US3189863A

US3189863A - Connector

Info

Publication number: US3189863A
Application number: US286890A
Authority: US
Inventors: Edward E Leach
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1960-06-23
Filing date: 1963-06-06
Publication date: 1965-06-15
Anticipated expiration: 1982-06-15
Also published as: DE1440010A1; GB1076145A; DE1490031A1; NL266293A; NL135886C; DE1490031B2; GB995417A; CH419277A; DE1440010B2

Description

E. E. LEACH June 15, 1965 CONNECTOR 2 Sheets-Sheet 1 Fla. 2

Filed June 6, 1963 A's/yawn? fan ka Elf/4c ATTOIEWAYS June 15, 1965 E. E. LEACH 3,189,863

CONNECTOR Filed June 6, 1963 2 Sheets-Sheet 2' v I INVENTOR. fpn zma 515/101 WW M United States Patent 3,18%863 CONNECTUR Edward E. Leach, White Bear Lake, Miinm, assignor to Minnesota Mining and Manufacturing Company, St. Paul, Minn, a corporation of Delaware Filed June 6, 1963, Ser. No. 286,890 10 Claims. (Cl. 339-99) This application is a continuation-in-part of my copending application Serial No. 38,152, filed June 23, 1960, now abandoned.

This invention relates to electrical connectors, and in particular to multiple contact connectors for application to multiple conductor insulated cables in the form of flat tapes having a plurality of parallel mutually insulated wire conductors.

Multiple-conductor cables consisting of a plurality of parallel side-by-side mutually insulated small-diameter copper wires within a flat plastic tape or insulating strip find particular application in the interconnecting of components such as are employed in electronic apparatus and telephone communication apparatus. The present invention provides means for making electrical contact with any or all of the several conductors of such a fiat cable, providing quick positive permanent electrical contact without any necessity for soldering and without any previous removal of insulation from, or other manipulation of, the cable or conductor. In particular, the invention provides means for making connection between selected conductors of two or more tape cables in a single compact connector.

In accordance with the principles of the invention, there are provided connector devices having a cable supporting member and a covering member each having a flat surface and between which a section of cable may be firmly held. One or more orifices in one of the members contains a contact member having one or more slotted openmouthed contact arms extending from the fiat face and into a corresponding narrow channel in the flat face of the opposing member, for penetrating the insulation of an interposed flat cable and making firm contact with a corresponding wire of the cable. An additional cable supporting member may hold a second cable segment against the opposite fiat surface of the covering member and may be similarly slotted to receive contact arms extending from said opposite flat surface for making electrical contact with wires of said second cable.

Exemplary forms of the connector device of this invention are shown in the appended drawing, in which:

FIGURE 1 is a view in perspective of a connector applied to a thin flat insulated conductor tape or cable;

FIGURE 2 is a top plan view of the base member of FIGURE 1;

FIGURE 3 is a partial sectional front view of a portion of the top member, and FIGURE 4- is a partial sectional front view of the corresponding portion of the base member of FIGURE 1 and with a flat cable in position for making connection;

FIGURES 5 and 6 are corresponding partial sectional side views of the top and base members of FIGURES 3 and 4;

FIGURE 7 is a side elevation, and FIGURE 8 a front elevation, partly in section, of a contact member as employed in the connector of FIGURE 1;

FIGURES 9, 10 and 11 are partial sectional front views of the top, central, and base members respectively of a multiple-tape connector and with tape cables in position for inter-connection;

FIGURE 12 is a plan view of the contact element of FIGURE 10 prior to insertion of the element into the central member;

FIGURE 13 is a bottom plan view of the central member of FIGURE 10;

"ice

FIGURE 14 illustrates in perspective and in exploded view the top, center, and base members of another form of multiple-tape connector;

FIGURE 15 is a partial sectional view illustrating the connector of FIGURE 14 as applied to two flat cables at right angles to each other;

FIGURE 16 is a view in perspective of the connector element of FIGURE 15; and

FIGURES 17-19 are views in perspective of additional forms of connector elements.

In FIGURE 1, a flat cable 10, consisting of a plurality of small copper or other conductive metal wires 11 within a plastic insulating strip 12, passes through a connector assembly 13, here indicated as comprising generally a base member 14 and a top member 15, the latter containing in this instance a single connector element 16.

The top 15 is perforated with a series of rectangular apertures 17, expanded into shallow fiat pockets or depressions adjacent the inner face of the top member, into which the connector elements 16 are inserted as shown in greater detail in FIGURES 3 and 5. The opposing inner face of the base member 14 is likewise provided with narrow slot-like apertures 18 into which the wirecontacting ends of the connector elements 16 are directed, as will also be apparent from FIGURES 4 and 6.

The outwardly curved edge face 19 of the top member 15 is designed to provide a snap fit within the inwardly curved surface 20 of the edge flange 21 of the resilient insulating base member 14. The flat cable 10 is thus firmly held between opposing flat surfaces of the base and top members, the firm resiliency of the flanges 21 permitting the snap closure action. Accurate alignment of top and base members is assured by the mounting lugs 28, the extended circular end portions of which fit within semicircular channels 29 in the base 14.

The contact member 16 has an extended spring handle 22 which is compressed within the slot 17 as shown in FIGURE 3, providing a close frictional fit. The lower U-shaped end of the contact member has two extended contact arms each formed of two

pointed segments

23 and 24 forming an open-mouthed slot 25 therebetween, and joined by a flat base segment 26.

In making a connection, the required contact members 16 are inserted in the appropriate slots 17, the flat cable 10 is inserted within the base 14, and the top 15 is forced into position between the resilient flanges 21 and into contact with the cable. The pointed segments of the con tact member perforate the plastic insulation of the fiat cable at each side of the corresponding wire. The wire is forced between the segments into the slots 25, providing a wiping or sliding metal-to-metal contact. The action also forces the

segments

23 and 24 apart against the resiliency of the base segment 26, so that fully effective contact is maintained between contact member and wire. Force is transmitted to the flat cable through the flat inner cable-supporting face of the base 14 at both sides of each of the slots 18, into which the contact arms of the members 16 are directed.

The connector of FIGURE 1 is useful in connecting various external circuit elements to the flat cable. Leadwir-es from such components are led through the holes 27 in the spring handles 22 and soldered or otherwise fastened in place. Attaching the connector to the flat cable then provides effective electrical contact between the several components and the appropriate conductors of the cable. It will be appreciated that the designation of the insulating members as base and top members is for convenience only and that either member may serve as a base, the other then serving as the top.

The connector indicated in FIGURES 9-11 is effective in making contacts between corresponding conductors in top member first bending to permit assembly and then snapping into place over the closely fitting exterior surface of the resilient flange 35 of the base member. Mounting flanges 36 on the sides of the central member '31 as shown in FIGURE 13 and fitting within corresponding channels in base and top members, provide for accurate alignment of the three members in much the same manner as in the device of FIGURE 1.

The U-shaped contact member 32 is provided with bifurcated contact arms at each edge of each leg of the U, providing a toal of four wire-receiving slots 37. Each leg has a central opening 38. The two legs of the U are initially not quite parallel, eg as shown in FIGURE 12,

so that the piece must first be placed under stress to fit I within the parallel slots 39 provided in the central member 31, and is then tightly frictionally held in place.

It will be seen that double contact is provided at each conductor by the U-shaped contact elements hereinbef-ore described. Contact elements which provide but a single contact with the wire are also useful and are here illustrated in connection with another form of connector as will now be described.

The modified form of conductor illustrated in FIGURE 14 makes possible the interconnecting of any wire of a lower fiat cable with any wire of an upper flat cable, the two cables being placed at right angles to each other. The top section 40 and base section 41 are interchangeable. Each has a fiat tape-supporting surface between opposed upraised resilient flange members, and is provided with a series of narrow transverse grooves. The center section 42 is rounded along the lower half of two opposing edges and along the upper half of two opposing edges to provide close resilient fit with the correspondingly shaped flanged sides of the top and base members, e.g. in cross-position as shown and with flat cables in position on the tape-supporting surfaces as indicated in FIGURE 15. The center section is perforated from one surface to one-half its thickness with a series of slots 43 which at the opposing half thickness are expanded to provide spaces 44 for insertion of contact members 45, also as shown in more detail in FIGURE 15. FIGURE 16 illustrates a contact member 45, having an upper bifurcated contact arm 46, a lower arm 47 facing in an opposite direction and in a plane at right angles to that of arm 46, a central connecting plate 48 at right angles to each of

arms

46 and 47, and a stub spring leaf 49 extending from a free edge of plate 48. The two arms are provided with central openings as previously described in connection with contact member 32 of FIGURE 10 for improving the resiliency characteristics of the contact member.

The contact element is forced into the desired position in the central insulating member 42, through a space 44 and slot 43, against the resistance ofiered by the stub spring 49 which is thereby slightly but effectively compressed against the wall of the space 44 to retain the contact member within the insulator body. The bifurcate 4 achieved as the several components are pressed together by aligning the external corners of the top and base members with those of the central member; but suitable mating flanges and recesses or other positive alignment means may be provided if desired,'e.g. as shown in connection With FIGURE 13.

Other forms of contact members or elements as examplified by those of FIGURES 17-19 may be employed in place of

contact members

32 or 45 to provide additional forms of multiple-cable connectors, the insulating components being suitably modified for insertion and retention of the modified contact members. As one example, the central member is recessed to receive a contact element as shown in FIGURE 17 and is doubly rounded at one set of edges to receive both the base and the top members, the. remaining set of edges being entirely flat. Such a connector is useful in extending a flat cable in the manner described in connection with FIG- URE 9.

The member illustrated in FIGURE 17 as a single pair of oppositely facing bifurcate contact arms separated by a centrally perforate resilient center section having an opposing pair of resilient retaining arms extending from thesides thereof and not quite parallel to each other. A single extended retaining arm having, a central bend is substituted for the two arms of FIGURE 17 in the otherwise identical contact member of FIGURE 18. In FIG- URE 19 the central section which supports the retaining side arms is extended and is at a right angle with each of the oppositely facing resilient perforate bifurcate contact arms.

Insertion of the desired contact elements into the suitably recessed, channeled, or slotted insulating top or center member provides maximum versatility as well as assurance that the edges of the contact arms will be permitted free resilient separation during application to a conductor. Where proper provision is made for free separation of'the contact arms, and quantities of connectors with identical placement of contact elements are desired, it is convenient and economical to form the connectors with the contact elements initially in place, eg. by injection molding. Certain of the contact elements may be interconnected within the imperforate molded connectorv body for providing cross-connection between contact arms extend from the insulator surface and with conductors, where desired. The following examples will serve effectively to illustrate the practice of the invention in terms of presently preferred specific materials and dimensions but are not to be taken as limitative. I

The flat cable consists of a total of twelve No. 28 gage solid copper wires uniformly spaced across a one-inch width of tape. The wires are embedded in a layer of polyethylene. A thin half-mil oriented Mylar polyester film is bonded over each face of the strip, making a total maximum thickness of 0.014 inch. The distance between each two adjacent conductors and between the outer conductor and the adjacent edge of the cable is identical.

The contact member employed with said cable in a connector as described inconnection with FIGURE 1 is made of a single flat piece of 0.010 inch spring brass, stamped in the form of a crossand folded to shape. The stem portion is .08 inch wide and initially .585 inch long, the doubled handle member 22 then. being .30 inch long. The cross-member is initially .08 inch wide and .214 inch long. The slots 25 are 007-008 inch wide and extend to a depth of .08 inch from the ends of the cross-member, the ends being cut at an angle of 45 to form the pointed tips of the contact members. As shown in FIGURE 8, the distance between the two bifurcate contact arms of the connector element 16, ie the width of the base segment 26, is equal to the width of the handle member 22. The inner edges of the

segments

23 and 24 are essentially flat and smooth, so that a wire conductor pressed therebetween is deformed without cutting or scoring.

The top and base members ofthe connectors are constructed of transparent molded electrically insulative hard resilient nylon polymer. The overall dimensions of the assembled connector, exclusive of projecting mounting lugs and metal leads, are approximately 1% x 1% x A inch. The dimensions of the edge flanges and the resiliency of the polymer are so balanced as to make it possible to close the connector against the cable by strong finger-pressure alone where connection is being made to not more than about two or three conductors; power tools, pliers or the like are ordinarily found necessary to close the connector where larger numbers of connections are desired. Once closed, the connector cannot again be opened with the fingers but must be pried open with a strong screwdriver or other suitable tool; or the cable may be cut and the connector discarded.

In a connector as described in connection with FIG- URES 9-11 and designed for use with the same fiat cable as above described, the contact member 32 is formed from a fiat sheet of Beryldur copper alloy .0126 inch in thickness. Each bifurcate contact member is .090 inch in length and .080 inch in width, the slot width being .007 inch. When folded as in FIGURE 12, the length of each leg to the outer surface of the base of the U- shaped contact member is .160 inch, and the legs are bent on a radius of .015 inch. The distance between the two legs is .08 inch when they are parallel to each other in the assembled connector. Centrally between the opposing slots in each leg member, stock is removed to form the elliptical opening 38 of FIGURE 10 approximately .040 inch long and .030 inch wide between the opposing slots, hereby increasing the ability of the slot-defining prong members to be resiliently separated when a wire is forced into the slot. The central strip forming the base of the U-shaped contact member and the extended tips of the legs thereof is .05 inch wide.

What is claimed is as follows:

, 1. A connector contact element having two sets of oppositely facing contact arms each consisting of a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces, said two sets being resiliently interconnected centrally of one side of each set in a generally U-shaped configuration, the arms of the U being resiliently divergent.

2. A connector for making electrical connection between selected corresponding wires of two flat cables each containing a plurality of parallel wire conductors in spaced side-by-side relationship within an insulating plastic cover, said connector comprising a base, a contact-supporting separator, a cover, and at least one contact element retained by said separator; said base having a transversely slotted cable-supporting portion and, at the sides thereof, upraised resilient inwardly and outwardly flaring side portions; said separator fitting snugly between said resilient side portions and against a first said cable placed upon said cable-supporting portion, having an opposing cable-supporting surface for supporting a second said cable, and being provided with spaced apertures for retentive positioning of contact elements; said cover having a transversely slotted pressure-applying portion and, at the sides thereof, down-turned resilient inwardly flaring side portions fitting snugly over the outwardly flaring side portions of said base; said contact element comprising a U-shaped spring retainer member retained under resilient tension within a said spaced aperture and having at each side edge of each arm of the U a contact arm extending from said separator, the opposing sets of contact arms being in position for fitting within corresponding slots in said base and said cover, each said contact arm consisting of a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces; and said base, separator, and cover members being provided with cooperating alignment means.

3. A connector for making electrical connection between selected wires of two flat cables each containing a plurality of parallel wire conductors in spaced side-by-side relationship within an insulating plastic cover, said connector com-prising a base, a central contact-supporting separator member, a cover, and at least one contact element retained by said separator; said base and cover each having a transversely slotted cable-contacting portion and, at the sides thereof, upraised resilient recessed side portions; said separator having two opposed edges having a lower rounded section fitting snugly between the recessed sides of said base, and two opposed edges having an upper rounded section fitting snugly between the recessed sides of said cover, said separator being provided with spaced apertures for retentive positioning of contact elements; said contact element being frictionally retained within a said aperture and having oppositely facing contact arms extending above the surrounding cable-contacting surfaces and fitting within corresponding transverse slots of said base and cover members, each said contact arm consisting of a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces.

4. A connector as defined in claim 3 in which the cover and base members are snugly fitted over different opposed edges of said central member and in which the oppositely facing contact arms of each contact element are disposed at right angles to each other.

5. A connector for making electrical connection between selected wires of two flat cables each containing a plurality of parallel wire conductors in spaced side-byside relationship within an insulating plastic cover, said connector comprising in order a base, a central separator member for separating said two cables and retaining at least one contact element, and a cover, said base and cover each having a transversely slotted cable-contacting portion, said base, separator, and cover being provided with means for providing accurate alignment and resilient snap closure assembly of said connector, each said contact element being retained by said separator member and having oppositely facing bifurcate contact arms extending from the surrounding cable-contacting surfaces and fitting within corresponding transverse slots of said base and cover members, each said contact arm having a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces.

6. A connector for making quick positive permanent electrical connection to selected of the several spaced parallel wires of a spaced-multiple-wire fiat cable, comprising a resilient base member having a flat transversely multi-slotted cable-supporting surface defined by two centrally separated upraised side segments along each longitudinal edge thereof, a cover member having a thin flat central mult-i-perforate contact-carrying portion defined by a downwardly extending mounting lug centrally of each longitudinal edge thereof, and at least one contact element carried by said cover member; said cover member having longitudinal convex edge segments on both sides of each of said mounting lugs, and said upraised side segments having correspondingly concave inner side surfaces, and said mounting lugs being so shaped and so positioned on said cover member as to fit closely between corresponding of said centrally separated side segments, for

providing accurate alignment and resilient snap-closure assembly of said connector; each said contact element passing through and extending beyond both faces of said cover member at a perforation therethrough and with an inner cable-contacting and aligned with a corresponding slot in said base and consisting of at least one pair of spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a wire-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces, said contact element additionally including as a resilient spring retainer means for removably fr-ictionally retaining said element in said apertured cover an extended leaf spring handle having a fixed leaf and a divergent free leaf attached thereto at a common end and adapted to be pressed closely against said fixed leaf on insertion into a said aperture.

7. A connector for making quick positive permanent electrical connection to selected of the several spaced parallel wires of a spaced-multiple-wire fiat cable, comprising: a resilient base member having a transversely slotted cable-supporting portion and, at the sides thereof, upraised resilient recessed side portions; a cover member having a thin flat central multi-perforate contact-carrying portion and opposing rounded edges fitting snugly between the recessed side portions of said base; and at least one cont-act element frictionally retained within a perforation of said cover member and having at least one bifurcate contact arm extending from the surrounding cablec ontacting surface and fitting within a corresponding transverse slot of said base, each said contact arm consisting of a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces; and said base and central members being provided with cooperating alignment means.

8. A multi-part insulating structure for use in providing a connector for making electrical contact with selected wires of a flat cable containing a plurality of uniformly spaced parallel wire conductors within a flat plastic insulating cover, said structure comprising a base member including a flat cable-supporting surface and upraised side members defining a central cable-receiving channel and having an inwardly flaring upper edge portion, and a flat cable-contacting top member the two side edges of which are outwardly flared from top and bottom to form a snap joint with the oppositely flared side members of said base member when said top is forcibly pressed into said channel; the cable-supporting surface of said base member being slotted with a series of spaced narrow slots beneath and at right angles to the several wires of a said cable, and the top member being slotted with a series of co-acting spaced narrow slots corresponding to said several wires for insertion of connector elements fitting therein and having extended flat bifurcated contact members fitting into said narrow slots in said supporting base; and said base and top members being provided with cooperating alignment means.

9. A connector for making quick. positive permanent electrical connection with at least one of the wires of a fiat cable containing a plurality of uniformly spaced parallel wire conductors within a plastic insulating cover, said connector comprising: a base member including a flat cable-supporting surface and upraised side members defining a central cable-receiving channel and having an inwardly flared upper edge portion, the cable-supporting surface of said base member being transversely slotted with aseries of spaced narrow slots; a flat cable-contacting top member the two side edges of which are outwardly fiared to form a snap joint with the oppositely flared side membersofsaid base member'when said top is orcibly pressed into said channel and onto a fiat cable laid therein, said top member being perforated with a series of spaced narrow apertures; and at least one metallic connector element having at least one bifurcate contact arm consisting of a pair of pointed spaced opposing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engaging opening, said jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces, said element fitting and being retained within a said perforation in said top member, said contact arm extending from said top member in position to fit within a corresponding transverse slot in said base member; said base and top members being provided with cooperating alignment means.

19. A connector for making quick positive permanent electrical connection withat least one of the wires of a flat cable containing a plurality of spaced parallel wire conductors within a plastic insulating cover, said connector comprising: a base member, a cover member, and at least one contact element having atleast one bifurcate contact arm consisting of a pair of pointed spaced oppos ing jaw members having narrow work-engaging surfaces including substantially parallel holding portions and gradually diverging accepting portions forming a work-engagling opening,tsaid jaw members being interconnected at the ends opposite said opening by resilient holding means yieldingly resistant to stresses tending to separate said surfaces; said base and cover members having opposing cable-contacting faces and cooperating alignment and retention means including upraised side members on one, said side members together with the cable-contacting face of said one member defining a central cable-receiving channel, and cooperating recessed side edges on the other; one of said base and cover members being perforated from its cable-contacting face with a series of spaced apertures, the other of said base and cover members being transversely slotted at its cable-contacting face with a series of correspondingly spaced narrow slots; each said contact element being retained within one of said apertures with its said contact arm extending therefrom and in position to fit within thecorresponding said slot.

References tilted by the Examiner UNITED STATES PATENTS 2,049,585 8/36 Gunthorp 339-221 2,057,718 10/36 Gunthorp 339221 2,587,239 2/52 Smith 339*98 2,947,965 8/60 Scoville 339 220 X 3,012,219 12/61 Levin et al; 339-98 7 3,027,536 3/62 Pasternak 33-9-248 X 3,058,088 10/62 Miller 33997 JOSEPHD. SEERS, Primary Examiner.

Claims

1. A CONNECTOR CONTACT ELEMENT HAVING TWO SETS OF OPPOSITELY FACING CONTACT ARMS EACH CONSISTING OF A PAIR OF POINTED SPACED OPPOSING JAW MEMBERS HAVING NARROW WORK-ENGAGING SURFACES INCLUDING SUBSTANTIALLY PARALLEL HOLDING PORTIONS AND GRADUALLY DIVERGING ACCEPTING PORTIONS FORMING A WORK-ENGAGING OPENING, SAID JAW MEMBERS BEING INTERCONNECTED AT THE ENDS OPPOSITE SAID OPENING BY RESILIENT HOLDING MEANS YIELDINGLY RESISTANT TO STRESSES TENDING TO SEPARATE SAID SURFACES, SAID TWO SETS