US2229758A - Electrical connector - Google Patents

Description

an. 28, 194 w c. N. METCALF ELECTRICAL CONNECTOR l- Filed March 21; 1949 INVENTOR. Can/55110715732141? V E I a,

ATTORNEY .5.

Patented Jan. 28, 1941 UNITED STATES 'zazavsa I i ELECTRICAL como'roa Charles N. Metcalf, Port Chester, N. m, assignor to Consolidated Edison Company of New York,

' New York.

- Application March 21,

N. Y., a corporation of New 1940, Serial No. 325,101

Claims. (01. 287-78) This invention relates to connectors for elec-' trical cables or other conductors.

According to the invention, connectors may be provided of a form particularly adaptable for 5 connecting tap-oil wires or cables to a main cable without severing the main cable, although certain features of the invention are also adaptable to various other applications. The invention provides an improved connector of the so-called compression type, that is,of a type which may be applied to the conductors and then subjected to pressure for permanently deforming the parts, to provide fixed engagement with the conductors or to tighten the embrace of the device upon the cables or wires; without bolts and screws or the like.

Heretofore cable tap-oil connectors have been available in various forms including devices adapted to be clamped to the cables by the use of screws, and any other forms ordinarily quite bulky and expensive, and requiring considerable time and labor for their application and subseqent proper insulation. Types which have bolts,and screws or the like are liable to become loosened upon heating and cooling of the cables, thus impairing the electrical eonductivity of the Joint. Also such types, particularly if they have protruding parts, are very diflicult to properly insulate without forming a bulky and unsightly 'joint. That is, the protruding parts not only obstruct the winding of the Joint with insulated tape, but tend to injure the insulation, and require that numerous layers be applied to safely cover the protruding parts. Also with a recently :25 developed procedure for insulating cable Joints,

pads or masses of soft rubber composition, unvulcanized or partially vulcanized are first applied to the joint and subsequently covered by tape. With such compositions it is of importance 40 that the connector be free of parts such as bolts and nuts which will tend to protrude through the inner soft insulating material. Y

In other cases, in efforts to avoid the time and skilled work required to properly insulate cable tap-oil joints, resort has been had to relatively bulky connecting members previously insulated in the factory and into which the cable ends may be secured as by sweating with solder. But aside from the expense and awkward size of such devices, it is necessary to cut the main cable and thus interrupt the power service in order to apply the device.

The present invention in its preferred forms obviates the above difllculties and also provides a 5 very compact, inexpensive connector which may be cheaply and quickly applied and safely insulated without severing the main cable or interrupting the power service, and with which the cross sections of the resulting joint, if insulated, need not very substantially exceed in size the 6 cross sections of the insulated cables connected. The invention also provides a connector of exceptional mechanical strength which will remain fixed firmly to both the cable and the tap-oil conductor, and permanently maintain an electrical connection of high conductivity between the two, even under severe operating conditions, and without the necessity, troubles and uncertainties of using solder on the job.

In the drawin 15 Fig. 1 is a perspective view showing the parts ofa preferred form of connector embodying the invention;

Fig. 2 is an end view of the same parts as applied to a main cable and a tap-oil cable, but 20 showing the parts prio'r to application of compressive force thereto for fixing the same in position;

' Fig. 3 is a view of the device, somewhat similar to Fig. 2 but showing the cross-sectional shape 25 of the parts and of the cables after the assembly has been compressed and fixed in position, ,-and also showing portions of the apparatus for compressing the connector;

Fig 4 is a side view of a completed joint using. 30 a connector according to the invention, the parts being shown prior to application of insulation thereto;

Fig. 5 is a top view of the assembly shown in Fig. 4, and s Fig. 6 is a perspective view of portions of an alternative embodiment of the invention.

As shown in Fig. l, the preferred form of the connector may comprise a pair of generally cylindrical portions as at l0 and I I secured together 40 -in side-by-side relationship and each adapted respectively to separately receive and embrace a cable or tap-oil. conductor. The portions l0 and H may be formed of sheet metal or metal of a sheet-like character preferably of medium hard 45 drawn copper or other metal of high electrical conductivity, and having considerable firmness and rigidity while being adapted to be permanently deformed in a manner hereinafter described. The members l0 and II may if desired 50 be made separately of sheet metal and then bent into the forms shown and secured together as by silver solder at i2. 01' if the connectors are to be made in large quantities, it may be found desirable to integrally form the portions 10 and H by extruding a continuous piece of metal of this shape, which may be cut into sections to form connector units as of Fig. 1.

It will be observed that a gap or opening as at It whereby the portion I0 may be applied to a cable without severing the cable. In the preferred form shown, the opposite edges extending along the gap or opening l3 may be bent downwardly, outwardly and then slightly upwardly as shown, to form oppositely directed a main cable as at is at an area where the insulation has been removed. Thereupon the channel portions I4 and 15 may be forced more closely together as by the use of pliers or other instrument with suitably shaped jaws, to engage the channel portions I4 and IS without injury. Then while the portions 14 and iii are being held nearly together, the member l6 may be slid on endwise, or forced on by endwlse tapping to the position shown in Figs. 2 and 4. At this time while the portion l0 may more or less firmly embrace the cable l9, it is not intended that the connector will as yet be necessarily fixed in' position with sufficient firmness to permanently insure the parts against displacement, or to insure a permanent satisfactory electrical contact with the cable. As will be noted in Fig. 2, there is still preferably a, small gap 20 between the channel portions it and i5. Thus there is room for these portions to be brought closer together for tightening the band portion l0 with the cable l9 under high compression therein. The manner in which this may be accomplished will be explained below in connection with Fig. 3.

The member i6 may preferably be formed of metal somewhat more rigid than the portions ill and II, although it need not be a metal of high electrical conductivity since it is not interposed electrically between the cables. It has been found that the member l6 may be satisfactorily made of relatively hard phosphor bronze and with the proportions and shape as shown, it will be capable upon slight deformation as hereinafter described, of germariently interconnecting the channel portions [4 and I5 while the cable is very tightly embraced.

Aft. the portions in and I8 have been assembled in respect to a, main cable as shown in Fig. 2, the end of a tap-off cable'or other conductor as at 2| may be introduced into the portion II as shown. The portion ll. may be of such dimensions as to rather closely fit the end of the tap-ofl conductor or may if desired be more closely fitted as by the use of a simple cylindrical adaptor.

The assembly is now ready to be subjected to compression for permanently fixing. the parts in place with the cables therein. For this purpose suitable connector presses of types heretofore known may be used. Such presses may be operated hydraulically, mechanically, or by an explosive discharge. One example of such a press is described and illustrated in an article of which the applicant is a joint author, published in the the portion III at the side opposite from the portion II is formed with "Electrical World" for January 15, 1938, page 128 (258). The portions of such a press which come into immediate contact with the connectors of this invention are shownin Fig. 3 as comprising a lower jaw member 22 for engaging the connector portion II, and a depressible plunger 23 having a protuberance as at 24 for engaging the upper surface of the connector portion II.

It will be noted that the lowerjaw 22 is so. shaped that when pressure is applied, the side edges of the member i8 will be tilted upwardly slightly or in other words, the portion IE will be given a curvature tending to conform somewhat with the curvature of the band portion ill and of the cable therein. In this way the channel portions l1 and 18 on member It will be brought more closely together, thus forcing the channel portions i4 and II more closely together or into contact, whereby the cable Ills gripped in a powerful embrace by the band ill. Meanwhile the protuberance 24 on the depressible plunger will permanently deform the connector portion II at its middle section, into the shape shown in Fig. 3, at the same time deforming the shape of the tap-off cable 2! therein in such a way as to interlock the connector portion II with the tapoif cable and to also hold the latter in a powerful embrace, insuring permanent good contact. The downward pressure may also deform the main cable I! into a somewhat elliptical shape as shown, which will better insure good and firm contact, but without danger of injuring the cable.

The upper surface of the connector portion H may be initially formed with a slight depression as at 25 if desired for receiving and properly centering the protuberance 24 of the press plunger. .After the pressure is applied, the upper surface of connector portion II will have a deep central depression, for example, such as at 26 (Figs. 4 and 5), penetrating into the tap-oil. cable sum ciently to amply secure the tap-oil against ever being pulled out of the connector.

The alternative embodiment of the invention shown in Fig. 6 may be similar to that above described, except that the upper portion ll, instead of being formed of sheet metal, may comprise a section of tubing or a section of a rod drilled with a central aperture as .at 21 for receiving the tap-oi! conductor. This member I! may be suitably milled as at 28 to properly fit the member ll at the area where the two are soldered together. Also the upper surface of the member ll may be milled or otherwise formed with a groove as at 25" corresponding in function to the groove 28 above described. The construction of Fig. 6 may be found more inexpensive and convenient in cases where it is desired to secure a relatively small tap-oi! wire to a considerably larger main cable. In respects other than above described, the embodiment of Fig. 6 may be constructed and used in a manner similar to the connector 'of Fig. 1. I

In addition to the advantages of this invention as hereinabove noted, it may be pointed out that the construction being such that the two cables are separately embraced, in the device as finally fixed in position, each cable is wholly encircled by a separate band without any possibility. of any appreciable spaces between the bands and the cables which would permit expansion and contraction of the cables and loosening of" the bands, and consequent impairment of the conductivity of the connection. Thus the difllculties heretofore encountered in attempting to embrace two cables within a single or mechanical strains. It is apparent further that by a single compression operation in a sim- Ple type of compressor, the device may be quickly and permanently fixed in position without interrupting themain power supply. That is, the two portions of. the device are particularly adapted to be compressed simultaneously by a single operation or the press. The deformation of the parts and of the cables in rubbing contact with each other during the compression, insures satisfactory andpermanent electrical conductivity between the two without the use of solder or the like. Hence, the device may be readily installed in place: under ground where the use of solder pots and flames are dangerous, inconvenient and troublesome. Also the device when constructed without solder may be used in places where there is danger of the temperature being too'hlgh to permit safe use of solder. For outdoor or overhead power line work the invention provides a connector of improved, compact appearance which will withstand any weather conditions .without injury.

While the invention has been described in detall with respect to particular preferred examples, it will be understood by those skilled in the art after understanding the invention, that various changes and further modifications may be made without departing from the spirit and scope of the invention, and it is intended therefore in the appended claims to cover all such changes and modifications.

What is claimed as new and desired to be secured by Letters Patent is:

1. A compression type tap-oil connector for electrically connecting a main cable without severing same, to a branch wire, comprising a band of sheet-like metal for embracing the main cable, said band initially having an opening on one side to permit its application to the cable. a member adapted to interconnect the edges of the band at said opening after application of the band to the cable, said member being constructed. and arranged to then be permanently deformed by compression inwardly of the cable and to thereby tighten the band on the cable. and compressible means fixed on said band at the area opposite from said opening for encircling the branch wire and also so constructed and arranged that said means and said band may be simultaneously fixed to the branch wire and cable respectively by compression inwarcli of the assembly.

2. An electric cable tap-oil connector appli-- cable without severing the main cable, comprising a pair of generally cylindrical portions secured together in side-by-side relationship, one of said portions being constructed and arranged for permanent deformation under compression in a direction toward the outer member to embrace and firmly grip the tap-ofi wire, the other of said portions having a longitudinal opening along its side opposite from said first named portion to permit application to the main cable, and a slidably applicable member for closing said opening, said member being constructed and arranged for permanent deformation under simultaneous compression in the opposite direction to tighten said other portion on the main cable.

3. in combination with a main cable, means for securingthereto a branch wire or .the like, including a band oi sheet-like metal embracing the cable, said band being parted along a longitudinally extending line, allowing its application to the cable without cutting the latter, the edges or the band being formed along said line with outwardly and oppositely directed channels, a member covering the parting line and having two opposite edges formed with inwardly directed channels within which said edges of the band are received, said member being permanently detormed under pressure in directions curving same toward conformity with the curvature of the band as embracing the cable, whereby said outwardly directed channels, due to the deforming curvature of said member, are brought sumciently close together to cause the band to tightly grip the cable, and whereby the channel portions of the band and member are tightly nested together and against the band.

4. In combination with a main cable normally of generally circular cross section, means for securing thereto a. branch wire or the like, including a band of sheet-like metal tightly embracing the cable, said band being parted along a longitudinally extending line, allowing its application to the cable without cutting the latter, the edges of the band being formed along said line with outwardly and oppositely directed channels, a member covering the parting line and having two opposite edges formed with inwardly directed channels within which said edges of the band are received, said member being permanently deformed under pressure in directions curving same toward conformity with the curvature of the band as embracing the cable, and the portion of the cable within said band being somewhat deformed to a generally oval cross-section.

5. In combination with a main cable, means for securing thereto a branch wire or the like, including a band of sheet-like metal embracing the cable, said band being parted along a longitudinally extending line, allowing its application to the cable without cutting the latter, the edges of the band being formed along said line with outwardly and oppositely directed channels, a member covering the parting line and having two opposite edges formed with inwardly directed channels within which said edges of the band are received and held sufiiciently close together to cause the band to tightly grip the cable, the channel portions oi the band and member being tightly nested together and against the band, and another member encircling the branch wire andfixed to said band at a position opposite from said line, the latter member having an area deformed into a correspondingly depressed portion of the branch wire at a position on said latter member opposite from said band.

CHARLES N. METCALF.

. CERTIFIQATE 0F CORRECTIOR. Patent No. 2,229,758. Jaguary 23; 191 1.

CHARLES, R. HETCALF.

It is hez 'eby certified that err-er appears in the printed spe 'ciiicatiozi of the above numbered patent requiring corretienas followe Page}; first column, line 65, claim 2, forthe word "gfulterrfiv freed ,--.6the1" and that 'the- Y said Letters Patent eholuld be readwith' thie cerrection therein that the same may-conform to the record or the cage inthePatent office. Signed and sealed mu ht}: day efN rch,"A. 1231941.;

, Henry Van Aradele, (Seal) Actingflommiaaioner-or Patents.

. CERTIFICATE OF CORRECTION.. Patent NQ. 252293-58.-

- M Jepuar'y 23,19L;1. N METdALF. e

It is hereby certified that error appears izrthe printed spe'e'ificat1ozi of the above numbered patent requiring cOIitiOlLEs followe; Pagej first column, -11ne 65, claim 2', for the wdrd "ehter'lfre d. --bther and that the- 381d Letters Patent ehd uld p read'with'thiecerrgctibmtherein that the same may-conform to the record or the case lathe-Patent office.

Signefi and sealed this hen day of-H rch,'"'A. n."19h1 I Henry Van Areda le; (Seal) .7 Actingcomnlsaioneror Patents.

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