US2582267A - Conductor protector - Google Patents

Description

Jan. 15, 1952 I MOORE 2,582,267

CONDUCTOR PROTECTOR Filed July 2, 1948 2 SHEETSSHEET l JNVENTOR. #455 4 7- Mama's Jan. v15, 1952 Filed July 2, 1948 A. J. MOORE CONDUCTOR PROTECTOR 2 SHEETS-SHEET 2 INVENTOR. ,44 Elf/P7 J /700/F' Patented Jan. 15, 1952 2,582,267 CONDUCTOR rno'rso'ron Albert J. Moore, Watchung, N. J assignor to The Thomas & Betts 00., Elizabeth, N. J., a corporation of New Jersey Application July 2, 1948, Serial No. 36,669

1 Claim. 1

The invention relates in general to an improved technique for securing an attachment such as a tap clamp to an electric conductor. The invention specifically relates to a shield for protecting an electric conductor from damage thereto which might otherwise occur when hot tap clamps or like attachments are applied to or removed from high tension electric conductors.

It is known in this art that when a clamp of any kind or, in fact, any attachment is installed on or removed from a live line there is always present the possibility of producing an'arc between the line and the clamp which are tends to burn the surface of the conductor or of the clamp, or of both. Attempts have been made heretofore in such situations to protect the conductor and attachment by means of a U-shaped stirrup which may be secured at its ends to the conductor by means of split bolts, by means of a flat ductile strip partially wrapped about the conductor, or by wrapping a layer of wire, called an armor rod, about the conductor and upon which rod so formed the clamp is placed.

These devices are difficult to install especially Where it is inconvenient to get to them, as in overhead lines; it is difiicult to screw the usual split end bolts or clamps necessary to secure these known forms of protective devices in place; and otherwise these known devices are too expensive,

both in their manufacturing cost and in the cost of installing them, to become commercially acceptable.

The primary object of the invention is to provide a simple form of line-protectin connection between a line conductor and an attachment thereto, such as a hot line tap clamp, and which connection can be installed from a remote position; which can be attached to a live conductor without arcing damage either to the conductor or tothe clamp; which can be readily snapped on to the conductor without necessity of otherwise manipulating any fastening means; which can be installed with the conventional tools such as a hot stick; which will tend to avoid abrasion of the line even while the line vibrates or is swinging back and forth in the wind; and which will permit the removal of the clamp without causing any arcing of the surface of the conductor.

Briefly, these objectives are attained by pro- 5- as such clamps have heretofore been attached directly to the conductor and without the protecting shield herein featured.

The present disclosure contemplates the possibility that any hot line clamp currently in use is to be disconnected or replaced from time to time. Accordingly, the metal shield herein featured includes its own inherent clamping means for automatically securing it more or less permanently to the conductor as an incident of its installation so that during the removal of the old or the installing of a new clamp in place the conductor so shielded is protected from the effects of arcing.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanyin drawings and in part will be more fully set forth in the following particular description of three forms of device embodying the invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings:

Fig. 1 is a view in perspective of a preferred embodiment of the invention featuring a simplified form of shield, disposed in operative position mounted on a conductor and providing an electric connection between an overhead main line and a tap depending therefrom;

Fig. 2 is a view in side elevation of the device shown in Fig. 1 before the assembly of tap, clamp and conductor shield is placed on the conductor;

Fig. 3 is a similar View with the assembly in position on the conductor and taken on the vertical medial plane of Fig. 1;

Fig. 4 is a transverse sectional view of one of the end latches taken on the line 4-4 of Fig. 1; and

Figs. 5-8, inclusive, are views of a form of shield slightly different from the form shown in the preceding figures, but equally fashioned to fit between the jaws of the clamp shown in Figs. 13; Fig. 5 being a plan view of the blank from which this modified form is made; Fig. 6 being a view in side elevation of the blank of Fig. 5 when bent into final form; Fig. '7 being a View in side elevation of the bent shield shown in Fig. 6, looking into the open side; and Fig. 8 being a transverse sectional view taken on the line 8--8 of Fig. 6, looking in the direction indicated by the arrows.

In the drawings, and referring first to the showing in Figs. 1-3, there is disclosed an overhead conductor A which may be considered as a distribution line strung from line poles. A tap B leading to a transformer or to a customer's feed clamp C is formed with two separable jaw-forming elements, an upper element l2 and a lower element l3, each formed from a blank of sheet copper of a gauge of material sufficiently thin to have at least a slight degree of resiliency. The two elements are hingedly connected adjacent one end and the portions thereof adjacent to the hinge are normally in substantially parallel relation to form a reinforced upper jaw l4 and a reinforced lower jaw i5. The outer freeend unreinforced portion of the upper element 1;:

beyond the jaw It forms an outstanding reach plate or hook it and the outer free end of the lower element !3 is bent down sharply from the lower jaw [5 to form a depending plate E1 to which the tap line B' is secured as by crimping and from which it hangs vertically, following conventional practices in this respect. The reach plate It and the rounded portion of the lower element between the plate I! and the jaw 55 form a wedge-like, outwardly open V-throat best shown in Fig. 2' for guiding the main line A on to the seat provided therefor at the outer portions of thejaws l4 and 15.

The jaws are at all times under a squeezing load imposed thereon by a combined clampingand locking mechanism i8 for clamping the jaws on to the conductor A during the installing or" the connector on the main line, as well as later, after the conductor is in its fixed operative engagement with the main line as shown in Fig. 3. A readily separable hinged connection 23 forms the fulcrum or hinge line of' the jaws. A corrugation 32 extends transversely of the jaw ill from edge to edge to form on its under side a downwardly facing channel or groove for fitting over the conductor A or for fitting over the shield herein featured when installed on the conductor A. The lower jaw is similarly corrugated to provide an upwardly facing channel or groove 59 facing the groove 32 and coacting therewith to form a seat for the conductor or for the shield when in use.

A coiled spring 59" at all times under load reacts between the eye-bolt 13 and the lower element [3 to squeeze the jaws l4, E5 on to the shield on the conductor A.

Located between the cable A and fitting in the seats 32 and 39 is a shield 59 particularly forming the novel subject-matter of this disclosure. In its most elemental form it is made from a thin sheet of springy sheet copper bent back upon itself longitudinally into an omega form in cross section. The shield 55 comprises primarily a central cylindrical crotch-forming portion 5! and a pair of outstanding guide flanges or lips 52 and 53. As noted in Fig. 2 the central cylindrical portion is normally closed so that in effect the portion 51 is a split tube with the guide flanges 52 and 53 diverging outwardly from each other and from the split. In general, the flanges 52 and 53 are symmetrically shaped, face each other, and, if curved slightly as in some cases, are both of the same curvature. The flanges coact to provide an open V-throat for receiving the conductor A from the V-shaped throat formed be- 4 tween the reach plate It and depending plate H.

The shield may be considered to be complete up to this point of a width measured lengthwise of the conductor equal to or preferably greater than the width of the clamp and without any additional means for clamping itself to the conductor A than is provided by its own resiliency in its tendency to clamp its cylindrical portion 5i on to the conductor A.

However, in the preferred form shown in Fig. 1 the cylindrical portion is provided at opposite ends with integral extensions to form spring clamping ends 54 and 55. These ends are of identical construction and are somewhat C-shaped in cross'section as shown in Fig. i. More specifically' described, each end includes a crotch portion 55 approximately a semi-circle in cross section and a pair of ears 5'? and 58 extending in the sam general direction as the guide lips 52 and 53, of less width than the guide lips 52 and 53, and similarly functioning to receive and guide the conductor A intothe pocket provided therefor by the crotch portion 56.

Each of the ends 54 and 55 in the inner portion thereof adjacent the main portion 5! has its ears of reduced width and inturned to form tongues. The tongues extend inwardly toward each other to form a pair of latches 69 and 6!, the inner edges of which bite more or less into the surface of the conductor A as shown in Fig. l and whose somewhat sharp edges engage edgewise between the strands of the conductor when a conductor of the stranded type is used to defeat relative rotary movement. The clamping ends 5-5 and 55 provide extensions from the main clamping portion 5| and act to increase the effective contact area of the clamp C or other accessory device. The extended length provided by the ends 55 and 55 assists materially in dampening out conductor vibrations.

Referring to the form of the invention illustrated in Figs. 5-8, there is shown in Fig. 5 a stamped blank 52 from which this form of shield may be formed. The blank includes a body portion 63 and two wings 54 and 55 each connected to the body portion by a narrow neck 66. The body portion 63 has its two opposing longitudinal edges parallel to each other and designed to be beaded in a subsequent operation along the dotted lines. The wings 54 and 55 are of slightly less width than the body portion 53. The. wings are provided with slots 5'? each formed by two short parallel slits and a third slit connecting adjacent ends of the parallel slits. The material between the slits is bent out of the plan of the balance of the material to form latches 68 and 69 similar to those shown at Bil-6|. The blank 62 is bent U-shaped about its long axis a-b to form at its center two outstanding guide lips 79 and TI corresponding to the guide lips 52 and 53, and at its ends to form the wings 65 and 65 into ears l2 and 73 corresponding to the ears 5.! and 58 in the preferred form. It is suggested that in this form the otherwise sharp free edges of both the body portion and the wings be rolled back sharply upon themselves to form rounded beaded edges 14. Curling or beading the thin edges tends to minimize what would be otherwise objectionable radio noise.

While it is herein suggested in describing the showing in Fig. 1 that the spring clamping ends 55 and 55 be all of the parts projecting beyond the central crotch-forming portion 5!, it is suggested that the clamping ends terminate at the outer ends of the part which includes the latches Gil-6|, that is, the outer ends with their ears 51-58 be omitted.

It is also suggested that all exposed edges be rounded to defeat electric losses and for this reason the forward edges of the ears 52-53 and 57-58 be rounded back upon themselves to form bfza lrls 80 of small diameter such as are shown a 4.

Any of the shields herein disclosed are effective to prevent burning and abrasion of the conductor when accessory devices are applied to or removed from the conductor; no tools other than conventional installation tools are necessary to install the shield in place or remove the attachment therefrom. The shield being made of thin flexible metal permits it to conform closely to different shapes and sizes of conductors and permits easy adjustability for a plurality of conductor diameters.

In operation the shield is first fitted between the spring-loaded jaws l4-I5 of the clamp C and located more or less centered in the seat provided by the corrugations 32, 39, as shown in Fig. 2. The eye-bolt 43 is then fitted in the reach rod shown in dash lines in Figs. 1 and 2 and elevated into position to cause the reach plate IE to overlap the conductor A. Then by swinging the reach rod from right to left as indicated in Fig. 2 the reach plate [6 slides along the conductor and thus acts to bring the conductor first into the V-throat provided by the central guide flanges 52-53 and then into the guide flanges provided by the two sets of ears 51 and 58. This has the effect of opening the shield to permit the conductor A to pass into the crotch portions of both the central part 5| and the ears 51-58. As noted in Fig. 3 the diameter of the conductor A is slightly greater than the normal closed diameter of the portion 5| and its clamping ends 54-55, so that the shield is held to the conductor by reason of its own springy resiliency. The clamping mechanism is then operated as indicated by the curved arrows to move the jaws into position to secure the clamp C first under resilient pressure and finally under a solid mechanical pressure to exert a squeeze pressure on the shield supplementing its squeezing engagement on the conductor A.

It will be understood that it is intended that the clamp with its shield remains locked on the conductor. However, in the event it is desired to remove the clamp, it is simply necessary to re-rotate the eye-bolt 43 to unlock the mechanical engagement locking mechanism l8, more or less release the spring tension, and thus permit the removal of the clamp from the shield which remains clamped on the conductor by reason of its inherent spring-clamping engagement therewith. The clamp may subsequently be replaced on the shield while so clamped to the conductor, or a new clamp or other attachment may be substituted for the clamp currently in use. An auxiliary tap hole 18 in the depending plate I! may be used in those cases where tap' B is connected to the clamp C through a form of connectors separate from the crimping hereinbefore suggested. It is also suggested that a hole 19 be formed in one or both of the guides 52-53 in outwardly spaced relation to the cylindrical portion, and thus to the conductor, to facilitate the removal of the shield from the conductor whenever desired.

The shields herein disclosed have many advantages; they prevent burning and abrasion of the conductor when necessary devices are applied to and removed from the line conductor; they require no other installing tools than those now in general use; their self-locking latches or detents are effective in securing them to the conductor particularly effective while the attaching device is being removed from or inserted on to the conductor; the thin metal of which the shields are formed permits them to conform closely to the conductor, insuring close contact and allowing a standard size shield to be used with conductors of different diameters; and whose conductor-gripping clamping ends beyond the clamp C increases the effective contact area of the associated clamp and are each capable of being sprung on to the conductor independently of each other and independently of the spring-clamping action of the main central clamping portion. This application contains subject-matter similar to the disclosure in copending application Serial No. 633,748, filed December 8, 1945, now Patent No. 2,555,099, issued May 29, 1951.

" each wing with the adjacent part of the body portion, the body portion along its longitudinal medial portion providing a strip adapted to be rolled into a cylinder, leaving the side portion therebeyond to form flanges, the edges of the wings being beaded, and each wing provided on opposite sides of the longitudinal medial axis of the blank with slots formed by two parallel and a connecting slit, and the material Within each slot bent out of the plane of the associated neck and extending at an angle to the material surrounding the same to form a resilient latch spaced from the edge of the associated wing.

ALBERT J. MOORE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 862,082 Lewis July 30, 1907 1,500,498 Johnson July 8, 1924 1,594,055 Filkins July 27, 1926 1,663,005 Hendee A Mar. 20, 1928 2,005,882 Arnold June 25, 1935 2,071,002 Rudd Feb. 16, 1937 2,107,061 Pittman Feb. 1, 1938 2,151,525 Pittman Mar. 21, 1939 2,423,627 Tinnerman July 8, 1947 2,427,182 ,Bergan Sept. 9, 1947 2,445,808 Stenstrom July 27, 1948 2,448,402 Thompson Aug. 31, 1948 FOREIGN PATENTS Number Country Date 757,413 France Oct. 9, 1933

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