EP0033794A1

EP0033794A1 - A plug receptacle electrical connector and a method of manufacturing such a connector

Info

Publication number: EP0033794A1
Application number: EP80300396A
Authority: EP
Inventors: Lynn Wilson Abernethy; Elvert Steven Watts
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1980-02-12
Filing date: 1980-02-12
Publication date: 1981-08-19
Also published as: ATE4011T1; DE3063938D1; HK81886A; EP0033794B1

Abstract

A plug receptacle electrical connector and a method of manufacturing such a connector.

The receptacle connector comprises a moulded insulating cover (1) which receives a moulded insulating base (36) carrying electrical contacts (60) for engaging contacts of a plug connector (100) inserted into a cavity (2) in the cover (1).

To enable the connector to be mounted on a circuit board with the contacts (60) connected to circuitry (not shown) on the board, the contacts (60) have lead portions (64) which project beneath the base (36), the bottom of the cover (36) being open to receive the lead portions (64). Rails (48) on the base (36), which engage in grooves (82 and 88) in the cover, being provided on the sides of the base (36) and having thereon latches (50) for engaging shoulders (52A) defined by the grooves (82 and 88). In the manufacture of the connector, the contacts (60) are selectively plated with gold stripes (not shown) for engagement by the contacts of the plug (100).

Description

There is described in United States defensive publication No. T961,003, a plug receptacle electrical connector comprising a moulded insulating cover and a moulded insulating base for reception in a cavity defined by the cover so that elongate contact portions of electrical contacts, projecting from a first surface of the base, extend across the cavity for engagement by respective contact elements of a plug electrical connector when such has been subsequently inserted into the cavity through a first opening in a front wall of the cover, the base being insertable into the cavity through a second opening in the cover opposite to the first opening, guided by opposed rails on the base which are engageable with complementary internal guide surfaces of side walls of the cover, latch means being provided-on the base to retain it in its fully inserted position in the cavity.
The contacts of this known receptacle connector are in the form of wire springs which have been connected by means of crimped ferrules to lead wires, the ferrules being fully received in the base to extend in the direction that the base is inserted into the cover, the lead wires projecting from the trailing end of the base and the contact portions of the contacts projecting from the leading end of the base.
According to one aspect of the present invention, a receptacle connector as defined in the first paragraph of the present specification is characterised in that the cover has an open side adjacent-to the front wall and to the side walls to receive, as the base is inserted into the cavity, lead portions of the contacts projecting, transversely of the direction of insertion of the base into the cover, from a second surface of the base opposite to the first surface thereof, the rails which project laterally of the base being receivable in grooves in the side walls and having thereon latches engageable with shoulders at the ends of the grooves nearest to the front wall, when the base has been fully inserted into the cavity.
An advantage of a connector according to the invention is that the base can be inserted into the cover and latched therein despite the fact that the lead portions of the contacts project transversely of the direction in which the base is inserted into the cover so that the lead portions can be inserted into holes in a circuit board upon which the base is to be directly mounted. Also the contacts can readily be produced in strip form, for selective gold plating prior to their assembly to-the base, as explained in detail below.
According to another aspect of the invention, a method of manufacturing a receptacle connector according to the invention is characterised in that it includes the steps of initially providing each contact, with the elongate contact portions thereof in axial alignment with the mounting portion thereof, inserting the free end of the contact portion of such contact into the passage of the base, from the second surface, until the greater part of the length of the contact portion projects from the first surface of the base and bending the contact portion towards the first surface about an edge of the passage adjacent to the first surface of the base.
For a better understanding of the present invention, reference will now be made by way of example to the accompanying drawings, in which:-

Figure 1 is a fragmentary perspective view of a plug receptacle electrical connector mounted on a printed circuit board and in exploded relation to a mating plug electrical connector;
Figure 2 is an exploded, perspective, view of the receptacle connector with parts of the housing thereof broken away;
Figure 3 is a perspective view of the receptacle connector with parts of the housing thereof broken away, and being about to be mounted on the printed circuit board;
Figure 4 is an enlarged sectional view taken on the lines IV - IV of Figure 1;
Figure 5 is a sectional view taken on the lines V - V of Figure 4;
Figure 6 is a fragmentary under plan view of the receptacle connector;
Figure 7 is a fragmentary enlarged perspective view of a foot of the receptacle connector;
Figure 8 is a diagrammatic perspective view of apparatus for selectively gold plating electrical contacts of the receptacle connector; and
Figure 9 is a perspective view of a contact which has been so plated, prior to its assembly to the receptacle connector.

Reference will now be made to Figure 1. The receptacle electrical connector comprises a two- part insulating housing one part of which is in the form of a moulded cover 1 with a cavity 2 opening inwardly from a front wall 4 of the cover 1, to receive the plug electrical connector 100 through a first opening 5 in the wall 4. The wall 4 spans, and is integrally formed with, a pair of opposed spaced side walls 6 and 8 which are, in turn, formed integrally with a polygonal top wall 10, which defines a keyway 2A parallel to, and communicating with, the opening 2, the keyway 2A being narrower than the opening 2 as seen in Figure 1. The wall 10 is provided with depending latching projections 12, which, as best seen in Figure 4, protrude into the cavity 2.
The cover 1, has, as shown in Figures 2 to 5, a back wall 14 having a lower end surface 16 (Figures 4 and 5) spanning the side walls 6 and 8. The back wall 14 is formed integrally with a shelf 18 projecting perpendicularly outwardly thereof into- the cavity 2 and having a plurality of parallel depending spaced partitions 20, each formed integrally with the wall 14 and terminating in line with the end surface 16 as shown in Figures 4 and 5. The spaces 21 between the partitions 20 open into the cavity 2 both forwardly and downwardly, as seen in Figures 2 to 5.
As shown in Figures 2 and 4, each of a pair of substantially U-shaped metal commoning members 22 comprises an elongate web 24 having a plurality (two in the present example) of prongs 26 formed integrally therewith and projecting outwardly therefrom in the same direction, and each having an enlarged portion 28 intermediate its ends.
As shown in Figure 4 the back wall 14 has formed integrally therewith a rearwardly projecting external boss 30 extending there along opposite to the upper portions of the partitions 20 and having therein a groove 32 receiving the webs 24 of the commoning members 22. The groove 32 communicates with a plurality of through openings 34 in the wall 14 each of which in turn communicates with one of the spaces 21 and receives a portion of one of the prongs 26, adjacent to the web 24.
In assembling the commoning members 22 to the cover 1, the enlarged portion 28 of each prong 26 is forceably inserted, from the rear of the cover 1, through opening 34 until it is disposed within the corresponding space 21 between a pair of the partitions 20, the material of the cover 1 being sufficiently resilient to permit the passage of the enlarged portion 28 through the opening 34 and to restrain withdrawal of the prong 26 from opening 34 after it has been inserted thereinto. As shown in Figure 4, each commoning member 22 is mounted in the cover 1 with its web 24 fully received in the groove 32 and its prongs 26 projected into selected ones of the spaces 21. The members 22 can be withdrawn from the cover 1 by means of a tool (not shown), for example a pair of pliers.
As best seen in Figure 2, the walls 6 and 8 have, formed rearwardly thereof, opposed internal grooves 82 and 84, aligned with, and communicating with, respective rearward external keyways 86 and 88 in the walls 6 and 8 and also communicating with the cavity 2. At their ends opposite to those which communicate with the grooves 82 and 84, the keyways 86 and 88 open into the external surface of a thickened portion 4A of the forward wall 4 of the cover 1.
The other part of the housing is in the form of a moulded base 36 (best seen in Figure 2) having a central recess 38 therein. The base 36 includes a front wall 40 spanning opposed spaced side walls 42 and 44 provided with laterally projecting rails 46 and 48 formed integrally therewith and each having a laterally projecting wedge-shaped latch 50 (only one of which is shown) presenting a rearwardly directed latching shoulder 52. Each rail 46 and 48 projects slightly forward beyond the wall 40. The base 36 further has integrally formed therewith at least one (two are provided in the present example) depending elongate foot 54 having projecting latching shoulders 56 adjacent to its free end 58.
The front wall 40 carries a plurality of spring beam electrical contacts 60 arranged in two staggered rows. Each contact 60 (best seen in Figures 2 to 4) which has been stamped and formed from a single piece of metal, comprises an intermediate mounting portion 62 adjoining a first lead end portion 64 and a second end portion 68. The portion 64 has a bifurcation 66 to provide two laterally outwardly deformed limbs adapted to be force fitted into a hole 96 (Figure 3) in a printed circuit board 94, the portion 68 being of reduced cross-section with respect to the portion 62 so as to constitute a contact spring and being provided with a knee 70, so that the greater part of the portion 68 extends obliquely with respect to the portion 62'. The front wall 40 of the base 36 has therein two staggered rows of passages 72 each dimensioned to receive the intermediate portion 62 of one of the contacts 60. Prior to the assembly of the contacts 60 to the base 36, each portion 68 is in a straight condition, the knee 70, being formed subsequently, as described below.
In assembling the contacts 60 to the.base 36, the free end of each portion 68 is inserted, from beneath the base 36, into and along one of the passages 72 until the bifurcation 66 of the contact 60 is adjacent to a bottom face 74 of the base 36, the portion 62 being thus positioned within the passage 72. A locking spur 76 on the portion 62 bites into the material of the base 36 to retain the contact 60 in its passage 72. When the portion 62 of the contact 60 has been received in the passage 72, the end portion 68 of the contact 60 is bent so as to project diagonally with respect to the portion 62 from the upper surface 73 of the base 36, thereby forming the knee 70, an upper (as seen in.Figure 4) edge of the passage 72 acting as an anvil for this purpose, as a result of which it is deformed to assume the arcuate shape as shown at 78 in Figure 4.
The base 36 is assembled to the cover 1 by inserting the former through a second opening 17 in the cover 1, beneath the end surface 16 of the cover 1, so that the rails 46 and 48 slide along the grooves 82 and 84, respectively, and into the corresponding keyways 86 and 88 so that the portions of the rails 46 and 48, which project beyond the wall 40, lie on either side of the wall portion 4A, when the wall 40 has abutted the wall portion 4A in the fully inserted position of the base 36, a forward shoulder 90 of the wall 40 engaging a complementary undercut shoulder 92 of the wall portion 4A. During the insertion of the base 36, the latches 50 of the rails 46 and 48 are forced along the grooves 82 and 84 until the latches 50 are freed to project outwardly into the keyways 86 and 88, immediately adjacent to the forward ends of the grooves 82 and 84 whereby the shoulders 52 of the latches 50 lie against shoulders 52A at the rearward ends of the keyways 86 -and 88, latchingly to restrain withdrawal of the base 36 from the cover 1.
During the insertion of the base 36, the contact spring-forming end portions 68 of the contacts 60 are resiliently depressed, as cantilevers, by the end surface 16, subsequently to rise by virtue of their own resilience when they have entered cavity 2, each to be received in one of the spaces 21 (see Figure 5) between the partitions 20 whereby the latter separate and electrically insulate the portions 68 from one another. Selected ones of the portions 68 are resiliently deflected by, and resiliently engage, the portions 28 of the prongs 26 which project into selected ones of the spaces 21 so that each member 22 electrically connects i.e. "commons", a pair of the contacts 60. The portions 68 now extend obliquely across the opening 2.. As shown in Figure 5, the contacts 60 in the first and fourth (from the left) and the fifth and eighth (from the left) spaces 21 are electrically connected in this way. Other combinations of the contacts 60 can of course be selected for common electrical connection.
Figure 3 shows the fully assembled electrical receptacle connector about to be mounted on the printed circuit board 94, the apertures 96 of which are arranged in two staggered rows to receive the lead end portions 64 of the contacts 60 therein. When the receptacle connector has been assembled to the board 94, the bifurcations 66 of the portions 64 are wedgingly received in corresponding apertures 96 to make electrical contact with metal plating (not shown) therein, which is in turn connected to printed conductors (not shown) of the board 94. Further apertures 98 in the board 94 receive the feet 54 on the base portion 36, the shoulders 56 of which feet latch beneath the underside of the board 94 in a manner explained below, mechanically to secure the receptacle connector to the circuit - board 94.
Figure 6 shows two core pin apertures 200 which extend through the bottom face 74 of the base 36 and which enable the shoulders 56 to be moulded at elevations below that of the face 74. The shoulders 56 are provided on flexible ears 75 (see Figure 7) which project laterally outwardly of the main body of the foot 54. As each foot 54 is inserted through a hole 98 the ears 75 are resiliently deflected inwardly towards the said main body. The shoulder 56 of each ear 75 is positioned at a different level axially of the said main body. If the board 94 is of a thickness which is no greater than as shown in Figure 4, both the ears 75 resile outwardly of the said main body upon full insertion of the foot 54 through the hole 98. If, however, the board is of greater thickness, only the shorter ear 75 will so resile, the longer ear 75 remaining compressed in the aperture 98.
As shown in Figure 1, the electrical plug connector 100, which is connected to the ends of a plurality of electrical wires 102, has on one side a resilient latch arm 104. The connector 100 is inserted through the opening 5 into the cavity 2 of the assembled receptacle connector so that the latch arm 104 is received in the keyway 2A of the cover 1 whereby the arm 104 is resiliently depressed by the latching projections 12 and subsequently resiles so that shoulders 105 on the arm 104 latch behind the projections 12 to retain the plug connector and the receptacle connector in mated relationship. The edges of contact elements in the form of contact plates (not shown) on the opposite side of the plug connector 100, which plates are electrically connected to the wires 102, each engage one of the contacts 60, electrical continuity being thereby established between the contacts 60 and the printed conductors on the board 94.
Such plug connectors are described in detail in United States Patent Specification No. 3,860,316, for example.
The contact plates of the plug connector and the contacts 60 of the receptacle connector are gold plated to assure good electrical contact therebetween when these connectors have been mated, each contact 60 being provided with a gold stripe 106 (Figure 9) plated thereon for engagement by a contact plate. The stripe 106 may be applied by the plating techniques discloses in any of United States Patent Specification Nos. 3,644,181; 4,001,093; 4,033,833 and RE 28,267, all of which relate to gold plating over limited areas. Figure 8 shows a-tank 108 containing an electrolyte bath 110 suitable for electroplating gold metal onto a cathode, in the form of a plurality of the contacts 60 still in their flat condition after having been stamped and formed from sheet metal stock, so as to be connected by a. carrier strip 112. The contacts 60 may initially be plated with nickel alloy or copper alloy to provide a base with an affinity for electrolytic gold plating. A plastics jig 114 with no affinity for gold plating receives the contacts 60 and the carrier strip 112 in a shallow channel 116 in the top surface of the jig 114. Another plastics jig 118 overlies the jig 114 and is secured thereto by fasteners (not shown), e.g. plastic screws.
The jig 118 has a window 119 therethrough which exposes limited surface areas of the contacts 60 onto which gold is to be plated. The assembly comprising the jigs 114 and 118, the strip 112 and the contacts 60, is immersed in the bath 110, with the strip 112 drooping in catenary fashion over the sides of the-tank 108.
The strip 112 and contacts 60 are connected into an electrical circuit (not shown), as a cathode, the circuit also comprising an anode, for example a carbon block (not shown). The anode may be immersed in the bath and placed in the window 119 in close proximity to the limited areas of the contacts 60 which are exposed by the window 119. When the circuit is energised gold ions in the bath 110 are caused to plate gold onto the contacts 60 in close proximity to the anode, where the greatest density of current passes through the bath between the anode and cathode. The strip 112 is pulled continuously through the channel 116 at a controlled speed, so that the contacts are passed beneath the window 119. which contains the anode, whereby each contact 60 has a gold strip 106 plated over a limited area thereof exposed by the window 119. Some gold plating will appear as uneven overplating 106A (Figure 9) on the side edges and on the under surface of the contact 60, as a result of stray current densities. However, since these stray current densities are weak, and since the terminals pass continuously along and through the jigs 114 and 118, the thickness of the overplating is small and contains negligible gold metal. The surfaces on which the overplating 106A occurs are not engaged by the plug connector contact plates.

Claims

1. A plug receptacle electrical connector comprising a moulded insulating cover (1) and a moulded insulating base (36) for reception in a cavity (2) defined by the cover (1) so that elongate contact portions (68) of electrical contacts (60), projecting from a first surface (73) of the base (36) extend across the cavity (2) for engagement by respective contact elements of a plug electrical connector (100) when such has been subsequently inserted into the cavity (2) through a first opening (5) in a front wall (4) of the cover (1), the base (36) being insertable into the cavity (2) through a second opening (17) in the cover (1) opposite to the first opening (5), guided by opposed rails (46 and 48) on the base (36) which are engageable with complementary internal guide surfaces of side walls (6 and 8) of the cover (1), latch means (50) being provided on the base (36) to retain it in its fully inserted position in the cavity (2); characterised in that the cover (1) has an open side adjacent to the front wall (4) and to the side walls (6 and 8) to receive, as the base (36) is inserted in the cavity (2), lead portions (64) of the contacts (60) projecting, transversely of the direction in which the base (36) is inserted into the cover (1), from a second surface (74) of the base (36) opposite to the first surface (73) thereof, the rails (46 and 48) which project laterally of the base (36) being receivable in grooves (82 and 84) in the side walls (6 and 8) and having thereon latches (50) engageable with shoulders (52A) at the ends of the grooves (82 and 84) nearest to the front wall (4), when the base (36) has been fully inserted into the cavity (2).

2. A receptacle connector according to Claim 1, characterised by keyways (86 and 88) formed in the side walls (6 and 8) of the cover (1) in axial alignment with the grooves (82 and 84) and communicating therewith, the shoulders (52A) being provided at the junctions between the keyways (86 and 88) and the grooves (82 and 84), portions of the rails (46.and 48) which extend beyond the latches (50) in the direction of the front wall (4) being received in the keyways (86 and 88) when the base (36) has been fully inserted into the cavity (2).

3. A receptacle connector according to Claim 2, characterised in that the keyways (86 and 88) extend through lateral edge portions of an increased thickness portion (4A) of the front wall (4), portions of the rails (46 and 48) extending on either side of such front wall portion (4A) when the base (36) has been fully inserted into the cavity (2).

4. A receptacle connector according to Claim 1, 2 or 3, characterised in that the second opening (17) is formed in a back wall (14) of the cover (1), which has a portion (18) defining spaces (21) for receiving free end parts of the contact portions (68), openings (34) in the back wall (14) receiving at least one commoning member (22) which projects into at least two of the spaces (21) selectively to interconnect the contact portions (68).

5. A receptacle connector according to Claim 4, characterised in that the or each commoning member (22) comprises a web (24) from which project in the same direction, a plurality of prongs (26) having enlarged portions (28) in the spaces (21).

6. A receptacle connector according to any one of the preceding claims, characterised in that the base (36) is formed with at least one foot (54) projecting from the second surface (74) thereof in the same direction as the lead portions (64) of the contacts (60), the or each foot (54) being provided with lateral ears (75) each having a shoulder (56) facing the second surface (74) of the base (36) and each being resiliently deflectable towards the foot (54), the shoulders (56) being positioned at different distances from the second surface (74).

7. A receptacle connector according to any one of the preceding claims, characterised in that each contact (60) which has been stamped and formed from a single sheet of metal comprises intermediate its contact portion (68) and its lead portion (64), a mounting portion (62) received in a passage (72) in the base (36), the lead portion (64) being longitudinally divided (at 66) to provide laterally outwardly deformed limbs adapted to be force fitted into a hole (6) in a printed circuit board (94), the contact portion being of smaller cross-sectional area than the mounting portion (62) or the lead portion (64).

8. A receptacle connector according to any one of the preceding claims, characterised in that those surfaces (106) of the elongate contact portions (68) which surfaces (106) are intended to engage the contact elements of the plug connector (100) have been selectively plated with gold.

9. A method of manufacturing a receptacle connector according to Claim 1, characterised in that- it includes the steps of initially providing each contact (60), with the elongate contact portions (68) thereof in axial alignment with the mounting portion (62) thereof, inserting the free end of the contact portion (68) of such contact (60) into the passage (72) of the base (36), from the second surface (74), until.the greater part of the length of the contact portion projects from the first surface (73) of the base (36) and bending the contact portion (68) towards the first surface (73) about an edge (78) of the passage (72) adjacent to the first surface (73) of the base (36).

10. A method according to Claim 9, characterised in that it includes the step of selectively plating those surfaces of the elongate contact portions (68) which are intended to engage the contact elements of the plug connector (100), with gold stripes (106) prior to the insertion of the contacts (60) into the passages (72), the contacts (60) being connected, during the selection plating operation by a carrier strip (112) and being drawn through a selective gold plating apparatus (108, 110, 114, 118).