US2820843A - Cross connector for electrical conductors - Google Patents

Description

Jan. 21, 1958 E. H. DREHER CROSS CONNECTOR FOR ELECTRICAL CONDUCTORS Filed March 29', 1955 2 Sheets-Sheet 1 FIGS FIG.6

INVENTOR ELMER H. DREHER own}, ,5 ATTORNEYS Jan. 21, 1958 E. H. DREHER 2,820,843

CROSS CONNECTOR [FOR ELECTRICAL CONDUCTORS Filed March 29, 1955 2 Sheets-Sheet 2 FIG l2 INVENTOR ELM ER H. DREHER cazm ATTORNEYS CROSS CONNECTOR FOR ELECTRICAL CONDUCTORS Elmer H. Dreher, South Norwallr, Conn., assignor to Sperry Rand Corporation, a corporation of Delaware Application March 29, 1955, Serial No. 497,698

1 Claim. (Cl. 174-87) This invention relates broadly to electrical connectors and more particularly to an improved connector of the conductor overlying the bared cross wire and lying in a solderless type for use in electrically connecting crossed conductors.

In the commercial manufacture of electrical apparatus having complicated wiring circuits, such as the chassis components of electronic computers and the like where a large number of elements such as tube sockets are connected to a common conductor through short wires, it becomes necessary to electrically connect these short wires to the common conductor. The joining of a bare cross wire to an insulated wire has heretofore generally been accomplished by connecting the cross wire, sometimes referred to as a pigtail, to a common wire through a series of soldering operations and by threading short sections of an insulation sleeve or tube, commonly referred to as spaghetti, upon the common Wire between each soldered joint at the junction of the cross and common wires. This method of joining large numbers of wires, disposed substantially at right angles to one another, is not only a slow and tedious operation but in addition is an expensive procedure.

The present invention contemplates the provision of a simple, practical and inexpensive electrical connector which has been especially designed for quickly connect ing a number of discrete cross wires or pigtails to a common wire or conductor by crimping or pressure forming the connector onto the wires in such a manner as to cause pressure separation of the insulation on one or both of the wires to effectively and positively insure and maintain an excellent electrical contact at the junction point of the wires. The term pressure separation as used herein is intended to mean forcefully rupturing the insulation on the wires at their junction points by crimping or externally applying pressure to the connector.

More specifically, the present invention contemplates the provision of a new and improved connector for crossed 1' ii cross wire against pull out and in firm electrical contact with the connector ferrule and common conductor.

Still another object of the invention is to provide the body or ferrule portion of the connector with one or more insulation piercing prongs or barbs for further insuring good electrical contact between the body or ferrule of the connector and the common or main insulated wire.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings wherein:

Fig. 1 is a perspective view of an electrical connector embodying features of the present invention, the connector having a bared cross wire inserted through transverse openings in the connector ferrule and an insulated trough extending longitudinally of the ferrule preparatory to crimping or pressure forming the ferrule to final shape;

Fig. 2 is a perspective view of Fig. 1 after the ferrule has been pressed or crimped to its final shape.

Fig. 3 is an enlarged transverse sectional view of the connector assembly of Fig. 2 substantially along the line 3-3 of Fig. 2.

Fig. 4 is an enlarged side elevational view of the connector assembly of Fig. 2 partly in longitudinal vertical section at the junction points of the crossed wires or electrical conductors.

Fig. 5 is a plan view of the blank used in forming the connector of Fig. 2.

Fig. 6 is a perspective view of the blank of Fig. 5 after being shaped to receive the cross wires or conductors to be electrically connected to one another.

Fig. 7 is a fragmentary plan view of an electrical device illustrating a plurality of tube sockets the wiring circuits of which include crossed wires joined bythe present invention.

Fig. 8 is an isometric view similar to Fig. 6 of a modified connector.

Fig. 9 is a cross section of the connector shown in Fig. 8 after it has been crimped or pressure formed onto a pair of cross conductors or wires.

Fig. 10 is a top plan view of a strip of connectors joined end to end to illustrate their formation by conventional progressive punching and forming dies.

Figll is an enlarged cross section of the assembly shown in Fig. 1. before the connector is'crirnped upon the crossed wires, and I i Fig. 12 is a cross section similar to Fig. 11 with the connector partially crimped' upon the crossed wires and before it is pressed to the final shape shown in Fig. 3.

In the embodiment of the invention shown in Figs. 1 to 6 the improved connector, for electrically connecting a pair of crossed wires or wires disposed substantially at right angles relative to one another without the use of solder, is preferably stamped from sheet-metal such as beryllium, brass, annealed copper or like conductive metals of equal hardness to form a flat blank, indicated by reference numeral id in Fig. 5 by the use of any conventional and Well known progressive punching and forming dies (not shown). Theblanks 10 may be stamped separately or they may be joined end to end in a continuous strip by short lands 11?; formed by punching transversely opposednotches 13 at spaced intervals along the edge of strip or roll stock sheet-metal 11 as clearly illustrated in Fig. 10.

Following the punching of thenotches 13 in the sheetmetal stripll, to define discreterectangular blanks 10, each blank is then subsequently provided with a pair of transverselyopposed apertures 14 intermediate its ends, with a pair of short fingers ortabs 15 adjacent the apertures 14- and with a pair of pointed insulation piercing prongs or barbs M as clearly shown in Figs. 5 and 10 for reasons presently made clear. I ,7

Upon providing each blank 10 withapertures 14, tabs l5, andinsulation piercing prongs 16, itslongitudinal sides 19 are then rolled or folded upwardly in paralleled relation with respect to one another by suitable forming dies to form the blank into a substantially U-shaped cross section providing a longitudinal trough B as shown in Figs. 6 and 10. The connector A shown in Fig. 6 or strips of connectors A joined end to end by thelands 12 as shown in Fig. 10, constitutes an article of manufacture which can be sold, shipped, or stored as such until they are used for electrically connecting cross wires in a manner hereinafter described.

Use of the connector A for electrically connecting a e .J ntz ti ss.

bare cross wire orpigtail 17 to an insulated wire orconduct'or 18 will now be described with particular attention directed to Figs. 1 to 4 and to 12. As shown in Figs. 1 and 11 thebared cross Wire 17 is first inserted into and through theapertures 14 of conductor A so as to rest upon the short outwardly projecting fingers ortabs 15. The insulated conductor orwire 18 is then laid in the longitudinally extending trough B of the connector so as to overlie thecross Wire 17 and insulation piercing prongs orbarbs 16 as best shown in Fig. 11. With thecrossed wires 17 and 18 positioned within connector A as shown in Fig. 11 external pressure is then applied to the exterior of the connector, by a suitable hand or power operated crimping or forming tool not shown, to cause theparallel wall sections 19 of the connector to be curled or rolled inwardly around theinsulated conductor 18 as shown in Fig. 12. This application of external pressure upon theconnectorforces conductor 18 downwardly within the trough B and drives thepointed prongs 16 upwardly through theinsulation 20 ofconductor 18 into electrical contact with the strands of wire that form thecore 21 of theinsulated conductor 18. As this downward pressure is applied to theconductor 18 during the rolling or curling of thesections 19 thebare cross connector 17 is forced toward thecore 21 ofconductor 18, with sufiicient pressure to cause pressure separation of theinsulation 20 as the conductors are forced into contact with one another. At the same time thewalls 19 of connector A are being bent or rolled around the exterior ofinsulated conductor 18, by suitable hand or power operated crimping or forming tools not shown, to drive theconductor 18 downwardly within trough B as above described, the tabs or fingers are bent upwardly against thecross wire 17 as shown in Fig. 12. This upward bending of thetabs 15 contributes to the forcing ofwire 17 through the insulation ofconductor 18 and causes the ends of the tabs to bite intoconductor 17 to effectively insure good electrical contact between theconductor 17 and the connector A. When theparallel wall sections 19 are fully crimped or formed around theconductor 18, andtabs 15 have been bent into contact with thecross wire 17, as shown in the sectional view of Fig.3,wire 17 has been driven through theinsulation 20 to bring it into electrical contact with the strandedcore 21 of saidconductor 18.

It has been found from actual use of these electrical connectors thatcross wire 17 is inclined to become slightly flattened or elliptical in cross section at the point of contact with the stranded core 21 (Fig. 4) through the external pressure applied to the connector A andtabs 15 during the crimping or forming operation of the connector onto the cross wires. An advantage of the construction just described is the extraordinarily high electrical contact that is formed between thewires 17 and 18 and the connector A without the necessity of removing any of theinsulation 20 from themain conductor 18 or performing any soldering operations. Moreover the gripping action of the short tabs orfingers 15 effectively prevents pull out of thecross wire 17 and their closure against thewire 17, in opposition to the curling of thewall sections 19, aids in pressure separation of theinsulation 20 to bring thecross wire 17 into good electrical contact with the stranded orsolid core 21 of thecommon conductor 18.

In an alternative form of the invention, as shown in Figs. 8 and 9, electrical contact between thecross wire 117 andsolid core 121 ofconductor 118 is established entirely through pressure separation of theinsulation 120 around theconductor 118. Thecross wire 117 andcore 121 of themain conductor 118 are forced into electrical contact with one another within theconnector 110 and use of thepointed prongs orbarbs 16 as previously described in connection with Figs. 5 and 6 is dispensed with.

By applying sufficient external pressure to theconnector 10 of Fig. 6 or theconnector 110 of Fig. 8, pressure separation-of the insulation has a tendency to displace a small portion of theinsulation 20 or 120 upwardly between the abutting edges of the clamping andretaining wall sections 19, as shown in Figs. 3 and 9, but this does not adversely effect the holding qualities of the connector upon the cross wires.

From the foregoing description and explanation it will now be clear that wiring circuits, such as illustrated in Fig. 7 involvinginsulated conductors 18 havingnumerous cross conductors 17 electrically connected thereto and to electrical devices such as the tube sockets S, can be modified and embodied in various other forms without departing from its spirit or the scope of the appended claim.

The invention claimed is:

An electrical connector of the type intended to be pressure-formed onto a pair of crossed conductors; comprising a body member having a trough-like retaining section and substantially parallel spaced wall sections formed integral with said retaining section to provide a trough for receiving one of said conductors which is insulated, and a pair of tabs punched from opposite sides of the body member and bent downwardly and outwardly therefrom to form apertures through which the other conductor may be disposed, said apertures disposed near the bottom of the body member on each side thereof and terminating below the tops of the wall sections, the other conductor being a bare conductor whereby when the wall sections are pressure-formed around the insulated conductor lying within the trough and the tabs are simultaneously curled against the bare conductor, electrical contact is established between said conductors by forcing said bare conductor through the covering of the insulated conductor.

References Cited in the file of this patent UNITED STATES PATENTS

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