US3388370A - Solderless connector for insulated wires - Google Patents

Description

June 11, 1968 R. A. ELM 3,388,370

, SOLDERLESS CONNECTOR FOR INSULATED WIRES I Filed April 14, 1966 I NVEN TOR.

BY FOBERf/Q ELM United States Patent 3,388,370 SOLDERLESS CONNECTOR FOR INSULATED WIRES Robert A. Elm, St. Paul, Minn, assignor to Minnesota Mining and Manufacturing Company, St. Paul, Minn, a corporation of Delaware Filed Apr. 14, 1966, Ser. No. 542,514 7 Claims. (Cl. 339-98) ABSTRACT OF THE DISCLOSURE A solderless wire-connector contains a slotted resilient metal connector plate slidably retained in a grooved insulating body having a folding self-locking cover unitary therewith.

This invention relates to wire-connectors and, in one important aspect, to insulated connectors for making solderless connection between parallel small insulated wires. Wire-connectors of the type described have particular utility in low voltage wiring, for example in the installation of additional or replacement wiring in automobiles, Where speed of application, complete insulation, and permanency of conductive contact under prolonged vibration are important requisites.

Solderless connectors for insulated small wires have heretofore been described, for example in US. 3,012,219, wherewith permanent positive contact is obtained by sliding a grooved resilient contact member into a receptive slotted wire-supporting base and over one or more insulated wires supported thereon. The contact member may be provided with an insulating cap which is ridged for positioning and retention within an insulating base.

The present invention likewise relies on a grooved resilient contact member slidably insertable within a wiresupporting base, but distinguishes over prior art conductors in a number of important respects. The contact member may be pressed into position with but moderate effort, to form a permanent conductive contact, with no possibility of injury to the insulating cap. The insulating body and cap are combined in a single unit; any possibility of improper assembly of the connector is thereby eliminated. In a preferred modification, one or all of the wires to be connected may be inserted from the side of the connector, so that X- and T-splices can be made as well as terminal or pigtail splices.

These and other advantages are attained by providing a hard but resilient insulating base which is preferably longitudinally recessed and openable along one longitudinal edge to accept and support a plurality of parallel insulated wires and is transversely slotted to accept and retain a flat slotted contact plate, and, integral therewith, a snapcover member for covering a said plate in contacting position and for retentively enclosing the wires within the said insulating base.

The principles of the invention will now be further described and illustrated by reference to the accompanying drawing and wherein FIGURE 1 is a view in perspective of a presently preferred form of wire-connector in readiness for use,

FIGURE 2 is a transverse cross-section of a portion of the wire-connector taken along line 2--2 of FIGURE 1 and after application to a pair of insulated wires.

FIGURE 3 is an end plan view of the base and cover member of the connector of FIGURE 1 in fully closed position and with the interconnected enclosed pair of wires indicated in cross-section,

FIGURE 4 is a view in perspective of an alternative base and cover member, and

FIGURE 5 is a somewhat schematic view in perspective of another alternative form of connector.

3,388,370 Patented June 11, 1968 ICC The wire-connector illustrated in FIGURES 1-3 is designed for use in connecting a pair of wires, as in connecting two parallel wires in a T-splice or X-splice. It will be appreciated that the same principles may equally well be applied to connectors for three or more wires, although two-wire connectors are of most significance commercially.

The wire-connector 10 of FIGURE 1 will be seen to consist of a slotted resilient flat metal insert or contact member 11 and an insulating base member 12 comprising a central body section 13, two opposed end sections 14, 15 and a cover 16. The base 12 is provided with longitudinal interconnected circularly cross-sectioned wireaccepting recesses or channels 17, 18 to which access may be obtained through either end or through a longitudinal edge slot or opening 19. The body 13 is transverse ly slotted at 20, the slot being extended into the lower half of the body as indicated in FIGURE 2 to provide space for entry of the three wire-contacting lobes 21, 22, 23 of the contact member 11. Lobes 21 and 23 are shown partly cut away to reveal further structural detail. Projections 24, 25 extend across the thickness of the slot 20 and serve as additional support for wires inserted within the connector body, a pair of wires being shown in crosssection in FIGURE 2 as consisting of metallic conductors 26, 27 and insulating plastic coverings 28, 29. The connector is effective with both solid and stranded conductors.

The base 12 is further longitudinally internally grooved at a location opposite the opening 19, the shallow groove 30 being provided to permit flexing of the edge wall of the base in the manner of a hinge, prior to or during insertion of wires through the opening 19 and thence into the wire-accepting channels 17 and 18. The hinge strucare permits substantial reduction in the thickness of the slot 19 since the two halves may be, pried apart to any degree required for introduction of wires.

The cover 16 is attached to the upper side edge of the body 13 along a flexible hinge area 31 of reduced thickness. The cover includes a flat top wall 32, flat side wall 33, and inturnod edge hook member 34. A cooperating hook member is provided along the lower segment of the body 13 at the opening 19.

The combination of the hinge formed at the groove 30- and the hook elements 34 and 35 provide an important feature of the invention by making possible initial opening of the connector body to permit wires to be laid in place without difficulty and then, after electrical connection has been established, providing for the permanent and secure enclosure of the entire connection.

The adjacent side edges of the resiliently connected lobes 21, 22, 23 of the contact element 11 are generally parallel, and the rounded end edges are smoothly divergent, providing wire-accepting openings and strong electrically conductive resiliently loaded contact surfaces for wires onto which the element is forced. The element 11 is tightly held within the narrow slot 20 so that it is permanently retained in place, but can be forced further into the slot and over the inserted wires by means of ordinary pliers or side-cutters. Once fully inserted, it is protected and insulated by folding the cover 16 into the closed position, with the hook 34 engaging the book 35 and thereby preventing any accidental subsequent separation of the upper and lower segments of the base 12 and exposure of the connection.

In a typical connector designed for connecting two plastic coated solid or stranded No. l4, 16 or 18 gauge copper wires, the connector element 11 is inch wide and A inch deep and is made of phosphor bronze sheet of ,1 inch thickness. The base 12 is inch in length, the body 13 being /2 inch and each end section an inch. The connector in closed position as shown in FIGURE 3 has a width of /2 inch and a thickness of inch. The wire- receiving channels 17, 18 are each A; inch in diameter. The insulating base is constructed in one piece of polypropylene and is most conveniently produced by injection molding. Other suitable materials for the base include nylon and polycarbonate, both of which are hard and tough polymeric material with sufiicient flexibility to permit hinge bending. Hardened copper, brass, Phosphor bronze and plated steel are all suit-able as materials for the contact member.

In the alternative structure shown in FIGURE 4 the cover 36 is provided with additional raised edge closure members 37, 38 as extensions of a hook member 39 and the fiat upper free portion of the body 40, as well as the hook member 45, is shortened to accommodate these members, thus providing a more rigid structure and more completely sealed enclosure for the contact member, not shown, when inserted in slot 41. In addition, only the outer wire-receiving channel 42 is fully open, the inner channel 43 being closed at one end by a closure tab 44 which further protects the free end of a wire introduced into said inner channel from the opposite end. If desired, the outer channel may be similarly closed at one end, the fiexure groove 48 and edge opening 49 then becoming unnecessary since both wires must be introduced from the open end of the appropriate channel.

Connectors such as illustrated in FIGURES l-3 are particularly useful in splicing together a pair of wires in a line or X-splice, whereas connectors having features shown in connection with FIGURE 4 are preferred for T-splices or, where both of the wire-receiving channels are closed at one end, for pigtail or terminal splices. In other modifications the connector may include channels for one, two, three or even more wires or wire-ends, with appropriate numbers of contact plates for connecting the wires in any desired sequence. For example, two wires may be connected with a single wire by means of two separate doubly slotted contact plates or alter natively with a single triply slotted contact plate. Another modification employs a singly slotted plate which in addi tion is provided with a spring socket or other non-permanent connector element fitting within an open-top channel and with which contact is made by a suitable plug. The structure is indicated in perspective and in exploded view in FIGURE 5. The contact element 50 includes a pair of contact legs fitting within a narrow slot 51 for making contact with a wire in the outer channel 52, and a spring contact clip 53 fitting within an open trough 54 and thereafter in position for receiving a plug connector 55 inserted endwise into the inner channel 56. The cover encloses the connector element after insertion and aids in retaining the wire within the channel 52, whereas the plug 55 may be inserted and withdrawn as desired.

What is claimed is as follows:

1. A solderless wire-connector comprising, in combination: a hard tough insulative body member channeled to provide at least two parallel wire-receiving and wiresupporting channels and slotted transversely of said channels to provide a thin slot extending from a flat surface of said body member across and perpendicular to said channels; a thin flat resilient conductive contact member of substantially the same thickness as said slot, slidably retained and fully insertable within said slot and slotted in line with at least one of said channels to provide resiliently connected first and second contact lobes having generally parallel contact surfaces for making resiliently loaded electrically conductive contact with a wire supported in said one of said channels; and a folding cover member, unitary with and extending directly from said body member along one edge, having a flat segment for positioning over said flat surface and over the exposed edge of a said contact member inserted within said slot, and an adjacent edge segment for positioning over a first side of said body member adjacent said flat surface, said edge segment and said body member being provided with cooperating locking means for holding said cover member tightly against said body member, said body being slotted along its entire length between said channels and between the outermost channel and the said first side to provide access from said first side to each of said channels.

2. The solderless wire-connector of claim 1 wherein said body member contains two wire-receiving channels, one of said channels being enlarged axially from said slot to provide a widened trough-like opening extending to said flat surface, and wherein said contact member comprises a single pair of contact lobes defining an open-neended wire-receiving slot in alignment with the other of said two channels and a spring clip contact element fitting within said trough for alignment with the said one channel.

3. The solderless wire-connector of claim 1 wherein said body is hinged at a line extending along the side opposite said first side and alongside the innermost channel and wherein said edge segment is of sufficient length to extend across the longitudinal access slot in said first side.

4. The solderless wire-connector of claim 3 wherein said contact member is slotted in line with each of said channels.

5. The solderless wire-connector of claim 3 wherein the body member includes, for at least one of said wirereceiving channels, a closure tab for closing an end of the channel.

6. An integral insulating member for a wire-connector, comprising a body portion and a cover portion; said body portion having generally rectangular upper and lower segments hingedly connected along one side and being oppositely doubly channeled along adjacent inner surfaces and parallel to said side to provide two parallel wire-receiving and wire-supporting channels in said body; said upper segment being slotted perpendicularly to said one side and to said channels to provide a thin open slot, and said lower segment being correspondingly slotted to provide a thin slot in line with said open slot and extending past said channels but short of the bottom surface of said lower segment, and including a hook member extending along the edge of said lower segment opposite the body hinge side; said cover portion being hingedly connected with said upper body segment adjacent the body hinge and comprising a face plate for covering the slotted upper surface of said upper body segment, an edge plate extending from and at an angle to said face plate for covering the edge of said body portion opposite the hinged edge, and an edge hook member along the terminal edge of said edge plate for interlocking with the hook member of said lower segment.

7. The method of making and insulating a solderless connection between two insulated wires, using a wireconnector having a hard tough insulative body member channeled to provide interconnected parallel longitudinal open-ended wire-receiving and wire-supporting channels open to one side of said body and slotted to provide a thin slot extending from an upper face across and perpendicular to said channels, and recessed along the lower edge of said one side to provide a hook-like projection, a cover member hingedly united with said body member near the edge of said face opposite said projection and including a face plate for covering said face, an edge plate for covering said one side, and an edge hook for interlocking with said projection, and further having a metal contact member slidably retained and fully insertable within said slot for making resiliently loaded electrically conductive contact with insulated wire supported within said channels; said method comprising: spreading apart the upper and lower segments of said channeled body member from said one side to expose the opposed inner surfaces defining said channels; inserting a wire into each said channel and bringing together said body segments about said wires; forcing said contact member into said slot and onto said Wires to make resiliently loaded contact therewith; and folding said cover over said upper face and said one side, and interlocking said edge hook with said projection.

References Cited UNITED STATES PATENTS 6 3,118,715 1/1964 POtl'llCh 339--98 3,202,957 8/1965 Leach 339-98 FOREIGN PATENTS 5 509,482 3/1952 Belgium.

699,856 11/1953 Great Britain.

MARVIN A. CHAMPION, Primary Examiner.

10 J. H. MCGLYNN, Assistant Examiner.

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