US 2744244 A
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Description (OCR text may contain errors)
May 1, 1956 w. L. scHuMAcHER ETAL 2,744,244
ELECTRICAL CONNECTOR Filed sept. 26. 1952 ll/ I4 United States Patent O ELECTRICAL CONNECTGR William L. Schumacher and Earl E. Folkenroth, Harrisburg, Pa., assignors to Aircraft-Marine Products, inc., Harrisburg, Pa.
Application September 26, 1952, Serial No. 311,576
4 Claims. (Cl. 339-258) This invention is related to electrical connectors of the type which are adapted to be detachably inter-engagedl with one another; two identical connectors of this type may be thus used to form a separable connection between two conductors.
Known forms of such connectors are of two general types, those which are, by construction or by use of locking members, inseparable under tension, and those which pull apart when subjected to a predetermined separating tension. The subject connector is of this latter class and is distinguished by its excellent conductivity and tensile strength characteristics in combination with its simplicity of construction, compactness, low cost and ease and surety of operation. These distinguishing advantages briefly state in part some of the objects toward which this invention is directed,
Among the major objects is the production of simple, compact, inexpensive, and reliable connectors which combine high current carrying capacity with very low contact resistance at the separable connections. Yet another object is to meet all of the foregoing objects in such a fashion that the connectors can be manufactured from sheet metal stock in continuous strip form and which may be subsequently severed from such strips and pressure-crimped onto wires by automatic connector-applying machines.
These and other objects are more fully pointed out in, or will be apparent from, the following specification and claims taken in conjunction with the accompanying drawings. Briey, these various objects are achieved in part by a novel connector comprising in one piece a spring clip orclasp, a blade, the clip and blade having oppositely directed detent-indent deformations which cooperatev with similar deformations of a like connector when interengaged therewith, and a guide tab to insure proper interengagement of the spring clip of one connector with the blade of another.
In the drawings:
Figure 1 is a top plan view of a connector embodying this invention with similar connectors, partly shown, integrally attached to its ends as such connectors would appear in the continuous strip form in which they may be made for use in automatic connector-applying ma chinery.
t -Figure 2 is a perspective view of a connector as is shown in Figure 1 after it has been severed from a strip and pressure-crimped onto an electrical conductor.
Figure 3 shows two such connectors in central longitudinal section after they have been severed from a strip, pressure crimped onto electrical wires, and placed in end-to-end, mutually reversed and inverted positions, from which positions they may be slidably inter-engaged.
Figure 4 is a central longitudinal section of such connectors as shown in Figure 3 after they have been slidably inter-engaged.
Figure 5 is an enlarged cross section taken at the line 5-5 in Figure 4.
Figure 6 is a perspective view of the connection shown in Figure 4.
Figure 7 is an enlarged cross sectional view, similar to Figure 5, of a connector having a different form of spring clip members.
The twin connectors shown in Figures 1 and 3 each comprises a wire engaging ferrule-forming portion 11, a clip portion 13 joined thereto by a neck 12, a blade portion 14 and a guide tab 15. The wire gripping portion 11 is shown as a U-shaped channel having a base 16 and side Walls 17 adapted to be crimped into gripping engagement with a conducting wire 18, for example, by curling said `side walls 17 inward and driving or pressing their longitudinal end edges against said wire, as indicated,v
in Figure 3. The wire gripping portion may take various other forms in connectors designed for different purposes.
The neck 12 is a flared extension of ferrule 11 and has,
side walls 19 of less height than the side walls of said ferrule but suilicient to reinforce the connector as la whole.
The clip or clasp portion 13 is of channel form with end portions of the side walls bent inwardly and downwardly toward the base 16e to form the spring clips. As indicated in Figure 3, end portions 22 ofvsaid clips are disposed at an angle to said base 16e with the end edges spaced a distance above said base slightly less than the thickness of the blade portion 14, said spring clips` are thus adapted resiliently to engage and hold the blade portion of a like connector inserted between them andl their base portion 16C. The length of these clips is such that their slight outward deflection, upon insertion of a blade portion beneath them, is less than would exceed their elastic limit, assuming that the connectors are made of commercial copper, brass, or mild steel commonly used for the purpose. The guide tab 15 is a narrowed extension of a central portion of blade 14, one of its functions being in part `suggested in Figure 3 which shows twoconnectors placed end to end and inverted. Said guide tab 15 is bent or inclined out of the plane of the blade portion 14 and directed away from the contact face 26 of the connector. During initial movement of twin con nectors toward interengagement, guide tabs 15 facilitate more rapid and accurate sliding engagement of blade upon blade; and thereafter aid in maintaining proper. longitudinal relative movement between the twin parts..
as the tab slides between the terminal edges of the spring clips into its end position. ln fact, unless the twin connectors are brought together in proper relation, tabs 15 will prevent interengagement of the clips with the blades. Thus, tabs 15 serve both to guide the connector blades into initial engagement and to insure that the blades thereof are brought properly beneath the retaining clips.
The aboveadescribed preferred embodiment of my in,
machine; thus the guide tab 15 serves several functions in.
the illustrated embodiment.
Figure 3 shows two deformations or embossments, one of which provides an indent or recess 23 in the outer face of the base portion 16C and a corresponding detent 24 projecting from the inner or contact face thereof. The other deformation occurs in blade portion 14 but with the detent and indent in reversed relation. A Thus, as. may be seen in Figures l, 2, and 3, detent 24' ofsaid other deformation projects from the outer face of blade portion- 1'4- andthe correspondingV indent 23 occurs as a recess in the contact face 27 thereof. The embossrnents providing said detents and indents are so positioned on the connectorsthatv they cooperate when the connectors are inter-engaged, as shown in Figures 4 and 6*, as releasable locking means which provide frictional resistance to displacement or separation by tension applied in a direcv` tion to pull the connectors apart.
The detent-indent deformations are disposed centrally or axially between the sides of the connectors so that the detent 24 of interengaged connectors may pass readily into and through the'spacebetween the clips' of" the complementary or twin connector. End portions 22 of the clips of one connector are arranged to make a wiping'orself-cleanng contactwith outer surfaceportions ofthe bladeof the other when two` connectors are interengagcd. The angle at which these end portions 22 are disposed` and thespacing" ofZ their free ends from surfacer 162,v is such that they rmly'engage blade 14 to bring the cornersof their'end edges into effective wiping orv cutting contact therewith'. This anglev is also such in clips uniform in other characteristics as tov enable the clips to yieldingly resist an uncurling force as well as a simple lifting force, such as that produced by the insertion of ablade I4 between their free edges and surface 16C.
Figure 7 shows a modification wherein the clip construction permits the connectors to be` made from narrower metal strip stock. Here, as seen in Figure 7`, the clips 2lb'` arebent inward and downward toward the base' and then back toward their junction with the base.
The end portions 22b of saidV clips are'ata less acute angle-with the base; there is suicient space between these end portions to allow guide tabs 15 and detents 24 to pass' longitudinally'between them; and the end edges of said clipsl are spaced from the surface 16e so that said edges bear yieldingly on the upper surface of blade 14 when twin connectors are operatively interengaged.
The angle of the clips with the base 16e is not critical; but varying this angle in different embodiments is one means of varying the resistance totpull-apart tension ofl inter-engaged connectors designed to meet different use conditions. If the angle isV approximately a right angle, the clips will not ex as readily and their resistance to pull-apart tension is maximum for connectors having uniform characteristics, such as stiffness ofthe sheet' metal stock, total length of the clips, height of the detents 24, and depth of the recesses 2'5. The spring clips have generally straight free end edges for making correspondingl'yextended contact with the blade of an inter-engaged connector. The front' corners of clips 22 which meet the advancing edge of the blade 14 when the parts are being inter-engaged are slightly'rounded to facilitate the entry of the blade beneath end portions of said clip.
The central axial location of the deformations permits the base portion 16e and the blades 14 to flex slightly when twin connections are being intereengaged, thus avoiding excessive displacement of the ends of the clips. The elongated contact between said clips of one connector and`blade 14 of a twin connector inter-engaged therewith, is effectively conductive due to their wiping or cutting action on the outer surface of said blade. The contact faces 26 and 27 of two inter-engaged connectors provide a` large area of conductive contact further to afford ample current-carrying capacity of the connection as a whole.
A further advantage of our invention lies in the fact that although the. connector is peculiarly adapted for interconnection with an identical. connector, itV is also adapted to be connected to ordinary straight tab, such as are` often provided as soldering tabs on electrical equipment, or more or less rectangular tongue terminals, such as. spade terminals, etc.
l. An. electrical connector for detachable. frictional in:v terengagement with a like connector comprising a clipV portion, a wire gripping portion at one end thereof, a blade portion extending longitudinally from the other end thereof, said clip portion and said blade presenting a continuous contact surface, said clip portion having a spring clip at each of its opposed side edges, with the free ends of said clips bent toward each other and inwardly toward said contact surface, the terminal edges of said clips being spaced from said contact surface a distance substantially less than the thickness of said blade, a deformation in said clip portion midway between said clips, a` deformation in said blade' portion, and a guide tab extending longitudinally from a free end portion of said blade and. inclined in a direction away from the plane of said contact surface, said parts being arranged and adapted, when two. connectors each embodying like parts are interengaged, to bring the spring clips of one connector into conductive and yielding frictional engagement with the blade portion of the. other, thereby to press the contact face of one connector into conductive contact with that of the` other and to yieldingly retain deformations ofA one connector in nesting relation with deformations of the other.
2. An electrical connector for detachable frictional interengagement witha like connector comprising a clip portion; a wire gripping portion at one end thereof; and a;
blade portion extending longitudinally from the other end thereofi said clip portion and said blade presenting a continuous contact surface, said clip portion having a spring clip at each of its opposed sideedges, said clips being inturned' and downwardly directed relative to said' contact surfacewith the terminal edges of said clips being spaced from said contact surface a distance substantially less than the thickness of'said blade for yieldably pressing the blade contact surface of the like connector upon interengagement into contact with said clip portion contact surface, a deformation in said clip portion midway between said clips, a deformation in said blade portion for nesting in mating relationship with the clip portion deformation of the like connector upon interengagement, and a guide tab having a width less than the distance between said terminal edges and extending longitudinally from the free end of said blade and inclined relative to the plane of'said contact surface for guiding the contact surface said blade portion along the blade contact surface and within the clip portion of the like connector.
3. A sheet metal electrical connector for detachable frictional interengagement with a like connector comprising; a channel-like ferrule-forrning portion adapted to be compressed into engagement with an electrical conductor, a clip portion having a substantially Hat contact surface wider than saidchannelrportion, a shank portion integrally coupling said ferrule-forming and clip portions, and a flat blade portion extending longitudinally from said clip portion, said clip portion havingV a spring clip at each of its opposed side edges, said spring clips initially extending substantially at right angles with said contact surface with the` end portion thereof being inturned and downwardly directed relative to said contact surface, the terminal edges of said spring clips being spaced from said contact surface a distance substantially less than the thickness of said blade portion for yieldably pressing the blade of the like connector upon interengagement into contact with said contact surface, the opposed side edges of said shank portion being upturned to provide strengthening ribs continuous with the side walls of the channel of said ferrule-forming portion and the initial'portion of said spring clips, a deformation in said clip portion midway between said spring clips, a deformation in said blade portion for nesting. in mating relationship with the clip portion deformation of the like: connector, and means for guiding the blade of the like connector into engagement with said contact surface;
4. A sheet metal electrical connector for detachable frictional engagement with a substantially hat blade` portion of a mating sheet metal connector comprising a channel-like ferrule-forming portion adapted to be compressed into engagement with an electrical conductor, a clip portion having a substantially flat contact surface wider than said channel portion, a shank portion integrally coupling said ferrule-forming and clip portions, said clip portion having a spring clip at each of its opposed side edges, said spring clips initially extending substantially at right angles with said contact surface with the end portion thereof being inturned and downwardly directed relative to said contactsurface, the terminal edges of said spring clips being spaced from said contact surface a distance substantially less than the thickness of the blade for yieldably pressing the blade upon engagement of the connectors into contact with said contact surface, the opposed side edges of said shank portion being upturned to provide strengthening ribs continuous with the side walls of the channel of said ferrule-forming portion and the initial portion of said spring clips, a deformation in said clip portion for nesting in mating relationship with a deformation in the blade, andmeans for gnding the blade into engagement with said contact surface.
References Cited in the le of vthis patent UNITED STATES lATENTS 1,995,115 Douglas Mar. 19, 1935 2,158,004 Douglas May 9, 1939 2,288,918 Parker July 7, 1942 2,335,843 Rogof Nov. 30, 1943 2,406,895 Olson Sept. 3, 1946 2,523,465 Graham Sept. 26, 1950 2,600,012 Macy June l0, 1952 2,615,736 Bergan et al. Oct. 28, 1952