US1902008A - Conductor clamp - Google Patents

Description

March 21, 1933- A. o. AUSTIN CONDUCTOR CLAMP Filed March 12, 1929 2 Sheets-Sheet l IN VEN TOR Y5 a a} v. m Mm w R. A m 0. T w A w March 21, 1933. A. o. AUSTl N CONDUCTOR CLAMP Filed March 12, 1929 2 Sheets-Sheet 2 Patented Mar. 21, 1933 UNITED STATES PATENT orrics] ARTHUR i AUSTIN, or NEAR BARBERTON, onro, ,AssIeNon, BY MESNE AssIeNMENrs,

ro THE OHIO BRASS coMrANY,'oF MANSFIELD, OHIO, A CORPORATION or NEW 7 JERSEY a CONDUCTOR CLAMP Application filed March 12, 1929. Serial No. 346,384.

This invention relates to clamps for supporting electrical conductors or other cables, and has for one of its objects the provision of a supporting clamp which will gradually transfer the load on the cable tothe clamp and avoid abrupt variations in the force transmitted. 7 I

,A further objectis to provide a clamp which will serve as a snub-her or damping device to dampen out vibrations in the conductor. 1 a

A further object is to provide a cable support which shall be of improved construction and operation.

Other objects and advantages Wlll appear from the following description.

The inveniton is exemplified in the combination and arrangement .of parts shown in the accompanying drawings and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is an elevation of a conductorclanip embodying one forni of the present invention. i

Fig. 2 is a section on line 22- of Fig. 1.

Fig. 3 is a fragmentary elevation showing a modification of the invention.

Fig. 4 is a section on line H of Fig. 3.

Fig. 5 is a fragmentary elevation of an- 7 other modification.

Fig. 6 is a sectionon line 6-6 of Fig. 5. 'Fig. 7 is a fragmentary elevation of a dif ferent modification. Fig. 8 is a section on line 8-8 of Fig. '4'. Fig. 9 is a fragmentary elevation of another form of the invention.

Fig. 10 is a top plan view of Fig. 9. a r

Fig. 11 is an elevation of another modification.

Fig. 12is a section on line -1212 of Fig. 11.

Fig. 13 is an elevation of another modifi.- cation.

Fig. 14; is a section showing another modified detail of construction. I

In building electrical transmission lines, it is'common practice to; stretch conductors at fairly highte'nsions. By increasing the tension, the sag in the line'can be: diminished I oscillation.

and consequently the number of supporting structures may be ,reduced. Experience seems to indicate, however, that as'the tension 1n the line is mcreased, there 1s an In:- creased tendency for the conductors to- V1:

brate which may cause serious damage from crystallization, particularly at the points of support. The vibration or oscillation of a conductor may be very large compared to the energy setting up the oscillation'under ordinary conditions. This seems to be due to the cumulative effect of the energy producing the oscillation, as clamps or attachments ordinarily used provide little or no means for the absorption of energy tending to produce In order to prevent damage at the clamp or point of attachment, improved conditions may be obtained by absorbing en.- ergy from the vibrating conductor and by, picking up the load gradually at the point .of support thus dissipatingthe' energy in the oscillation and gradually taperingoif the stress. This tends to eliminate any hard spot along the conductor support and'prevents flexing of the strands in theconductor tor readily and which will not seriously lower the fiashover voltage between conductor and ground.

' In the form of the invention showninFig.

1, the conductor 10, which may be of reinforced aluminum, copper, bronze, steel, or other-suitable material, is placed between a lower seat piece 11 and an upper seat piece 12. The seat pieces 11 and 12 conform to the conductor 10 on their innersurfaces'and to spring members '13 and 14 on their outer surface. By providing additional spring members 15 and 16 on the lower side. and 17 and 18 on the upper side, it is possible, not only to take up the load gradually from the conductor, but any vertical movement in the conductorv will tend to cause the adjacentspring leaves to slide over each other {and absorb energy in the manner characteristic of the leaf spring. The upper seat piece 12 together with the spring members 14, 17' and 18 may be very much shorter or even longer than the lower seat piece with its supporting springs. In general, the upper members will be shorter except in cases where it is desired to produce considerable absorption of energy due to the friction between the parts in which case they may be made of equal length or longer than the lower seat member.-

With the arrangement shown, it is possible to transfer-the load from the conductor to the supporting 'clamp gradually and, at the same time, all looseness between the clamp members and the conductor may readily be prevented. Any looseness, together with vibration, would permit of the battering of the conductor and the destruction of the same very quickly, By properly shaping the sup clampingmembers 19 and 20 are clamped to the seat pieces and their supporting spring members by bolts 21. The seat pieces'll and 12 may be formed of drawn or cast sections or may be made outof thin sheet material. Where the seat pieces are of fairly rigid section, they are provided with a series of slots 22. This permits these members to flex with the conductor and supporting members. Through the central portion of the clamp, however, the seat pieces 11 and 12 will be supported by thesupporting spring members and the clamping members 19 and 20 so that they willbe quite rigid and the slots may be eliminated. These slots may be uniformly or otherwise spaced in accordance with the amount of movement required. The ears of a clevis -23 are provided for attaching to the insulator or tower support.

It is evident that any number and type of spring supporting members may be used to obtain the desired results. The spring members may be made to contact throughout their length or only at points desired. By spacing them farapart at the point of support and allowing them to touch at their extremities, greater slipping action will result for a given deflection due to a vibration on tions 24 being bent to provide flat bearing surfaces for the springs 26 while their edges engage the sides of the cable and the portions 25 curved about the cable and have their edges 27 bent back so as to form a bearing on the supporting spring member 26.

In the modification shown in Figs. 5 and 6, portions 30 of the seat conform to the conductor and portions 31 form bearings against the supporting spring pieces to maintain proper alignment. The various spring pieces together with the seat pieces may be prevented from moving in a sidewise direc-' tion by small interlocking projections 32.

The slots permitting flexure of the seat pieces may be varied in accordance with the amount of bending in the conductor as shown in Fig. 7, a section of which'is shown in Fig. 8. A difierent means for providing flexure in the seat pieces is shown in Fig. 9, a plan of'which is shown in Fig. 10. In this construction, the seat piece made of thin pressed material may be formed in a general U-shape in cross section; It is evident, however, that a U-shaped section will be exceedingly stifl' andwill not give the desired'result, but will concentrate the flexure at the point where the cable enters the seat piece. Where the seat piece is still it will either concentrate the stress or the bending will cause the seat piece to fail at some point, concentrating the flexing at this point and causing damage not only to the seat piece, but to the conductor members as well. .The desired flexibility of the U-shaped section, however, may be provided by fluting. or waving the sides. The open side of the U-shaped section is spread out at 33 and brought in-at 3 1. It will be seen that while the central portion of the U-shaped seat piece may be fairly smooth, the edges may be fluted to such an extentthat seat may be readily flexed without exceeding the elastic limit. I

The vibration damper scheme for limiting movement of conductors may be applied to dead-end clamps, rail bonds, or other devices where it is desired to prevent damage to the conductor from crystallization.

Figs. 11 and 12show one form'of the inventionapplied to a dead-end clamp designated generally by the numeral 60. The conductor 1O enters the clamp which has a grip piece 35 held by bolts 36. The clamp may be equipped with a snubbing groove 37 commonly used on many clamps or the conductor may enter into one of the compression types of terminals or clamps, the absorbing or stress controlling springs being applied to a clamp of this kind in a manner similar to that shown in Fig. 11 or any suitable mechanical method. The spring members 38, 39 and 40 are secured to the body of the clamp by a holding block 41 and bolts or cap screws 42.

The arrangement of parts in Figs. 11 and 12 is similar to that in the suspension clamps shown in Figs. 1 and 2. The seat piece 43 forms a suitable bearing between the spring members and the conductor 10. Where it-is desired to provide an absorption of'energy due to the slipping of the spring parts upon each other and upon the" seat piece 43, the

clamp may be equipped so that it'szmass maybe increased by weight members '44. These members may constitute an'integral portion of the clamp body or if made separable, the

amount of weight maybe changed to sui different conditions. .2

lVhere it is desired to increase the energy absorption to dampen out or limit thevibration as much as possible, thismay be donebyconstructing the damping means so-that a greater frictional movement will-be produced by agiven amplitude of vibration upon the incoming conductor. One form of construetion for doing this is shown in Fig. 13. In this figure the spring members are separated by spacers and This increases the angle between the spring members at their points of contact. As this angle isincreased,

'a given vertical movement of'the conductor 10 and the seat piece 43 wil'l'produce a greater longitudinal slip between the adjacent spring parts so that the absorption of energy will be increased. In this case, the spring parts may run entirely free from each other to the points'of contact at 47 and 48. "The I absorption is still further increased by bearing or frictional pads 49 located between the spring members. These frictional pads have of any suitable material-such as fibreJor a.

non-corrosive metal,= such as aluminum, bronze, or other material. g

The desired longitudinal friction maybe increased even though the coefficientof' the material is low by providing inclined surfaces for the bearing which will increase the effective pressure between the surfaces for jagiv-en lateral pressure; This construction may be applied to vibration dampeners of other forms than those shown as, for instance, those shown in my prior applications, Serial Nos. 258,097; 258,445 and 266,584, In the arrange ment shown in Fig. 14, spring members 50 and 51 are provided with friction shoes 52 and 53 having interfittingprojections54 and 55. The friction blocks 52 and 53'are fas tened to the s rin members 50 and 51 in p '.a channel shaped seat member engaging said any suitable way such as by projections 56 or by riveting or clamping inposition.

It is evident that a scheme of this-kind is applicable as a vibration dampener and may be clamped to a conductor in anylocation where desired to prevent or limit the oscillation. Under these conditions, the dampener consists of the absorbing system together,

with a mass so as to obtain relative-movement and the necessary force to causeabsorptlon.

While I have shown-the damper arranged forsuspension insulators .and dead-end clamps, it is apparent that it may be applied equally well to other forms of insulator supports such as bus or pin type insulators or to other structures that support flexible cables. I Iclaim:

The: combination wvith a flexible conductor, of a support for said conductor, a spring member secured'to said supportand having connection with said conductor ata point spaced from said support, and said connection comprising frictionally engaging surfaces that are moved upon, each other by relative movement of said conductor and spring member for damping out movements of said spring member and conductor.

. 2.- The combination with a flexible conductor, of a clamp for holding said-conductor, and a spring fingerextending from said clampalong said conductor, said spring finger being spaced from said conductor adjacent said clamp but having frictional connection'wit-h said conductor at a point spaced from said clamp, said connection comprising frictionally engaging surfaces moved on each other-by movement of said conductor.

'ductor, of a clamp for supporting said congductor, a' spring finger extending from said clamp along said conductor and a frictional member engaging said spring finger and havmg sliding frictional connection therewith at a point spaced from said claimp'for' dampmg vibrations'of said conductor. 7

The combination with a conductor, of a clamp forengaging said conductor, said clampcomprising leaf springs extending along said conductor and having the surfacesthereon in relatively movable frictional engagement with each other to dampen out vibrations of said conductor, said :leaf spring havingopen contour in cross section to facilitate bending thereof.

v 5. In combination a clamp for supporting a conductor,said clamp having a seat extendingalong said conductor and having graded resiliency for gradually taking up the load on said conductor, and frictional means comprising relatively slideable frictionally engaging surfaces for damping movements of 3. Thecombination with a flexible consaid seat imparted thereto by said conductor. i

6. The combination with a conductor, of

along said conductor, and means for supportmg said seat 1n a fixed position at one point ,thereof, .said seat havingithe walls thereof weakened at theiriedges to permit flexing of saidconductor. .7 1 l e 8. The combination with a conductor, of a clamp having a channel shaped seat engaging said conductor, said seat beingopen' at one side to facilitate flexing thereof, a spring for supporting said seat against said conductor, and friction means comprising ment with one another for damping out vibrations of said conductor.

10. The combination with aconductor, of V a clamp for holding said conductor ina fixed position at one point thereof, yielding fingers extending from said-clamp along said conductorand graded in resiliency to take up gradually the load 'on'said con-ductor, and means frictionally engaging said fingers and moved lengthwise thereof byvibrations of said conductor for damping out said vibrations.

11. The combination with a conductor, of a'pair of channel shaped, seat members disposed at opposite sides of said conductor, a

clamp for holding said seat members, in con tact with saidconductor midway between the end ofsaid seat members, said seat members havingthe side walls thereof weakened to permit flexing thereof, and a plurality of leafv springs heldagainst the outer faces of said members by said clamp, said springs be-' ing graded in resiliency to take up gradually the load on said conductor and having frictional contact with one anotherfordamping out vibrations of said conductor.

12. The combination with a conductor, of a channel shaped seat member engaging said conductor, a spring engaging said seatrmemher for holding said seat member against said conductor, and interengaging means for preventing relative transver.semovement of said spring and seat member.

13. The combination with a conductor, of a spring held channel shaped member engaging said conductor, said member having the sides thereof fluted at the edges to permit flexing of said member; v v

14. The combinationwith a conductor, of

a channel shaped seat member engaging saidconductor, said seat member having the sides graded along said conductor to vary 'the flex ibility ofs'aid seat member at diiferentTpositions along said conductor.

15. The'combinationwith a conductor, of a sheet metal channel forming a seat for said conductor, a spring engaging the face of said channel opposite said conductor, said channel having backwardly bent lugs thereon for engaging said spring to prevent relative transverse movement of said spring and channel. V

I 16. The oombination'with a conductor, of a channel shaped seat member engaging said conductor, and a spring for holding said seat member againstsaid conductor, the side walls of said channel having slots thereon to permit flexing of said seat member, the spacing of said slots being graded along said con-' ductor to vary the flexibility of said seat member.

17. The combination with a conductor, of a vibration damper connected with said conductor, said dampercomprising a pair of fricalong said conductor, said finger comprising a U-shaped seat memberhaving the side walls thereof weakened to permit flexing thereof, and a grading spring for holding said seat member incontact with said conductor.

l9.- The combination with-a conductor, of a supportfor said conductor, aspirng finger having one end thereof spaced-from said conductor, said fingerbeing inclined to'the said conductor, and frictionally engaging means interposed between said conductor and the end of said spring finger nearest'said conductor.

20. The combination with a strand, of .a channel shaped spring member having said strand disposed within the channel thereof and extending only partially about said strand, and means for holding a portion of said spring member against transverse movement to cause said spring member to be flexed when said strand is vibrated.

21. The combination with a strand, of a channel shaped spring having said strand disposed in the channel thereof, said spring extending only partiallyabout said strand, and means for holding said spring against transverse movementat one portion thereof to cause said spring to be flexed when said strand is vibrated, said spring having the edges thereof weakened to facilitate flexing of said spring.

22. The combination with a strand, ofa channel shaped spring having said strand disposed in the channel thereof, said spring extending only partially about said strand, means for holding said spring against transverse movement at one portion thereof to cause said spring member to be flexed when said strand is vibrated, the edges of said spring being undulated to facilitate flexing of said spring.

23. The combination with a strand, of a bar spring extending along said strand, means for holding said spring at one portion thereof against transverse movement relative to the adjacent portion of said strand, said spring being spaced away. from said strand at the portion so held but .hav,-. ing movable frictional connection with said strand at a point spaced from said held portion. a

24. The combination with a strand, of a channel shaped spring member having said strand disposed in the channel thereof, means for clamping said spring member to the strand at one portion of saidspring member, means for spacing said spring member away from said strand at the clamped portion thereof, said spring member having connection with said strand at a point spaced from said clamped portion, and means interposed between said spring member and strand at said last named point for affording frictional resistance to relative longitudinalmovement of said spring member and strand produced by transverse vibration of said strand. r

25. The combination with a strand, of a pair of leaf spring members clamped to said strand at one portion thereof and extending away from said clamped portion to provide resilient ends forgradually taking up transverse forces on said strand, said spring mem: bers having frictional connection with each other at a point spaced from the clamped portion thereof, and being spaced apart at the clamped portions thereof.

26. The combination with a strand, of a a support for said strand comprising, a leaf spring member disposed beneath said strand and clamped thereto but having a free end extending along said strand away from the Y clamped portion and disposed entirely below the longitudinal axis of the strand for gradually taking up the weight of said strand,

27. The combination with a strand, of a support for said strand comprising a leaf spring member disposed beneath said strand and entirely below the longitudinal axis of the strand and extending longitudinally thereof,

means for clamping said leaf spring member to said strand at a point spaced from the end of said spring member, leaving the end portion of said spring member free to flex when said strand is vibrated vertically, and frictional means engaging said spring member for damping out vibrations thereof.

28. The combination with a strand, of a down, said spring members having frictional contact with each other to damp out vertical I vibrations of said strand.

29. The combination with a strand, of means fordamping vibrations of said strand comprising an open channel spring member having said strand disposed in the channel thereof, said spring member having the edges thereof undulated to facilitate flexing of the spring member.

30. The combination with a strand, of

means for damping vibrations of said strand comprising an open channelfshaped spring member having the edges thereof undulated to facilitate flexing of said spring member,

and means having movable frictional connection with said spring member for damping vibrations of said strand and transforming the energy of such vibrations into heat.

31. The combination with a strand, of a spring having a portion thereof fixed in spaced relation to said strand, said spring being extended from said fixed portion along said strand atan angle thereto, and having frictional connection with said strand at a point spaced away from said fixed portion.

In testimony whereof I have signed my name to this specification this 11th day of March A. D. 1929. j a

r ARTHUR O. AUSTIN.

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