US2637764A

US2637764A - Interlocking electrical connector

Info

Publication number: US2637764A
Application number: US104067A
Authority: US
Inventors: Fletcher E Maxwell
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-07-11
Filing date: 1949-07-11
Publication date: 1953-05-05
Anticipated expiration: 1970-05-05

Description

May 5, 1953 F. E. MAXWELL INTEBLOCKING ELECTRICAL CONNECTOR 3 Sheets-Sheet 1 Filed. July 11, 1949 INVENTOR, J/efc/zeri i/Zaxzaell y 5, 1953 F. E. MAXWELL 2,637,764

INTERLOCKING ELECTRICAL CONNECTOR Filed July 11, 1949 3 Sheets-Sheet 2 INVENTOR, jlefc/zer 5772mm]! HTTORNEK 7 Patented May 5, 1953 UNITED STATES Parent OFFLCFE.

INTE RL OCKIN G ELECTRICAL .1 CONN EGTOR;

Fletcher E. Maxwell, Glendale; Calif;

Application l uly L1, 1949, Serial No. 104,067

This invention relates to. so-called. socket. connectors for electrical conductors. andparticularly to an improved form thereoiiin which the connecting elements are interlocked with each other incident to completion of the electrical connection.

An object. of the: invention is to. provide a, plug and socket type of electrical conduct'orconn'ect ing means which: is so constructed and arranged that the elements are first inserted one within the otheran'd given a relatively'rotary movement to eifect the. electrical connection.

Another'object of the invcntionisto provide a plug and socket type of connector for electrical conductors in which the wall socket portion isso constructed and arranged that'it may be installed in a conventional outlet box inthe same manner as conventional wall socket units.

Still anoth'erobjeot of the invention is' to provide a plug; element which is adapted foruse with the above wall socket" and which, further, is' so constructed and arranged that two conductorsmay be interconnected with identicalplugs;

A still further object or theinventionis to provide a plug and socket type of connecting means for electrical conductors in which the live contact point is shielded toprevent accidental contact therewith.

Still another object of the invention is to pro-- vide a plug and socket ty e of connecting means for electrical conductors in which the two* elements to be connected have identical; semi-cir cula'r mating projections and socket portions and having the contact elements housed or' guarded by the semi circular' projections insuch manner thatthecontacts are interengaged by relative rotation of the connecting elements.

Still. another object of the inventionis to: provide a. connecting means for electrical conductors comprising awall socket element and a; plug type. element which: may. be engaged with" said wall socket orwith an identical plug element;

A still further object of the invention is taprovicle. a: connecting means? adapted to: connect-plugs and; sockets of: the type comprising the. present invention with conventional. screw type plugs and sockets}.

Still. another object of the invention. is. tozpro;- vide a. connecting means; foireleetrlcal conductors which the above: enumerated: objects; are achieved and which issimple and economical to. manufacture and. install and which: is both. safe and reliabl ineuse.

' With thev above objects iniview together with such. other objects. and. advantages as. may subsequently appear, the invention resides in the parts, and in the construction, combination and arrangement of partsdescribed, by Way of. example. in the following.- specification and? illustrated, alsoby, way of example in the accompany,- ing' drawings: which form a part. of said specifi cationand in. wliichdrawings:

Fig. 1. isa front. elevation of a WaIISOCkBUaSrsemblyembodying the invention,

Fig. 2 is an enlarged, sectional top-plan. view taken on the line 2.2-of Fig.. 1,.

Fig. 3-. is. a-iront-elevation. of a. wall socketassembly mounted in. a conventional outlet box,.

Fig. fisasicle elevationof the wall socketassemblv; the associated outlet. box. being shown insection-on thelinell liof. Fig. 3,,

Fig. 5.1is. a rear, sectional elevation taken; on. the lines 5-5 of.Figs..2land 4,.

Figs, 6. and? are side elevationsof themating faces. of. the,v contact carrying assemblies of the Wall. socketstructure. as indicated. by the. arrows 6.6" and.lll,.respec.tively,,onFig. 5,.

Fig. 8. is an. exploded. view of the. component parts. of'one of the contact carrying. assemblies; the. parts being shown in front elevation,

Figs. 9. and. 10 are sectional front. elevations. on the lines iii-Q and. iii-All? of. Fig. 2;, respectively, showing. the upper socket of the wall. socket open and.v the. lower socket engaged by a. plug element and theinter-engagement of the plug and' socket contact elements- Fig; 11 isacontactemi elevation of'a plugfelem'ent'. adapted for cooperation either with. the socket assembly shownin Figs. 1 to 10; inclusive, or with another plug having identical contact means,

Fig; 1'2 is a side elevation, partly. in section, of the plug shown in Fig. 1.1,v

Fig. 13 is an opposite endelevati'on' of the plug shown in Figs: 11 and 12,

Fig: 14 is a side" elevation of the contact carrying assembly" of the plug; the View being taken from the-same direction as" Fig; 12,

Fig. 1551 is an end elevation of the assembly sliown in Fig. 1'4; showing theconductor-attacm. ing means carried by the contact elements,

Figs; lfi 'and 1 7 are side elevations' oi-the mating. faces of: the component: parts of. the contact assembl'yof the plug;

Eigsz. 18. and 19. are. transverse sectional. views taken on the lines Iii-I28 and i:9|'9 of:Fig.. 1 2; respectively,

Fig. 2.0 is. a; socket;- encl elevation. of" anadapter having. at one, end a'. contact means such as: em.- ployed the present invention and at; the other. a. conventionalwinternally threaded: socket to receive a lamp or the like,

Fig. 21 is a medial sectional elevation taken on the line i9l9 of Fig. 20,

Fig. 22 is a medial section taken on the line 2222 of Fig, 21,

Fig. 23 is an elevation of the externally threaded end of another form of adapter,

Fig. 24 is a medial elevation taken on the line 24-24 of Fig. 23,

Fig. 25 is a medial section taken on the line 25-25, of Fig. 24,

Fig. 26 is a side elevation showing the endwise relative movement incident to the interengagement of two identical plugs; partly completed portions of the casing elements of the plugs being broken away for clearness of illustration, and

Fig. 27 is a view similar to Fig. 25 but showing both the endwise and rotative movements completed.

Referring first to Figs. 1 to inclusive there is shown a wall socket assembly adapted for use in conventional outlet boxes. The assembly is mounted in a wall W including a studding W having an outlet box B mounted thereon by a nail or screw N. Leads L and L extend through a conduit C to the outlet box and are secured to the binding post screws P and P" of the assembly. The front of the asssembly is covered by a conventional cover plate F, having the usual openings formed therein and which is secured in place by means to be later described in detail.

The socket assembly per se is formed of nonconductive material and a thin rectangular base member I having recessed side portions 22 and having a rib 3 rising from one face thereof around its sides except where interrupted by the recesses 2-2, a combined contact carrying and shield element 4, a side wall element 5 and a second sidewall and contact carrying element 6; all of said elements having interfitting faces so arranged as to hold them in alignment for mounting in an outlet box. The sides of said

members

5 and 6 are each provided with clearance spaces 5a and 5a, respectively, disposed in alignment with the recesses 22 in the base member I. The mounting means comprises a. U-shaped metal strap I having out-turned perforated end portions 83 adapted to be secured to the usual in-turned ear portions E of the outlet box by screws S threaded into the ear portions E, E of the outlet box (see Fig. 4). A screw 3 having its head adjacent the strap 1 and passing therethrough and thence through aligned holes H], II, i2 and [3 in the members I, 4, 5 and 6, respectively, and thence through a hole in the center of the cover plate F and engaged by a nut 3' at the exterior of the cover plate serves to hold the socket assembly together and secured to the strap 7.

The member 6 rests on and extends along one side of the base plate i and on its rear face is provided with a recess I4 into which the locating rib 3 extends (see Fig. 2) and the outer side face and the ends of the member are in alignment with the corresponding side and end edges of the base plate. The rear face of the member is provided with a groove l5 to receive a contact member 16 one end of which carries the binding post screw P and the contact portion of which is bifurcated and includes outwardly extending shanks I? and is which terminate in laterally extending contact portions i1 and I8 disposed within vertically disposed recesses i9 and 26 formed in semi-circular bosses 2| and 22 at the outer face of the member 6. Spaced from the curved portion of the periphery of the bosses 2| and 22 are skirt portions 23 and 2t, respectively the outer ends of which extend through one side of each of the openings 0 in the coverplate F and the

grooves

25 and 26 between the adjacent faces of the respective bosses and skirt portions are adapted to receive annular flange portions of the plug assembies used with these sockets as will be later described in detail. In rear of the

bosses

21 and 22, the member is cut away to form recesses 21' and 23 of segmental outline adapted to receive a portion of the cooperating plug element incident to rotation of the plug element after insertion into the socket in the manner to be later described. Preferably, the element 6 is moulded from a suitable plastic or ceramic material with the contact member moulded in place.

The rear face of the element 4 rests on and covers all of the surface of the base member 1 not covered by the element 8 and is provided with a groove 29 which mates with the rib 3 on the base member. On the edge thereof adjacent the element 6 the element 4 carries two inverted L- shaped

members

33 and 38 disposed so that one face thereof lies against the flat side face of each of the bosses 2| and 22 as best shown in Figs, 3 and 9, and the shank portions cover the grooves in the member 6 in which the shanks H and I8 of the

contact members

11 and 18 are housed as shown in Fig. 10. The outer, wider portions of the members 33 and 3| are each provided with narrow

rectangular slots

32 and 33 disposed opposite the contact member recesses l9 and 20 in the element 6 and are so disposed that a contact element on a plug will enter through the slot and engage the contact element in the element 6 upon rotation of the plug as will later be described. Also extending outwardly from the base member 4 at an acute angle to each of the members and 3i are

thin wall members

34 and 35 so disposed that one flat side thereof lies against the walls 38 and 3'! of the

recesses

27 and 23.

The element 4 is preferably moulded and is formed from non-conductive material and has incorporated therein a bifurcated conductor 38 carrying the binding post P at the juncture of the two

arms

39 and 40 thereof. The arm 39 extends along and flush with the rear face of the element 4 to a point 4! opposite the mid width of the member 34 and thence extends directly to the outer face of that member, thence parallel to and along the face of the member 34 and across the end thereof and terminates in a contact portion 42 which lies at about the middle of the recess 2'! and which i spaced from and curved about the axis of the socket. The arm 40 extends directly to the mid width portion of the member 35 and thence along the outer face and across the end of the member 35 and terminates in a contact portion 43 which is similarly disposed in the recess 23. It will be noted in Fig. 8 that the free ends of the contact portions do not extend beyond the faces of the L-shaped members 30 and 3! which are remote from the

members

34 and 35.

The element 5 has a flat inner face 44 adapted to rest on the outer face of the element 4 and is provided with dowels 45 adapted to engage holes 46 in the member 4 to hold the two elements in alignment. The element is formed with larger and smaller

circular surfaces

41 and 48 which are generated about the same centers as the

grooves

25 and 26 and which form

ledges

49 and 50 at the same level as the bottom of the grooves. These curved surfaces together with the adjacent faces of the members 30 and 3| form semicircular sockets 5| and 52 adapted to receive the plugs for which these sockets are adapted. Additionally, the element 5 includes curved outwardly

projectingskirt portions

53 and 54 which project through the cover plate F at the sides of the socket openings, opposite the

skirt portions

23 and 24, respectively.

Between the sockets 5i and 52 the element 5 is provided with a laterally extending tongue portion 55 through which the hole 42 extends and the member 6 is provided with an oppositely laterally projecting tongue portion 56 which overlies the tongue portion 55 and through which the hole 13 extends. Also, each end face of the element is provided with laterally extending tongues 5'! and 5B which engage suitable notches 59 and Ed in the ends of the element 5 to assist in holding theseveral parts or the socket in alignment for insertion of the screw 9. Thus through the various interlocking faces including the rib 3 on the base plate i, the mating grooves 14 and 29 on the elements it and 4, the dowels on the element 5 engaging the holes 46 on the element i, th meeting faces of the

elements

4, 5 and 6 together with the tongues and grooves on the ends thereof make it possible for the entire assembly to be held together for assembly with the strap l and screw b. At the same time, the conducting elements iii and 38 are completely insulated from each other and are covered except for the various contact points and the necessarily exposed binding post portions. The wall socket assembly is the same size as conventional wall socket assemblies, and is installed in conventional outlet boxes in the conventional manner. The binding posts are located in the conventional position so that no special skill is required to make the installation.

Referring now to the plug assembly portion of the invention and particularly to Figs. 11

to 19, inclusive there is shown a plug adapted to be attached to a light cord or similar conductor and to be connected to and disconnected from a wall socket assembly of the type above described or to be connected to or disconnected from an identical plug assembly. The plug assembly includes a cylindrical casing ti formed of non-conductive material having at one end a reduced diameter bore 62 through which the end of the conductor extends for attachment to the binding posts. Mounted in the larger bore 63 of the casing is the contact carrying and shielding assembly comprising elements M and 65 which have semicircular body portions (it and 57 which, when the elements are assembled, comblue to form a circular outline that fits snugly within the bore E3 and to rest against the end wall 68.

The element St at its inner end is formed with two segmental recesses $9 and it divided by a centrally disposed wall member 1i and the inner end of the element St is provided with similar recesses 69' and lil' divided by a similar wall member H and when the two elements are assembled, these recesses combine to form sectorshaped housings for the binding post ends of the contact members '12 and i3 separated by the wall members ii and H (see Figs. 15 and 16); portions of the wall members extending through the bore 62vto separate the leads of the cord to which the plug is attached.

The element 64 includes a sector shaped portion M which extends beyond the end of the easing 6! and this portion 64 from about the plane of the end of the casing to a point within the casing is undercut to provide a recess I5 through the sidewall 76 of which the contact end 7'! of the contact member 72 projects (see Figs. 16 and 18). The element 64 is provided with a groove ill which leads from the recess 69 parallel to the axis of the plug thence angularly laterally to a second parallel portion and thence at right angles to and through the wall it: and in this groove the contact member i2 is losely positioned (see Figs. 16 and 18). The contact member 13 extends from the binding post cavity it, ill along a groove '5' formed in the member 84 and extending parallel to the length thereof and terminating in a laterally disposed sector-shaped recess 86 in which the contact portion 8! of the member iii is disposed (see Figs. 16 and 19).

The element .65 is generally similar to the element St from the binding post end to a point even with the inner wall 82 of the recess 75: and from that point extends outwardly as a thin inverted L-shaped portion 83 the outer face of which intersects the axis of the plug assembly and the inner face of which overlies and covers the grooves l8 and i9 and the recess 86 except for a rectangular opening EM opposite the recess 8i? for the entrance of a contact point of another plug or socket. The

elements

6 and 65 with the contact members 12 and it are held in assembled relation by

dowels

35 and 86 on the member which engage corresponding holes t? and 35 in the meeting face of the member 65 (see 1i) and the assembly is then placed in the casing 6i and secured therein by a screw 89 which extends through holes Bil and 3! in the members and 65 and is threaded into the opposite wall of the casing at 92 (see Fig. 12).

The mode of effecting a connection between the plug and socket is illustrated in the lower portions of Figs. 9 and 10. The plug is first inserted endwise into the socket with the semicircular portion thereof entering the correspond- .ing portion of the socket and with the semi-circular boss 22 of the member 6 entering the corresponding socket or clearance portion of the plug; the groove 25 receiving the skirt portion 93 of the plug casing to permit this endwise movement. The plug is then rotated clockwise as viewed in these figures and upon such movement the contact point Tl on the plug will enter the slot 33 in the member 3i and engage the contact point i8. Simultaneously, the member 83 will move over the end of the contact point 43 bringing the contact point 8i into engagement therewith to complete the electrical connection. It is to be noted that when thus engaged the plug and socket are interlocked and can not be separated without first rotating the plug to efiect breaking the circuit. In installation of the socket it is preferable that the hot wire be connected to the binding post P so that the hot contact points ii and it associated therewith are those that are shielded by the members to and 3|. It will be further appreciated that this novel construction permits the direct interconnection of identical plugs since the semi-circular projec tions of each will enter the semi-circular recesses of the other whereupon relative rotation of the plugs (see Figs. 26 and 27) will interlock the plugs with incident interengagement of the contacts Ti and SI of one plu with the contacts Bi and H respectively of the other plug. It will be appreciated that in preparing cords having these plugs at each end, if the contacts are reversely connected to the conductors, the safety 7 feature of having the "hot contact shielded will be preserved.

Referring now to Figs. 20, 21 and 22, there is shown an adapter to connect a plug of the type forming part of the present invention with a conventional internally threaded socket such as a lamp socket. In this form of the invention the internally threaded metal shell 94 is moulded in place in a cylinder or casing 95 having a wall portion 95' extending across it intermediate its ends. The shell 94 has a laterally extending tongue portion 96 through which a rivet 91 disposed in the Wall 95 extends and the other end of the rivet is engaged by the out-turned end 98 of the contact element 99 which is generally similar to the element I2 in the previously described form of plug assembly. A second rivet I extending through the wall 95 at a point diametrically opposite the rivet 91 secures a contact element IOI adapted to engage the center contact of a light bulb or other connecting element screwed into the shell 94 and at the opposite side of the wall 95 the rivet I00 is engaged by the out-turned end I02 of a contact element I03 which is generally similar to the contact element I3 in the plug assembly shown in Figs. 11 to 19. The members I04 and I05 in which the contact elements 99 and I03 are housed are generally similar to the

members

64 and 95, respectively, except that the portions that formed the cavities for the binding posts and the dividing wall between the cavities are dispensed with. A screw I06 extending through one wall of the casing 95 thence through holes I01 and I08 in the members I04 and I05 and threadedly engaging the opposite wall of the casing holds the parts in assembly.

Referring now to Figs. 23, 24 and 25, there is shown an adaptation of the plug element of the present invention to an externally threaded plug for engaging the conventional type of screw threaded socket. In the form shown, an externally threaded sleeve I09 is molded in place on a casing member IIO which is in the form of a hollow cylinder having a larger diameter portion III at one end and a smaller diameter portion I I2 at the other end which terminates in an end wall H3. The outer face of this end wall is provided with two diametrically opposite notches or recesses H4 and H5 into one of which a laterally extending tongue portion IIG of the sleeve I09 extends and is engaged by a rivet I I! extending through the end wall II3. A contact element I I8 having a portion thereof extending over the center of the end wall I I3 is disposed in the recess I15 and secured therein by a rivet H9 mounted in the end wall II3. The contact assembly is similar to that shown in Figs. 20, 21 and 22 except that the contact elements I20 and I2I are formed with extensions having S-shap-ed bends formed therein terminating in out-turned portions I22 and I23 so that they will engage the heads of the rivets H9 and I I! respectively, with sufficient pressure to insure proper contact. The parts are held in assembly by the screw I06 in the same manner as shown in Figs. 20, 21 and 22.

While in the foregoing specification I have described a specific mode of execution Of my invention, it will be understood that this is by way of example and that I do not intend thereby to be limited to the exact form disclosed and that the invention embraces all such modifications of the parts and of the construction, combination and arrangement of parts as shall come within the purview of the appended claims.

I claim:

1. A connector for electrical conductors comprising a pair of assemblies having identical interengaging and contact effecting elements; each of said assemblies comprising a semi-cylindrical plug portion and a plug receiving socket having a plug receiving opening disposed with the flat side thereof in juxtaposition to the flat side of said plug; said plug within said opening being reduced segmentally in cross section with resultant increase of said socket to segmental form of greater than semi-circular extent, a first contact member projecting into said socket, a second contact member housed within said plug and terminating in a contact surface adjacent the outer end of said plug, and an opening in a side wall of said plug opposite said contact surface through which said first contact member of one of said assemblies may enter and engage said contact surface of the other assembly when said assemblies are interengaged with the plug portion of each assembly disposed in the socket portion of the other assembly.

2. A plug and socket connected means for electrical conductors comprising a wall socket assem bly adapted to be mounted in a conventional outlet box and having a pair of binding posts for connecting it to a source of electrical energy and having a base portion supporting a plurality of sockets for engagement with connector plugs, each of said sockets including a semi-cylindrical plug receiving recess and a semi-cylindrical plug portion disposed with its fiat side forming the flat side of said semi-cylindrical recess; each of said plug portions adjacent the bottom of said semicylindrical recess being cut away to form a segmental shaped recess, a plurality of contact members disposed one in each of said segmental shaped recesses connected to one of said binding posts and a plurality of contact members disposed one in each of said semi-cylindrical plug portions and connected to the other of said binding posts, and a plug element constructed and arranged to engage said sockets.

3. A plug and socket connector means for electrical conductors comprising a plug element having a pair of binding posts for connection to the leads of a lamp cord or the like at one end thereof and having a semi-cylindrical recess at the other end with a semi-cylindrical plug portion disposed adjacent to said recess with the flat side of said plug portion forming the fiat side of said recess; said plug portion adjacent the bottom end of said semi-cylindrical recess being cut away to form a segmental shaped recess, a contact member connected to one of said binding posts and extendin into said segmental shaped recess, a second contact member connected to the other of said binding posts and extending into said semicylindrical plug portion, and a slot in the flat side face of said plug portion affording access whereby a contact member of another connecting means may enter for engagement with said second contact member.

4. A plug and socket connector means for electrical conductors comprising a wall socket assembly adapted to be mounted in a conventional outlet box and having a pair of binding posts for connecting it to a source of electrical energy, said assembly comprising a base plate, having a peripheral rib, a contact carrying member having a thin base portion engaging the rib on said base plate and a pair of inverted L-shaped flange portions and a pair of shorter flange portions lying in planes intersecting the planes of said 9 i inverted L-shaped flange portions at acute angles, a' contact element carrying one of said binding posts mounted on said contact carrying element and having contact points overlying said smaller flanges, a socket forming element mounted on the base of said contact carrying element and having curved wall portions which cooperate with inverted L-shaped flanges to define semi-cylindrical recesses, a second contact carrying eiement mounted on the base plate adjacent to said first contact carryin member and said socket for1ning element and engaging the rib on said base plate; said second contact carrying member having face portions which mate with the outer sur-- faces or" said flanges, a contact element carrying said other binding-post mounted in said second contact carrying member and having contact portions housed in recesses in said mating faces, a slot in each of said'inverted l.--shaped flanges opposite said last named contact points and a screw passing through said base plate, both of said contact carrying members and socket forming member effective to hold said members in assembled relation, and a detachable plug having correspondin semi-cylindrical plug and socket means adapted to be connected with and disconnected from said assembly.

5. A plug and socket connector means for electrical conductors comprising a wall socket as sembly adapted to be mounted in a conventional outlet box and having a pair of binding posts for connecting it to a source of electrical energy, said assembly comprising a base plate, having a peripheral rib, a contact carrying member having a thin base portion engaging the rib on said base plate and a pair of inverted L-shaped flange portions and a pair of shorter flange portions lying in planes intersecting the planes of said inverted L-shaped flange portions at acute angles, a contact element carrying one of said binding posts mounted on said contact carrying element and having contact points overlying said smaller flanges, a socket forming element mounted on the base of said contact carrying element and having curved Wall portions which cooperate with said inverted L-shaped flanges to define semi-cylindrical recesses, a second contact carrying element mounted on the base plate adjacent to said first contact carrying member and said socket forming element and engaging the rib on said base plate; said second contact carrying member having s-ec tor shaped plug forming portions, the flat faces of which mate with the faces of said inverted L-shaped portions to form semi-cylindrical plug portions of the substantially same cross-sectional area. as said sockets, a contact element carrying said other binding post mounted in said second contact carrying member and having contact portions housed in recesses in said sector-shaped portions, a slot in each of said inverted L.-shaped flanges opposite said last named contact points and a screw passing through said base plate, both of said contact carrying members and said socket forming member effective to hold said member in assembled relation, and a detachable plug having corresponding semi-cyiindrical plug and sock et means adapted to be connected with and disconnected from said assembly.

6. A plug and socket connector means for electrical conductors comprising a cylindrical, non conductive casing element having a transverse wall portion intermediate its ends, an internally threaded metal sleeve mounted in one end of said casing having a laterally extending portion en gaged by a rivet extending through said wall portion, a contact element mounted on said wall portion by a second rivet extending through said wall portion at a point remote from said, first named rivet and having a portion thereof disposed at the center of said end wall, connecting means at the other end of said casing comprising two members having semi-circular base portions disposed in said casing and secured in said casing by a screw extending diametrically acros said casing and both of said base portions; one of said members having a sector-shaped portion extending beyond said casing and having a segmental shaped recess formed therein adjacent said base portion, a first contact member mounted in a groove in said one member having one end in engagement with one of said rivets and the other end extending into said segmental shaped recess, a second contact member mounted in a second groove in said one member having one end in engagement with the other of said rivets and having the other end thereof disposed in a sector shaped recess in said sector shaped portion, the other of said members having a flange portion of inverted L-shape disposed with one side there of adjacent the flat face of said one member; said inverted L-shaped portion covering the grooves in said one member and having a slot formed therein opposite said sector shaped recess to admit a contact of another connecting assembly for engagement with contact portion in said recess; said sector shaped portion of said one member and said inverted L-shaped flange of said second member together forming a plug portion of semicylindrical cross section and the space between the wall of said. casing and the side of said flange forming a semi-cylindrical recess of substantially equal cross section adapted to engage a connecting element having identically disposed sockets, and plug elements.

'7. A plug and socket connector means for electrical conductors comprising a cylindrical shell having a reduced diameter opening at one end for entrance of a conductor and having inserted from the other end two members "raving semicylindrical base portions secured therein by a screw extending diametrically across said casing and said base por ions, one of said members having a sector shaped portion extending beyond said casing and having a segmental-shaped recess formed therein adjacent the base portion of said member, a first contact member mounted in a groove in said one member, a contact member disposed in said groove and extending from a binding post carried by said contact member adjacent said reduced diameter opening along said groove and terminating in a contact point disposed in said segmental shaped recess, a second groove in said one member, a second contact member disposed in said second groove and extending from a binding post carried by said second contact member adjacent said reduced diameter opening along said second groove and terminating in a contact portion disposed in a recess in said sector shaped portion; the other of said members having a flange portion of inverted L-shape disposed with one side thereof adjacent the flat face of said one member; said inverted L-shaped portion covering the grooves in said one member and having a slot formed therein opposite said sector shaped recess to admit a con tact of another connecting assembly for engagement with contact portion in said recess; said sector shaped portion of said one member said inverted L-shaped flange of said second in niber together forming a plug portion of semi-cylindrical cross section and the space between the wall of said casing and the side of said flange forming a semi-cylindrical recess of substantially equal cross section adapted to engage a connecting element having identically disposed sockets, and plug elements.

8. A connector means for electrical conductors comprising two assemblies each having a pair of contact elements including means for attachment to a pair of conductors, each of said assemblies having a semi-cylindrical plug portion and an adjacent semi-cylindrical socket portion, having an end wall; the curved faces of said portions being generated about a common axis and the plug portion of each assembly being insertable into the socket portion of the other assembly; each of said plug portions having a segmental shaped recess cut in one side thereof; said recess extending from the plane of said end wall axially of said plug portion to a point slightly in excess of the length of said plug portion; one of said contact members in each of said assemblies terminating in a contact point projecting into said segmental shaped recess and the other of said contact members terminating in a recess formed in the outer end of said plug portion and positioned to be engaged by the first named contact member of the other assembly when the two assemblies are inserted one within the other and given a relative rotative movement; the segmental shaped recesses of each assembly providing clearance space for that portion of each of the plug portions which overlie the said recesses and certain of the interengaging faces of said plug portions and said recesses when interengaged serving to absorb all stresses incident to forces tending to separate said assemblies by direct pull parallel to said axis.

9. A connector for electrical conductors comprising a pair of assemblies having identical interlocking and contact effecting elements; each of said assemblies comprising a semi-cylindrical plug portion and a plug receiving socket having a semi-cylindrical plug receiving opening disposed with the flat side thereof in juxtaposition to the flat side of said plug portion; said plug portion within said opening being reduced segmentally in cross section with resultant increase of said socket to segmental form of greater than semi-circular extent, a first contact member having an electrical contact effecting surface disposed in said socket and lying in a plane normal to the axis about which the curved surface of said plug portion is generated, a second contact member having an electrical contact effecting surface disposed wholly within said plug and lying in a plane parallel to the plane of said first contact member, and an opening in a wall of said plug portion opposite said second named contact surface through which said first named contact member may enter and bring said contact effecting surfaces together when said assemblies are interengaged with the plug portion of each disposed in the socket of the other and subjected to relative rotation; the entry of said first contact members into said openings in said plug walls serving to interlock said assemblies against separation while said contact surfaces are interengaged.

FLETCHER E. MAXWELL.

References Cited in the file of this patent UNITED STATES PA'IENIS Number Name Date 366,654 Duby July 19, 1887 367,931 Runels Aug. 9, 1887 1,265,163 Bahls May 7, 1918 2,015,715 Doane Oct. 1, 1935 2,190,230 Cole Feb. 13, 1940 2,197,981 Meston Apr. 23, 1940 2,386,177 Andersen Oct. 9, 1945 FOREIGN PATENTS Number Country Date 10,260 Great Britain of 1891