US2427182A - Electrical coupling disconnector - Google Patents

Description

Sept. 9, 1947.

M. D. BERqAN ELECTRICAL COUPLING DISCONNECTOR Filed Jan. 15, 1943 5 Sheets-Sheet 1- 8 m. y mR w Mod 5 vm D w on 7 K 2 M. W C L 1.1 :2 w \\2 mu wN hm MN 5 3 2 .lw u S Sept. 9, 1947- M. D. BERGAN ELECTRICAL COUPLING DISGONNECTOR 3 Sheets-Sheet 2 Filed Jan. 15, 1943 B a 2 u R 9 m. 2 3 8 5 S 2 a mm w MR m l .*U m E O I v 1 u A .B T I T Il..l D ans a d-u m a. E T v GP E mw Mfl 9 9 g Q 3 a. m. 3 Q a 2 N6; 8 2 3 3 2. s 2 a 2 a 2 2 S 2 l fwd .N m. A 6 0;

Sept. 9, 1947. M. D. BERGAN ELECTRICAL COUPLING DISCONNECTOR 3 Sheets-Sheet 3 'Filed Jan. 15, 1945 ATTORIYEY.

Patented Sept. 9, 1947 ELECTRICAL COUPLING DISCONNECTOR Martin D. Bergan, Westfield, N. J., assignor to The Thomas 8 Betts 00., Elizabeth, corporation of New Jersey N. :L, a

Application January 15, 1943, Serial No. 472,436

13 Claims. (Cl. 173-328) This invention relates to electrical wirin connectors, such as conductor terminals and splicers, plug-in connectors and the like, and more particularly to a new and useful electrical coupling disconnector.

One of the purposes of this invention is to produce a new connector receptacle in theform of a coupling sleeve means having one portion thereof making electrical connection by applying pressure to a conductor or wire terminal as well as another portion thereof making an anchorage or mechanical connection by engaging a latching means with the terminal, and the two portions acting in combination to provide this dual connecting function, as well as affording a quick disconnection by manually pulling the terminal from the receptacle sleeve means.

Another purpose of the invention is to produce an electrical connector having a minimum outside diameter, with disconnect terminal means having contact surfaces of maximum area which slide together and Wipe their way into an overlapping electrically joined relation with each other, together with anchorage means comprising the connector'receptacle heretofore mentioned rendering the terminal means secure or substantially positive in joined relation, and wherein the parts are held together against relative longitudinal and rotative loosening motion.

One of the advantages of minimum outside diameter for a given connector resides in the fact that it is more useful in wiring harness installations where there are a large number of conductor wires bundled or banded together requiring many connectors and where essential to reduce bulk and weight of the wiring harness when used in aircraft or other machines and installations. Also, the maximum area pressure wiping contact surfaces act to clean each other when they slide together and thus reduce electrical resistance and avoid heating at the connection. Furthermore, the connector parts being secured against vibratory loosening action increases the capacity of the joint, both electrically and mechanically, avoids atmospheric contamination, and minimizes corrosion.

An important feature of the invention resides in the dual function of this disconnecting coupler, wherein separately operative portions thereof act independently to establish the electrical and mechanical connections, an important factor in a variety of installations, particularly in the wiring of machine sub-assemblies on factory production lines, since a sectional wiring harness of one sub-assembly may be quickly connected with the wiring harness of another sub-assembly when the main assembly of an aircraft or other completed machine is reached on the production line. Likewise, the connector facilitates replacement and repair work since a damaged section of wiring harness can be removed from a sub-assembly of a machine and a new wiring set installed without disturbing the undamaged wiring.

Furthermorarthe capacity of this new connector to hold its joint as well as release it, for wire coupling and splicing work as above indicated, also adapts this invention to panel and instrument wiring installations, as well as grounding or bonding connector usage with overboard fuel tanks or other electrically grounded apparatus which sometimes must be jettisoned by jerking away and dropping from a craft without time or tools to release the connectors.

A further purpose is to produce an electrical disconnector having a pair of flat electrical contact surfaces of maximum area which frictionally wipe each other to eiiect a surface union when introduced into a given minimum-size connector sleeve receptacle means, in combination with pressure exerting means carried with the sleeve which expands to attain maximum tension and thereafter maintains such expanded tension for exerting a constant clamping pressure without contracting back to its original size and hence without loss of contact pressure, together with a latching means which likewise expands but only momentarily and then instantly moves or contracts back to its original size to establish a latched mechanical connection.

This description and the accompanying drawings disclose the principle as well as the structural organization of the invention and suggest future modifications and equivalent embodiments to those 'who may avail themselves of the benefits of the invention.

Electrical connectors of the type herein are more generally used for small-size stranded wires or cables but to facilitate this description, the drawings show the connector on a larger scale than ordinarily produced for the trade and as heretofore made from time to time in many different forms in selecting the illustrated construction preferred at this time.

Figs. 1 thru 13 show the invention adapted to wire line splicing or coupling operations, wherein a pair of duplicate-dimensioned or twin wire terminals plug into a coupling sleeve for connect and disconnect operations.

Fig. 1 shows a sheet metal blank or stamping which is formed into a splicing or coupling sleeve adapted to receive and anchor a pair of terminals, together against longitudinal and rotative vibration and thus Join two wires when the invention is used as a line splicer.

Fig. 2 is a group of three views showing the completed splicing or coupling sleeve, including a top, a side, and an end view thereof.

Fig. 3 is a section on the line 3-3 of Fig. 2 made through a longitudinal slit and transverse slot of th coupling sleeve receptacle.

Fig. 4 is a group of three views showing the wire terminal, comprising (at the left) its open or tubular end for receiving and permanently securing it to a conductor wire, also a side view of said terminal in its full length, and (at the right) an end view of its latching bead with integral contact tongue of solid formation carried on the tubular end.

Fig. 5 also is a group of two views showing a pair of the terminals, one of which has been plugged into the coupling sleeve, whil the other terminal is in readiness to enter the sleeve and make wiping contact with the first terminal.

Figs. 6 and 7 are, respectively, top and side views of the connector, that is, a wire terminal plugged into each end of the coupling sleeve making a complete assembly of the low-resistance wire splice; and Fig. 8 is also a side view with the coupling sleeve shown in section.

Figs. 9 and 10 are, respectively, cross sections made on the lines of like number applied to Fig. 8.

Fig. 11 is a cross section make on the line I I- ll! of Fig. 8 and is enlarged in its companion view, Fig. 13.

Fig. 12 is a group of two views, a side and an end elevation, of magnified scale, showing the tip of the terminal, to more fully illustrate the relation between its contact tongue (electrical connecting portion) and latching neck (mechanical connecting portion). The view is presented to emphasize the preferred commercial form of the invention selected to illustrate th principles involved.

Fig. 13 is a magnified cross-section developed from Fig. 12, and particularly being a cross-section made on the line ll-l3 of Fig. 8, showing two of the terminal contact tongues plugged together into a coupling or splicing sleeve, to disclose a structural feature providing diametrically disposed clearances by which to derive, from a minimum size coupling sleeve, the maximum of its clamping pressure against engaged contact surfaces. The view is greatly enlarged over its companion view (Fig. 11) in aid of illustrating the principle of one of the more important forms of the invention.

Figs. 14 and 15 show the invention used for panel and instrument wiring or other electrical installations. These views present a modified form of the connector sleeve converted to a plu in socket for use with one wire terminal of the same form and having the same mode of connecting operation as heretofore disclosed for two terminals. Thus Figs. 14 and 15 show the invention adapted to uses other than wire coupling operations in conductor line splicing.

Fig. 14 is a side view of a single wire terminal inserted into the new plug-in socket shown in longitudinal section, the socket having a known means for mounting it in service position on an instrument panel or other structural part of any machine or apparatus, either in a power circuit or an electrical grounding line.

Fig. 15 is a cross section on the line l5l5 of Fig. 14 showing a maximum-area contact formed within the socket adapted to connect with a single terminal.

Figs. 1 thru 13 Referring further to the drawings (Figs.1 and 2), a flat sheet blank I 0 is shown as formed of metal and rolled to make a coupling sleeve II for the electrical connector. The longer parallel side edges ll of this blank define the length of the completed coupling sleeve and provid a longitudinal split or slit (also l2) extending through and from end to end of the sleeve. This longitudinally split sleeve is formed of hard or of semi-hard material and is tough and radially resilient, in that its slit l2 permits the sleeve to expand and contract in diameter with the edges of the slit separating and approaching each other. The slight spacing at the slit I2 maintains the resilient radial and circumferential tension of the sleeve so it will act spring-like to yieldingly grip one or more wire terminals received thereinto. As will more fully appear, the sleeve II is not necessarily a current transmitting part as such, and it need not necessarily be made of metal.

A transverse slot 13 is formed near or proximate each end of the coupling sleeve H. Two separate halves of each slot may be notched in alignment into the opposite edges i2 of the blank I 0 and, when fashioned into the sleeve l l, the notch pairs come together to form the segmental slot l3 having a partial circumferential reach, more or less, of about In this example of the invention, the two slots l3 cut across the lengthwise slit l2 which "dispose the slots and slit on the same side of the sleeve. However, good results are accomplished by disposing the slot or slots It! on the side of the sleeve opposite the slit l2, as indicated at i3 in Fig. 1. This connector sleeve l I has been made in both of these forms in arriving at the present preferred form.

The partial circumferential or segmental slot or slots l3 may be spaced from each end of the connector or coupling sleeve H in about the relative proportions or distances shown. Accordingly, in this example of the invention, that side of the sleeve having the slit !2 is seen to be divided by the slots i3 into a pair of arcuate spring arms or segments i i forming a central portion of the sleeve and somewhat longer axially than each pair of segmental spring arms l5 forming the two end portions of the sleeve. On the other hand, all three pairs of segmental springs H5 and I5, asdivided by the single lengthwise slit l2 intersecting the two transverse segmental slots l3, are of equal segmental or partial circumferential length. Hence, the axially longer or larger central spring pair or means I4 is stifier for compressively exerting a greater force than the smaller end spring means l5. As later explained, the

central springs l4 perform a distinct function in- Y dependently of the end springs 15.

Thus it is seen that the slit and slot means I2, I3 is an example of structural interrupting means which enables the resilient characteristic of the coupler sleeve (Fig. 2) or the receptacle (Figs. 14 and 15) to manifest itself by a springing or giving action, in connection with receiving a conductor terminal thereinto. In fact, this structural interrupting means l2, I3 (in its exemplary form shown here) provides two independently springing or giving portions, one of which build up a spring-loading or pressure tension and holds it, while the .other portion does not. The utility of these two functions will be understood as this description proceeds.

Next, it will be described the wire terminal, in

, pairs, that is, of twin or identical construction,

adapted to be detachably inserted into the above described coupling sleeve II, and. its description begins with Fig. 4. The terminal is of tubular formation at one end, solid at its other end, and is shown in this example as formed in one piece from rod stock. A body or tubular portion l6 has an inside longitudinal wire receiving bore or socke't l1 adapted to receive the bare wire strands S cleaned of insulation W, asshown on one of the wire cable ends in Fig. 5. The bore IT is closed at its bottom or inner end and makes a snug fit with the Wire strands S. The bore surface may be roughened or serrated in order to increase its swaged grip on the wire, as understood in the art, in the event crimping is employed to secure the terminal on the wire as shown in the present example of the invention.

The wiring end of the tubular body, portion [6 may be expanded to form a cuff or insulation grip i8 increased in diameter over the body of the terminal. Thus, the cuff l8 has an inside bore l9 of a diameter adapted to receive the insulation W of the stranded wire S. The wire insulation W is received into the cuff bore l9 and the clean wire end S into the bore l1, both having a snug fit in their respective sockets to produce a wire conductor en'd fitted and tipped with this new terminal to join with another wire similarly prepared, as seen in Fig. 5, etc.

A latching neck or stem 20 is carried on the tubular body portion i 6 of the terminal as an extension from the bottom closed end of its wire bore ill and may be co-axial therewith. This cylindrical neck 20 is of reduced diameter and may be somewhat shorter in length than the tubular body 16. A head in the form of a head or flanged shoulder M is made on the neck 20, say

at the outer extremity of the latter, and the bead is slightly larger in diameter than the neck and concentric therewith. In this example, the bead H is an annulus circumferentially defined on the neck 20 as a flanged rim or shoulder, but other forms of shoulder means may be used for the latching function hereinafter explained.

The shoulder means or bead 2i ovals or gradually reduces in diameter toward its outer segmental end forming a surface extremity 22 slight- 1y less in diameter than the inside of the coupler sleeve H, by which to effect a smooth low-resisting and piloting entry into the end of the split sleeve. Likewise, the rear side of the bead is made with an annular bevel or chamfer of steep or approximately 45 formation by which to reduce down to the neck 2'0 in order to enable the terminal to be disconnected from the sleeve by pulling on the terminal until the annular bevel cams its way from behind the edges of the spring latching segments l5.

Particularly, the diameter of the latching neck it conforms approximately to that of (or it may be a few thousandths of an inch smaller than) the inside diameter of the coupling sleeve ii and in length is about equal to the axial length of the latching springs it at each end of the sleeve. Furthermore, the annular bead 2i has a rim or axial thickness conforming to or slightly less than the width of the transverse slots l3 in the sleeve H to effect a free but snug fit thereinto.

Consequently, the terminal neck 20 and bead 2| bead 2| of larger ize to enter and then expend their tension in contracting instantly around the neck 20 behind the rim of the bead.

An electrical contact tongue 23 extends axially and integrally from the beaded end 2| of the latching neck 20 on the wire terminal I6. In this example, the tongue is somewhat longer than the latching neck, and more particularly is about the same length as that of the central spring segment pair [4 of the coupling sleeve H. The tongue 23 is substantially half round in cross-section, and its radius may be the same as that of the neck 20. The equal radii of the segmental tongue 23 and neck 20 male portions may be slightly less by a few thousandths of an inch than the inside radius of the female coupling sleeve.

The are or partial circumference of the tongue 23 measures approximately or more, defining a segmentary cross-section, the chord 24 of which defines the plane of a flat contact wiping surface (also 24) of maximum area for a given size terminal and sleeve assembly ll, I6. When the two complementary inner flat sides 24 of two terminal tongues slide together in registry, they form in cross-section a circular joint assembly,

' axially of the two necks 20, to make a snug pressure fit within the central portion M of the sleeve ll.

However, it is preferred to so increase the 180 arc defining the segment of the tongue, to about to ,more or less, that when two terminals (which are counterparts of each other) are in overlapping registry and fitted together in the sleeve II it followsthat two tongues 23 form in cross-section an oval joint assembly, symmetrically co-axial with their necks 20, slightly oblong and hence out of round so to speak, perceptibly more than a true circle. The oval bulge of two overlapping contact tongues produces a maximum pressure fit within the spring segments l4, more so than could be attained by two precisely half-round tongues. The central springs M bulge just a little out of a true circle, the result being that maximum pressure is exerted on the overlapping tongues 23. Moreover, the central spring means I 4 remain expanded to maintain a sustained pressure between the electrical contact surfaces 24, as distinguished from dropping into a detent groove with a loss of pressure (as in conventional practice) which results in less effective electrical transmission.

In the assembly views of the drawings, note the wider opening of slit it between the center spring pair it than between the latching springs it at the end or ends of the coupler sleeve H. For example, compare the wider opening of slit H2 in Fig. 10 to that of Fig. 9. Also, observe the expanded spring segments I l in Figs"? and 8. This differential results from the central springs it remaining expanded and thus retaining their flexure and strength to exert a sustained pressure on the terminal tongues 23 to urge their contact surfaces 24 together. On theother hand, the contracted latching segments i5 show a closer spacing at the slit i2 due to relaxed tension in 7 closing down on the neck 20 and latching it within the sleeve N.

Fig. 12 is greatly magnified over its companion view Fi 4 to show a structural relation between the terminal neck 20 and its tongue 23 constituting the present exemplary construction preferred over other forms previously made in the course of achieving the results herein. The neck axis is indicated at NA coincident with the chord 24, and the tongue axis is marked TA. The neck axis NA and the coincident chord 24 (plane of overlapping contact surfaces 24) also constitute the axis of the coupler sleeve As said before, the radii of the segmental tongue 23 and the cylindrical neck 20 are equal but slightly less than the inside radius of the sleeve H.

In producing the terminal, the radius of the arc defining the outer rounded surface of the tongue 23 (and being the radius of the neck 20) has its center on the tongue axis TA perceptibly eccentric to the neck axis NA and located slightly inside the arc of the segmental tongue upon a line perpendicular to the chord or fiat surface 26 which subtends slightly more than 180 by extending the arc until its ends reach the chord 24, the latter being coincident with the neck axis NA. This arrangement makes the chord 24 slightlyless in length than the inside diameter of the sleeve H (see Fig. 13 greatly magnified over its companion view Fig. 11) and, together with the cocentricity of the tongue 23 to the neck 2|], affords tongue and sleeve clearance at C.

Accordingly, as best seen when magnified as in Fig. 12, the bottom line of the tongue segment 23 is on the same line or flush with the circumference of the bead 2|, despite the fact that the tongue is slightly eccentric to the bead, and the amount or value of the eccentricit may be approximately the diiference between the radii of the neck 20 and its slightly larger bead 2|. The diameter of the bead 2| is slightly more than the inside diameter of the coupling sleeve II in order to snap into the sleeve slot I3 and latch behind the segmental springs I5, the bead 2| and neck 20, in effect, being displaced eccentrically to the sleeve axis when in this final position.

By using the radius of the neck 20 for generating the segment of the tongue 23, and by locating the center of said radius on the axis TA which is oil-center from said neck axis NA as above explained, as well as extending the are thus generated to the chord 24 coincident with the neck axis, a mode of operation is achieved which gains maximum efficiency between the pressure wiping contact surfaces 24 of two terminals plugged into one coupler sleeve Ii. In the first place, the two necks 20 with their shoulderllke beads 2| are in axial alignment with each other and slide on the axis of the sleeve when initially inserted thereinto from each end, thereby making a properly centered entry into the sleeve. Likewise, the two tongues 23 when in registry constitute an assembly having concentricsymmetry (although each tongue is eccentric to the terminal body l6 and neck 20) with respect to the neck axis NA which, as said before, is also the axis of the connector sleeve means II.

By reason of the foregoing conditions, the two, contact surfaces 24 of the twin terminals Wipe together on the neck and sleeve axis NA despite the eccentricity of each tongue 23. Such an arrangement of two overlapping male parts 23 plugged into one female part not only makes for positive electrical connection independently are in registry the result is a slight out-of-round or oblong in. cross section, as aforementioned. This feature provides the crescent-shape space or clearance C (Fig. 13) at each side of the overlapping tongues 23, between them and the inside of the sleeve symmetrically disposed, on either side of the chord 24 defining the width of the two engaged contact surfaces. Therefore, the two complementary tongues in registry have a major diameter which is slightly greater than the inside diameter of the sleeve and a minor diameter slightly less than said sleeve diameter, resulting in the side clearances C.

Providing the two crescent shaped side clearance areas at C (Fig. 13) promotes or increases to the maximum the application of sustained pressure exerted by the free ends of the spring segments I4 bearing against the tongue contact or tongues 23 inside the sleeve II. This is due to the fact that the side clearances C, at diametrically opposite positions, afford free fiexure of the two spring segments l4, since the bases thereof, where they join the sleeve, meet n0 interfering engagement with the tongues and hence are not restricted in fiexure. This feature is brought out in Fig. 13 which may be read as a cross-section of two Fig. 12 tongues plugged together into the coupling sleeve II or simply an enlarged cross section on the line I 3 of Fig, 8.

The tip end of the flat contact surface 24 of the tongue 23 is swaged 01? or reduced to an end b'evel finish 25, with a rounded nose finish 26, merging with the arcuate outer surface of the segmental tongue. Such finished tip not only makes for its quick entry into the coupler sleeve I but also the finding of its wiping registry with another terminal tongue previously inserted. The rear end of the flat contact surface 24 may be swaged at 21, thus merging with the segmental end surface '22 of the bead 2|, to reinforce the integral juncture of the two portions 2| and 23.

In the use of the connector, the wire is prepared by trimming oil? the insulation W to a square shoulder and baring the wire by'cleaning it to expose the strands S. Thereupon, the wire is inserted into the terminal 58. The cufi I8 is now crimped at 3i! onto the insulation W to make a neat non-fraying joint, and the tubular body It is also crimped at 3| onto the cable strands S. Thus, the wires to be connected or spliced are tipped and fitted with the twin terminals.

Two terminals l6 plug into the coupling sleeve without selecting any particular location for their tongues 23 in relation to the sleeve slit l2.

Accordingly, a wiring mechanic first snaps a terminal l6 into one end of the sleeve in any position in which he happens to be holding the two parts at the moment, the end of the sleeve coming to rest against the shoulder stop formed where the reduced diameter of the neck 20 joins the body It. Then the other terminal is partially inserted into the other end of the sleeve and rotated slightly until the two fiat inner sides 24 find registry with each other, whereupon the me-- chanic rams the second terminal home until its latching bead 2| also snaps into the other latching slot |3 at the other end of the sleeve. This 9 plugging-in operation causes the resilient sleeve portions I4 to give and thus store tension, that is, become spring-loaded, in order to exert a force in an effort to return to normal unsprung position or positions. The rounded or chamfered front and rear sides of the bead enable it to expand the sleeve spring segments l by which to enter and likewise expand said springs to cam its way out when the terminal is given a pull to disconnect it from the socket.

The entry of the second terminal wipes the two plated contact surfaces 24 together under the pressure of the two expanding central spring segments M which remain expanded, that is, springloaded, under tension to press together and maintain the surface union of the two fiat contacts 24. There is no dropping ofi'of the elastic give which imposes the contact pressure, as in conventional practice, since the spring segments M arenot detent-latching springs, and are not called upon to latch and perform a mechanical holding connection.

The coupling sleeve 8 l secures itself around one or both terminals it against relative rotative vibration between the parts under the most extreme conditions of machine vibration, should the latter develop. This feature resists the development of corrosion which gains headway between contact surfaces when eventually a slight vibratory motion develops. In this connection, the ends of the transverse slots l3 (as well as l3 in Fig. 1)- not only grip the rims of the beads ti but likewise there is the sustained clamping pressure of the spring segment pair it against the terminal portions 23 to secure the parts against vibratory loosening action.

. In sliding into the expanded sleeve end it, the

beaded neck 20, ill moves co-axially with the sleeve, but when the bead or shoulder portion 2! snaps into its latching slot I3 there follows a transverse displacement which then disposes the bead and neck axis NA eccentrically to the sleeve axis. This mode of operation lets that side portion (about one-half) of the bead fl, which is opposite to the slot iii, come to rest against the inner surface of the sleeve, thereby forcing the other half of the bead out into the slot. This not only insures a sustained latched anchorage of one half the bead in registry within the slot it, but moreover causes the latching spring segments it to contract and grip positively around the neck 20. In this connection, see Figs. 8 and 9 wherein is shown the final eccentric position of the beaded neck in the sleeve; observe the clearance between the neck 2d and sleeve ll. This clearance is forced by engagement of about one half the circumference of the bead 2i resting against the sleeve, said half being opposite the slit l2 forming the spring segments l5, thereby forcing the neck toward the segments and gaining from the latter the maximum of their latching tension. These are important features relating to the mechanical connection functioning independently of the electrical connection.

It will be seen that the two fiat contact surfaces M wipe together in a common plane, as distinguished from bringing one terminal rectilinearly into engagement with the other. This wiping contact produces a molecular surface union not attained when fitting plane surfaces together by engaging them with motion perpendicular to their surfaces. The wiping action cleans the surfaces, excludes atmospheric contact, and gains maximum efficiency from the plated contact surfaces 24 which are usually silvered in quality type of connectors where maximum current transmission with minimum sizeparts is essential to a particular requirement in electrical installations. It is well known that the advantages of plated surfaces of non-wiping contacts is largely lost, that there is a lack of surface union, and that the development of corrosion is not inhibited.

From the foregoing, it will be seen that the central portion I 4 of the sleeve act to make the electrical connection and the end portion 55 thereof makes the mechanical connection. This is an important advantage, in that the pressure function of the central pring means M cannot also perform with maximum efficiency the latching function of the end spring means l5, any more so than the latter (having lost their tension for latching purposes) can perform the function of the former. The maintenance of the compressive tension of the spring means M and the dissipated latching tension of the spring means it result in an effective dual-function connector, by which good electrical conductivity and secure mechanical anchorage is attained.

It will also be noted that the coupling sleeve H is not necessarily in the current path. This is due to the fact that the one surface union of the maximum-area wiping contacts 24 of the two joined terminals #6 is, by reason of the invention, of lower electrical resistance than that of the incidental two electrical connections afforded by the higher resistance through the detent-like engagement of'the two pairs of latching arms It with the terminal necks 2t, 2!. Accordingly, the sleeve Ill need not necessarily be made of metal to thus suit it to current transmission. Indeed, if the sleeve is made of dielectric material, there is theadvantage of insulatingly concealing the metallic terminals l6.

Accordingly, it is to be appreciated that the coupling sleeve it when used as a wire plicer, if of metallic formation, may carry some of the current, but its real function is otherwise and a dual one. It applies pressure to the contact surfaces M and independently latches onto the flanged necks 21], M of the terminals.

Figs. 14 and 15 This form of the invention is modified in respect to the connector sleeve mean it heretofore disclosed to produce a single-wire plug-in connector. The sleeve is made here in a second form of equivalent construction as'a socket receptacle adapted to receive and make electrical and mechanical connection with one terminal it previously explained, thus adapting the terminal to wiring jobs other than splicing operations.

Accordingly, the same reference characters are applied to the wire terminal It as in previous views, but new reference characters are applied to the plug-in socket designated generally at 35 as another species of this dual-function connec tor. This plug-in socket 35 is made in the form of a split sleeve, on one end of which is shown an integral eye 36. A screw 37 through this eye secures the plug-in socket 35 to a panel P used in connection with instrument wiring work or the panel P may represent other electrical apparatus. The eye and screw means 3B, 31 is merely an example of one known means of mounting the plug-in socket in service position on a panel or other member.

The connector socket 35 i made with a longitudinal split 38 formed from end to end and continued as a split 39 through the outer end. Likewise. a transverse segmental latching slot H is made near the outer end of the socket and intersects the longitudinal slit 38, 39. For convenience in use of part numbers, it will be noted that the longitudinal slit 38, 39 forms, in eifect, a long and short pair of spring segments or arms 38 and 39 having the same construction and function as shown at I4 and 15 in the previously described coupling sleeve I l. I

The inner end portion of the plug-in socket 35 is swaged inwardly from one side at 42 to form an internal flat wiping contact surface facing the split and spring arms 38 and conformin in structure and function to the flat contact surfaces 24 of one ofthe terminals I6 previously described. The inwardly swaged contact 42 is of maximum area for a given size plug-in socket 35 and reduces the central portion of the latter to subtantially a half-round segmental formation opposite the sprin segments 38. The latter embrace or reach over the flat contact 24, while the latching segmental spring arm 39 complete or reach about the outer open end of the socket.

The tongue 23 of a terminal [6 is inserted into the plug-in socket 35 with the result that the two contacts 24 and 42 wipe together in frictional overlapping engagement under the pressure of the two expanded yielding spring arms 38. These two arcuate spring arms retain their expanded position and maintain their pressure against the single terminal tongue 23 in a fashion similar to the function of the central springs M of the coupling sleeve ii holding two terminal tongues 23 under pressure. The terminal latching bead or annular shoulder 2!, having expanded the spring arm pair formed by the slit 39 when entering the plug-in socket 35, now drops into the latching slot ll and shoulders against its edges in the same fashion as heretofore described in connection with the first form of the wire connector.

It will be noted that the plug-in receptacle 35 is necessarily in the current path, in consequence of which the internal surface of the spring segments 38 are just as much a part of the electrical contact area as is.the flat contact 42 thereof. Accordingly, the electrical contact area not being limited to the fiat surface 24 of the terminal l6, it follows that the clearance C feature described in the first form of the invention is not to all purposes essential in the plug-in socket 35 in attaining good performance with the latter.

Accordingly, this new plug-in socket 35 is adapted to receive and make electrical and mechanical connection with one wire terminal l6 instead of two. This follows by reason of the fact that the contact 42, swaged at the midportion of this plug-in socket, constitutes the counterpart of one of the terminal tongues .23 and thereby adapts the terminal i6 to wiring jobs other than splicing operations.

This second form of the invention is also useful in electrical grounding installations. The plug-in socket 35 may be ground-connected or bonded in any suitable manner with a fuel tank or other apparatus or part P where the latter must be grounded to the frame-work of a machine or to a ship. For example, by shoving off a fuel tank or giving it a start, the inertia thereof jerks the terminal 16 from its plug-in socket 35 and the fuel tank or other apparatus P is readily jettisoned without the use of tools or loss of time. In this connection, the terminal i6, when thus used as a bonding jumper for electrical ground to the present showing of the invention.

What is claimed is: 1. An electrical disconnector comprising, in

combination, a terminal and a receptacle means; the terminal having a contact portion carried at one end of a neck with an annular shoulder of tapering form larger in diameter than said neck; and the receptacle means being made in the form of a. sleeve which is provided with a longitudinal split, and-which is provided also with a segmental transverse slot, thereby rendering the receptacle means radially resilient, as well as forming pairs of spring segments integrally with said receptacle means; the contact portion entering, engaging, expanding and holding one pair of spring segments in expanded condition to frictionally and compressively effect the electrical connection, and the neck and shoulder entering and latching with another pair of spring segments, with the annulartaper of the shoulder abutting said latter spring segments which contract and latch around said neck independently of the aforesaid expanded compressive action on said contact portion.

2. -An electrical connector comprising terminal means having a latching neck and an annular latching bead, with a tongue segmental in cross section extending longitudinally from the latching neck, and having a flat wiping contact sur-' face; in combination with a connector receptacle means, having therein a fiat wiping contact surface which is the counterpart of the first-named contact surface, as well as a longitudinal split and transverse slot formed in the connector receptacle means, thereby forming pairs of segmental springs; the latching neck inserted into the connector receptacle means acting to wipe the flat contact surfaces into overlapping engagement andto expand a pair of the segmental springs and maintain same expanded under pressure to hold said overlapping engagement, with the latching bead disposed within the transverse slot, and a pair of segmental springs contracted around the latching neck.

3. An electrical connector comprising terminal means having a latching neck and an annular latching bead, with a tongue segmental in cross section extending longitudinally from the latching neck, and having a flat wiping contact surface; in combination with a connector receptacle means, having an inside diameter greater than the width of the flat wiping contact surface, and also having therein a flat wiping contact surface engageable with,the first-named contact surface, and a longitudinal split and transverse slot formed in the connector receptacle means, thereby forming pairs of segmental springs; the latching neck when inserted into the connector receptacle means acting to wipe the flat contact surfaces into overlapping engagement and to expand a.

pair of the segmental springs and maintain same expanded under maximum pressure by reason of a clearance space on each side of the engaged contact surface, with the latching bead disposed 13 within the transverse slot, and a pair of segmental springs contracted around the latching neck.

4. An electrical connector comprising a terminal having a neck with a bead formed on its outer end, with a tongue segmental in cross section extending from the bead, and a flat contact surface formed axially on the tongue, in combination with a plug-in socket having an outer open end, including means carried on its inner end for mounting said socket in service position, a longitudinal slit and a transverse slot provided in the socket, thereby forming compression and latching segments which are radially expansible, the mid-portion of the socket which is opposite the longitudinal slit and adjacent one side of the transverse slot being swaged inwardly toward said slit, thereby reducing the inside of the socket to a flat contact surface extendin axially therein and formed as a counterpart of the contact surface on the tongue, the compression segments reaching over the fiat contact surface of the socket and expansible outwardly therefrom and held under expanded tension by the contact tongue inserted thereinto for pressing said tongue against the fiat contactsurface of the socket to efiect an electrical connection between the two contact surfaces, the latching segments adjacent the other side of the transverse slot expansible for entry of the neck and bead and contractible around said neck to latch it in the socket for holding the terminal head in the transverse slot to effect a mechanical connection between the socket and terminal.

5. A plug-in socket adapted for use in connection with an electrical terminal means of the type having a contact tongue and a neck with a latching bead; comprising sleeve means having an outer open end, including means carried on the inner end for mountin it in service position, a longitudinal slit and a transverse slot provided in the sleeve means, thereb forming spring-like compression and latching segments, a mid-portion of the sleeve means which is opposite the longitudinal slit and adjacent one side of the transverse slot being swaged inwardly toward said slit, thereby reducing the inside of the sleeve means to a fiat contact surface extendin axially therein, the compression segments reaching over the fiat contact surface and expansible outwardly therefrom and being adapted to receive and bear against a contact tongue of a terminal means of the type aforesaid to press said tongue against the flat contact surface, and the latching segments adjacent the other side of the transverse slot reaching about the outer open end of the sleeve means and contractible inwardly thereof and being adapted to latch around the neck of a terminal means.

6. An electrical coupling disconnector comprising a pair of wire terminals of identical size and form each of'which has a latching portion and a wiping contact portion, in combination with a coupler sleeve provided with a longitudinal slit through both extremities and extending throughout its length, and also provided with a transverse slot spaced from each extremity, a pair of spring segments located centrally of the sleeve, as well as a pair at each extremity thereof, the segments as formed by the slit and the two slots being rendered radially resilient, one of the aforesaid terminals mounted in each extremity of the sleeve with both of their contact portions wiped together under the pressure of the central spring segments maintained under tensioned expansion to effect an electrical connection between the two terminals, and each terminal having its latching portion gripped in the spring segments at each extremity of said sleeve, the latter spring segments expanding to receive the latching portion and contracting to effect a mechanical connection between the coupler sleeve and each terminal.

7. An electrical coupling ,disconnector comprising wire terminals, each of which includes a body adapted to be secured to a wire, a neck formed on the end of each body, an annular bead formed on the outer end'of each neck. a se mental contact tongue formed on each neck beyond the annular bead, and a flat wiping contact surface provided on each tongue coincident with the axis of the neck; in combination with a coupling sleeve, a longitudinal slit cutting through and extending from end to end of the sleeve, a transverse slot made near each end thereof, thereby forming a pair of compression, spring segments centrally of'the sleeve, as well as a pair of latching spring segments at each end thereof, and into each end of which sleeve the neck of each terminal is inserted with the two fiat contacts wiped together in overlapping engagement at the mid-portion of the sleeve and eccentric to its axis, the pair of centrally located compression spring segments expanding under entry of the contact tongues and remaining expanded for exerting sustained pressure thereon to establish electrical connection between the terminals, while the pair of latching spring segments at each end of the sleeve expand under entry of the annular beads until the latter enter the transverse slots whereupon said latching p g ments contract and griparound the neck of each terminal to establish its mechanical connection with the coupling sleeve.

8. An electrical coupling disconnector comprising wire terminals, each of which includes a body portion adapted to be secured to a wire; a neck formed axially on the end of each body portion, an annular bead formed on the outer end of each neck concentric therewith, a tongue having a fiat surface coincident with the axis of each neck as well as a segmental surface generated on an axis eccentric to the neck and extending longitudinally from the outer end of said neck; in combination with a coupling sleeve provided with a longitudinal slit therethrough from end to end, as well as a transverse slot near each end thereof, thus rendering the sleeve radially resilient and into each end of which the tongue and neck of each terminal are inserted, with the fiat surfaces of the two tongues wiping each other as they slide overlappingly into the central portion of the sleeve, the overlapping segmental tongues acting to expand the central portion of the sleeve and remain gripped under pressure thereby, with each neck latched into each end of the sleeve and each head latched within a transverse slot, and a portion of each head at rest against the inner surface of the sleeve to force its opposite portion into the transverse slot and also to displace the neck eccentrically of and toward one side of the sleeve.

9. An electrical coupling disconnector comprising terminal means having a body portion adapted to be secured to a wire: a neck carried on the terminal means, an annular bead formed on the neck, a tongue segmental in cross section extending longitudinally from the neck, the arc of the tongue forming a flat contact surface subtended by a chord coincident with the axis of the neck; in combination with a connector receptacle having an inside diameter slightly greater than the length 01' the chord, a, longitudinal slit with a transverse slot formed in the receptacle rendering it radially resilient, thereby forming pairs oi spring segments, two of the terminal means aforesaid when introduced into the receptacle with the tongues in overlapping engagement having clearance on each side between said tongues and said receptacle, with the annular bead engaged in the transverse slot, and with one pair of spring segments maintained expanded under pressure against the tongues to produce pressure at the flat contact surfaces thereof, and another pair or spring segments at each end of the receptacle contracted and latched around each neck.

'10.An electrical terminal comprising a tubular portion open at one end, with a bore extending inwardly from the open end adapted to receive and make connection with a wire and being closed at its inner end, a neck shorter in length and smaller in diameter than the tubular portion and tudinally from the outer beaded end of the neck,

the arc of the segmental tongue being defined on an axis eccentric to that of the neck and annular bead, the are being subtended by a chord which measures more than 180, and the chord defining a flat wiping electrical contact surface on the tongue.

12. An electrical terminal comprising a body portion adapted to be secured to a conductor, a neck formed on the body portion, an annular bead concentrically formed on the outer end of the neck on a radius slightly greater than said neck, and a segmental tongue extending longitudinally from the outer beaded end of the neck, the arc of the segmental tongue being formed on an axis eccentric to that of the annular bead and measuring more than as subtended by a chord which defines a flat contact surface coincident with the axis, the segmental tongue'and the neck being formed by equal radii.

13. An electrical terminal comprising a body portion adapted to be secured to a wire. a neck extending from the body portion, an annular bead formed on and of larger diameter than the neck; and a tongue segmental in cross section having a lengthwise flat contact surface extending longitudinally from the end oi the neck, the radius of the arc of the segmental tongue being substantially the same as that of the neck, the center of the radius being located eccentrically to the axis of the neck, and the location as well as the width of the lengthwise fiat contact surface being defined by a chord which is coincident with the axis of the neck and shorter than its diameter.

MARTIN D. BERGAN.

REFERENCES cream The following references are of record in the file of this patent:

UNITED STATES PA'I'EN'IS Number Name Date 2,034090 Douglas Mar. 17, 1936 2,257,317 Wade Sept. 30, 1941 2,010,453 Douglas Aug. 6, 1935 2,318,648 Penfold May 11, 1943 2,299,787 Bea] Oct. 27, 1942 2,061,961 Culver et a1 Nov. 24, 1936 2,214,587 Kraut Sept. 10, 1940 2,297,336 White Sept. 29, 1942 513,949 Munson. Jan. 30, 1894 925,293 Cheney June 15, 1909

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