US 3109051 A
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Description (OCR text may contain errors)
Fi 1ed Sept. 21. 1961 United States Patent Filed Sept. 21, 1961, Ser. No. 139,654 6 Claims. (Cl. 174-87) This invention relates to connectors for electric wires of the type wherein an insulating cap is utilized to twist together the ends of the wires to assure a good electrical connection between them and also to provide a cover and insulation for the twisted wires.
Heretofore there have been many proposed structures for twisting together a plurality of conductors, a common arrangement being the provision of a spring of generally conical shape disposed within a conical opening of an insulating cap. Moreover, such caps can become dislodged thus to defeat the purpose of the insulation provided by the cap utilized to twist the wires together.
In carrying out the present invention, in one form thereof, an insulating cap is provided with a locking ele ment through which a plurality of bare conductors may protrude as through openings or narrow slots or on opposite sides of a locking bar. The cap is provided with closely spaced parallel surfaces to receive therebetween the extending ends of the bare conductors. By holding the conductors stationary and twisting the cap, the conductors are twisted together to establish a strong low-resistance connection between them and at the same time to prevent removal of the cap by any endwise force applied thereto. In the twisting of the wires, they form a locking engagement with the locking element to maintain thecap securely in place. i
For a more complete description of the invention and for illustrations of several modifications thereof, reference is to 'be had to the following description taken in conjunction with the accompanying drawings, in which:
is an exploded perspective view partly in section illustrating a prefenred form of the invention;
'FIG'rZ" is a vertical sectional View of the wire connector of FIG. 1 and illustrating three conductors twisted together; and
FIGS. 3, 4 and 5 illustrate in perspective alternative forms of the locking element to be utilized in the arrangement of FIGS. 1 and 2.
Referring now to the drawing, the wire connector of FIGS. 1 and 2 comprises three parts. First, an insulating and twisting cap 11 has a reentrant portion forming a locking recess 11a of diameter slightly larger than that of a washer-shaped disc forming a locking element 12. The locking element 12, disposed wholly within the cap 11, is held in place in recess lla by a lower member 13 of cylindrical form and having an inwardly extending circular ledge 14 so as to form with the cap 11 the recess 11a between the opposing walls extending from the inner surface of the cap and within which recess the'locking element may freely rotate. The lower member 13 is bonded to the lower face 11b as by an adhesive or plastic-solvent throughout the bonding area 110. Solvents and cements for plastic materials are well known to those skilled in the art, and the particular solvent or cement utilized will be selected in accordance with the insulating material utilized for the several parts 11 and 13.
With the wire connector 10 assembled as illustrated in FIG. 2, the bared ends of conductors '18, 19 and 20 are threaded through elongated slots 12a and 12b of the locking element 12 and upwardly and into the cap 11. This cap has two closely spaced surfaces disposed parallel to each other, one of them, the surface 11d, being shown in FIG. 1, and both surfaces 11d and 112 being shown in FIG. 2. Inasmuch as the surfaces are closely spaced, it will be seen that by grasping the three conductors 1-8,
3,139,05 l Patented Oct. 29, 1963 2 19 and 20 and turning the twisting cap 11 (the locking element or disc 12. then being stationary), the bared ends of the conductors will be forcibly twisted together.
Since the narrow rectangular-shaped recess 11g formed by the closely spaced surfaces 11d and 111s restrains the end portions of the bared conductors 18-20, the twisting of the wire is localized in the enlarged twisting chamber 11h formed in the base portion of the cap 11. Thus, as the twisted end forms, the ends of the wires descend, because the end portions are being shortened to formthe twist. The ends eventually occupy the position shown in FIG. 2. In this position, it will be noted that two of the wires extend through the elongated slot 12a of locking element 12 and one extends through the elongated opening 12b of that element. Thus as these three wires are twisted together, they formla mechanical interlock with the dividing structure 12c between the two openings, and as a result the cap '11 may not be withdrawn from the twisted ends. In this connection, it will be remembered that the locking element 12 is escurely held within the cap 11 by the ledge 0r flange 14 of the lower member 13, though rotatable relative thereto.
The dimensioning of the rectangular slot or passage between the two walls 11d and 11a will be in accordance with the diameters of the wires to be twisted together. Some play can be tolerated, and thus a single cap can accommodate wires of a plurality of sizes. However, wires which are not forcibly twisted together because too small for a given spacing will require a smaller cap with a smaller spacing, and wires which cannot protrude into the space between the surfaces 11d and 11a will require a larger cap with a larger spacing.
It is to be observed that the lower member 13 extends downwardly a considerable distance from the ledge or flange 14, thus to provide a skirt or insulating cover of reasonable length for the portions of the insulated conductors 1820 adjacent their bared ends.
Further in accordance with the invention, the cap 11 provides a solderless and tapeless electrical connection having a plurality of turns, thus assuring high currentcarrying capacity, low resistance, and the mechanical interlocking of the wires with the insulating cap.
Now that the principles of the invention havebeen explained, it will be understood that variations may be made within the scope of the appended claims. For example, the locking element or disc 121 of FIG. 3 may be provided with a plurality of openings 12w through which may extend a bared end of each conductor to be joined together within the insulating cap 11. The cap functions as before to twist the ends of the wires together.
The twisted ends of the wires in conjunction with the interconnecting structure between the openings in the locking element 12! form the mechanical interlock which secures the cap in place onthe conductors and prevents dislodgement and withdrawal therefrom.
Though the locking element 12 of FIG. 1 may be preferred, with FIG. 3 a first alternative, nevertheless a simpler form of locking element Me, as shown in FIG. 4, may be utilized. This locking element comprises interlocldng structure 12111 which may be a rod, round, square or rectangular, having arcuate end portions 12p and 12:
adapted to nest within a locking recess 11a as described above in connection with FIGS. 1 and 2. By reason of the structure of FIG. 4, the cap 11 may be molded as a single unit including an inwardly extending shoulder or ledge 14 disposed below a space adapted to receive the arcuate portions 12p and 124 By utilizing material for the locking element 12c which is somewhat elastic, it can be sprung into place behind the ledge. In this connection, the locking element lie (and the other locking elements of this invention) need not be of insulating material and, hence, can be made of a resilient or elastic conductors.
metal, preferably a material compatible with that of the Copper and its alloys will be used for copper conductors and aluminum alloys for aluminum conductors.
As illustrated in FIG. 5, the locking element may include a centrally disposed slot 121- through which the conductors can extend, this slot being provided in a narrow rectangular locking element 12g having arcuate ends 12h. As descn'bed in connection with the element 12:: of FIG. 4, the element 12g may be sprung into place by bowing it into the arcuate form illustrated by the broken lines 12 to clear the ledge or flange 14. Where a slot 12r is utilized, the mechanical interlocking comes about by reason of the enlarged space occupied by the twisted ends of the conductors which, as clearly shown in FIG. 2, will greatly exceed the width of the slot and thus will prevent withdrawal of the insulating cap 11 from the twisted ends of the conductors.
Summarizing, the wire connector of the present invention provides for positive twisting together of a plurality of conductors to form low-resistance electrical connections between them, andat the same time locks in place an insulating cap. The tapeless and solderless joint provides a high quality electrical connection immune to vibration and shock and of maximum safety from the insulation standpoint even for high voltage connections.
What is claimed is:
1. An electrical Wire connector for bared ends of insulated conductors comprising a unitary cap of insulating material having a closed end and an open end, said cap near its open end having on the inner surface thereof opposing walls forming therebtween a circumferential recess, a locking element wholly within said cap and having at least a substantial portion of its periphery disposed between said spaced Walls for preventing dislodgement of said element axially of said cap and being freely rotatable relative to said cap, said cap at its closed end having closely spaced surfaces for receiving said bared 'ends of said conductors When inserted therein through said open end of said cap, said locking element being engaged by the portions of said bared ends adjacent the insulated portions of said conductors and thereby adapted to be held stationary during rotation of said cap to twist together said bared ends to form a low resistance connection therebetween, said locking element having at least a portion thereof extending across said open end and en- 'gageable' by the twisted endsof said conductors for securing said cap to and over said twisted ends and for preventing dislodgement therefrom.
2. The wire connector of claim 1 in which said portion extending across said open end lies along a diameter thereof and on each side of which there is provided an elongated opening through which said bared ends of said insulated conductors may extend.
3. The Wire connector of claim 1 in which said locking element is in the form or" a circular disc having a plurality of openings throughwhich said bared ends of said conductors may extend.
4. The wire connector of claim 1 in which said locking element includes a narrow slot of slightly larger width than the diameter of the bared ends to be inserted through them and into said cap.
5. An electrical Wire'connector for bared ends of in sulated conductors comprising an insulating cap having a closed end and an open end, said cap having a recess located inwardly of an outer ledge, a locking element of resilient material which can be bent to shorten its length for snapping it into place behind said ledge, said recess and ledge with said element snapped into place providing a relatively rotatable mounting for said locking element with respect to said cap, said locking element having portions engageable by said conductors after being twisted together to prevent removalof said cap from said conductors, and said cap having closely spaced surfaces engaging said bared ends of said conductors for twisting them together thereby to form a low resistance connection therebetween and with the twisted ends forming a locking means with said structure for holding said cap in place over said twisted ends of said conductors.
6. An electrical wire connector for bared ends of in sulated conductors comprising an insulating cap having a reentrant portion and a bottom portion including an inwardly extending ledge to form With said reentrant portion a recess of circular shape, a locking element disposed Within said recess, said bottom portion being bonded to said cap for establishment for said locking member of a relatively rotatable mounting relative to said cap, said locking element having portions engageable by said conductors after being twisted together to prevent'removal of said cap from said conductors, and
said cap having closely spaced surfaces engaging saidbared ends ofsaid conductors for twisting them together thereby to form a low resistance connection therebetween and with the twisted ends forming a locking means with said structure for holding said cap in place over said twisted ends of said conductors.
References Cited in the file of this patent UNITED STATES PATENTS