachedI when said ,cross arm is swung upon said supporting structure about the other supplementary pivotal connection..

7. In combination a supporting structure,

a cross arm mounted on said structure, a pivf otal connection between said cross arm and structure, twosupplem'entary pivotal connections between said crossarm and structure,

`said supplementary pivotaly connections bcing spaced at opposite sides of the axesof rof tation of said rst named pivotal connection, each of said supplementary pivotal connections being arranged to separate when saidl cross arm swings about the other supplementary pivotal vconnection and meansv for preventing separation of each of said'supple- Iiientary pivotal .connections when acting as the pivot about which said cross arm swings.

: 8.`In combination a supportingl structure,

a cross arml mounted on said structure, a piv-V otal support .for said crossarm, a pair of spaced pin and slot connectionsbetween said cross arm and structure, each slot bein arranged to permit its pin to'escape there rom when said cross arm'is swung about the other' pinas a pivot and-meansfor preventing escapev of each pin from its slot when the cross arm is swung about that pin as a pivot.

9.,In combination a supporting tower, a'.

cross arm pivotally mounted on ysaid tower at one. side thereof, said-cross arm projecting into the interior of said tower beyond said` p-ivotal support, and bracing means for saidcross arm connected withthe inwardly pro- Jecting portion thereof, and disposed within y the contour of said tower for norma-1 position of said cross arm', said inwardlyprojecting portion and bracing means being arranged to swingv through` the sideof said tower when saidk cross arm is swung upon its pivotal supportf"k 10. l Incombination a supporting structure, a cross arm carried by said. structure and hav- `inghorizontally spaced pivotal connections therewith, each ofsaid connections being separable to permit horizontal pivotal movement of said 'cross arm about the other connection, andmeans ,for preventing separation' of one of saidconnectionswhen said cross arm is swung about that connection away fromnon mal-position.

I n` combination a. supporting structure,y a bearing means` mountedon saidstructure,

'zeV

iio

and havingl horizontallyspaced pivot`fslots-, a cross arm, spaced pivot pins mounted onfsaidf c-rossarm anduingaging-said slots, eachV ol said pins being 'vniovable` outwardly through its Yslot'lwhen"saidfcross arm is swung about theotlicrpin, and means -for preventing escape ofa-pin from -itsslotwh'en said cross arm is'niovedfafbout that` pin awayifrom its normal position.

12. Iny combination, a supporting tower, a cross-armA extending away from said tower, a conductor carried by said cross aim, a pivotalfconnection between said cross arm and tower disposed substantially in the central vertical plane of said cross arm, braces eX- tending laterally Jfrom said cross arm and, having pivotalconnections with said tower at opposite'sides of the central vertical plane of said `cross arm, each of said pivotal connections being arranged to permit outward movement of the bracerconnected therewith when said cross arm is rotated toward the side thereof adjacent the other pivotal connection.

13. In combination a skeleton tower, a wood cross arm projecting away from said tower and having the inner end thereof ex` tending into the interior of saidtower, metal bracing for said crossarm connected with the portion thereof extending into the interior of said tower, a pivotal support for said crossarm disposed substantially'in the central vertical'plane of said cross arm, and means fixedl to said cross arm atopposite sides of'thecentral vertical plane thereof having pivotal contact with said tower and held in engagement with said' tower and forming pivotal connection between said cross arm and-'said tower by theweight of said cross arm for stabilizing said cross arm in its normal central position but arranged to permit pivotal movement of said cross arm when'subjected'to a transverse unbalanced Iload of predetermined minimum magnitude.

14. In combination a supporting tower, a`

"wood cross arm movably supported on said tower, said cross arm having a portion thereof extending into the interior of said tower, and metallic bracing for said cross arm, said bracing holding said cross arm against vertical inovement and being disposed within the interior of said tower topermit maximum utilization of the insulating properties of the portion of the cross arm projectingbeyond the tower;

16. In combination a lsupporting tower, a cross `arm movably mountedV on said tower, horizontally spaced pivots for said cross arm, said cross arm being arranged to swing about one of said pivots when moved in one directionfrom its normal position and to swing about the other of said pivots when moved in the opposite direction from its normal position, and means arranged to be brought into operation by the movement of said cross arm for locking against transverse displacement, the pivot about which said cross arm is swung.

17 In combination a supporting tower, a cross arm movably mounted on said tower, horizontally spaced pivots for said cross arm, said cross arm being arranged to swing about one of said pivots when moved'in one direction from its normal position and to swing aboutthe other of said pivots when moved in the opposite direction from its normal position, and means automatically operated by the pivotal movement of said cross arm for locking against transverse displacement, the pivot about which said cross arm is swung.

18. In combination a supporting tower, a cross arm movably mounted on said tower, horizontally spaced pivots for said cross arm, said cross arm being arranged to swing about one of said pivots when moved in one direction from its normal position and to swing about the other oi said pivots when moved in the opposite direction from its normal position, and means operated by a. movement of said cross arm, additional to its pivotal movement, for locking against transverse displacement, the pivot pin about which said' cross arm is swung.

In testimony whereof I have signed my name to this specification this 29th day of January A. D. 1929.

ARTHUR O. AUSTIN.

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