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(11) | EP 0 025 368 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
Electric socket contact Elektrische Kontaktbuchse Contact électrique à douille |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
[0001] This invention relates to a socket contact for a separable electrical connector of the type including first and second connector members.
[0002] Separable electrical connectors of the plug and receptacle type are used in many applications for connecting multiple pairs of corresponding conductors. Such connectors are widely used in the aerospace field and complex electronic systems in which a single connector may connect hundreds of pairs of wires. In such systems, the connectors must be miniaturized to minimize the weight and size. The wires at the receptacle are connected to individual terminals and the wires at the plug are connected to corresponding terminals. Typically, each of the terminals in one of the connectors is a socket contact, each of the terminals in the other connector is a pin contact and the pin contacts are adapted to telescopically engage with the corresponding socket contacts when the plug and receptacle are in a mated relationship. In order the miniaturize the connectors, the pin and socket contacts need to be very small; for example, the socket contact may be less than 2.5 mm in diameter and less than 13 mm in a length.
[0003] Connectors of the type described must be capable of quick and easy connection and disconnection without undue force. Yet each set of contacts must provide excellent electrical conductivity and be capable of repeated connections and-disconnections without damage or significant deterioration. When miniature contacts were first introduced, they were manufactured by machining from metal stock since that was the only feasible way to hold the tolerances required for the mating the contacts. However, machined contacts are relatively costly. In recent years such contacts have been made from sheet metal by forming and rolling to produce a "formed" contact.
[0004] Formed socket contacts have been developed which comprise an assembly of contact sleeve or liner of spring metal having plural contact fingers at the mating end and a supporting sleeve thereon. The wire receiving end is provided with plural openings and has a supporting sleeve thereon and is crimped into engagement with the wire. Additionally, a mounting flange is provided in the midsection of the contact sleeve. In this construction, the inner sleeve has an open seam from one end to the other, i.e. the abutting edges of the rolled sleeve are not welded or brazed together. A socket contact of this construction and method of making are described in US-A-4 072 394. Formed contacts with welded or brazed seams are disclosed in the following patents: US-A-3 286 223; US-A-3 317 887; and US-A-3 721 943.
[0005] In the socket contact described, the contact fingers constitute cantilever beams deflected in a radial direction by the insertion of the mating pin contact. Each of the contact fingers is supported only at its root in the contact sleeve. In order to ensure a good electrical connection between the socket contact and the pin contact, it is necessary to have each finger exerting an appropriate resisting force to radial deflection. If the resisting force is too great the insertion force required for the pin contact is excessive; if the insertion force for the pin contact is too small, the electrical connection between the pin and socket contacts may be defective.
[0006] The present invention overcomes the limitations and disadvantages of the prior art arrangements by providing an electric socket contact comprising an elongate sleeve having a wire receiving opening at a rear end and a pin contact receiving opening comprising an annulus formed of resilient contact fingers at a forward mating end, characterized in that a supporting sleeve is disposed in external coaxial relation with said elongated sleeve, an outer sleeve is disposed in external coaxial relation with said supporting sleeve and there is provided mounting means for immovably securing the supporting sleeve to the outer sleeve whereby the supporting sleeve has its rearward end adjacent the wire receiving opening and its forward end extending slightly beyond the forward ends of the contact fingers, said outer sleeve including guide means providing a socket entrance for guiding the pin into centered relation with the annulus at the forward mating end, the wall of the elongated sleeve defining slots extending axially from a mating end and thereby providing contact fingers, each finger extending as a cantilever beam and terminating at a free end, the slots being three in number and circumferentially equally spaced thereby providing a set of three equally spaced contact fingers.
[0007] The invention thus provides a socket contact which exhibits a desired contact force and a centering action upon entry of a cooperating contact pin.
[0008] One way of carrying out the invention is described in detail below with reference to the drawings which illustrate one specific embodiment of this invention, in which:
FIGURE 1 shows the socket contact assembly in elevation with certain parts broken away;
FIGURE 2 shows detail of construction of the wire receiving end of the socket contact;
FIGURE 3 shows the socket contact of this invention in an electrical connector;
FIGURE 4 shows a contact blank which has been stamped from sheet metal to form the contact sleeve;
FIGURE 5 is an elevation view with parts broken away of the contact sleeve of the socket contact of this invention;
FIGURE 6 is an end view of the sleeve of FIGURE 5;
FIGURE 7 is a sectional view of the supporting sleeve for the socket contact of this invention;
FIGURE 8 is a sectional view of an outer sleeve of the socket contact; and
FIGURE 9 shows a detail of construction.
[0009] Referring now to the drawings, there is shown an illustrative embodiment of the invention in a socket contact especially adapted for use in separable electrical connectors. The socket contact comprises a contact liner of the formed type, i.e. it is fabricated from thin sheet metal by stamping and rolling. The contact is adapted for mounting in a dielectric insert of an electrical connector member and for telescopic engagement with a pin contact mounted on a mating connector member.
[0010] The socket contact, with the parts assembled, is shown in FIGURE 1. In general, the socket contact 10 comprises a contact liner or sleeve 12 disposed in co-axial relationship within a supporting sleeve 14 which extends substantially the full length of the contact sleeve. An outer sleeve or front hood 16 is disposed in co-axial relation over the supporting sleeve 14 and extends from the pin receiving or mating end 18 to a point near the midsection of the contact sleeve 12. The back end of the contact 10 terminates in a wire receiving opening 20 which receives a conductor or wire 22. The mating end 18 at the front of the contact is adapted to receive a pin contact 24. Before proceeding with the detailed description of the socket contact 10, it will be helpful to consider the mounting of the socket contact in an electrical connector member.
[0011] FIGURE 3 shows a fragmentary view of an electrical connector of the type of which the socket contact of this invention may be used. The electrical connector comprises a re- ceptable 30 which contains a dielectric insert 32 in which are mounted a plurality of socket contacts 10. The electrical connector also includes a plug 34 which contains a dielectric insert 36 in which are mounted a plurality of pin contacts 24. The receptacle 30 and the plug 34 are adapted to be oriented and drawn together in a mated relationship (by means not shown) so that the pin contact 24 is telescopically inserted into the socket contact 10 to provide an electrical connection therebetween. In this illustration, the insert 32 defines a recess 35 which contains a retention device 40. The socket contact 10 is mounted in the insert 32 by the contact retention device 40 which includes plural deflectable spring fingers 42 which engage a rearward shoulder 44 on the socket contact 10. The socket contact 10 is inserted from the rear of the insert through the retention device and the spring fingers 42 deflect to allow the hood 16 to pass by and then the fingers seat against the rear shoulder 44. Accordingly, the socket contact 10 is maintained in a fixed position within the insert.
[0012] Referring now, especially to FIGURES 2, 5 and 6, the contact sleeve 12 will be described in greater detail. The contact sleeve 12 is formed from a resilient sheet metal, preferably a beryllium copper alloy, by stamping and rolling process. The process of forming the sleeve 12 is suitably that described in the above cited U.S. Patent No. 4,072,394. A contact blank 12' which has been stamped from sheet metal for forming contact sleeve 12 is shown in FIGURE 4. The contact sleeve 12 comprises a cylindrical portion 50 having an open seam 46 which is formed by the abutting or closely spaced, longitudinally extending edges 52 and 54 of the portion 50. The contact sleeve 12 is provided with an oblique flange 56 at the rearward or wire receiving end 20 to serve as a stop or locating shoulder for the supporting sleeve 14. Adjacent the wire receiving end 20 of the contact sleeve 12 the wall thereof defines a set of five elongated openings 58 which are equally spaced circumferentially of the sleeve with one of the openings 58 being centered on the open seam 46. At a position forward of the openings 58 the contact sleeve 12 is provided with a plurality of annular inwardly directed ribs 60. As shown in FIGURE 2, the wire receiving end 20 of the contact sleeve 12 receives the end of the wire 22. An inwardly directed stop tab 62 is provided by lancing a portion of the walls of the supporting sleeve 14 and the contact sleeve 12. Preferably the tab 62 is located diametrically opposite the open seam 46. The wire 22 is stripped of insulation at its end and the bare conductor is inserted into the contact sleeve 12 and seated against the stop tab 62. When the socket contact is to be installed on the wire 22 for use in a connector, the double wall thickness of the contact sleeve 12 and the supporting sleeve 14 is crimped inwardly at four equally spaced locations to provide indentations 64, as shown in FIGURE 9, whereby the contact sleeve 12 is crushed inwardly against the bare wire to provide a good electrical and mechanical connection.
[0013] Reverting back to FIGURES 4 and 5, contact sleeve 12 is provided with a set of three equally spaced tines or contact fingers 66 at the forward or mating end 18 of the sleeve 12. The contact fingers 66 are formed by punching two equally spaced slots 68 into the sheet metal of the contact sleeve 12 while it is in a flat condition. The slots 68 extends from the pin mating end 18 of the contact sleeve 12 to a location adjacent midsection of this sleeve and each slot 68 terminates in an arcuate configuration at the root of the contact fingers 66. The contact sleeve 12 in that portion extending from the root of the fingers 66 to the free ends of the fingers is tapered to a smaller diameter at the mating end 18. In other words, each of the contact fingers 66 slopes radially inwardly at its free end. After the forming operation, the contact sleeve 12 is heat treated so that the contact fingers 66 are stress-relieved in the tapered position illustrated. Additionally, the free ends of the fingers 66 are coined to provide bevelled ends 70 to facilitate entry of the pin contact 24 into the contact sleeve 12.
[0014] The supporting sleeve 14 as shown in FIGURES 1 and 7 is a cylindrical metal tube. The sleeve 14 is preferably constructed of stainless steel and is formed by deep drawing to provide a tube having a relatively thin wall of a few hundredths of a millimeter in thickness. The supporting sleeve 14 is provided with an annular, outwardly extending flange 76. The supporting sleeve 14 is disposed externally of the contact sleeve 12 and, as shown in FIGURE 1, the rearward end 78 thereof is in abutting engagement with the stop shoulder 56 on the contact sleeve 12. The forward end 80 of the supporting sleeve 14 extends slightly beyond the ends of the contact fingers 66. It is noted that the forward end of the supporting sleeve 14 is radially spaced from the contact fingers 66 leaving room for radial deflection of the fingers upon the entrance of the pin contact 24. The annular flange 76 on the supporting sleeve 14 is located near the midsection of the contact sleeve 12 and serves to secure the mounting flange 44 which is formed on the outer sleeve or hood 16. The supporting sleeve 14, as shown in FIGURE 2, is interlocked with the contact sleeve 12 by means of the tab 62 and it serves as a support structure for the contact sleeve 12 in the formation of the crimped indentations 64.
[0015] The outer sleeve or hood 16, as shown in FIGURES 1 and 8 is a cylindrical tube disposed in external co-axial relation with the supporting sleeve 14. The hood 16 is preferably made of stainless steel by a deep drawing operation and has a wall thickness of a few hundredths of a millimeter. The forward end of the hood 16 is provided with an inwardly turned annular bight 86 which forms an annular channel 88 adapted to receive the forward end 80 of the supporting sleeve 14. The rearward end of the hood 16 has an enlarged diameter to form a bell mouth 44' which is adapted to fit over the annular flange 76 on the supporting sleeve 14. With the hood 16 positioned on the supporting sleeve 14, the bell mouth 44' thereof is rolled over the flange 76 to provide the annular retention flange 44, as shown in FIGURE 1. At the forward end of the hood 16 the annular bight 86 provides a socket entrance adapted to guide the mating contact pin 24 into centered relationship with the contact fingers 66. For this purpose, the inside diameter of the annular bight 86 is substantially the same as the outside diameter of the bevelled surfaces 70 and there is a small axial spacing between the end of the bight 86 and the ends of the fingers.
[0016] As described above, the socket contact 10, as shown in FIGURE 1, is connected with a wire 22 and is mounted in a connector as shown in FIGURE 3. In this example, the socket contact 10 is positioned in the insert parts 33 and 32 with the fingers 42 of the retaining device 40 seated against the rearward face of the flange 44. In use of the connector, the pin contact 24 on the plug 34 is axially aligned with the socket contact 10 and when the plug and receptacle are drawn together the pin contact 24 is telescopically inserted into the socket contact 10. As the pin contact 24 enters the socket contact, the contact fingers 66 are first engaged by the pin at the bevelled surfaces 70 which facilitate entrance of the pin contact and minimize the axial loading on the contact fingers. The contact fingers are radially deflected as the pin contact enters the socket contact. The three contact fingers 66 exert radial forces on the pin contact and due to the equal angular spacing thereof, the pin and socket contacts tend to remain on center with each other. Each of the three contact fingers exerts a normal force against the pin contact due to the resiliency of the fingers and maintains a good electrical contact therewith. The normal force exerted by the three contact fingers, and hence the axial resisting force against the pin contact, is less than that provided in a socket contact of the same materials and dimensions but having two contact fingers instead of three; additionally the third contact finger enhances the electrical contact. The contact sleeve 12 of this invention having three contact fingers is especially well adapted to fabrication by stamping and rolling as compared to socket contacts with two or four contact fingers, especially where the open seam 46 is disposed diametrically opposite one of the contact fingers.
1. An electric socket contact comprising an elongated sleeve (12) having a wire receiving
opening at a rear end and a pin contact receiving opening comprising an annulus formed
of resilient contact fingers (66) at a forward mating end, characterized in that a
supporting sleeve (14) is disposed in external coaxial relation with said elongated
sleeve (12), an outer sleeve (16) is disposed in external coaxial relation with said
supporting sleeve (14) and there is provided mounting means (44, 76) for immovably
securing the supporting sleeve (14) to the outer sleeve (16) whereby the supporting
sleeve (14) has its rearward end (78) adjacent the wire receiving opening and its
forward end (80) extending slightly beyond the forward ends of the contact fingers,
said outer sleeve (16) including guide means (86) providing a socket entrance for
guiding the pin into centered relation with the annulus at the forward mating end,
the wall of the elongated sleeve (12) defining slots (68) extending axially from a
mating end (18) and thereby providing contact fingers (66), each finger (66) extending
as a cantilever beam and terminating at a free end, the slots (68) being three in
number and circumferentially equally spaced thereby providing a set of three equally
spaced contact fingers (66).
2. An electric socket contact according to Claim 1, characterized in that said mounting
means (44, 76) comprises an outwardly extending flange (76) medially of support sleeve
(14) and an annular retention flange (44) formed at the rear end of outer sleeve (16)
fit about the outwardly extending flange (76).
3. An electric socket contact according to Claim 1, characterized in that the guide
means (86) includes an annular bight (86) in coaxial relation with the annulus of
contact fingers and forms an annular channel (88) received about the forward end (80)
of supporting sleeve (14).
4. An electric socket contact according to Claim 3, characterized in that there is
provided means (62) for immovably securing the supporting sleeve (14) to the contact
sleeve including a finger extending into the contact sleeve between said wire receiving
opening and the means for immovably securing the supporting sleeve to the outer sleeve.
5. An electric socket contact according to Claim 4, characterized in that said contact
sleeve terminates in an obliquely extending flange (56) at the wire receiving opening
and the rearward end (78) of said supporting sleeve (14) is positioned against said
obliquely extending flange (56).
6. An electric socket contact according to Claim 5, characterized in that outer sleeve
(16) and support sleeve (46) are seamless, that the elongated contact sleeve includes
an open seam (14) extending between its ends and defines plural openings (58) in the
wall thereof adjacent the wire receiving opening, said plural openings (58) being
spaced circumferentially around the contact sleeve with one of the openings being
in alignment with the seam (46) whereby the wall of the supporting sleeve (14) and
the wall of said contact sleeve between the openings (58) may be crimped inwardly
against a wire (22) disposed in the wire receiving opening.
1. Elektrischer Buchsenkontakt mit einer länglichen Buchse (12), die eine einem Draht
aufnehmende Öffnung an einem hinteren Ende und eine einen Stiftkontakt aufnehmende
Öffnung an einem vorderen Passende aufweist, welche einen aus elastischen Kontaktfingern
(66) gebildeten Ring umfasst, dadurch gekennzeichnet, daß eine Lagerbuchse (14) in
äußerer koaxialer Lage relativ zu der länglichen Buchse (12) angeordnet ist, daß eine
äußere Buchse (16) in äußerer koaxialer Lage relativ zu der Lagerbuchse (14) angeordnet
ist, daß Montageeinrichtungen (44, 76) zur unbeweglichen Befestigung der Lagerbuchse
(14) an der äußeren Buchse (16) vorgesehen sind, so daß das hintere Ende (78) der
Lagerbuchse (14) benachbart zu der den Draht aufnehmenden Öffnung angeordnet ist und
sich das vordere Ende (80) der Lagerbuchse geringfügig über die vorderen Enden der
Kontaktfinger hinaus erstreckt, daß die äußere Buchse (16) Führungseinrichtungen (86)
aufweist, die eine Buchseneinführung zum Führen des Stiftes in eine zentrierte Lage
relativ zu dem Ring an dem vorderen Passende bilden, daß in der Wand der länglichen
Buchse (12) Schlitze (68) angeordnet sind, die sich in Axialrichtung von einem Passende
(18) aus erstrecken und dadurch Kontakfinger (66) bilden, daß jeder Kontakfinger (66)
sich in Form eines auskragenden Trägers erstreckt und ein freies Ende aufweist und
daß drei Schlitze (68) vorgesehen sind, die gleiche Umfangsabstände voneinander aufweisen,
so daß auf diese Weise ein Satz von drei in gleichen Abständen angeordneten Kontaktfingern
(66) gebildet wird.
2. Elektrischer Buchsenkontakt nach Anspruch 1, dadurch gekennzeichnet, daß die Montageeinrichtungen
(44, 76) in der Mitte der Lagerbuchse (14) einen auswärts verlaufenden Flansch (76)
und am hinteren Ende der äußeren Buchse (16) einen ringförmigen Halteflansch (44)
aufweisen, der um den auswärts verlaufenden Flansch (76) herumgepaßt ist.
3. Elektrischer Buchsenkontakt nach Anspruch 1, dadurch gekennzeichnet, daß die Führungseinrichtungen
(86) eine ringförmige Ausbuchtung (86) in koaxialer Lage zu dem Ring der Kontaktfinger
aufweisen und einen ringförmigen Kanal (88) bilden, der sich um das vordere Ende (80)
der Lagerbuchse (14) erstreckt.
4. Elektrischer Buchsenkontakt nach Anspruch 3, dadurch gekennzeichnet, daß er Einrichtungen
(62) zur unbeweglichen Befestigung der Lagerbuchse (14) an der Kontaktbuchse aufweist,
die einen Finger umfassen, der sich in die Kontaktbuchse zwischen der den Draht aufnehmenden
Öffnung erstreckt, sowie die Einrichtungen zur unbeweglichen Befestigung der Lagerbuchse
an der äußeren Buchse.
5. Elektrischer Buchsenkontakt nach Anspruch 4, dadurch gekennzeichnet, daß die Kontaktbuchse
an der den Draht aufnehmenden Öffnung in einem schief verlaufenden Flansch (56) endet
und daß sich das hintere Ende (78) der Lagerbuchse (14) gegen den schief verlaufenden
Flansch (56) erstreckt.
6. Elektrischer Buchsenkontakt nach Ansprüch 5, dadurch gekennzeichnet, daß die äußere
Buchse (16) und die Lagerbuchse (46) nahtlos ausgebildet sind, daß die längliche Kontaktbuchse
eine offene Naht (14) aufweist, die sich zwischen ihren Enden erstreckt und eine Vielzahl
von Öffnungen (58) in ihrer Wand benachbart zu der den Draht aufnehmenden Öffnung
bildet und daß die Vielzahl der Öffnungen (58) mit Umfangsabstand um die Kontaktbuchse
herum angeordnet ist, wobei eine der Öffnungen zu der Naht (46) ausgerichtet ist und
die Wand der Lagerbuchse (14) sowie die Wand der Kontaktbuchse zwischen den Öffnungen
(58) gegen einen Draht (22), der in der den Draht aufnehmenden Öffnung angeordnet
ist, einwärts gefaltet sein können.
1. Un contact électrique à douille qui comprend un manchon allongé (12) ayant une
ouverture de réception de fil à une extrémité arrière et une ouverture de réception
de contact à fiche comprenant une région annulaire formée par des doigts de contact
élastiques (66) à une extrémité d'accouplement avant, caractérisé en ce qu'un manchon
support (14) est disposé dans une relation coaxiale externe avec ledit manchon allongé
(12), un manchon extérieur (16) est disposé dans une relation coaxiale externe avec
ledit manchon support (14) et il est prévu des moyens de montage (44, 76) pour assujettir
fixement le manchon support (14) au manchon extérieur (16) de telle sorte que le manchon
support (14) a son extrémité arrière (78) adjacente à l'ouverture de réception de
fil et son extrémité avant (80) qui s'étend légèrement au-delà des extrémités avant
des doigts de contact, ledit manchon extérieur (16) comportant des moyens de guidage
(86) qui forment une entrée de douille pour guider la fiche dans une relation centrée
avec la région annulaire située à l'extrémité d'accouplement avant, la paroi du manchon
allongé (12) comportant des fentes (68) qui s'étendent axialement à partir d'une extrémité
d'accouplement (18) et forment, de ce fait, des doigts (66) de contact, chaque doigt
(66) s'étendant à la manière d'une poutre en porte-à-faux et se terminant à une extrémité
libre, les fentes (68) étant au nombre de trois et étant régulièrement espacées autour
d'un cercle formant ainsi un jeu de trois doigts (66) de contact régulièrement espacés.
2. Un contact électrique à douille selon la revendication 1, caractérisé en ce que
lesdits moyens de montage (44, 76) comprennent une collerette (76) s'étendant vers
l'extérieur formée au milieu du manchon support (14) et une collerette de retenue
annulaire (44) formée à l'extrémité arrière du manchon extérieur (16) adaptée autour
de la collerette (76) s'étendant vers l'extérieur.
3. Un contact électrique à douille selon la revendication 1, caractérisé en ce que
les moyens de guidage (86) comportent un bord recourbé annulaire (86) disposé dans
une relation coaxiale avec la région annulaire formée par les doigts de contact et
formant une rainure annulaire (88) reçue autour de l'extrémité avant (80) du manchon
support (14).
4. Un contact électrique à douille selon la revendication 3, caractérisé en ce qu'il
est muni de moyens (62) pour assujettir fixement le manchon support (14) au manchon
de contact, ces moyens comportant un doigt qui s'étend dans le manchon de contact
entre ladite ouverture de réception de fil et les moyens servant à assujettir fixement
le manchon support au manchon extérieur.
5. Un contact électrique à douille selon la revendication 4, caractérisé en ce que
ledit manchon de contact se termine par une collerette (56) s'étendant obliquement
à l'extrémité de réception de fil et l'extrémité arrière (78) dudit manchon support
(14) est positionnée contre ladite collerette (56) s'étendent obliquement.
6. Un contact électrique à douille selon la revendication 5, caractérisé en ce que
ledit manchon extérieur (16) et ledit manchon support (14) sont sans joint, en ce
que le manchon de contact allongé comporte un joint ouvert s'étendant entre ses extrémités
et comporte plusieurs ouvertures (58) dans sa paroi adjacente à l'ouverture de réception
de fil, lesdits multiples ouvertures (58) étant espacées circonférentiellement autour
du manchon de contact, l'une des ouvertures étant alignée avec le joint (46) de sorte
que la paroi de manchon support (14) et la paroi dudit manchon de contact entre les
ouvertures (58) peuvent être serties vers l'intérieur contre un fil (22) disposé dans
l'ouverture de réception de fil.