US2617844A - Wire terminal connector - Google Patents

Description

WIRE TERMINAL CONNECTOR 'Filed June 29. 1949 l 2 SHEETS-SHEET 1 g. aNsuLATaoN 'QQ A ZKM l, .Zaadza .5a-nda MSM NOV. Il, 1952 A, SANDA 2,617,844

` WIRE TERMINAL CONNECTOR Filed June 29. 1949 2 SHEETS-SHEET 2 Ix Y Patented Nov. l1, 19512 WIRE TERMINAL CONNECTOR` Laddie A. Sanda, Chicago, Ill., assignor to Soreng i Y Manufacturing Corporation, Chicago, Ill., a corporation of Illinois Application June 29, 1949, SerialNo.` 102,000

This invention relates to electrical connectors and refers more particularly to connectors for securing electrical conductors to electrical instrumentalities.

Heretofore the connection of an electrical conductor to an electrical instrumentality, such as a switch, has entailed the use of at least, one

tool, as for example, a screwdriver, a staking tool or a soldering iron, and has Vusually been accomplished at the cost ofa considerable amount of time and labor. In some instances, moreover, as where solder connections have been used, subsequent disconnection of the conductor has also proved to be difcult and time consuming.

By contrast, it is an object of this invention to provide a connector VVdevice whereby electrical conductors may be quickly and securely connected to an electrical instrumentality without necessitating the use of any toolswhatsoever in making the connection. v L

The bestknown past connector of this type has been the Pfanstock clip which, although quick and convenient to use, was relatively cumbersome and bulky and had the serious disadvantage of permitting'a straight length of wire to slip out of the connector if sufficient ax-ial force Werevapplied to the wire.

Itis-therefore an object of this invention to provide a device of the character described which will enable simple and rapid connection of a Wire to an electrical instrumentality and will also permit the wire to be` readily disconnected, at any time, but which will nevertheless securely retain it against axial displacement.

It is a further object of this invention to provide an `extremely inexpensive electrical connector of the character described which may be readily fabricated fromsimplestampings held together by a single bolt, rivet Vor bonding connection.

Another object of this invention resides inthe provision of an electrical connector of the character described capable of insuring an excellent electrical connection with a wire secured thereto, by reason of the fact that a substantial length of the wire is pressedinto rm engagement with a iiat surface on the connector.

A further object of this invention is to provide an extremely simple and compact terminal connector of the character described whichv will not only hold a wire connector in good mechanical and electrical engagement with a contacting element on the connector'but which will also exert increasing gripping force upon the wire as increasing axial displacing force is applied to the same.

' With the above and other objects `in view, which will appear as the description proceeds,

this invention resides in the novel construction,` combination and arrangement of parts substan-` 5v claims. (C1. 173-259) tially as hereinafter described and more particularly defined by theappended claims, it being understood that such changes in the precise embodiment of the-hereindisclosed invention may be made as come within the scope of the claims. VThe accompanying drawings illustrate several complete examplesof the physical embodiments of,the"inventionconstructed according to the best modes sovfar vdevised Afor the practical application of the principles thereof, and in which:

Figure 1 is a plan view ofthe electrical connectorof .this invention with a Wire secured in place therein; f y n. V

Figure 2 is a-sectional view taken. along planeof the line Z-'Zfin Figure/1;

Figure 3 `is a front elevational view of the Figurel connector; i l.

Figure 4 is a' perspective view of the spring member and guide lmein'ber of the connector of this invention` shown in their proper relationship the for assembly, a portion ofthe guide member beingcut away to show detail;'

Figure isa views'imilarto Figure 2 but showing the connector `Without a wire `in place therein;

Figure 6 is aV plan view of a modified embodiment of ltheconnector of ,this invention; f

, Figure 7 is a sectional view taken along the plane of the line 'I-'I in Figure 6;

Figure 8 is a view similar to Figure 7, but showing the modied embodiment of the connector without a wire secured therein; and

Figure 9 is an exploded perspective View of the essential portions of the modified connector.

Referring now more particularly to the accompanying drawings, in which like numerals designate like parts throughout the several views, the

numeral 5 designates generally the electrical connector of this invention. For the sake of illustration the connector is shown mounted upon an insulative base 6 such as the terminal plate or back of an electrical switch or other electrical instrumentality (not shown) and with an electricalconductor 'l secured therein.

The base of the connector comprises a single conductive element 8, preferably consisting of a substantially rectangular piece of flat metal, but in any event having a ilat surface 9 along which the bare end of the Wire conductor 1 is Vadapted to lie and with which it is adapted to have contacting engagement. Y

The wire is held firmly against the conductive element by means of a spring member l0, and a guide member Il secures the spring member against rotational displacement relative tothe conductive element.

The guide member and the conductive element are held spaced apart and parallel to one another by means of an insulative spacer l2 interposed between them at the rear of the connector and comprising either an integral overhanging ledge on the insulative terminal plate of the electrical instrumentality with which the connector is used, as shown, or a separate block of insulative material.

The spring member Ily whichcooperates with the conductive element 8 to provide in effect a clamp, preferably comprises agunitary stamping fabricated from a substantially flat strip of fiexible metal such as stainless steel, spring brass or the like, but while it is preferably made of conductive material it is not necessarily so, since the engagement of a wire with the surface 9 of the conductive element affords an excellent electrical connection thereto.

The rear attaching portion I3 of the spring member is relatively wide and fiat and is adapted to flatwise overlie the rear portion of the guide member II, the spring member, the guide member and the conductive element '8 being secured to one another and to the insulative spacer I2 in superimposed relation by means of a rivet I5 or other suitable securement means passing through aligned holes in the several members.

The front portion I6 of the spring member is narrower than its rear attaching port-ion I3 and is substantially U-shaped as viewed from the side, the legs I1 and I8 of the U being substantially parallel to one another. The attaching portion of the spring member is bentat an angle to its U-shaped front portion so that the latter is held in a position in which its legs overlie` one another and the flat surface 9 of the conductive element, and are disposed at an acutemangle to said surface, with the free `edge I9 of the lower leg I8 adjacent to the surface and adapted to be flexed upwardly away from` the same. In other words, from the rear attaching portion I3, the spring member extends forwardly upwardly to provide a Wide, relatively 'stiff upper leg I1 'and thence narrows and curves back upon itself to provide a flexible spring portion 20, from which the lower leg IB projects rearwardly downwardly toward the surface 9. l

The lower leg I8 is substantially rigid by reason of the fact that an integral wing-like flange 2| is bent downwardly toward the conductive element, at right angles to the body of the leg, along each side edge thereof. The lower free edge I9 of saidleg is cut off squarely, along a line parallel to the surface Il, to provide a sharp edge'adapted to bite into the surface of a wire conductor topreolude axially forward displacement of the wire; The bottom edge 22 of each flange yis rounded or arcuate to enable the lower edge "I9 of the leg lto swing through'a relatively wide are, to thus accommodate wire'conductors of a wide range of thicknesses.` Y

The guide member Il is preferably formed as a unitary stamping. The front portion of the spring member passes through a slot 23 in the flat body portion 24 of the guide member, the slot being substantially equal in width to the front portion of said spring member so that the sides of the slot afford guiding engagement with the spring member. A rail-like ledge 25, bent upwardly along each side edge of the guide member, stiffens the member and at the same time precludes rotation of the spring member about the rivet I5, since the rear attaching portion of the spring member has a width equal to the distance between the ledges 25.

A pair of spaced apart lug-like abutments 25 are bent downwardly at right angles to the front of the guide member so as to be disposed one at each side of the surface 9 in positions where 4 they preclude lateral displacement of a wire from beneath the sharp edge I9, It will be noted that the flanges 2l cooperate with these lugs in preventing such displacement of the wire.

The guide member also has a pair of shoulders 28 which, in the Figures 1 to 5 embodiment, cornprise lugs located forwardly of the lower leg I8, in a position to engage the upper surface of the leg i3 vnear the junction of the leg proper with the curved flexible portion 23 of the spring member. When forward axial force is applied to the wire the lower leg I3 tends to in effec-t pivot about the curved exible portion of the spring member, but because of the acute angle which the leg I8 defines with the surface 9, the rearward motion of its free edge, 4consequent to the Vapplication of such force to the wire, forces the upper end portion of the le'g upwardly against the shoulders 23. Since the shoulder -lug's are fixed, however, the resultant 'force causes the edge I9 to bite more deeply into the "surface of the wire. Y

rI'he modified embodiment ofthe terminal of this invention shown in Figures `6 to 9 is particularly adapted for installation 'at the "col-ner of a switch box or the like formed by the `juncture of two of its walls.A Thefg'uide member `I I' is precluded from rotating "with respect to the switch box by reason of the fact that its luglike abutments 26' engage Vthe-edges of -a slotlike recess 5' at the `'corner of the as may be seen in Figure?. The guide "member is not provided with upturn'ed side ledges, but instead relative rotation between the vspring member I and the guide member is precluded by Vmeans of a downwardly turned tongue 3i) 'hat the rear of the guide member engaged in'a mating slot 3| in the rear edge of the 'guide member.

The important functional difference between the two illustrated embodiments resides in the fact that the lugs carrying th'esh'oulders 28 on the guide member of the embodiment shown in Figures l to 5 are not present `in the modified embodiment 'of Figures 6 to 9. Instead, the flange 2| on the lower leg of thespring member ex'- tends farther forwardly, and its upper edge 32 engages a shoulder 33 which comprises the rear edge of the slot 23 in the guide member.

Since the upper edge of each of the flanges in this embodiment sl'antsy rearwardly upwardly, the application of axial forward `forceupon the wire, resulting in forward movement of the leg and consequently of the flanges, 'will'cause the flanges to cam themselves downwardly'on the shoulder 33 and thus force the free edge 'I9 of the lower leg into firmer biting engagementwith the wire. In other words, the flanges cooperate with the shoulder toprovide a Vsort of `wedging effect in conesquence tothe'applic'ation of 'forward axial force to the wire.

Thus, in the modified form of -vth'e'ir'iv'ention shown in Figures 6 to V9, -as in the YFigures 1 to 5 embodiment, a p'art'o'n the lower lleg'may be said to cooperate with shoulders onthe guide member to provide a camming or wedging action by which the sharp edge I9 iS forced into firmer biting engagement with the wire in consequence to the application of forward axial force thereto.

It will be seen that the installation of Ya wire in either embodiment of the connector of this invention is exceedingly simple, since it is only necessary to skin or bare the end of thewii'e and to push it axially 'rearwardly under the sharp edge, where it will then `bersecurely retained against forward axial displacement by 'the edge itself vand against ,latralldsplacement bythefabutments 26 andthe langes-Zl.

Removal of the wire is readily accomplished by inserting a screwdriver under the edge I9, to lift the same out of engagement with the wire, and then withdrawing the wire axially forwardly. l,From the foregoing description taken together with the accompanying drawings itiwill be readily apparent that this invention provides an extremely simple and compact electrical connector whereby electrical conductors may be quickly Aand simply hooked up to an electrical instrumentality .without the use of any tool and will' be permanently and. securely retained` in place but may. nevertheless be instantly disconnected at' any time.

\ What I claim as my invention is: y

1. In a wire connector of the character described: a contact element of conductive material having a substantially flat surface along which the bare end portion of a wire is adapted to lie in contacting engagement with the element; a spring strip member having one of its ends fixed with respect to said contact element and extending therefrom forwardly and upwardly away from said surface and thence curved rearwardly and downwardly toward the surface at an acute angle thereto, with its free end adjacent said surface and adapted to be exed upwardly away from the same; a sharp `edge on said free end of the spring member substantially parallel to said surface on the contact member and adapted to bite into the surface of a wire conductor inserted between said free edge and said surface with its axis transverse to said sharp edge, to preclude forward axial displacement of the wire; a substantially at guide member xedly secured above said flat surface, spaced therefrom and parallel thereto, said guide member having a slot through which the curved portion of said spring member projects and shoulder means adjacent said slot adapted to cooperate with a part on the downwardly inclined portion of the spring member to provide a fulcrum about which said portion of the spring member is adapted to pivot into firmer biting engagement with the surface of the wire in consequence of forward axial movement of the wire; and a flange at each side edge of the lower portion of the spring member to stiffen the same.

2. In a wire connector of the character described: a contact element of conductive material having a substantially flat surface along which the bare end portion of a wire conductor is adapted to lie in contacting engagement with said surface; a spring strip member having one of its end xedly secured with respect to said contactor element and having its other end portion substantially straight and extending rearwardly downwardly toward said surface, at an acute angle thereto, the medial portion of said strip member being curved and being adapted to be exed upon upward movement of the free end of the strip; a sharp edge on the free end of said spring member, parallel to said flat surface and adapted to bite into the surface of a wire lying along said Vflat surface and having its axis transverse to said sharp edge to preclude forward axial displacement of said wire; and a substantially at guide member fixedly secured above said at surface, spaced therefrom and parallel thereto, said guide member having a slot through which the curved portion of said spring member projects, and having a shoulder adjacent said slot adapted to cooperatewith' said other' endportiofi of said spring, member atapoint thereon spaced from 4the sharp' ed'getoA provide a fulcrum about which said portion pivots .to cause said. edge to bite more deeply into the surface ofthe .wire upon forward laxial movement ofrthe'wire.

3.In a wireconnector of' the character described: a conductive element having a substantially at surface along which the bare end of a wire conductor is .adapted to lie, in'contacting engagement with vthe element; a curved spring element overlying said flat surface and spaced therefrom, said spring element having one of its ends flxedly secured with respect to the conductive elementand its other end free to ex toward and from said surface; a rigid elongated wire clamping element having its upper end connected with the free end of the spring member and extending rearwardly downwardly therefrom, at an acute angle to said surface, with its free lower end adjacent to said flat surface and adapted to be flexed upwardly away from the same; a sharp edge on the lower end of said rigid element, parallel to said flat surface and adapted to bite into the surface of a wire interposed beheath said free edge with its axis transverse thereto, to preclude axially forward displacement of the wire; a substantially flat guide member fixedly secured above said flat surface, spaced therefrom and parallel thereto, said guide member having a slot through which the free end of said spring element extends; and shoulder means on said guide member against which the free end of said spring element is adapted to abut upon flexure of the spring away from said surface to thereby cause said rigid element to wedge its sharp edge into firmer biting engagement with the surface of a wire upon the application of forward axial force to the wire.

4. In a wire connector of the character described: a contact element of conductive material having a surface against which the bare end portion of a wire conductor is adapted to be placed to lie therealong in contacting engagement therewith; an elongated spring member having one of its ends xed with respect to said contact element and extending forwardly and upwardly away from said surface and thence rearwardly downwardly toward the same at an acute angle thereto, the free end of said spring member being adjacent said surface and adapted to be flexed upwardly in consequence to the interposition of a wire conductor between the surface and said free end; a sharp edge on said free end of the spring member adapted to bite into the surface of a wire conductor lying along said contact element to preclude forward axial displacement of the wire; a downwardly extending flange along each side edge of the rearwardly extending portion of the spring member; shoulder means xed with respect to the contact element and spaced above the contact element; and abutments on said flanges engageable with said shoulder means upon insertion of a wire beneath said edge to cam the sharp edge on said portion of the spring member into firmer biting engagement with the surface of said wire in consequence of axial forward movement of the wire.

5. In a wire connector of the character described: a conductive element having a substantially fiat surface along which the bare end of a wire conductor is adapted to lie in contacting engagement with the element; a curved spring element overlying said fiat surface and spaced therefrom, said spring element having one of its ends f7 xedly :secured .with :respect to the conductive .element .and its other end .freezto ilextowardand .from said, surface; v`a rigidV elongated .wire clampingk element havingV its upper-end connected with .thefree end of the springimemberfand'extending rearwardly downwardly therefrom, atan acute anglerftosaid surface, with-itsifree lower endadjacent; :to said Aflat surface and adapted lto -be flexed upwardly awayfrom the `same; a sharp edge on. the lower end of said rigid element, paralellito said flat surfaceand adaptedto bite into the surface of a .wire interposed beneath said edge .withlits axis transverse thereto, to preclude axially forward displacementl of the-wire; means on said Ywire .clamping element providing an upwardly facing abutment beneath the `lower surface of vsaid element `and spaced above lsaid sharp edge; anda `downwardly facing abutment -fixed ,with respect to said conductive element and spaced thereabove and against which lsaid abutment on the wire clamping element abuts when said clamping velement is flexed upwardly upon insertion of a wire beneath said edge, to thereby cause said element lf8 to wedge-.itselfintorrmerbiting engagement with the wirerupon lthe application of axially forward force to thewire.

LADDIE' yA. SANDA.

5 x REFERENCES CITED i The `following references are of record in the file of this patent:

10 UNITED STATES PATENTS Number Name 4Date 740,358 Esmond Sept. 2K9, 1903 1,387,252 Fredricks Aug. 9,;1921 1,581,816 Russell Mar. 31, 1925 15 1,635,256 Carter "July 12, 1927 1,950,826 Smart :Man v13, 1934 2,445,772 Frese July 27, 1948 2,503,559 Miloche Apr. 11, 1950 0 FOREIGN PATENTS Number Country Date 216,289 Great Britain r May 29, 1924

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