US3197729A

US3197729A - Semi-rivet connector

Info

Publication number: US3197729A
Application number: US215931A
Authority: US
Inventors: John C Sarazen
Original assignee: Burndy Corp
Current assignee: FCI USA LLC
Priority date: 1962-08-09
Filing date: 1962-08-09
Publication date: 1965-07-27
Anticipated expiration: 1982-07-27

Description

July 27 1965 J. c. sARAzEN 5 3,197,729

SEMI-nvm commcToR Filed Aug. s. 1962 jhu/M@ rroe/vfy United States Patent O 3,197,729 SEMI-RIVET CONNECTOR John C. Sarazen, White Plains, N.Y., assigner to Burndy Corporation, a corporation of New York Filed Aug. 9, 1962, Ser. No. 215,931 1 Claim. (Cl. 339-97) This invention pertains to electrical connections for iat flexible cables, and more particularly to connections established by a contact element which penetrates the cable insulation and deforms the conductor thereof to establish contact without further cutting or piercing of the conductor.

Flat iiexible cables now on the market commonly comprise a flexible ribbon of copper or other conductive metal included within a iiat iiexible insulating jacket of dielectric material such as silicone rubber or various forms of polyester o1- polyvinyl plastics. A typical cable may include 25 conductors each .0027 inch thick and .040 inch wide; these may be disposed side by side on .070 inch centers in the central plane of a iiat insulating body 2.0 inches wide and v.010 inch thick. The thickness of the dielectric covering on each side of the conductor may be of approximately the same order of magnitude as the conductor itself, so that the total cable thickness is approximately three times that of the conductor.

To contact the conductors of cables of this type it has heretofore been necessary to remove a portion of the cable insulation to expose the bare conductors. It has been found that removal of a portion of the insulation from cables of this type is a tedious, uncertain and generally difiicult undertaking. The uncertainty and difficulty of this process increase considerably if the insulation is to be removed from only one or from selected conductors of the cable.

Accordingly, it is an object of this invention to provide means for contacting the conductors of a iiat flexible cable without removing the insulation therefrom.

It is a further object of this invention to provide means for contacting the conductors of a fiat cable at any point A along the cable axis.

Another object is the provision of a means for contacting an individual flat cable conductor independently of other connections to the same cable.

Still another object of this invention is to provide a fiat cable insulation piercing contact element which is reliable, reusable, and inexpensive to manufacture.

The above objects as well as other and further objects, features and advantages of this invention will be made more apparent by reference to the following specification taken in connection with the accompanying drawings, wherein:

FIGURE 1 is a pictorial representation of a single contact element formed in accordance with this invention;

FIGURE 2 is a side view of a modified version of the contact element of FIGURE l;

FIGURE 3 is a plan view of a further embodiment of this invention showing a contact element adapted for perpendicular rather than axial connection to a at cable;

FIGURE 4 is an enlarged partial sectional view taken along line 4 4 of FIGURE 2;

FIGURE 5 is a partial side sectional view of an installed contact element taken along line 5 5 of FIG- URE 6;

FIGURE 6 is a pictorial representation of the contact elements of FIGURES 2 and 3 connected to a section of iiat cable, one contact element being shown coupled to an external conductor termination;

FIGURE 7 is a front end view of a connector assembly embodying the contact element of FIGURE 1;

FIGURE 8 is a plan view of a connector for slicing two cables, which employs a further modification of the contact element of FIGURE l.

Referring now to FIGURES l and 2 of the drawings a contact element formed in accordance with this invention may be seen to comprise a strip or sheet of conductive material 12 having a plurality of uprightly projecting tangs or lances 16. Tubularly formed section 18 is illustrated as one convenient means for connecting external conductors to the contact. Means, such as projecting ears 2t), may be provided when it is desired to secure the contact element to a base or other means for lixedly retaining the element in a given position.

Tangs 16 are preferably formed by a puncturing operation which produces an aperture 14. The tangs 16 result from the displacement of the material which originally occupied the aperture area. FIGURE 4 is a cross section View through a pair of tangs formed about an aperture in this manner. As a result of the puncturing operation, inner surface 15 is deformed relative to outer surface 13 causing the tips of the tangs to curl slightly outwardly away from the puncturing axis. I have found that this outward curl and the resultant inclination of edges 17 causes the tangs to flange over and fold back against the strip 12 when compressed against a relatively puncture resistant surface. In iiat flexible cables of the type herein described the conductor 32 is relatively more resistant to puncturing than the dielectric jacket 34.

A main feature of this invention is the anging over of the tips of the tangs 16 upon contact with the conductor 32 which secures the contact element to the cable by gripping the insulation. Separation of the contact element from the cable by a pull along the aperture axis unbends the flanged over tips and restores them to very nearly their original position, thereby permitting reuse of the contact. To operate properly in the manner specified, a contact element formed in accordance with this invention preferably has tangs which project normally from the surface 19 of conductive strip 12 a distance equal to between l and 3 times the combined thickness of the conductor 32 and a layer of dielectric jacket 34. These dimensions insure that a tang will be adequate in length to penetrate dielectric 34 and Contact conductor 32 without further puncturing. In use, the contact lil is pressed into intimate contact with the upper surface 31 of a cable 30 while the lower surface 33 is supported on any convenient, substantially flat surface. The tangs 16 first penetrate dielectric 34 and are spread slightly apart as a result of the forces acting on outwardly inclined edges 17. Upon initial contact with the conductor 32 the tangs continue to spread apart until outer surface 13 has bent around and at least slightly under the dielectric at the conductor-dielectric interface, thereby causing a slight wiping action between the conductor 32 and tang inner surface 15. Further pressure on contact lil compresses surface 15 slightly into the conductor to insure intimate contact and also deforms the conductor by compressing the directly underlying portion of dielectric 34. When the supporting surface is removed from beneath cable surface 33 the compressed portion of dielectric 34 recovers most of its original thickness to produce a slight surface discontinuity, indicating that the tip of the tang is contained in the cable as is shown in FIGURE 5.

Contact achieved in this manner provides a relatively large surface area contact, preserves the structural and electrical integrity of the conductor, and, since it is contained within the cable, avoids the oxidation and corrosion problems attendant upon exposed conductor connections.

As shown in FIGURE 6 the contact embodiments of FIGURES 2 and 3 may be fastened to a iiat cable so as to remain there independently of any additional external 3 retaining means. For this usage it is preferable to have at least two spaced apart sets of tangs such as at the

apertures

14 and 14A to fix the contact in position and to prevent rotation relative to the cable which tends to loosen the contact.

For establishing external connections to a contact element, an external conductor 24 may be provided with a conductive termination 26 secured to the conductor by crimpable barrel portion 27 and having a cylindrical plug `portion 28 adapted to be tightly received within tubularly formed portion llS or 18A of the contact.

The terminal connector illustrated in FIGURE 7 ernbodies two of the contact elements shown in FIGURE 1 secured to a base 40 by means of projecting ears 20 embedded therein. A pressure applying bar 42 adapted to be compressed against base 40 by bolts 44 passing through apertures 46 and threadedly engaging nuts 4S is provided to simultaneously compress the tangs into and within the cable. The base 40 and the pressure bar or sheet 42 are preferably formed of a rigid dielectric material such as hardened rubber, Bakelite or a phenolic plastic, to assure proper gripping of the cable therebetween.

The cable splice connector illustrated in FIGURE 8 employs a contact element or plurality of contact elements 52 which constitute a modification of the contact element of FIGURE l, having a conductive strip 12B and an aperture 14B formed at each end thereof and having downwardly projecting tab ears 20B for securing the strip to the base. In use, one end of each of the cables to be joined together is placed over the upwardly projecting tangs 16B of the contacts so that a conductor within the cable is aligned above the aperture. An upper pressure applying plate (not shown) is then compressed against the base S0, by means of nuts and bolts passing through apertures 56 in the manner illustrated in FIGURE 7, to compress both cables against the tangs.

The invention has thus been described but it is desired to be understood that it is not confined to the particular forms or usages shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of the invention; therefore, the right is broadly claimed to employ all equivalent instrumentalities coming within the scope of the appended claim, and by means of which objects of this invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to obtain these objects and accomplish these results.

I claim:

An electrical connection comprising: an electrical cable including a ribbon conductor having a flat flexible dielectric covering on a surface thereof; a contact element formed of a strip of substantially malleable conductive metal having a plurality of spaced-apart pointed tangs extending from a surface thereof; a connector portion on said contact element for electrically coupling an external conductor thereto; said contact element surface being disposed in area contact with said dielectric covering; a plurality of saidtangs having body portions adjacent said contact element surface extending through said covering and further having deformed end portions which have been malleably curled over at an angle to the said body portions of said tangs and extend generally along the interface between said covering and said ribbon conductor, said end portions contacting said conductor and securing said contact element to said cable by gripping said covering.

References Cited by the Examiner UNITED STATES PATENTS 2,344,766 3/44 Deakin 339-99 2,495,103 l/50 Huppert 339-220X 2,515,105 7/50 Weisberg- 339--97 X 2,930,021 3/60 Hasselhorn et al. 339-99 3,064,072 11/62 Graff et al. 339-97 X 3,079,458 2/63 Hedstrom 339-17 X FOREIGN PATENTS 832,087 2/52 Germany. 626,837 7/ 49 Great Britain.

JOSEPH D. SEERS, Primary Examiner.