US 2856593 A
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Oct. 14, 1958 [a W m" S. L. GOOKIN CONNECTOR JOINT AND METHOD OF MAKING SAME Inven tor Jy/uester L. 60021 272 United States Patent CONNECTOR JOINT AND METHOD OF MAKING SAME Application June 21, 1954, Serial No. 438,271 2 Claims. (Cl. 339-220) This invention relates to means for securing one end of a length of wire or the like to a work piece, and is more particularly concerned with a novel method, and a joint formed thereby, for economically fastening a terminal portion of an electrical conductor to a panel such as a printed circuit base plate or wiring board as it is sometimes called. While the invention has special utility in connection with the assembly of electronic equipment, its use is not so limited.
A common problem in the electronics industry is that of suitably anchoring the end portion of an upstanding insulated conductor to a panel or work piece so that the bared wire extremity of the conductor may make effective connection with a component or circuit mounted on or adjacent to the work piece. It generally is considered desirable that an end portion of the insulation covering on the fastened conductor be seated beneath a surface of the work piece, and that the bared extremity project to a limited extent in order that it may readily be soldered. It is essential, of course, that the preliminary mechanical connection be simple and that the connection be made secure and reliably permanent. Since much of this type of work may involve printed circuits and miniature components it is especially important that the installation of a connector be capable of being accomplished mechanically with precision and without the necessity of using tools or forces that might harm the equipment being worked upon.
In view of the foregoing it is an object of this invention, in one aspect, to provide an improved connector joint of the eyelet type which, with but slight modification of existing fastener inserting machines, may be easily formed to receive and anchor a conductor endwise to a work piece. In keeping with this object a feature of the in vention resides in the provision of a joint comprising a connector having the general tubular configuration of an eyelet or grommet, normally of malleable conductive metal, the connector having a preformed head adapted to abut one side of the work piece when the connector is thrust through a hole therein to extend beyond the other side of the work piece, and the barrel of said con nector comprising two aligned tubular portions of different cylindrical bores, the larger bored tubular portion being adjacent to said preformed head and being adapted to receive endwise the insulation-covered end portion of a conductor, and the smaller bored tubular portion being adapted snugly to receive at least a part of the uncovered end portion of the conductor, an annular external shoulder on the barrel intermediate said tubular portions being bent radially, at least in part, toward the preformed head to afford clinching formation of part of said larger bored tubular portion with the work piece.
In its method aspect, as hereinafter described, the invention contemplates the provision of an eyelet type connector of the type above indicated, insertion of the barrel of this connector through a preformed hole in a work piece until the connector head abuts one side there- 2,856,593 Patented Oct. 14, 1958 of, engaging said head to brace the connector against endwise movement with respect to the work piece, and applying pressure endwise to the above-mentioned annular shoulder to bulge or clinch said larger bored tubular portion of the barrel while maintaining the form of the smaller bored portion for reception of the bare wire.
The above and other features of the invention will now be described in detail in connection with an illustrative embodiment and with reference to the accompanying drawings thereof, in which:
Fig. 1 is an exploded view showing an eyelet type of connector ready to be thrust through a plate, and a terminal portion of a conductor to be thrust into the connector when installed, a preformed head of the connector being partly broken away to indicate contour;
Fig. 2 is a vertical section of the connector shown in Fig. 1 about to be secured by dies;
Fig. 3 is a view similar to Fig. 2 but showing the connector joint formed;
Fig. 4 is a vertical section illustrating the connector of Fig. 1, and a modified die slitting and curling a preformed shoulder of the connector;
Fig. 5 is a bottom view of the modified die shown in Fig. 4 and indicating its prong curling die blades;
Fig. 6 is a vertical section illustrating the alternate or prong-for1 ed connector joint, a conductor being received therein; and
Fig. 7 is a perspective view of the prong-formed connector joint, portions being broken away more clearly to illustrate its structure.
Referring to Fig. 1, a tubular connector bearing the general reference character 10 is of malleable metal, though it will be understood that for special applications the connector may be of plastic or non-conductive material without departing from the scope of this invention. One end of the connector 10 is provided with a preformed head 12 which merges with a barrel having two aligned tubular portions 14 and 16 respectively having different bores. The bore of the portion 14 is adapted, as best seen in Fig. 6, to provide a snug fit for the insulated end portion I of a conductor, and the bore of the portion 16 is adapted, frictionally to engage the projecting bare terminal portion T of the conductor. The barrel portions may be of any suitable length and wall thickness, it normally being preferred that the larger bored portion 14 shall have a length greater than the thickness of a workpiece W from which it is to project. Also it is preferred that the external configuration of the barrel portion 14, herein shown as cylindrical, shall be such as to be snugly received in a preformed hole 18 (Fig. 1) in the work piece W. The length of the barrel portion 16 is preferably such as to permit the uncovered wire of the conductor to project therefrom sufiiciently to permit subsequent soldering or other processing. Between the tubular portions 14, 16 the connector barrel has a preformed annular external shoulder 20 adapted to be subjected to endwise bending pressure as will hereinafter be described.
The connector 10 may be thrust endwise into the hole 18 as shown in Fig. 2 by hand or by any suitable means, for example by an anvil 22 (Figs. 2 3, 4) of a conventional fastener inserting machine. A forming tool 24 in the machine is arranged to move relatively toward and from the anvil 22 for cooperation therewith. In conventional manner the anvil 22 is adapted to engage the preformed head 12 to brace the connector 10 against bodily movement endwise in one direction. During operating movement of the tool 24, i. e. in moving from its relative position shown in Fig. 2 to that shown in Fig. 3, an annular internal clinching surface 26 thereof is arranged to engage the shoulder 20 endwise and thereby cause it radially to bulge outwardly with a part of the barrel portion 14 as at 28 and be clinched against the workpiece as illustrated in Fig. 3. The barrel portions 14, 16 are maintained substantially in their same undeformed configuration after bending, except for that part of the portion 14 bulged outwardly along with the shoulder 20 and compressed to provide a tight mechanical doubling and clinching of the connector all around the periphery of the hole 18 on the side of the work piece remote from the preformed head 12. Upon withdrawal of the forming tools 22, 24, if not done previously, a conductor may be thrust axially (by manual or other means) into the clinched connector which is then anchored in the work piece as shown in Fig. 3. In many applications the frictional contact between the conductor and the clinched connector afiords adequate holding power, at least until soldering can be done. Where additional holding power is required prior to soldering, the bare wire I end may be bent over the end of the barrel portion 16 and/or the barrel portion 16 may be crimped against the bare terminal T as shown at 30 in Fig. 6.
Figs. 4, 6 and 7 show the formation of an alternative connector joint by a method and means similar to that just described. This alternative method and means employs the same form ofconnector 10 and bracing anvil 22. A slitting-curling die 25 (Figs. 4, however, has a different construction. Preferably, for example, as
shown, a pair of oppositely disposed shoulder piercing projections 32, 32 are provided. Each projection 32 has an internal sharp blade 34 (Fig. 5), an arcuate prongcurling surface 36, and a relieved surface 38. Relative operating movement of this die 25 to receive the barrel portion 16 axially causes the preformed shoulder 20 of the connector to be pierced and slit by the blades 34, the surfaces 36 then curling outwardly and progressively longitudinal tongues or prongs 40 formed from the shoulder 20 and adjoining longitudinal portions of the barrel portion 14. The oppositely disposed prongs 40 need only to be curled outwardly until they clinch the work piece in cooperation with the head 12. It will be apparent that more than two clinching prongs may be provided if the die 25 be appropriately designed or if it be rotated about its own axis between operating strokes through less than 180. I
While the holding power of the prongs 40 is normally less than that afforded by the circular clinching bulge shown in Fig. 3, certain advantages may be recognized in their use. The prongs for example may be more easily formed during or immediately after the connector 10 has been inserted in its hole, i. 'e. less bending force is required and hence there is likely to be less shock or jarring of the work piece. The slit barrel portion 14, moreover, may provide a more readily solderable joint. Either type of connector joint may be formed by commercial eyeleting machines having suitable forming dies 24 or 25, the connectors 10 being fed with facility in the usual raceway structure. My novel method accordingly provides an inexpensive joint for anchoring wire conductors or the like to workpieces.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: i
1. A joint comprising a flat member having a hole therein, and a tubular connector having a preformed head abutting one side of the member, said connector extending through said hole and having aligned barrel portions of different bores joined by an annular shoulder, the larger bored barrel portion being adjacent to said head and extending beyond the other side of the member, prongs slit longitudinally from said shoulder and that part of the larger bored barrel portion extending beyond the member being curled outwardly and toward the member to clinch it.
2. The method of forming the joint defined in claim 1 comprising forming a hole in the member, thrusting the connector through the hole, holding the connector head in abutting relation with one side of the member,
and longitudinally slitting the larger bored barrel portion progressively from peripherally spaced points in said shoulder toward the member thus to provide clinching prongs curled not more than and engageable with the member.
References Cited in the file of this patent UNITED STATES PATENTS 1,702,158 Gagnon Feb. 12, 1929 1,704,515 Rau Mar. 5, 1929 1,876,876 Douglas Sept. 13, 1932 2,370,776 Carlson Mar. 6, 1945 2,464,405 Knauf Mar. 15, 1949 2,519,121 Del Camp Aug. 15, 1950