US2574796A - Hot line connector - Google Patents

Description

A. J. MOORE Hb'r LINE CONNECTOR Nov. 13, 1951 2 Sl-lEETSSl-IEET 1 Filed Feb. 1, 1947 Nov. 13, 1951 A. J. MOORE HOT LINE CONNECTOR 2 SHEETS-SHEET 2 Filed Feb. 1, 1947 INVENTOR. 1445!. P7 MOO/Pf Patented Nov. 13, 1951 HOT LINE CONNECTOR Albert J. Moore, Union, N. J. assigno t to- The Thomas& Betts 00., Elizabeth, N. J a corporation of New Jersey Application February 1, 1947, Serial No. 725,775".

2 Claims, (Cl. 173F273) The invention, relates in general to electric connectors and specifically relates to connectors known as hot line or live line connectorsv or clamps.

It has been known in this art to provide such connectors with taplines variously secured thereto so as to trail therefrom with two-jaw clamping means-fashioned for hooking overan overhead hot live ormain line, and then, by meansv of a longreach rod usually called a hot clamp stick to turn the screwof a clamping mechanism reacting between the jaws to secure the connectorboth mechanically and electrically to the main line.

These known devices do not give satisfaction under all of the conditions under which they must operate in actual practice. One difilculty which has developed with such devices now on the market is thatthe clamping screws which bear on the jaws eventually back off from their initial tightly secured position under the influence of vibration and bodily swingmovement present in the mainline. Also expansions and contractions to which such known devices are subjected, by reason of the wide range of temperatures to which these. devices are exposed, contribut'e tothe dissatisfaction with known types. of such connectors.

The primary object of this invention is to pro vide a. simple form ofhot line connector which will avoid such objections to presently known devices, and to provide a connector of the clamping type which will be easy to apply to the overhead live line, which can be held theretoresiliently-at least during the initial clamping operations, and which when once securely clamped thereto with a non-resilient engagement will so remain in locked position until intentionally unlocked in the act of removing. thesame.

Broadlythis. aspect of the invention is attained by providing a single, screwecontrolled combined clamping-and locking mechanism for squeezing the jaws:v on to the main line and characterized by having twooperative positions, in one of which positions the jaws are spring backed resiliently and thus free to open automatically to receive the main line and subsequently resiliently clamp d between the jaws by the spring; and in the other position of the clamping mechanism the jaws are positively screw locked in their line squeezing positions and thus not free to open accidentallyunder service conditions;

The present disclosure features in suchform of claming mechanism a singlescrew control fash ion-ed tobe operatedat a distanceby means-of along reach or hot clamp stick which control can berotated' to change the-clampingpressure 2 on the jaws fromaspring imposed pressure. totan inflexible rigid chain of pressure: transmitting partsleading through the screw from one to the other of the jawsand thus tocause alocking of the jaws in their clampingposition.

Screw type clamps now in general use are cast or forged and are rather heavy massesvoi metal. Under certain wind conditions theweight of these clamps develop a fly wheel efiect hyreason of its vibration with resulting damage'pto; the line. As it is an object Qfthe, present disclosure to provide a long contact between connector and line to. obtain better distribution'of contact pressure and permit essential stream line. flowof current, it would follow that known forms of screw type clamps would become even heavier if developed to include these; desirable features.

Accordingly it is another object of-the inven tionto provide along contact and at-the same time to-reduce-the massof metal in the connectorso asto minimize the undesirable fly wheel effect.

It is also known altho t a ene al P ctice to make such jaw clamps of sheet; copper, usually from blanks stamped from sheet material and bent to shape and usually bent into a somewhat U-form. Of course, it is an economical require ment that such clamps be made cheaply and thus, ofthe least amount of material particularly in its thickness dimension.

With known forms of such clamps undesirable stresses and strains were developed in thematerial especially in the region adjacent the fulcrum of the jaws and in the areas thereof which contain the screw clamping mechanism. These strains'were developed both in the course of bends ing the blanks into their U-form as wellas subsequently during the installing of the'deviceon the main line and also still later while the clamps were in operation especially when in use over long periods of use, and the resultingweakening. of the structure by reascn'of such strains became quite noticeable in the cases where a too thin gauge of stock material was used.

Accordingly another object of the invention and featuring economy in'production cost is to provide a connector which can be made of a-less gauge material than has been found possible heretofore and which will be free, or at least substantially free, of any such distorting strains and, stresses even when made of an unusually thin gauge of material like springy sheet copper.

This object is attained first by making the clamp of two separable parts, eachparthavingi-ts sheet metal corrugated and thus reinforced" in those regions where bending stresses were most liable to develope; and second, by providing a form of knuckle-like, initially loose form of hinge connection between the parts so separately formed and which hinge connection Will be capable of automatically adjusting its elements to fit the main line without causing strain in one part to be transmitted across the fulcrum or hinge to the other part.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of one form of hot line connectors 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 plan view looking down upon a preferred embodiment of the invention installed in operative position hung from a main hot line;

- Fig. 2 is a view in side elevation of the device shown in Fig. 1 in position as it is being applied to the main line, with the bolt element of the clamping mechanism in its lowermost retracted position, and with the jaws distended into open position by the intruding main line;

Fig. 3 is a vertical sectional view taken on the line 3-3 of Fig. 1, with a showing similar to that of Fig. 2, but with the bolt advanced to lock the jaws in position clamped to and hung from the main line;

' Fig. 4 is a plan view of the underside of the lower jaw shown in the preceding figures and,

Fig. 5 is a detail view in axial section taken on the line 55 of Fig. 3 except that the bolt is in its retraced position and the bearing sleeve lowered in Fig. 2.

In the drawings there is shown a hot line connector I0 used for connecting the conductor A of an overhead main line B with the conductor 0 of a tap line D secured to and trailing down from the connector ID.

The connector includes a clamp ll formed of two separable jaw forming elements, an upper element l2 and a lower element I3, each formed from a blank of sheet copper of a gauge of material sufiiciently thin to have at least a slight degree of resiliency particularly in the clamp forming areas not intentionally reinforced as hereinafter described. In the illustrated case the elements are stamped from No. 14 (064) sheet copper.

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 an upper jaw I4 and a lower jaw I 5. The outer free end portion of the upper element beyond the jaw l4 forms an outstanding reach plate or hook it and the outer free end of the lower element I3 is bent down sharply from the lower jaw to form a depending plate I! to which the tap line D is secured and from which it hangs vertically. The reach plate [6 and the rounded portion of the lower element between the plate I! and the jaw 15 form a wedge-like outwardly open throat for guiding the main line A onto the seat provided therefor at the outer portions of the jaws I 4 and I5.

The jaws are at all times under a squeezing load imposed thereon by a combined clamping and locking mechanism [8 herein featured for clamping the jaws onto the conductor A both during the installing of the connector on the main line as well as later after the connector is in its fixed operative engagement with the main line.

The upper element 12 is a fiat strip of metal straight for the major portion of its length; is of maximum width as indicated in Fig. 1 along the portion thereof designed to engage the main line conductor A, and reduces in width therefrom in both directions to economize in the use of metal where not needed. One end of the strip which forms the upper element [2 is rounded back upon itself to form a wide closed lifting or removing eye l9 at one end of the device and located so as to be conveniently accessible for engagement by a reach rod.

The flat portion of the strip forming the upper jaw l 4 meets the adjacent side of the eye approximately at right angles thereto to form an open downwardly facing semi-cylindrical groove 20. Immediately in advance of the groove the strip is provided with two punchings projecting downwardly from the body of the strip to form a pair of downwardly projecting embossments 21-22 disposed in transverse alignment and parallel to the groove. The groove 20 on one side and the embossments 2 I-22 on the other side of a transverse line coact to form the socket element of a readily separable hinge connection 23 forming the fulcrum or hinge line of the jaws. Just in advance of the embossments 2l-22 the strip is punched completely therethrough to provide a nut receiving hole 24. In this hole is fastened the inner end of a long upstanding nut 25 forming part of the clamping mechanism I8. The lower end of the nut is peened or rolled over the edge of the hole and the nut is thus securely and rigidly fastened to the top jaw and projects upwardly therefrom as a rugged column. The lower portion of the bore of the nut is provided with threads 26 preferably of small pitch and above the threaded portion a bore is enlarged to provide a grease chamber 21. The. outer end of the chamber is normally closed by a readily removable disc 28.

The jaw I4 is reinforced in the area of the nut by a system of corrugations including a ring 29 in which the hole 24 is centered and from opposite sides of which ring extend two parallel legs 3ll3l projecting forwardly for substantially the full length of the upper jaw It as shown in Fig. 1. Another of the corrugations 32 extends transversely of the jaw from edge to edge, intersects the corrugations 30 and 3| and forms on its underside a downwardly facing channel or groove for fitting over the conductor A as shown in Fig. 3. The outer ends of this channel are flared outwardly and upwardly to provide half bell-shaped or funnel- like ends 33 and 34 of greater cross section at their outer ends than the portions of the conductor contained therein. Adjacent the inner side of the groove 32 the metal is lanced out and bent inwardly from the plane of the strip to provide a pair of depending lugs 3536 acting as stops for limiting the advance of the conductor A as it is moved into position located between the jaws l4 and [5 as shown in Fig. 2.

The lower element 13 as best shown in Fig. 14 is formed from a blank of less length than the blank from which the upper element was formed and is bent midlength into an L-form to form the lower jaw l5 and the vertically depending plate l'l. One end portion of the jaw is bent back sharply on itself to form a knuckle-like ridge 3! fitting in the groove 20 and constituting the companion element of the hinge connection 23. The jaw I5 is corrugated to provide reinforcements identicalv. with and: facing. those. described for the upper jaw andin-cludes. a ring. 33,. in. this: case forming arugged bearing; ring, and also includes on innerside. an: upwardly: facing: channel" or groove: 39; facing: the grooves 32 and coastin therewith to form aseattor;theconduotor Thebearing: ring: d8: is. provided centrally there;- of? witharboltzhole: 4E1: alignment with the open threaded end: ofitheborezof thenut. Thejaw: l3 isaprovidedrwith a. pair of; rectangular holes 42|'.-42g for receiving the stop lugs .35-3t= when the. jaws withouttha conductor A therebetween are closechimbearing engagementwitheacirother. The. clamping mechanism t8 includesa. long eye-bolt 43 having at its lower'endsa. turning eye 414.. The. other or upper end' of the. bolt is. provided with threads; 4 5. in threaded: engagement with theJtln'eads'Zli of the nutv 25. The. lower imthreadedi shank. portion.- of. the. bo1tis; passed freely through. the bolt hole 4.0' as best. shown. in At: its intruded end. the .bolt is: provided with; a stop: flange. 54 operating: in. the grease chamberZl'... The retreat of the boltis limited by the engagement of the flange 55 with a shoulder defining the. bottom. of. the grease chamber.

Thesmoothshank of the bolt isprovideclibelow the;;jaw. 1.3,. as. best shown inFig. 5, with: anthrtegral. bearingfi'ange #6.. A sleeve 41$ is. mounted on. the. shank free. to; rotate. thereon; and is. providedeat itsupperyend withaninturneciflange 48 riding on the flange: 46 and; provided. at; its. lower end. with an out-turned flange. 4.9 forming. a spring. seat. A coiled. spring: 513 at. allltimes. under load encircles the sleeves? and bears at. one end on the flange 49; and at. the: other and bears againstthe. underside of the. embossed ring..3fl.. It is arfeature. of. this disclosure. that the length; of the sleeve is slightly greater than the length of the. solid column which would be formed if the spring was compressed with its turns in contact in front elevation. At its lowermost point. the

plate. terminates in a long: straight integral extension. which is. rolled. back longitudinally upon itself. to form a. long open-liketu-bular socket designed. to receive. and be secured to an exposed end. of the. conductor. C. of the. tap line D..

It. is'suggested that the relatively flat portion of the depending; plate It in the part thereof between the bend at its upper portion and the socket 5| indicated by the reference character 56; and in prolongation of-the socket be reinforced by corrugating it. It is also suggested that the part so corrugated be provided with a hole 55 extending therethrough to provide means for attaching another Wire (not shown) corresponding to the lead C or to receive an auxiliary connection.

Normally, that is, before the conductor A is installed in place, the jaws I i-l5 are in mutual bearing engagement under load imposed thereon by the tensioned spring 50 with the lugs 3535 intruded into their respective holes ii-42, and with the elements of the hinge connection held resiliently in interbearing engagement by reason of the load imposed thereon by the spring.

In preparing the connector for use an end .of the tap conductor C is inserted into the bore of the. socket; 5:l=' and the socket". crimped: thereonat one ormore places: as indicated by. the crimps 52.-5 3. formed. bysmeans. of; a crimpingtoolzor'machine following conventionally practices in se= curing conductors to. tubular members.

In operation and assuming that the tap. line has been secured to: theconnector as previously indicated, the assembly is liftedby. a suitableliit rod G engaging in the lift eye IE9 or bolt eye 44 until the reach: plate It overhangs, finds and is ho'okedioverthe exposed; portion. of the conductor A. The broad surface. presented by-the undersideof-the plate l6 resting on the main line tends to. bring, the seat. formed .by' thergrooves 32-49 intoalignment. with the. conductor. of the; lift: stick the connector is. moved? laterally relativev to the. conductor. A and in the direction indicated. by the; right arrow on Fig. 2,- that. is, from right to; lefit of this: showing; The. conductor: A. in eii'ect: slides on. the underside, ot the plate: [6 and" moves. towards the crotchof the then closed jaws to; force them apart transversely and against the resistance. of the: spring 50 at this time thesspring isunder its leastload; Eventual ly: the; conductor A reaches the. position indicated in Fig. 2, having forced the jaws apart. causing them: to: swing about the hinge line provided by the: hinge. connection. 23.: As: the two elements ti -1:3: are not integrally connected at. the hinge; as is usually with. such. devices, the jaws are: free to adjject: themselves automatically each to. fit. its associated groove to the. main lineA withoutrestraint; from the other; clamping jaw similarly. This; may. mean that the ledge 31: is not; exactly parallel to the groove: 20 in which. it turns: but any deviation which under any condition is small will be immaterial to the hinge action. As; the? conductor Awreacheszthe position shown in. Fig. 2V and starts. on. to. its, channel seat. the spring acts; with ai'snapi action: to. force the. condirctonsquarelyintetheseat as; shown: in- Fig. 3; The stops. 355: and 3.6 are. disposed in the path of seating movement: of: the conductor and; prevents;- the conductorirom overshooting: its. seat. Up tit-this point. thexjawsa-resolely under control ofthe spring. The: springloaded tension isisufficient' where only a. temporary and. quick 001% nectiom is; desiredsfiorany reason, soithat the device;- may be .used' with the .bolt in; retractedi position. and vdthout necessarily: using. the locking mechanism herein featured;

When. the conductor is so: seatedsthe lower exposedreye; end of? the bolt. is. engaged by; a suitable form; oiireachi rod H and rotated clockwise thereby, as indicated byctheiellipticali arrowinF-ig. 2; The. belt advanced. in the nut. until the upper flanged end. 48: of thesleeve 41.1 engages and bears fi'rinL-yon the underside of the-ring 38 as indicated Fig 3;. incidentallyfurther compressing the spring-til. The clearance between the limiting stops 28--54 at the top of the bolt is prefixed so that the desired degree of positive locking pressure is imposed between the clamping jaws in their engagement with the main line held between them. During the rotation of the bolt before its solid engagement with the lower jaw is had the spring is acting to hold the connector resilientl; to the main line and thus acts to stabilize the de vice against axial rotation around the axis of rotation of. the bolt. When the bolt is fully advanced the conductor A is held rigidly between the clutch jaws l4-|5, primarily by reason of the solid metal-to-metal engagement of the sleeve 41 with the.lower jaw l5. Differently expressed, there is a solid inflexible chain of connected parts By means leading from the rugged nut 25, through the chain of metal parts formed by the bolt, its flange 46, the sleeve 41, and its flange 48 bearing on the ring 38 of the lower law It is appreciated that at this time the spring 50 under its maximum load is bearing on the flange 46 in a tendency to provide sufficient friction to resist any tendency of the bolt .to back out of the nut by reason of line vibration or otherwise.

When it is. desired to disconnect the tap from the main line it is simply necessary to rotate the bolt counter-clockwise as indicated by the elliptical arrow in Fig. 3 so as to remove the collar 4'! as a whole from its bearing engagement against the lower jaw, and in this way the jaws are restored to the control of their single and sole squeeze force inherent in the spring. When the bolt has been retracted to'the limit permitted by stop flange 54 or sufficiently to permit the jaws to be sprung apart, and thus permit the conductor to clear its seat, an outward pull on the lift eye, that is, from left to right of the showing in Fig. 3, permits the spring to react between the conductor A and the jaws to kick the connector as a whole backward and away from the conductor with a snap action and thus the device perates both when being applied to and when removed from the hot line to act in a tendency to prevent damage to the conductor A due to arcing. Other applications containing subject matter similar to the disclosure herein are applicants copending application, Serial No. 36,669, filed July 2, 1948, and an application filed by Lucian A. Thomas, Serial No. 633,748, filed December 8, 1945, now Patent No. 2,555,099, issued May 29,

I claim:

1. A hot line tapping device including two sheet metal jaws forming elements hingedly connected at one end, each element being corrugated adjacent its mid-length to provide a pair of inwardly facing grooves for receiving the line therebetween, one of the elements provided between its groove and its hinged end with a nut fixedly secured thereto; the other element in the part thereof facing the nut provided on its outer side with a bearing surface and with a bolt hole extending through said part, a combined clamping and locking means for exerting a squeeze pressure on the jaw elements, said mean including a screw element passed loosely through the bolt hole, having one end in threaded engagement with the nut and its opposite end forming a turning eye, said screw element provided between the turning eye and the adjacent jaw element with a pair of spaced apart shoulders, with the outer shoulder of greater diameter than the inner shoulder, the inner shoulder adapted when the screw element is rotated in one direction to engage the bearing surface'and solidly lock the jaws relative to each other particularly in the portions thereof which include the nut and the bearing surface, and a coiled spring encircling the screw element at all times under load having one end bearing on the outer shoulder and at its inner end bearing on said bearing surface, and the free end portions of the jaw elements outwardly beyond the 'nut and bearin surface having at least a slight degree of resiliency and coacting to provide a resilient wedge-like open throat for guiding the line into the seat therefor provided by the grooves whereby the device with its elements in unlocked position and under sole control of the spring can be forced on to the main line against the resistance of the spring.

2. A hot line connector provided with means for securing a tap line thereto, said connector in cluding two clamping jaw elements formed of sheet metal with the elements hingedly connected, each element provided with a corrugation forming an inwardly facing groove for receiving one side of a main line clamped between the elements, one of the elements provided in offset relation to its corrugation with a nut fixedly secured thereto, a bolt passed loosely through the other element and in threaded engagement with the nut, said bolt on the side facing said other element provided with a bearing flange, a sleeve on the bolt and at the end adjacent said other element hav ing an inturned flange overlapping the bearing flange' on the bolt and at its outer end provided with an outturned flange, and a coiled spring at all times under load encircling the bolt and sleeve, bearing at one end on said other element and at its other end on the outturned flange of the sleeve, and said sleeve having a length greater than the length of the spring when compressed to a solid column.

ALBERT J. MOORE.

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

UNITED STATES PATENTS Number Name Date 1,172,604 Johnson, Jr Feb. 22, 1916 1,500,498 Johnson July 8, 1924 1,500,499 Johnson July 8, 1924 1,800,756 Sass Apr. 14, 1931 1,911,820 Fitzgerald May 30, 1933 2,114,940 Rudd Apr. 19, 1938 2,115,592 Smith Apr. 26, 1938 2,205,322 Thomas et a1 June 13, 1940 2,319,602 Hendley May 18, 1943 2,448,402 Thompson Aug. 31, 1948 FOREIGN PATENTS Number Country Date 677,498 France Mar. 11, 193.0

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