US3857995A

US3857995A - Electrical connector

Info

Publication number: US3857995A
Application number: US00309078A
Authority: US
Inventors: C Wyrick
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1972-11-24
Filing date: 1972-11-24
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31

Abstract

An electrical connector for use with an insulated electrical conductor, comprises a ferrule having a transversely extending rib which is located in the ferrule. The rib is generally cylindrical in cross section and extrudes the insulation from the conductor without risk of breaking the conductor as the ferrule and rib are deformed around the conductor.

Description

United States Patent [191 Wyrieli [451 Dec, 31, 1974 [22] Filed:

[ ELECTRICAL CONNECTOR [75] Inventor: Charles Thomas Wyrick,

Mechanicsburg, Pa.

[73] Assignee: AMP Incorporated, Harrisburg, Pa.

Nov. 24, 11972 [2]] Appl. No.: 309,078

[52] US. Cl. 174/84 C, 29/1935, 29/630 F, 339/97 C, 339/98, 339/276 T, 339/276 SF [51] Int. Cl H02g 115/08.

[58] Field of Search.... 174/84 R, 84 C, 88 R, 94 R; 339/95 R, 95 A, 97 R, 97 C, 276 R, 276 T,

' [56] I References Cited UNITED STATES PATENTS 2,261,372 11/1941 Holke 174/84 CU 3,355,698 11/1967 Keller .,339/97C Primary ExaminerDarrell L. Clay Attorney, Agent, or Firm-AMP Incorporated 571 v ABSTRACT An electrical connector for use with an insulated electricalconductor, comprises a ferrule having a transversely extending rib which is located in the ferrule. The rib is generally cylindrical in cross section and extrudes the insulation from the conductor without risk of breaking the conductor as the ferrule and rib are deformed around the conductor.

19 Claims, 25 Drawing Figures had sharp edged ridges, generally of rectangular shape,

for extruding the insulation from the conductor. The sharp ridges were disadvantageous in that when the connector was crimped onto the conductor, the sharp ridges tended to break or weaken the electrical conductor, particularly if of the stranded type. Further, the sharp ridges restricted the flow of the extruded insulation within the connector, which could result in a poor electrical connection'since the improperly extruded insulation could hold the connector away from the conductor, preventing it from making of good electrical contact. Even if good electrical contact was made, it often was necessary to use excessive pressure to -extrude the insulation, this being particularly inconvenient if the crimping operation was performed with a hand tool. Further, forming'of the sharp ridges in the body of the connector itself, was costly since material had to be cutaway or removed from the body of the connector.

The electrical connector of the present invention has eliminated the aforementioned disadvantages and comprises a ferrule having a transverselyextending rib of generally circular cross section secured to the ferrule. The rib is positioned on the ferrule to extrude the insu- .lation from the conductor and make contact therewith whenthe connector is crimped onto the insulated conductor. When the cross section of the rib is generally circular, space is provided into which the extruded insulation'may flow, to insure good electrical contact without excessive crimping pressure. The connector of the present invention may be easily and economically fabricated from simple rod or wire and sheet metal stock, and expensive machining operationsare minimized.

A primary object of the present invention is to provide a solderless or crimp-type electrical connector.

Yet another object of the present invention is to provide an electrical connector which can be economically and easily fabricated.

Another object of the present invention is to provide an electrical connector for use with an insulated electrical conductor.

Still another object of the present invention is to provide an electrical connector which provides space to receive the electrical insulation that is extruded during crimping.

An equally important object of the present invention is to provide a method for economicallyand easily fabricating a solderless or crimp-type electrical connector.

These and other objects and advantages of the present invention will become apparent from the following description taken in conjunction with the accompany- FIG. 3 is an enlarged cross-sectional view taken along the line 3-3 of FIG. 1;

FIG. 4 is an enlarged cross-sectional view taken along the line 44 of FIG. ll;

FIG. 5 is an enlarged cross-sectional view taken along the line 55 of FIG. ll; 7

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5;

FIG. 7 is a perspective view of a second form of an electrical connector shown prior to installation on the conductor;

FIG. 8 is a perspective view of the electrical connector shown in FIG. 7 installed on an electrical conductor;

FIG. 9 is a sectional view taken along the line 9-9 .of FIG. 8;

- FIG. 10 is a perspective view of a third form of an electrical connector shown prior to conductor;

FIG. lll is a cross-sectional view of the electrical connector of FIG. 10 after the connector has been assembled on the electrical conductor;

FIG. 12 is a sectional view taken along the line l2-I2 of FIG. 11;

FIG. l3is a sectional view showing a way of securing components of the electrical connector together;

FIG. 14 is plan view showing a fourth form of an electrical connector;

FIG. 1S is an elevational view of the electrical connector shown in FIG. 14; 1

FIG. 16 is an elevational view shown a fifth form of an electrical connector; I

FIG. l7-is a plan view of I the electrical connector shown in FIG. I6;

'FIG. 18 is an elevational view taken along the line l8l 8 of FIG. 17; l

FIG. 19 is a perspective view of a sixth form of an electrical connector; I

FIG. 20 is a sectional view of a seventh form of an electrical connector;

FIG. 21 is a view of the connector of FIG. 20 after further forming; v

FIG. 22 is a perspective view of an eighth form of an electrical connector;

FIG. 23 is a perspective view of a ninth form of an electrical connector;

FIG. 24 is a plan view of the electrial connector of FIG. 1 shown during one step of manufacture; and

FIG. 25 is a plan view similar to FIG. 24, but showing the connector at a subsequent step of manufacture.

In FIGS. 1-4, is illustrated a solderless or crimp-type electrical connector 10 of the present invention. The electrical connector 10 has a ferrule portion 20 at one end forming an electrical and mechanical connection with an electrical conductor, such as Wire 12 having ininstallation on the sulation 14 and a stranded electrical conductor 16.The

connector 10 also has a terminal portion 18 at the other end. The terminal portion 118 is, in this instance, a washer type terminal having a center opening 19, but can be of another type, as for example an alligator clip, a plug or another such connector for connecting the .wire 12 to another electrical conductor.

Ferrule portion 20 is formed from sheet stock having front rear and spaced side edges and is provided with a transversely extending rib 22 (FIGS. 2 and 4). Preferably the rib 22 is an elongated member with a circular cross section, and the rib is attached to the inner surface of the ferrule portion. Both the ferrule portion 20 and the rib 22 are made of electrical conductive material. Since the rib and ferrule portion are separate, it is possible to make each from a material which particularly suits its task. Preferably, the rib is made of 0.005 to 0.035 inch diameter solid copper rod or wire, and the ferrule portion is made of 0.006 to 0.025 inch thick brass. Preferably the height of the rib above the ferrule portion should be not greater than the thickness of the insulation 14 of the wire 12 to insure a good grip on the wire and good extrusion of the insulation. The rib 22 lies transverse, in this instance perpendicular to the axis of the connector. The rib is initially separate from the ferrule portion. In FIG. 13 the rib 22 is bonded to the ferrule portion 20 as by welding, brazing or soldering. The rib may also be bonded by ultrasonic welding which is particularly well suited to welding dissimilar metals.

The ferrule portion 20 of the connector is symmetrical about its longitudinal axis, and each side has two pairs of relatively long

rectangular tab portions

26 and 28 located, respectively, at the front and the rear thereof, for holding the connector onto the wire. A shorter rectangular tab portion 30 is provided on each side between the

longer tab portions

26 and 28. The tab portions 30 also assist in holding the wire in place and support the rib 22. When bent into their final positions the

tab portions

26, 28 and 30 form rectangular windows or openings 31 and 32 on either side of the center tab portions 30. As is shown in FIG. 2, the ferrule portion 20, including the rib 22 is given a U shape preparatory to being crimped onto the wire.

The connector 10 may be installed on the wire 12, without removing the insulation 14 from the end thereof. The wire 12 with insulation 14 in place is located in the U shaped ferrule portion 20, across the rib 22. The ferrule portion and rib 22 are then crimped by a machine or by a hand tool to force the ferrule portion 20 and the rib 22 around the wire so that the spaced side edges of the ferrule portion generally parallel to the longitudinal axis are now closely adjacent each other, the ferrule portion and rib being deformed into cylindrical and ring shapes, respectively.

As shown in FIG. 4, the shorter tab portions tend to meet circumferentially, and as shown in FIG. 5, the pairs of longer tab portions 28, also tab portion 26, contact each other intermediate their ends, with their outer ends then being bent inwardly toward the center of the wire 12. to pierce the insulation l4 and hold the wire 12 in the ferrule portion 20.

Upon crimping, the rib 22 makes good electrical contact with the conductor 16 of the wire without breaking or materially weakening the conductor. As is shown in FIGS. 4 and 6, rib 22 has extruded insulation 14 from the wire 12 and is compressed tightly into electrical contact with the conductor 16. The circular cross section of the rib 22 provides two spaces on each of the outer sides ofthe rib for receiving some of the extruded electrical insulation 14, as indicated at 34 in FIG. 6. When the rib is ultransonically welded to the ferrule portion,'the rib may become embedded in the ferrule, thus reducing or eliminating the spaces on each side of the rib. When the rib 22 is made from a material of a similar hardness as the electrical conductor 16, both rib 22 and the conductor 16 may be deformed somewhat during crimping.

The connectors of the present invention may be economically and easily fabricated in a continuous strip which may then be formed into rolls or cut into short lengths'and may be either hand assembled or machine assembled onto the wire, as was described. A method of forming a plurality of connectors 10 in a strip 129 is shown in FIGS. 24 and 25. Thus, a length wire forming a plurality of ribs 22 is continuously secured, as by ultrasonic welding, to a length of flat sheet metal. A stamping or punching operation is performed on the wire and sheet metal, cutting out sprocket holes 130 (for machine feeding the completed strip) at the edges, blanks 132, blanks 134 which include unwanted segments of the wire, blanks 136 and the openings 19 for the washers 118. Also cuts 138 are made between the

adjacent tabs portions

26 and 28 of adjacent connectors 10. The ferrule portions 20 and ribs 22 of the connectors 10 are then given U shapes by bending so that the

tab portions

26 and 28 and 30 extend perpendicularly from their original plane, and the strip 129 of connectors 10 is now in the form shown in FIG. 25. The strip 129 can be then rolled into a coil for easier handling or cut into short lengths. Individual connectors can also be cut off at the dashed lines 142 from the feed strips 146. The connectors can either be feed into a machine or a hand tool for final assembly onto a conductor.

Additional forms of the connectors embodying the present invention are shown in FIGS. 7-23. The additional forms are similar to the connector 10, just described, in that they all comprise a ferrule portion formed of sheet metal and having a transversely extending rib ofa round cross section secured thereto and a terminal portion. All the connectors may be given a U shape preparatory to being assembled on the wire, and when-assembled the ferrule portion and rib will assume generally cylindrical and ring shapes, respectively.

FIGS. 7-9 show a second form of an electrical connector 40 which is somewhat similar to connector 10, but has no tab portions, such as 26 and 28 for penetrating the insulation. The connector 40 is held onto the wire by the ferrule portion 46, the rib 42 and by the rear end 44 (FIG. 9) of the ferrule portion 46 which has been rolled inwardly into the insulation of the wire as shown. Friction between the outer surface of the wire 12 and the ferrule portion 46 helps hold the wire in place.

FIGS. 10-12 show a third form of an electrical connector 50 which is similar to the connector 40 shown in FIG. 8, but the rib 52 is located in the ferrule portion 54 at tab portions 56 which extend beyond the corresponding ends of the rib 52. The tab portions 56 may be forced inwardly over the ends of the rib 52 into the insulation 14, as is shown in FIGS. 11 and 12 to better hold the wire.

The following connectors described differ from the connector already described primarily in the manner of securing the rib to the ferrule portion.

FIGS. 14 and 15 show a fourth form of an electrical connector comprising a rib 72 and a ferrule portion 74. The rib 72 of the connector 70 is mechanically secured to the ferrule portion 74. As is shown, the rib 72 extends through two openings or slots 76 near the edges of the ferrule portion 74, and the ends 78 of the rib 72 are deformed or bent over to hold it in place.

FIGS. 16-18 show a fifth form of an electrical connector 80 which comprises a rib 82 and a ferrule portion 84. The rib 82 is secured to the ferrule portion 84 by small tabs 86 which are bent over the flattened ends 88 of the rib, the tabs 36 being shown in FIG. 16 in their unbent positions by dashed lines.

In FIG. 19 a sixth form of an electrical connector 911 is shown and comprises a rib 92 and a ferrule portion 94. The ends 91 of the rib 92 are shown bent at right angles parallel to the outer sides 93 of the ferrule portion 94. The ferrule portion 94 has small tabs 96, shown in dashed lines in their unbent position, extending from the sides 93. The tabs 96 are bent over the ends of the rib 92 to hold it in place.

FIGS. and 21 show a seventh form of an electrical connector 100 which comprises a rib 102 and ferrule portion 104. The rib 102 is locked in place by pairs of small opposite facing lances or serrations 103 which are formed in the ferrule portion 104 and bite into the rib. The small serrations 103 may be formed by a stamping or punching operation, and their hold on the rib is further strengthened by bending the connector 100 to its U shape as shown in FIG. 21.

In FIG. 22 an eighth form of an electrical connection 110 is shown and comprises a ferrule portion I12 and a rib 116. The U shaped ferrule portion 112 has a pair of spaced, transverse inwardly extending indentations 114 formed as by stamping to locate the U shaped rib 116. At the outer sides of the ferrule portion 112 are small tabs 118 which are bent over the ends of the rib lI6 to locate it in place.

In FIG. 21 a ninth form of an electrical connector 120 is shown and comprises a ferrule portion 122 and a rib 126. The ferrule portion 122 is provided with a series of longitudinal grooves 125 which are parallel to the longitudinal axis of the connector. The grooves 124 increase the frictional grip between the rib I26 and the ferrule portion 122. The ferrule portion 122 is also pro vided with small, facing serrations 128 on each side, which are forced into the rib 126 to hold it in place.

From the foregoing it will be apparent that a novel and useful electrical connector for use with an insulated electrical conductor has been provided. The con nector may be economically fabricated from flat sheet metal forming a ferrule portion and round wire forming a rib for making electrical contact with the conductor by extruding the insulation from the electrical conductor without breaking the conductor.

I claim:

1. An electrical connector for use with an insulated wire, comprising a ferrule portion having a wire engaging surface and spaced side edges, a rib on said surface and extending transversely with respect to said side edges and the longitudinal axis of said ferrule portion, and a terminal portion adapted to be connected to an electrical conductor, said ferrule portion together with said rib being adapted to be crimped into a generally cylindrical shape around the wire so that said side edges of said ferrule portion are adjacent each other, said rib being generally circular in cross section to penetrate and extrude insulation on the wire and to make good electrical contact with the wire without cutting into the wire as the ferrule portion and rib are crimped around the wire, and said rib being a separate piece secured to said ferrule portion.

2. An electrical connector as in claim 1, wherein said rib is an elongated member adapted to be crimped into a ring around the wire.

3. An electrical connector as in claim I, wherein said rib is made from solid electrical wire.

4. An electrical connector as in claim I, wherein said rib is bonded to said ferrule portion.

5. An electrical connector as in claim I, wherein said rib is ultrasonicly welded to said ferrule portion.

6. An electrical connector as in claim I, wherein said rib and said ferrule position are made of different met als.

7. An electrical connector as in claim I, wherein said rib and ferrule portion are mechanically held together.

6. An electrical connector as in claim 1, wherein said ferrule portion has extending tab portions which are bent over toward the center of the conductor and are adapted to extend into the insulation of the wire.

9. An electrical connector as in claim 8, wherein said rib is located in said tab portions and said tab portions extend beyond the ends of said rib and are bent over the ends of said rib.

10. An electrical connector as in claim I, wherein said rib is located generally in the center of said ferrule portion and lies in a plane perpendicular to the longitudinal axis of said connector.

11. A method for forming a strip of electrical connectors each having a ferrule portion and arib for use in extruding insulation from an insulated conductor, comprising the steps of:

locating a generally elongated wire having a circuit cross section longitudinally along a flat elongated sheet metal strip,

bonding said wire to said sheet metal strip; and

stamping said sheet metal strip and said wire to form said ferrule portions and said ribs of the connectors.

12. The method of claim 11, comprising the additional step of bending said ferrule portions and said ribs into U" shapes.

13. The method of claim 11, wherein the step of bonding comprises ultrasonically welding said wire to said sheet metal strip.

14. A strip of electrical connectors to be used with insulated wire, said strip comprising a plurality of connectors and means for holding said connectors in said strip, each of said connectors having a ferrule portion, each ferrule portion having a wire engaging surface, each connector having a rib on said wire engaging surface, said rib extending transversely with respect to the longitudinal axis of its associated ferrule portion, and each connector having a terminal portion adapted to be connected to an electrical conductor, each of said ferrule portions and each of said associated ribs being adapted to be crimped into a generally cylindrical shape around'the wire, each of said ribs being generally circular in cross section to penetrate and extrude insulation on the wire and to make good electrical contact with the wire without cutting into the wire as the ferrule portion and rib are crimped around the wire, and said ribs being separate pieces secured to said ferrule portions.

15. A strip of electrical connectors as in claim 14, wherein said ribs are solid electrical wire.

16. A strip of electrical connectors as in claim 14, wherein said ribs are bonded to said ferrule portions.

3,857,995 '7 8 17. A strip of electrical connectors as in claim 14, ribs are generally U" shaped. wherein said ribs are ultransonicly welded to said ferrule portions.

A Strip of electrical connectors as in Claim 14, wherein said ribs are bonded to said ferrule portions. wherein each of said ferrule portions and each of said 19. A strip of electrical connectors as in claim l8,

Pam'nt No 33 579995 Dated December 3 197 1 i mm-( Charles Thomas Wyr'ick almvewldemznified pate-rat Column '6, Claim 11, line 32, the word.

"circuit" should be changed to read. -ciIcLllaf -"w Signed and sweled this 18th day @f Fenmwry 1975C.

(SEAL) Atteem G0 PMRSHALL DAWN Cmmmixeseimmer mi Petemte and Trademarks;

AMP 288 3 7 IUEWJFE (5 69 Patent N00 3,857,995 Dated December 31% 197A E e a-5( Charles Thomas Wyrick it is certified tha 6323701 appears in azove -rl-fieniziflad patent and that said wrrec ed. ea eizew'n balm:

Column 6, Claim 11, line 32, the Word "circuit should be changed to read ---=ciI=cu1ar- Signed and sealed this 18th day @f Feiammry 1975s (SEAL) RUTH m MASQN Cmmmissdidner @f Pate-mt Amzeacimgg (iii-deer and Trademarks;

AMP 2684

Claims

3. An electrical connector as in claim 1, wherein said rib is made from solid electrical wire.

4. An electrical connector as in claim 1, wherein said rib is bonded to said ferrule portion.

5. An electrical connector as in claim 1, wherein said rib is ultrasonicly welded to said ferrule portion.

6. An electrical connector as in claim 1, wherein said rib and said ferrule position are made of different metals.

7. An electrical connector as in claim 1, wherein said rib and ferrule portion are mechanically held together.

8. An electrical connector as in claim 1, wherein said ferrule portion has extending tab portions which are bent over toward the center of the conductor and are adapted to extend into the insulation of the wire.

10. An electrical connector as in claim 1, wherein said rib is located generally in the center of said ferrule portion and lies in a plane perpendicular to the longitudinal axis of said connector.

11. A method for forming a strip of electrical connectors each having a ferrule portion and a rib for use in extruding insulation from an insulated conductor, comprising the steps of: locating a generally elongated wire having a circuit cross section longitudinally along a flat elongated sheet metal strip, bonding said wire to said sheet metal strip; and stamping said sheet metal strip and said wire to form said ferrule portions and said ribs of the connectors.

12. The method of claim 11, comprising the additional step of bending said ferrule portions and said ribs into ''''U'''' shapes.

14. A strip of electrical connectors to be used with insulated wire, said strip comprising a plurality of connectors and means for holding said connectors in said strip, each of said connectors having a ferrule portion, each ferrule portion having a wire engaging surface, each connector having a rib on said wire engaging surface, said rib extending transversely with respect to the longitudinal axis of its associated ferrule portion, and each connecTor having a terminal portion adapted to be connected to an electrical conductor, each of said ferrule portions and each of said associated ribs being adapted to be crimped into a generally cylindrical shape around the wire, each of said ribs being generally circular in cross section to penetrate and extrude insulation on the wire and to make good electrical contact with the wire without cutting into the wire as the ferrule portion and rib are crimped around the wire, and said ribs being separate pieces secured to said ferrule portions.

17. A strip of electrical connectors as in claim 14, wherein said ribs are ultransonicly welded to said ferrule portions.

18. A strip of electrical connectors as in claim 14, wherein each of said ferrule portions and each of said ribs are generally ''''U'''' shaped.

19. A strip of electrical connectors as in claim 18, wherein said ribs are bonded to said ferrule portions.