US3697931A

US3697931A - Electrical plug contact

Info

Publication number: US3697931A
Application number: US103464A
Authority: US
Inventors: Kurt Joseph Achten
Original assignee: Illinois Tool Works Inc
Current assignee: Illinois Tool Works Inc
Priority date: 1971-01-04
Filing date: 1971-01-04
Publication date: 1972-10-10
Anticipated expiration: 1989-10-10
Also published as: AU3747271A; GB1381742A; NL7200049A; AU464226B2; IT946288B; DE2165579A1; JPS527158B1; CH566649A5; GB1381741A; CA938009A; FR2121232A5

Abstract

A plug connector element having a plurality of contact arms which are configured to permit the longitudinal edges thereof to abut upon total compression of the plug connector, such as when associated within a complimentary socket element, thus providing a relatively stable connection. The plug connector element is further provided with a sleeve or ferrule portion which is connected to the contact arms as well as to an associated conductor wire in such a manner as to assure penetrating engagement with the conductor wire while maintaining continuous contact between the contact arms and the conductor wire.

Description

United States Patent Achten [541 ELECTRICAL PLUG CONTACT [72] Inventor: Kurt Joseph Achten, Granada Hill,

Calif.

[73] Assignee: Illinois Tool Works Inc., Chicago,

[22] Filed: Jan. 4, 1971 [21] Appl. No.: 103,464

[52] US. Cl. ..339/95 R, 339/252 P, 339/276 T [51] Int. Cl. ..l-I0lr ll/20, HOlf 13/06 [58] Field of Search ..339/95, 252, 276

[56] References Cited UNlTED STATES PATENTS 3,252,127 5/1966 Woodward ..339/217 .1 3,123,427 3/1964 Yopp ..339/252 P R25,798 6/1965 Platz. ..339/252 P 3,205,469 9/1965 Frank et a1 ..339/18 C 3,375,486 3/1968 Clayton ..339/252 P 3,400,358 9/1968 Byrnes et al ..339/252 P 1 Oct. 10,1972

3,538,491 11/1970 Longenecker et a1 ..339/256 Primary Examiner.loseph H. McGlynn v Attorney-Robert W. Beart, Michael Kovac, Jack R. Halvorsen, Thomas W. Buckman and Olson, Trexler,

Wolters & Bushnell [5 7] ABSTRACT A plug connector element having a plurality of contact arms which are configured to permit the longitudinal edges thereof to abut upon total compression of the plug connector, such as when associated within a complimentary socket element, thus providing a relatively stable connection. The plug connector element is further provided with a sleeve or ferrule portion which is connected to the contact arms as well as to an associated conductor wire in such a manner as to assure penetrating engagement with the conductor wire while maintaining continuous contact between the contact arms and the conductor wire.

16 Claims, 26 Drawing Figures PATENTED B 10 I972 3.697.931

sum 1 UF 5 INVENTOR K an .1 Ach/en PATENTEnom 101912 3.697.931

sum 2 or 5 INVENTOR K uri J Achfen His A H 'ys PATENTEUncnomn 3,697,931 sum 3 or 5 INVENTOR Kun J Ach fen His AH'ys PATENTEDUBTWIQT? 3.697.931

SHEET I; 0F 5 INVENTOR Kurt J Achfen E i l l 5 ,1 5 BY :h' I. 4/

His Auys PATENTEDBBT 1 I912 3.697.931 sum 5 or 5 INVENTOR Kurf J Aer/2 fen BY h His AH'ys ELECTRICAL PLUG CONTACT BACKGROUND OF THE INVENTION In present day electrical equipment, it is common practice to employ pin and socket connections of relatively small configuration in highly dense spacings. It is not unusual for present day electronic computer equip ment to require electrical contacts spaced as close together as 0.050 inches on centers.

One example of a prior art attempt to provide a contact system for use in miniature environments has been the use of twisted wire strands as the male contact member of a plug socket system. This approach, while adequately allowing for the proper density of contacts, is obviously inherently structurally instable. The use of wire strands presents a relatively flexible male plug member which is fragile and highly susceptible to forces tending to bend it from its longitudinal axis. This construction has necessitated the use of a housing system to properly protect the strand members when not in use.

In small environments, a plug connector member should structurally resist bending moments which may possibly occur should the male member be slightly out of line with the longitudinal axis of the socket member.

Manufacturing techniques and structural configurations for the connection of conductor wire to a plugtype contact member utilized in the prior art relating to connectors in general, are not entirely adequate for use in the miniature environment.

SUMMARY OF THE INVENTION Accordingly, it is the principle object of this invention to provide a male contact plug which will provide excellent electrical contact with an associated socket and terminal while inherently resisting forces tending to bend the plug member.

An advantage of this invention is the provision of a plugin connector element which increases in columnar strength as it is inserted in an associated socket terminal.

Moreover, an object of this invention is to provide a plug-in connector which is attached to a conductor wire in such a manner as to provide a penetrating, positive electrical contact between the connector and the wire prior to subsequent operations on the wire and ferrule which prevent separation between the two elev ments.

A related advantage of this invention is, therefore, the provision of a ferrule portion of a plug-in terminal which inherently enhances the electrical conductivity while simultaneously protecting itself from separation from a conductor wire.

A related object of the invention is to provide an efficient method of constructing a plug-in terminal connector from sheet material.

In accordance with the invention, the above and other objects and advantages are accomplished by a terminal connector of the plug-in type which includes a probe portion having a generally bullet-shape and including a plurality of contact arms which are slightly bowed outwardly and which, in their relaxed position, present an outer diameter slightly larger than the inner diameter of an associated socket terminal connector. The contact arms are of such a width as to substantially radially abut one another upon compression when operatively associated with a mating terminal socket.

A ferrule portion is attached to a conductor wire in such a manner as to positively insure electrical contact by using a radially inwardly extending seam means for impingement with the conductor wire. The ferrule means if further designed to accept, between conductor wire and inner surface of the ferrule, the free extending ends of the contact arms.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an enlarged perspective view of the plug connector of the present invention.

FIG. 2 is a perspective view, on a scale smaller than FIG. 1, of one environment in which the present invention is utilized, i.e., mating pin and socket bodies.

FIG. 3 is a side elevational view of the plug connector.

FIG. 4 is a side view, partially in section, showing the plug-in connector operatively associated with a socket connector.

FIG. 5 is an enlarged end sectional view taken along the lines 5-5 of FIG. 3.

FIG. 6 is an enlarged end sectional view taken along the lines 6-6 in FIG. 4.

FIG. 7 is an enlarged end sectional view taken along the lines 7-7 in FIG. 4.

FIG. 8 is an enlarged end sectional view similar to that of FIG. 7 prior to final formation of the ferrule.

FIG. 9 is an enlarged fragmentary perspective view of the plug connector prior to crimping.

FIG. 10 is a fragmentary perspective view similar to FIG. 9 showing the contact arms after crimping.

FIG. 11 is an end sectional view taken along the lines 11-11 in FIG. 4.

FIG. 12 is a perspective view of the flat blank from which the plug connector is formed.

FIG. I3 is a plan view of the blank after the edges of the base portion are deformed to a position generally perpendicular to the planeof the base.

FIG. 14 is a sectional view taken along the line 14- 14 of FIG. 13.

' FIG. 15 is a plan view of the blank showing partial formation of a cylindrical ferrule from the base portion of the blank.

FIG. 16 is a sectional view taken along the line 16- 16 of FIG. 15.

FIG. 17 is a plan view of the blank after formation of the bowed portions of the contact arm.

FIG. 18 is a sectional view taken along the line 18- 18 of FIG. 17.

FIG. 19 is a sectional view taken along the line I9- 19 of FIG. 17.

FIGS. 20 and 21 are perspective views of successive steps inthe assembly of the contact following the drawing of the bullet nose.

FIG. 22 is a plan view of an alternate method of producing blanks.

FIG. 23 is a plan view of an alternate embodiment of a blank used in the formation of a connector plug.

FIG. 24 is a sectional view similar to FIG. I7 utilizing the alternate embodiment of FIG. 24.

FIG. 25 is an exploded perspective view of an alternate embodiment of this invention.

FIG. 26 is an enlarged perspective view of an alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, FIG. I shows a plug-in connector with a ferrule portion 12 and a probe or contact portion 14. The probe portion includes a tip with arms 18 emanating therefrom which extend longitudinally of the axis of the connector. At least two of the free extremities of arms 16 are shown to be inserted in the bore of a barrel or ferrule portion 12. The ferrule portion 12 is formed from a sheet of electrically conductive material. Ferrule 12 includes a seam 22 extending longitudinal thereof. The seam 22 protrudes radially inwardly of the ferrule 12 for impinging contact with an associated conductor wire.

FIG. 2 illustrates an environment in which the connector of the present invention can be utilized. Electronic computer equipment and the like requires large numbers of terminal connections within a small area and thus, pin bodies 26 and socket bodies 28 are generally utilized to achieve this density. FIG. 2 shows how a plurality of plug connectors can be simultaneously associated with corresponding sockets housed in body 28. This figure is meant to be illustrative of the environment utilized and in no way meant to be restrictive as to the particular structure necessary to accommodate the connectors of the present invention.

In the embodiment illustrated by FIG. 3, it is shown that the arms 16 each include a generally bowed portion 18 which allows the arms to be radially spaced from one another in the uncompressed state of the connector. Portions 18 of the arms provide a spring-like characteristic to the probe 14, effectively establishing a radially outwardly biased condition in the probe I4.

The plug connector 10 is normally utilized with an associated socket terminal connector 34 as shown in FIG. 4. Connector systems of the plug-in socket variety depend on surface contact between the outer surface of a plug and the inner surface of a socket to provide a completed circuit, thus enabling current to flow from one terminal to another. In this type of environment, constant, agressive surface contact between the plug and the socket is extremely desirable. The configuration of the present invention provides this desired agressive electrical contact in addition to providing a maximum area of surface contact between the plug and the socket.

Referring to FIG. 5, it will be seen thatthe arms' 16 are of generally arcuate configuration which enables substantially uniform continual contact between the probe 14 and the socket 34 which is also generally of a circular cross-sectional configuration.

As will be seen in FIG. 4, the probe 14 is inserted in an aperture 36 of the socket 34 in the normal fashion. However, it should be noted that the arms 16 are of such a width as to allow the edges 38 of the arms to substantially abut one another upon the insertion of the probe in the socket. This substantial abutment of edges 38 with one another essentially transforms the probe 14 from a series of spring-like and relativelyflexible elements 16, into a configuration which provides an electrical connection with strong resistence to bending about its longitudinal axis. The abutment of the edges 38 upon insertion in an associated socket 34 produces a column effect which greatly increases the stability of the connection. FIG. 6 shows a cross-section of the mating probe and

socket members

14 and 34 respectively, and specifically illustrates the abutment of edges 38 with one another which aids in producing the desired stability in the connection.

The bowed portions 18, when inserted in the socket 34, are continually and agressively forced into surface contact with the inner periphery 40 of the socket 34 as the result of the spring-like tendencies of the arms 16.

Thus, it is apparent that the probe 14 provides a maximum of surface contact between the connector 10 and socket terminal 34 while significantly increasing the stability. of the connection through the abutment of edges 38 within the socket.

The tip 20 is of a generally conical configuration, thus facilitating the entry of the probe .14 into the aperture 36. Once the probe 14 is inserted within the socket 34, as shown in FIG. 4, the outer diameter of the probe is substantially equal to the inner diameter of the socket 34. However, as a result of the springlike tendencies of the arms 16, the outer diameter of the probe, in an uncompressed condition, as shown generally in FIG. 5, is of a larger diameter than the inner diameter of an associated socket 34.

It should be understood that this invention must operate within the range of tolerances necessary in the construction of the various elements. For this reason, the arms 16 are shown slightly spaced radially from one another a distance 74 in FIG. 1. Without such spacing, the connector would present a binding interference fit in an associated socket 34, if the socket is on the low side of an acceptable tolerance range or if the arms 16 are on the high side of an acceptable tolerance range. FIG. 4 shows actual abutment between edges 38. This configuration will exist if the dimensions of the arms 16 or aperture 36 approach the limits of the tolerance variations discussed above. In other situations, within the manufacturing tolerances of the various members, the arms 16 will be slightly spaced apart upon compression. This slight spacing will not prevent the probe from providing a substantial column effect and substantial stability to the connector.

The present invention discloses the use of three arms 16 in a probe and the width of each arm 16 may be approximately one-third the inner diameter of its associated socket terminal. This dimensional relationship will provide a columnar configuration upon the compression of the probe as shown in FIG. 4 and 6. Should a different number of arms be utilized in a probe, the columnar configuration can still be achieved by relating the inner periphery P of a socket connector with a number N of contact arms such that the width of the arms approximate P/N.

The present invention is also concerned with providing a terminal plug-in connector which insures positive contact between a probe and the terminal end of an associated conductor wire. Thus, in the present embodiment shown in FIG. 9, the free extending extremities 42 of the contact arms 16 are shown to extend longitudinally within a sleeve or ferrule portion 12. These free extremities are also preferably of a concave configuration similar to that shown in FIG. 5, thus increasing the surface contact area between the conductor wire 46, the contact arm 16 and the inner surface of the electrically conductive ferrule 12. It is seen from FIG. 9 that current is capable of flowing from the conductor wire 46 to the probe 14 through substantial surface contact between the conductor 46 and the extremities 42.

While various means and methods may be utilized to connect the ferrule with the probe of the present invention, e.g., soldering, crimping, etc., it may be desirable to provide further features to insure proper carrying of current from the conductor 46 to the probe 14. Crimping sections 24, shown in FIG. I and FIG. 11, are utilized to substantially increase metal to metal contact between the conductor wire 46 and the ferrule 12. FIG. II shows how the crimp section 24 substantially decreases the cross-sectional area in which the conductor 46 is confined and thus continuously forces surface contact between the ferrule 12 and the conductor wire 46. The free extending extremities 42 are preferably simultaneously deformed as the ferrule obtains it crimpted section 24. FIG. described the crimped areas 50 which are associated with the crimped sections 24 of the ferrule 12. Thus, it is apparent that the free extending extremities 42 effectively increase the electrical surface contact between the probe 14 and the conductor 46 while at the same time provide a mechanical interlock between the ferrule 12, probe 14 and a conductor 46. The step configuration formed by crimped areas 50 effectively precludes axial separation between the associated elements of the plug-in terminal connector.

As a further feature of the present invention, the ferrule portion 12 is constructed in such a manner as to insure a penetrating contact between the conductor 46 and the ferrule 12. As shown in FIG. 1, generally, and in FIGS. 7 and 8 more specifically, the ferrule 12 is provided with a seam 22. This seam 22 is formed by turning the longitudinal edges 23, of the blank from which the ferrule 12 is formed, in such a manner as to extend radially inwardly of the ferrule. As shown in FIG. 7, this seam 22 penetrates the conductor wire 46 in an impingement area 48 and thus further increases the electrical contact between the conductor wire 46 and the connector 10 generally. This impingement acts to prevent relative rotational motion between the conductor 46 and the ferrule 12. The very nature of the impingement of the seam 22 with the wire 46 tends to exert forces on the longitudinal edges 23 in such a manner as to continually .force these edges in a juxtaposed position, thus retaining the seam configuration. The tendency of the conductor wire 46 to retain the seam 22 in a closed position thus enhances the structural integrity of the ferrule 12. The seam 22 therefore aids in fulfilling both structural and electrical requirements of the ferrule 12.

In the preferred construction of the invention three arms 16 emanate from a central conical tip and extend longitudinally of the conductor axis; however, any desired number of arms may be used. Two of these arms 18 have free extending extremities which are received in the ferrule 12 between the conductor wire 46 and the inner surface 41 of the ferrule. The remaining arm is integrally connected to the ferrule 12 forming a one-piece connector body. This one-piece construction further reduces the possibility of intermittent current flow since the probe 14 and ferrule 12 are not discrete members and do not necessarily require conductive contact between arms 42 and ferrule 12.

The present invention is also concerned with a method of forming a plug-in connector having the above mentioned characteristics. Accordingly, FIG. 12 shows a one-piece blank 52 from which the connector 10 is constructed in a dieformingoperation. The blank 52 is of a generally thin electrically conductive material. Material such as berylium-copper, or the like, has been found to be generally well suited for use in the contemplated environment. The blank shown utilizes positioning holes 54 in a carrier strip 82 for advancement of the blank material to the appropriate die station. The working portions of the blank 52 generally may be described as a rectangular base portion 58 and an integrally connected star-shaped portion 60. The star-shaped portion includes a central portion 56 and radially spaced arms 16 emanating therefrom. One of such arms 16 being connected to the base portion 58 generally along the longitudinal centerline thereof.

Referring now to FIG. 13, the longitudinal edges 23 are shown to be deformed to a position generally perpendicular to the plane of the base portion of the blank 58. This positioning is amplified in the sectional view of FIG. 14.

FIG. 15 discloses the rolling or partial forming of the barrel-like configuration for the ferrule portion 12.

' FIG. 16, a sectional view through the base portion 58,

is somewhat similar to the view of FIG. 8 which shows the partially formed configuration of the connector. Both FIGS. 8 and 16 show the longitudinal edges 23 which ultimately are to form the seam 22.

FIG. 17 generally shows the initial operation on the star-shaped portion of the blank 60. The central portion 56 and adjacent portions of. the arms 16 are deformed downwardly, from a predetermined die plane A, into the general configuration shown in FIG. 18. The lower level 68, ultimately forms the bowed portions I8 of the connector as shown in FIG. 9. The portions of the star-shaped blank 60 which remain along the die plane A are the free extending extremities 42 of the probe 14, also as shown in FIG. 9. The formation of two levels, as in FIG. 18 also includes the formation of the arms 16 into an arcuate cross-sectional configuration. This is shown more specifically in FIG. 19.

FIG. 20 shows the general shape of the blank after drawing and forming the bullet-shaped conical tip from the central portion 56. The drawing is accomplished by appropriate mating dies. The blank 52 has now generally assumed the bullet-shaped configuration described above in relation to the connector 10. It should be noted that in actual practice the blank 52 may be progressively deformed through the stages of FIGS. 13 through 20 without moving from station to station. This has been found to be most efficient when producing miniature parts of the type described.

FIGS. 20 and 21 illustrate the final stages of assembly of the connector 10 to an associated terminal wire 46. In FIG. 20, the free extending arms are positioned in a generally coplanar relationship prior to final preassembly with the ferrule portion 12. In FIG. 21, the free extending extremities 42 are clipped in and retained behind longitudinal edges 23. Thus, it is apparent that the deformed edges 23, which ultimately form the impinging seam 22, also act to retain the ferrule 12 and associated arms 16 in a semi-assembled position immediately prior to final assembly with an associated conductor wire 46. This semi-assembled condition reduces the handling problems which are inherently present in constructing elements of the size contemplated by this invention.

The blank 52 may be advantageously deformed to present a lip or shoulder portion 70 which will allow easy separation, by an appropriate cutting tool, from the scrap material. The connector may be retained on the carrier strip to assist in connecting the wire to the ferrule. After the connection, the shoulder portion 70 may be severed from the strip 82.

The above method may be utilized to produce connectors from a single sheet of conductive material which are all oriented in one direction. However, an alternate embodiment of this invention is shown in FIG. 22. Blank 62 describes an alternating blanking procedure which is an efficient utilization of the stock material. After the initial formation of the star portion 60a and the base portion 58a of the blank, the formation of the connector may be accomplished in a manner similar to that described above.

Also contemplated in the invention, is an alternate embodiment of the basic blank 52. The embodiment shown in FIG. 23 includes

tabs

64 and 66 on the free extending extremities of the arms 16. These tabs are of a width greater than the width of the bowed portions 18.

FIG. 24 is similar to FIG. 7 and shows the use of these

tab portions

64 and 66 in a completed connector. Referring back to FIG. 7 it is seen that due to the integral connection of one of the arms 16 to the ferrule 12, only two free extending extremities are present between the conductor wire 46 and the inner periphery 41 of the ferrule. This leaves a void 72 into which a conductor wire 46 may be forced, possibly allowing intermittent non-continuous contact between the conductor and the ferrule 12 or probe 14. However, as shown in FIG. 24, this void area is eliminated through the use of

tabs

64 and 66. Thus, it is possible to accommodate smaller diameters of conductor wire in essentially the same connector without appreciably changing the dimensions of the blank. The

tabs

64 and 66 will also provide more surface contact between the conductor. wire 46 and the probe 14. A ferrule having an inner periphery P1 can thus obtain a uniform surface contact and reduction in cross-sectional area within the ferrule, by expanding the width of the free extending arms 42 to a width of approximately Pl (Nl), where N is the number of arms 16 in the contact probe.

While the invention has been described above as a one-piece ferrule-probe combination, it is anticipated that the connector could be formed from two discrete members. FIG. 25 shows an alternate embodiment of the invention in which ferrule 12a and probe 14a are separate elements not integrally connected through one of the arms 16, as shown generally by the blank in FIG. 12. The ferrule 12a could receive the extending extremities of all arms 16a and further receive a conductor 46a in a manner similar to that described with respect to the preferred embodiment above. The

elements

14a and 12a could then be restrained from axial separation through the crimping procedure described relative to FIGS. 10 and 11.

It is also envisioned that the connector can be manufactured having only two arms. The embodiment shown in FIG. 26 includes a ferrule 12b with a probe 14b. The probe has two arms 16b configured similar to the arms 16 described above. This two-armed connector is capable of forming a relatively rigid electrical connection by utilizing a plurality of tabs 80 which extend substantially normal to their associated arm 16b in such a manner as to allow each tab 80 to be in alignment for abutment with a similar tab on the other arm 16b. This configuration will provide substantial abutment of the contact arms when the probe 14b is compressed in an associated socket connector.

Thus it is apparent that there has been provided, in accordance with the invention, a plug-in connector which insures continuous current flowbetween terminal wires to be connected, especially in miniature environments. The connector described above utilizes a probe which includes contact arms designed specifically to provide continually biased electrical contact with an associated socket terminal while at the same time substantially increases the stability of the connection by forming a column-like member upon insertion in the associated socket. The connector in the present invention further provides a ferrule portion which aids in the preassembly of the probe and which insures a penetrating positive electrical contact between itself and an associated conductor wire. The structure relating to the above described invention also provides a connector which has a relatively long life due to the spring-like tendencies of its contact arms and a novel association between a probe member and the ferrule member which substantially reduces the possibility of axial separation of the two.

While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within'the spirit and broad scope of the intended claims.

lclaim:

l. A one-piece plug connector formed from sheet material comprising a sleeve and a contact portion, the contact portion comprising a bullet-nose tip with a plurality of arms emanating therefrom and extending generally longitudinally behind the tip,'one arm injacent arms to substantially abut and form a columnar structure upon compression of the contact portion, wherein the connector is capable of sustaining electrical contact with a mating socket portion while resisting bending of the contact portion.

2. A connector in accordance with claim 1 wherein the plurality of arms includes a portion adjacent the tip having a first width which allows abutment of the longitudinal edges upon radial compression of the arms, the remaining arms including a portion received in the sleeve having a second width which is greater than the first width.

3. A connector in accordance with claim 2 wherein the sleeve includes a seam means extending longitudinal and protruding radially inwardly thereof for impinging contact with an associated conductor wire.

4. A one-piece plug connector for association with a mating socket connector including a probe portion and a barrel portion, the probe portion having a bullet-nose tip and a plurality of longitudinally extending contact arms emanating therefrom, said contact arms comprising at least one free extending arm and one arm integrally attached to the barrel portion, each contact arm including outwardly bowed portions for aggressive mating contact with an associated socket, the bowed portions being of such a width as to allow the edges of the contact arms to substantially abut when the probe is in compressed condition, thereby imparting columnar strength to the probe upon insertion in the mating socket, the free extending arms extending into the barrel portion and having a width greater than the width of their associated bowed portions to uniformly decrease the cross-sectional area within the barrel, the barrel including seam means extending radially inwardly and situated between two of the free extending arms, whereby an associated conductor is positioned in the barrel in such a manner as to be impinged by the seam means and operatively connected to the contact arms through both the barrel and free extending arms.

5. A one-piece plug connector in accordance with claim 4 for association with a mating socket having a contact surface with an inner periphery P, the probe portion having N number of contact arms each having a width of approximately P/N, said contact arms being radially spaced from one another in their non-compressed state, the barrel portion having an inner periphery P1, and the free extending arms having a width of approximately P1 (Nl).

6. In a connector plug for a conductor terminal, contact means and ferrule means formed in one-piece from a sheet of conductive material, the contact means including three arms emanating from a central conicaltipped portion and folded back to be received in the bore of the ferrule, one of said arms integrally connected to the ferrule, each arm being bowed outwardly from the longitudinal axis of the plug to provide a resiliently biased electrical contact with a cooperating socket connector, the ferrule means including inwardly extending seam means impinging an associated conductor thus affording positive electrical contact while retaining the ferrule in a closed configuration, the two free arms extending into the ferrule for operative association between the ferrule and conductor and straddling the inwardly extending seam.

7. in an electrical connection of the plug and socket type, a contact probe including longitudinally extending means for providing agressive, substantially constant electrical contact with an associated socket while substantially increasing the column strength of the probe upon insertion in an associated socket, a conductive sleeve means for connecting an associated conductor to the contact probe, said sleeve means formed from sheet material and including a longitudinal seam formed from edges of the sheet material, said seam extending radially inwardly for impingement into the associated conductor, said probe including a conical shaped tip at one end for facilitating entry of the plug into a socket, the other end of the probe including a plurality of arms inserted in the sleeve and positioned between the conductor and the inner surface of the sleeve, said sleeve and associated arms including at least one crimped section for increasing the electrical contact between the conductor, probe, and sleeve as well as preventing relative axial movement between the conductor, probe, and sleeve.

8. An electrical connection as set forth in claim 7 wherein the arms have a generally arcuate cross-section for increasing the surface contact of the arms between the sleeve and conductor.

9. A plug-in connector as set forth in claim 8 wherein the free ends of two contact arms are positioned between the conductor wire and the inner surface of the ferrule portion thus providing substantial surface contact between the conductor, ferrule, and contact portions.

10. A plug-in connector for electrically connecting the terminal ends of a conductor with a cooperating socket connector, including contact means and a ferrule portion, the contact means being of a generally bullet-like configuration including a plurality of arms integrally connected to a generally conical shaped tip portion, at least one of said arms being integrally connected to said ferrule portion, said arms having portions bowed outwardly from the longitudinal axis of the contact means, the bowed portions forming a biased electrical engagement between the contact means and an associated socket connector, said arms being of sufficient width and being spaced radially from one another so that the longitudinal edges of the arms substantially abut when operatively associated with a socket connector, the ferrule portion receiving an end of a conductor wire and further receiving free ends of the arms of the contact means with the conductor wire, whereby the contact means provides a radially biased contact with a socket connector while providing a connection which has relatively large column strength.

11. A plug connector, comprising a sleeve having a contact portion extending outwardly from one end thereof, the sleeve and contact portion formed from electrically conductive sheet materials, said sleeve including a formed seam means extending radially inwardly forming a penetrating contact with an associated conductor wire, the contact portion including a nose with a plurality of longitudinally extending arms emanating therefrom, the arms having portions bowed outwardly from the longitudinal axis of the contact portion and radially spaced from each other, the free ends of the arms received in the sleeve for electrical contact between the sleeve, arms and conductor, said sleeve including at least one crimped portion for insuring contact between the sleeve and conductor, the portions of the contact arms received in the sleeve also including crimped sections which generally eliminate relative axial movement between the sleeve and arms.

12. The method of making a one-piece plug connector comprising steps of stamping from a sheet of conductive material a blank having a generally rectangular base portion and a generally star-shaped portion having a plurality of arms emanating from a central, generally circular portion, one of said arms integrally connected to the base portion, turning the longitudinal edges of the rectangular base portion to a position generally perpendicular to the plane of the base portion, folding the base portion to a generally U-shaped cross-sectional configuration, deforming the star-shaped portion into a bullet-shaped configuration with the center of the circular portion becoming the tip of the bullet-shaped configuration, while slightly bowing the portions of the arms nearest the tip portion, pushing the free extending arms into the base portion behind the longitudinal edges, inserting a conductor wire into the base portion, and closing the base portion to form a barrel around the wire and free extending arms.

13. The method of making a one-piece plug connector in accordance with claim 12 wherein the bulletshaped configuration having slightly bowed arms is formed by depressing the circular portion and portions of the arms connected to the circular portion to a lower horizontal plane than the remainder of the blank, and drawing the lower plane portion into a bullet-shaped configuration with the circular portion being of a generally conical configuration.

14. The method of making a one-piece plug connector in accordance with claim 13 wherein the plurality of .arms are formed of a predetermined width and the free extending arms are formed with an outer extremity portion of a larger width than the generally bowed portions of the arms.

15. The method of making a one-piece plug connector in accordance with claim 13 including locking the free extending arm inside the Ushaped base portion adjacent the longitudinal edges of the base portion, closing the U-shaped base portion while impinging the longitudinal edges of the base portion into the associated conductor wire, crimping the base portion while deforming portions of the free extending arms inwardly thus impinging the conductor with both a portion of the surface of the base portion as well as portions of the free extending arms.

16. The method of making a one-piece plug connector in accordance with claim 13 including forming the arms with a curved cross-sectional configuration.

Claims

1. A one-piece plug connector formed from sheet material comprising a sleeve and a contact portion, the contact portion comprising a bullet-nose tip with a plurality of arms emanating therefrom and extending generally longitudinally behind the tip, one arm integrally connected to the sleeve and the free ends of the remaining arms being received in the sleeve, said arms including radially outwardly biasing means for generally resisting radial compression of the contact portion while allowing the longitudinal edges of the adjacent arms to substantially abut and form a columnar structure upon compression of the contact portion, wherein the connector is capable of sustaining electrical contact with a mating socket portion while resisting bending of the contact portion.

5. A one-piece plug connector in accordance with claim 4 for association with a mating socket having a contact surface with an inner periphery P, the probe portion having N number of contact arms each having a width of approximately P/N, said contact arms being radially spaced from one another in their non-compressed state, the barrel portion having an inner periphery P1, and the free extending arms having a width of approximately P1 (N-1).

6. In a connector plug for a conductor terminal, contact means and ferrule means formed in one-piece from a sheet of conductive material, the contact means including three arms emanating from a central conical-tipped portion and folded back to be received in the bore of the ferrule, one of said arms integrally connected to the ferrule, each arm being bowed outwardly from the longitudinal axis of the plug to provide a resiliently biased electrical contact with a cooperating socket connector, the ferrule means including inwardly extending seam means impinging an associated conductor thus affording positive electrical contact while retaining the ferrule in a closed configuration, the two free arms extending into the ferrule for operative association between the ferrule and conductor and straddling the inwardly extending seam.

13. The method of making a one-piece plug connector in accordance with claim 12 wherein the bullet-shaped configuration having slightly bowed arms is formed by depressing the circular portion and portions of the arms connected to the circular portion to a lower horizontal plane than the remainder of the blank, and drawing the lower plane portion into a bullet-shaped configuration with the circular portion being of a generally conical configuration.

14. The method of making a one-piece plug connector in accordance with claim 13 wherein the plurality of arms are formed of a predetermined width and the free extending arms are formed with an outer extremity portion of a larger width than the generally bowed portions of the arms.

15. The method of making a one-piece plug connector in accordance with claim 13 including locking the free extending arm inside the U-shaped base portion adjacent the longitudinal edges of the base portion, closing the U-shaped base portion while impinging the longitudinal edges of the base portion into the associated conductor wire, crimping The base portion while deforming portions of the free extending arms inwardly thus impinging the conductor with both a portion of the surface of the base portion as well as portions of the free extending arms.