US3731251A

US3731251A - Means for terminating flat cable

Info

Publication number: US3731251A
Application number: US00243635A
Authority: US
Inventors: W Sinclair
Original assignee: Thomas and Betts Corp
Current assignee: ABB Installation Products Inc
Priority date: 1972-04-13
Filing date: 1972-04-13
Publication date: 1973-05-01
Anticipated expiration: 1990-05-01

Abstract

Novel means for terminating flat cable comprising a flat, elongate base member selectively apertured to provide an access way between a pair of conductor receiving portions disposed on opposing surfaces of the base member, wherein selective conductors of the flat cable may be disposed adjacent one or the other of said conductor receiving portions and connected to a selectively formed terminal positionable within an associated terminal receiving recess in said conductor receiving portions, affording additional separation between adjacent conductors. In a further embodiment coupling means are provided to permit the interconnection of a plurality of conductors to one or more metallic strips interposed within one of the conductor receiving portions to provide a common termination point therefore. A suitably formed enclosure which may be provided with spaced ribs for receiving a portion of the terminals affixed to the base member may be employed to provide an enclosed assembly. The base member further includes a cable receiving portion adapted to provide a support for a selective portion of the flat cable.

Description

United States Patent [191 Sinclair 1541 MEANS FOR TERMINATING FLAT CABLE [75] inventor: William Young Frenchtown, NJ.

Sinclair,

[73] Assignee: Thomas & Betts Corporation,

Elizabeth, NJ.

221 Filed: Apr. 13,1972

21 Appl.No.: 243,635

[52] US. Cl ..339/17 F, 339/14 R, 339/19, 339/91 R, 339/103 M, 339/176 MF [51] Int. Cl. ..H05k 1/06, l-lOlr 3/06, H0lr 31/08 [58] Field of Search ..339/l4,17, 18,19, 339/75, 91, 95, 97, 99,103,107,176;

317/101 F, 101 CC [56] References Cited UNITED STATES PATENTS 1 May1,1973

Primary Examiner-Joseph H. McGlynn Assistant Examiner-Terrell P. Lewis Attorney-David Teschner et al.

[57] ABSTRACT Novel means for terminating flat cable comprising a flat, elongate base member selectively apertured to provide an access way between a pair of conductor receiving portions disposed on opposing surfaces of the base member, wherein selective conductors of the flat cable may be disposed adjacent one or the other of said conductor receiving portions and connected to a selectively formed terminal positionable within an associated terminal receiving recess in said conductor receiving portions, affording additional separation between adjacent conductors. in a further embodiment coupling means are provided to permit the interconnection of a plurality of conductors to one or more metallic strips interposed within one of the conductor receiving portions to provide a common termination point therefore. A suitably formed enclosure which may be provided with spaced ribs for receiving a portion of the terminals affixed to the base member may be employed to provide an enclosed assembly. The base member further includes a cable receiving portion adapted to provide a support for a selective portion of the flat cable.

15 Claims, 14 Drawing Figures Patented May 1, 1973 4 Sheets-Sheet 1 FIG. 3

Patented May 1, 1973 4 Sheets-Sheet FIG. 5

Patented May 1 4 Sheets-Sheet Patented May 1, 1973 4 Sheets-Sheet 4 FIG. 12

FIG. 13

MEANS FOR TERMINATING FLAT CABLE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention is directed to the field of connectors and principally to a novel means for terminating flat cable.

2. Description of the Prior Art With the advent of methods for miniaturizing circuitry for reducing the space requirements therefore there has been increasing use of what is commonly known as flat cable employable as a convenient means for electrically interconnecting components or assemblies. The cable is generally characterized by a plurality of parallel conductors embedded within a dielectric film and suitably formed to provide a relatively thin ribbon like assembly. Prior art connectors developed to provide a termination for such flat cable generally comprised a relatively thin plastic member having a plurality of conductor receiving recesses suitably spaced to conform generally to the spacing between adjacent parallel conductors in the flat cable. However, in many instances, the extremely limited spacing between adjacent conductors served to cause great difficulty in the attachment of terminals to the bared conductor ends. Other prior art devices, such as exemplified for example, in US. Pat. No. 3,189,864 issued June 15, 1965 to Angele et al. and U.S. Pat. No. 3,605,060 issued Sept. 14, 1971 to Praeger et al., attempted to provide at least a partial solution to the above problems wherein the bared conductor ends were selectively deformed to provide an alternating arrangement of offset conductors to increase the spacing between adjacent conductors. In the former device, the conductor surfaces were used as contact surfaces, and in the latter device the individual conductors were attached to opposing surfaces of a dielectric material having disposed thereon a series of flat conductive portions in the form of a printed circuit or the like. The former device was extremely limited in its application, being readily susceptible to breakage or extreme wear of the conductive portions, due to the nature of the construction, while in the latter device it was necessary to provide an intermediate connector plate or printed circuit for connection to a further element or circuit.

SUMMARY OF THE INVENTION The invention overcomes the problems and limitations noted above with respect to such prior art devices by providing means for terminating flat cable which is simpler, more economical, more versatile, and more universally adaptable than such devices. A generally flat base member is provided with one or more transverse slots or apertures through which selective conductors of the flat cable may be fed for disposition adjacent one of a pair of conductor receiving portions disposed on each of the respective opposing surfaces of the base member. Each of the conductor receiving portions are further provided with selectively proportioned terminal receiving recesses, each adapted to receive an associated, suitably formed terminal which may be connected to the bared portion of an associated flat cable conductor, thus providing an arrangement whereby the conductors ofthe cable may be disposed in selective alternating arrangement adjacent either of the conductor receiving portions of the base member. In at least one embodiment, coupling means, which may comprise for example a metallic strip, may be advantageously employed to couple two or more of the bared ends of the flat cable conductors disposed adjacent one of the conductor receiving portions to provide a common juncture therefore, wherein a single terminal may be attached to the coupling means to provide, for example, a common point for the conductors attached thereto. In a further embodiment, the flat cable terminating means may further include a selectively apertured base member enclosure which may be provided with a series of internally disposed protrusions or ribs serving as terminal guide means. The base member and enclosure may be provided with appropriately contoured recesses and mating protrusions to insure positionally selective interengagement. Stop means which may comprise a raised shoulder on the base member may be employed to limit the insertion of the base member into the enclosure.

The device may be conveniently adapted for use with a flat cable having either round or flat conductors of like configuration, or alternating signal and ground conductors of different configuration. It is therefore an object of this invention to provide improved means for terminating the conductors of flat cable.

It is another object of this invention to provide means for selectively terminating the individual conductors of a flat cable.

It is yet another object of this invention to facilitate the termination of closely spaced flat cable conductors.

It is a further object of this invention to provide means for supporting and terminating the selectively staggered bared conductor ends of flat cable.

It is still another object of this invention to provide means adapted to facilitate the intercoupling and termination of flat cable conductors.

It is yet a further object of this invention to provide means for terminating selective groups of conductors of a flat cable.

It is still another object of this invention to provide means for selectively routing and terminating the conductors of transmission line type flat cable.

It is still a further object of this invention to provide an enclosed flat cable terminating means.

Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings which disclose, by way of example, the principle of the invention and the best mode contemplated for carrying it out.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a perspective view of a flat cable terminating means base member constructed in accordance with the concepts of the invention.

FIG. 2 is a perspective view of the opposing side of the device of FIG. 1.

FIG. 3 is a perspective view, partly in section, of the device of FIG. 1 showing a portion of a flat cable coupled thereto.

FIG. 4 is a perspective view of the assembly of FIG. 3 showing the opposing surface thereof.

FIG. 5' is a fragmentary perspective view, partly in section, showing a portion of a flat cable terminating means base member and the employment of conductor coupling means therewith.

FIG. 6 is a fragmentary perspective view showing a further embodiment of a flat cable terminating means base member constructed in accordance with the concepts of the invention.

FIG. 7 is a perspective view of another embodiment of a flat cable terminating means base member constructed in accordance with the concepts of the invention.

FIG. S is a perspective view of yet a further embodiment of a flat cable terminating means base member constructed in accordance with the concepts of the invention.

FIG. 9 is a perspective view of still another embodiment of a flat cable terminating means base member constructed in accordance with the concepts of the invention.

FIG. It) is a fragmentary perspective view, partly in section, showing a manner of offsetting selective conductors of a flat cable preparatory to engagement with a base member constructed in accordance with the concepts of the invention.

FIG. 11, is a fragmentary perspective view, partly in section, of a flat cable terminating means enclosure constructed in accordance with the concepts of the invention.

FIG. 12 is a top plane view showing a flat cable terminating means including an enclosed base member adjacent a member adapted to receive said means.

FIG. 13 is a fragmentary perspective view, partly in section, of an embodiment of a portion of a flat cable terminating means base member including therewith coupling means and terminations affixed thereto according to the concepts of the invention.

FIG. 14 is a further embodiment of a fiat cable terminating means base member constructed in accordance with the concepts of the invention.

Similar elements are given similar reference characters in each of their respective drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Turning now to FIGS. 1, 2, 3, and 4 there is shown a flat cable terminating means base member 20 constructed in accordance with the concepts of the inven tion. Base member 26) is formed preferably from a plastic material having preferably high dielectric properties including, for example, such commonly employed materials as Nylon, Delrin, polyvinyl chloride, pblystyrene, polypropylene, phernolic resin, epoxy resin, and melamine resin, and comprises a first conductor receiving portion 22 and a second conductor receiving portion 24 disposed, respectively, on the opposing

surfaces

26 and 28 of base member 20. Adjacent the second conductor receiving portion 2 and generally overlying an opening 30 extending between the opposing

surfaces

26 and 28 of base member 20 is a cable receiving portion 32 at least partially defined by a pair of raised

portions

34 and 36 adjacent, respectively, each of the shorter ends 38 and 40 of base member 24). As will be described in more detail, the opening 30 provides an access way for selective conductors of a flat cable wherein such conductors may be selectively positioned adjacent either of the

conductor receiving portions

22 and 24. Disposed within the first conductor receiving portion 22 are a series of selectively proportioned first terminal receiving recesses 42 extending generally laterally between a first or leading edge 44 of base member 2d, and the opening 30. Each of the recesses 42 are appropriately contoured to provide a preferably close fitting chamber for the receipt of a portion of a terminal such as 436 (FIG. 8) adapted to be attached to the bared end of a corresponding flat cable conductor situated within a selective one of the recesses 12. A plurality of second terminal receiving recesses 48, which are shown as a series of spaced, aligned notches adjacent the leading edge d4 of base member 26, are disposed adjacent the opposing surface 2 thereof and similarly proportioned to provide at least partial chamber or seat for an associated terminal such as 46. The opening 30 in base member 20, although shown as a generally elongate rectangular slot, may comprise a series of restrictively proportioned openings as shown at 5th in H6. 8 or at 52 in FIG. 9, where necessary or desirable to provide a separate access way for one or more flat cable conductors. Although the

openings

50, 52 are illustrated as essentially circularly or rectangularly configured, other suitable shapes may be readily employed without departing from the spirit of the invention. Extending longitudinally adjacent a second or trailing edge 54 of base member 2i?) remote from edge 4M is a raised portion 56 which may be employed as stop means in a manner more fully described below. Disposed rearwardly of the base member opening 30 are a pair of selectively formed protuberances S3 which may be employed as locking means in a manner described in more detail hereafter. Disposed on the first surface 26 of base member 2% generally adjacent its first edge 44 are a pair of raised portions 64 which may be employed as orienting means in a manner more fully described below. Although the shapes of the respective first and second terminal receiving recesses 34 and 4S, respectively, are shown as essentially dissimilar in FIGS. 1 and 2, an arrangement such as that illustrated at 92 in FIG. ll may be employed, where for example, it is desired to provide a configuration similar to the second terminal receiving recesses 23 on both of the opposing

surfaces

26 and 28 of base member Ztl. Returning now to FIGS. 3 and-4 there is shown a typical application employing the use of base member 20 as a terminating means for a flat cable 62 engaged therewith. Although flat cable 62 may comprise a plurality of similarly formed round or flat conductors, for purposes of illustration and to more fully appreciate the advantages and versatility of the present device, reference is herein made to a configuration similar to that shown in FIG. 10 wherein there is shown a plurality of differently configurated flat cable conductors dd embedded in an insulating material 68,

' conductors as being essentially relatively thin round conductive wire each spaced intermediate a pair of heavier, generally rectangularly shaped conductors 6%, such arrangement being commonly employed in transmission iine applications wherein the conductors 66 are generally designated as signal leads and conductors 64 function as grounding or shielding means therefor. It will of course be readily apparent to those skilled in the art that the arrangement shown in MG. 10 may be readily employed for use as other than transmission line cable and that the particular configuration shown forms no part of the invention nor is it essential to the operation thereof. To effect the termination of cable 62 a portion of the insulation 68 is removed to expose a selective length of the

conductors

64, 66. The removal of the insulation 68 may be accomplished by scraping, abraiding, cutting or other means well lrnown in the art to expose a selective length of

conductors

64 and 66 for subsequent termination. The end of cable 62 adjacent the exposed portion may then be positioned within the base member cable receiving portion 32 and either temporarily or permanently held in position by the use of adhesives, appropriately formed fixtures, clamps, or other like apparatus, where necessary or desirable. To effect the arrangement shown in FlG. 3 and 4, the conductors 66 are then each offset somewhat from the plane of the cable 62 and advanced through the opening 30 of base member and individually disposed in a corresponding one of the first terminal receiving recesses 42. It will of course be readily appreciated that less than all of the available conductors 66 may be so deployed, where necessary or desirable and the remaining conductors 66 either cut back to the insulation portion 68 of cable 62 or brought to the opposing surface 24 of base member 20 and disposed adjacent a selective one of the second terminal receiving recesses 48. Each of the respective conductors 66 is now available for attachment to a respective terminal 46 and the terminal 46 positioned within a first terminal receiving recess 42 in a manner more clearly shown in FIG. 4. The attachment of terminal 46 to a respective conductor may be effected by any one of a number of commonly employed methods including soldering, welding, crimping, bonding, and the like. Where suitable equipment (not shown) is available, a manufacturing technique may be employed wherein a plurality of conductors 66 may be affixed to their associated terminals 46 in a single operation where, for example, the terminals 46 are supplied in strip form. The terminals 46 may thereafter be separated from one another and disposed within the recesses 42. The terminals 46 are shaped in such manner as to insure that the tab receiving opening 69 defined by the opposing arms 74) of terminal 46 is aligned substantially centrally between the first and second terminal receiving recesses 42 and 4%, respectively. The opposing side walls forming each of the recesses 42 although shown as extending essentially normal to the base of the recess may be inclined inwardly to further restrictively contain or engage the portion of the terminal 46 disposed within the recess 42, where necessary or desirable. One or more of the remaining conductors 64 may then be disposed adjacent the second conductor receiving portion 24 of base member 20 for attachment to either an associated terminal such as 46, or a coupling means which may take the form ofa metallic strip 72 (H6. 3) serving as a common jumper or a bus bar. The metallic strip '72 may comprise a single element extending essentially across the entire length of the base member second conductor receiving portion 24, or may comprise, as partially shown in FIG. 13, two or more shorter elements such as 74 and 76 which may be selectively spaced to permit the insertion therebetween of one or more conductors 64 and an associated terminal such as 87 attached thereto. The metallic strips 72, 74 and 76 may be affixed to the base member 20, if necessary or desirable, and attached thereto by means of screws, rivets, adhesives, or any other suitable method. An appropriately formed terminal such as 753 shown in FIG. 5 may thereafter be attached to coupling means 72 and brought out through its respective second terminal receiving recess The tab receiving opening $0 in terminal 78 is arranged in generally colinear alignment with the adjacent tab receiving openings 69 wherein a plurality of aligned tabs such as shown at 62 in HS. 12 may be conveniently engaged therewith. As is shown more clearlyin Fifi. 6, a terminal such as 'Ftlmay be attached to each of the strips 7 and 76 to provide a plurality of common points advantageousin those applica tions where separate grounding or coupling points are desired. The spacing between terminals 78 may, of course, be selected to conform to, for example, the spacing between mating tabs on a further member such as 83 (FlG. 13). Although there has been generally illustrated a corresponding number of first and second

terminal receiving recesses

32 and 48, respectively, disposed in generally coincident relationship providing an essentially symmetrical arrangement in each of the embodiments described above, this arrangement may be conveniently modified or altered as necessary or desirable wherein the first terminal receiving recesses 42 may be positioned in offset relationship with respect to the second terminal receiving recesses 48, and mi merically unequal thereto. Returning new to FIG. 1 there is shown a plurality of spaced projections 84 adjacent the opening 3i; in base member 26 and in aligned relationship with respect to the second terminal receiving recesses ill, the spacing between adjacent projections 8% serving preferably as guides or channels for the conductors 6%, thereby establishing a predetermined spaced relationship tberebetween. One of more of the projections as may be further divided as shown, for example at 536, in PEG. '7, wserein the additional slots so formed may be conveniently employed as guides or channels for those conductors 66 which are not disposed within the first conductor receiving portion 22 and which have not been cut back to the insulation 68 of flat cable 62 where, for example, it is desired to retain such conductors 66 for future use. As mentioned heretofore, base member 26 may be modified as shown, for example, in Flt]. lid wherein a metallic strip or similar coupling means such as '72 or a plurality thereof such as '74 and 76 may be disposed on both sides of the base member 2b. in such case, the first conductor receiving portion 22 of base member 20 is modified as at Q2 in H6. id to provide an arrangement similar to that shown with respect to the base member second conductor receiving portion illustrated in FllG. 3. in this manner, either or both of the first and second conductor receiving portions 22. and 24's may be employed as a juncture for two or more of the conductors 6d or 66.

Turning now to lFiGS. ii and 12 there is shown an enclosure 8%; constructed in accordance with the concepts of the invention and proportioned for disposition over the base member Sill. Extending within the enclosure 3% is a slot-like chamber till having a width proportioned preferably to provide a close tit about the base member 20 and comprising an entry way l d communicating with a first edge 96 of enclosure $38. Disposed within the chamber it'd generally remote from edge $6 are a plurality of spaced ribs serving preferably as guide means for the portions of the

terminals

36 and 78 extending beyond the edge 44 of base member 20. Extending transversely within the chamber 90 are a pair of spaced recesses 100 appropriately contoured to matingly cooperate with the projections 60 on base member to provide a means for insuring a selective orientation between the base member 20 and the enclosure 88 where such orientation is either necessary or desirable. This arrangement may be conveniently reversed, however, wherein the enclosure 88 may be provided with projections such as 60 and the base member 20 provided with a recess matingly engageable therewith to effect a similar purpose. The insertion of the base member 20 within the enclosure 88 may be limited or controlled by the selective positioning of the shoulder 56 on base member 20 wherein said shoulder 56 is caused to abut the edge 96 of enclosure 88 upon the assembly of the respective components. As may be more clearly seen in FIG. 12, the enclosure 88 may thus be advantageously employed as a protective cover to prevent inadvertent contact with, or possible damage to the base member 20 and exposed terminal and conductor portions. To prevent the inadvertent removal of the enclosure 88 from the base member 20, and to provide locking engagement therebetween, a pair of selectively spaced and suitably contoured recesses 102 may be provided within a first planar portion 104 of enclosure 88 to receive therewithin the pair of similarly spaced projections 58 disposed on the base member 20 as the base member 20 is selectively advanced into position within the enclosure chamber 90. The arrangement shown may, of course, be reversed wherein the recesses 102 may be replaced with inwardly directed projections such as 58 (FIG. 2), and projections 58 replaced with recesses such as 102 to provide a similar locking arrangement.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Means for terminating flat cable comprising: a generally flat, elongate base member formed of electrically insulating material and having generally planar opposing surfaces defining the thickness thereof, a cable receiving portion, a first conductor receiving portion, and a second conductor receiving portion, each of said first and said second conductor receiving portions being disposed adjacent an associated one of said opposing surfaces generally adjacent said cable receiving portion, said base member further having a selectively apertured portion adjoining said first and said second conductor receiving portions to provide an access way between said first and said second conductor receiving portions, said first conductor receiving portion further having a plurality of selectively proportioned first terminal receiving recesses arranged in aligned j uxtaposition adjacent an edge of said base member adjoining said first conductor receiving portion, said second conductor receiving portion further having at least one second terminal receiving recess generally overlying a selective one of said first terminal receiving recesses; and a plurality of terminals, each adapted to be connected to the bared end of an associated flat cable conductor, and further adapted to be positioned at least partially within an associated one of said first and said second terminal receiving recesses, wherein the bared end of at least one of the individual conductors of a flat conductor cable may be disposed adjacent a selective one of said first and said second conductor receiving portions and coupled to an associated one of said terminals to permit a termination thereat.

2. Means as defined in claim 1 further comprising coupling means disposed within at least one of said first and said second conductor receiving portions for electrically interconnecting the bared ends of at least two of the conductors of a flat conductor cable disposed adjacent thereto.

3. Means as defined in claim 2 wherein said coupling means comprises at least one selective length of metal lic material affixed to said base member.

4. Means as defined in claim 2 wherein at least one of said plurality of terminals is further adapted to be connected to said coupling means to provide a termination thereat.

5. Means as defined in claim 1 wherein said base member selectively apertured portion comprises a single generally elongate opening extending between said base member opposing surfaces.

6. -Means as defined in claim 1 wherein said base member selectively apertured portion comprises a plurality of selectively proportioned openings, each extending between said base member opposing surfaces.

7. Means as defined in claim 1 wherein said cable receiving portion is disposed generally adjacent said base member second conductor receiving portion.

8. Means as defined in claim 7 wherein said cable receiving portion at least partially overlies said base member selectively apertured portion.

9. Means as defined in claim 1 further comprising a base member enclosure formed of electrically insulating material and having a selectively proportioned chamber having an entryway adapted to permit the insertion of a selective portion of said base member into said chamber.

10. Means as defined in claim 9 wherein said enclosure further comprises a plurality of spaced, generally parallel ribs disposed within said chamber generally adjacent an edge of said enclosure remote from said entryway to provide guide means for at least a portion of an associated one of said terminals.

11. Means as defined in claim 9 wherein said enclosure further comprises first contoured means and said base member further comprises second contoured means formed complementary to said first contoured means and matingly engageable therewith to selectively orient said base member with respect to said enclosure upon the insertion of said base member within said enclosure.

12. Means as defined in claim 11 wherein said first contoured means comprises at least one selectively formed recessed portion and said second contoured means comprises at least one selectively formed-raised portion.

13. Means as defined in claim 9 further comprising stop means to limit the insertion of said base member within said enclosure chamber.

14. Means as defined in claim 13 wherein said stop means comprises a shoulder extending outwardly from said base member, said stop means being selectively positioned to abut at least a portion of an edge of said enclosure generally adjacent said entryway upon the insertion of said base member into said enclosure chamber a predetermined distance.

Claims

1. Means for terminating flat cable comprising: a generally flat, elongate base member formed of electrically insulating material and having generally planar opposing surfaces defining the thickness tHereof, a cable receiving portion, a first conductor receiving portion, and a second conductor receiving portion, each of said first and said second conductor receiving portions being disposed adjacent an associated one of said opposing surfaces generally adjacent said cable receiving portion, said base member further having a selectively apertured portion adjoining said first and said second conductor receiving portions to provide an access way between said first and said second conductor receiving portions, said first conductor receiving portion further having a plurality of selectively proportioned first terminal receiving recesses arranged in aligned juxtaposition adjacent an edge of said base member adjoining said first conductor receiving portion, said second conductor receiving portion further having at least one second terminal receiving recess generally overlying a selective one of said first terminal receiving recesses; and a plurality of terminals, each adapted to be connected to the bared end of an associated flat cable conductor, and further adapted to be positioned at least partially within an associated one of said first and said second terminal receiving recesses, wherein the bared end of at least one of the individual conductors of a flat conductor cable may be disposed adjacent a selective one of said first and said second conductor receiving portions and coupled to an associated one of said terminals to permit a termination thereat.

3. Means as defined in claim 2 wherein said coupling means comprises at least one selective length of metallic material affixed to said base member.

6. Means as defined in claim 1 wherein said base member selectively apertured portion comprises a plurality of selectively proportioned openings, each extending between said base member opposing surfaces.

12. Means as defined in claim 11 wherein said first contoured means comprises at least one selectively formed recessed portion and said second contoured means comprises at least one selectively formed raised portion.

15. Means as defined in claim 1 wherein said base member comprises a corresponding number of said first terminal receiving recesses and said second terminal receiving recesses, said first and said second terminal receiving recesses being symmetrically disposed adjacent their respective first and second conductor receiving portions.