WO1997040554A1

WO1997040554A1 - A contact assembly for a coaxial connector

Info

Publication number: WO1997040554A1
Application number: PCT/US1997/007031
Authority: WO
Inventors: Lawrence Se-Jun Oh; David Anthony Skotek
Original assignee: The Whitaker Corporation
Priority date: 1996-04-25
Filing date: 1997-04-25
Publication date: 1997-10-30

Abstract

The contact assembly (1) consists of a plurality of right angle coaxial contact members (4) and a shell consisting of three shell members (40, 50, 60). The shell members have channels (68, 58) to receive preinsulated contact tails (18) and openings (57, 62) through which the tails (18) pass. Near the mating end of each channel, annular grooves (42, 54) cooperate with grooves (31) of the contact members (4) to secure the contact members (4) in the shell members (40, 50, 60). Compliant sections (16) secure each of the contact members (4) to a printed circuit board.

Description

A CONTACT ASSEMBLY FOR A COAXIAL CONNECTOR

This invention relates to electrical connectors and more particularly to coaxial connectors using right- angle coaxial contact assemblies.

The use of coaxial connectors in high-frequency signal applications is well known in the art. When transmitting a plurality of high-frequency signals through an electrical connector, it is necessary to shield around each signal passing through the contacts from adjacent signals passing through adjacent contacts. This is accomplished by providing a conductive shell around the contacts which is insulated from the contacts and connected to ground in order to shield the signals from each other. These shells are typically made by forming from a piece of sheet metal or by machining from a piece of stock.

In some applications where it is desirable to mount a shielded coaxial connector to a printed circuit board, the contacts in the connector are disposed in a stacked arrangement such that they are in a series of rows and columns. The connectors are mounted to the board either in a straight through arrangement or in a right angle arrangement. Some examples of these connectors will now be discussed.

PCT publication WO87/07441 discloses a shielded electrical connector having housing sections of conductive material coated with an insulating material which is disposed between the contacts and the conductive housings. While this is not a typical coaxial contact type arrangement, it does provide shielding between adjacent contacts through the conductive housings. The housings may be formed by die casting from a suitable conductive material. This design, however, is costly to manufacture and very labor intensive due to the coating of the conductive housings with the insulating material. U.S. Patent No. 5,169,343 discloses a coaxial connector module having an electrically conductive casing or shielding members, each enclosing two terminals in an electrically insulating manner and cooperating with an insulative housing to complete the coaxial connector module. This patent teaches that the shield members are designed in a modular fashion to offer greater design flexibility for the coaxial connector which is not restricted to a specific number of contact elements. Since the shield members only surround two contact elements, a series of such shield members must be used in order to create connectors having more than two contact elements. For example, in an electrical connector having six contact elements, three shield members must be used. The problem with this design is that there are many parts which are necessary to create a connector having a large number of coaxial contact elements. The increased number of parts also increases the labor and manufacturing costs for such a connector.

Similarly U.S. Patent No. 5,344,340 discloses a coaxial connector for connecting two printed circuit boards. This patent teaches a coaxial connector having a conductive parallelepipedal body which surrounds the coaxial contacts. As shown in FIG. 2, this patent teaches a conductive parallelepipedal body much like the shielding member of the 5,169,343 patent which can only accommodate two contacts and must be used in a modular fashion to create connectors having a greater number of contact elements. Once again the problem with this type of arrangement is that a plurality of conductive shield members must be produced thus increasing the manufacturing and labor costs involved with such a connector. It is therefore an object of this invention to provide a shell member which is easily manufacturable for shielding between a plurality of coaxial contact elements arranged in a stacked arrangement for right- angle connection to a printed circuit board. e o ec o e v by providing a unitary shell which accommodates a plurality of coaxial contact elements arranged in a stacked arrangement having their outer conductors fixed to the shell and their inner conductors insulated from the shell and passing through the shell in a right-angle fashion.

The invention will now be described by way of example with reference to the accompanying figures of which:

Figure 1 shows a three-dimensional view of a contact assembly according to the present invention.

Figure 2 shows a cross-sectional view of a coaxial contact member for use in the assembly of Figure l. Figure 3 shows a three-dimensional view of the unitary shell as viewed from the top.

Figure 4 shows a three-dimensional view similar to that of Figure 3 as viewed from the bottom.

Figure 5 shows an exploded three-dimensional view of the contact assembly of Figure l.

Figure 6 shows a cross sectional view of a first alternate embodiment of a coaxial contact for use in the assembly of Figure 1.

Figure 7 shows a second alternate embodiment of a coaxial contact subassembly.

Figure 8 shows a three-dimensional view similar to that of Figure 1 for an alternate contact assembly.

Figure 9 shows a three-dimensional exploded view of the shell subassemblies utilized in the contact assembly of Figure 8.

Figure 10 shows a three-dimensional exploded view similar to that of Figure 9 as viewed from the bottom.

FIG. 1 shows a completed right-angle stacked coaxial contact assembly 1 which is prepared for insertion into an insulative housing (not shown) to form an electrical connector. The contact assembly is designed, for example, to accommodate six coaxial contacts 4 each having an outer conductive member 10 and a signal conductor 12. Each outer conductive member 10 is electrically connected to a unitary shell 2 having ground contacts 8 connected to a board mounting face 14 for electrical contact to ground traces on a printed circuit board (not shown) . The signal conductors 12 pass through the unitary shell 2 and are insulated from the outer conductive member 10 and the unitary shell 2. These signal conductors 12 exit the board-mating face 14 for electrical connection to the printed circuit board signal traces through a contact 6. Each of the major components of the contact assembly 1 will now be described in greater detail. Referring to FIG. 2 the coaxial contact member 4 will now be described. This figure shows one contact member 4, but it should be understood that the upper row of contact members 4 have a longer tail 18 than the lower row of contact members 4. The signal conductor 12 of the coaxial contact member 4 is formed from two subassemblies 15 and 26. The first subassembly 15 consists of a right angle section of a contact tail 18 having a compliant section 16 at a board mounting end and a pin termination section 22 at the other end which mates with the second subassembly 26. The contact tail 18 is overmolded with insulative material 20 which is profiled to have a socket receiving section 21. The contact tail 18 terminates at a pin contact 22 inside the socket receiving section 21.

The second subassembly 26 is formed from a contact 30 having sockets 24 and 28 at each end thereof. The subassembly is overmolded with an insulative material 25 similar to the first subassembly 15. The first socket 24 is designed to mate with the pin contact 22 of the first subassembly 15. The socket contact is held in position by engagement with the pin contact 22 and the socket receiving section 21 of the first subassembly 15. The overmolded insulative material 25 of the second subassembly abuts the mating face 23 of the socket receiving section 21. The two contact subassemblies 15,26, after being joined together are inserted into the outer conductive member 10. This outer conductive member 10 is generally cyl ndr cal an as an annu ar groove 31 for cooperation with the unitary shell 2, a clip receiving section 33, and a mating opening 36. A securing clip 32 having fingers 34 extending therefrom is disposed in the clip receiving section 33 of the outer conductor 10.

Referring now to FIGS. 3 and 4, the unitary shell 2 will be described in greater detail. Note that FIG.3 shows the shell member as viewed from the top surface 49 and FIG. 4 shows the shell member 2 as viewed from the bottom surface 65 or board mounting end. The unitary shell 2 consists of three shell members 40,50, and 60 which cooperate to form a plurality of contact receiving channels extending from a front face 52 to a board mounting face 65. The top shell member 40 is designed to have a plurality of stud-receiving openings 46 which pass from a bottom surface 48 to a top surface 49. The bottom surface 48 of the top shell member 40 is profiled to have a series of partial channels 43 and a series of partial annular grooves 42 formed in the partial channels 43 near the front face 47. Along two sides of the top shell member 40 are projections 44 extending partially along the length of each side.

Referring now to the intermediate shell member 50, it can be seen that a complementary series of partial channels 58 are formed in the top surface 51. The partial channels 58 extend from a front face 52 back towards the rear of the connector, ending at an opening 57 which passes from the partial channels 58 on the top surface 51 to the bottom surface 59. The partial channels 58 also have partial annular grooves 54 formed therein near the front face 52 of the intermediate shell member 50. While the top surface 51 of this shell member 50 has partial channels 58 formed therein to cooperate with the top shell member 40, the bottom surface 59 of this intermediate member 50 also has complementary partial channels 53 to cooperate to with a bottom shell member 60. Along each side of the intermediate shell member 50 are a pair of cutaway sections 55 to receive projections 44 of the top shell member 40 and projections 69 of the bottom shell member 60. Stud receiving openings 56 pass from the bottom surface 59 to the top surface 51 of the intermediate shell member 50.

Referring now to the bottom shell member 60, this member has a plurality of studs 66 extending from its top surface 63 in alignment with stud receiving openings 56,46 of the second and first shell member 50,40. Also formed in the top surface 63 are a series of complementary partial channels 68 which extend from the front face 67 rearward to a series of openings 62 which pass from the top surface 63 to a bottom surface 65. Similar to the intermediate shell member 50 and upper shell member 40, the lower shell member 60 has partial annular grooves 70 formed in the partial complementary channels 68 near the front face 67 of the bottom shell member 60. Also similar to the upper shell member 40, this lower shell member 60 has partial projections 69 extending partially along a pair of sides which cooperate with cutaway sections 55 of the intermediate shell member 50.

Assembly of the contact assembly 1 will now be described in greater detail with reference to FIG. 5. First, the bottom row of coaxial contact elements 4 are inserted into respective openings 62 of the bottom shell member 60 such that the annular grooves 31 of the outer conductor 10 cooperate with partial annular grooves 42. The intermediate shell member 50 is then placed over the bottom shell member 60 such that the annular grooves 31 cooperate with the partial annular grooves 54 securing the bottom row of contact members 4. Also, the partial channels 68 cooperate with the partial channels 53 to form part of the contact receiving passageways disposed in the first row. Studs 66 of the bottom shell member 60 pass through openings 56 of the intermediate shell member 60 to achieve similar cooperation between the annular grooves 31 and 54. The upper row of contact members 4 are then placed into respective openings 57 of . 40 is then placed over the entire assembly such that studs 66 of the bottom shell member 60 pass through openings 56 and 46 of the intermediate and top shell portions 50 and 60 respectively. Similarly, partial channels 58 cooperate with partial channels 43 to form part of the contact receiving passageways disposed in a second row. The studs 66 are then peened at the top in order to secure them to the openings 46 of the top shell member 40. The top row of contact member 4 are secured by similar cooperation of the annular grooves 31 with partial annular grooves 42 and 54. Finally compliant ground pins 8 are inserted into openings 61 (FIG. 4) in order to make electrical connection between the unitary shell 2 and the circuit board traces (not shown) . The completed contact assembly 1 is then inserted into a housing (not shown) , having a plurality of contact receiving passages from the rear end. The contact members 4 pass from the rear end of the housing to a mating face and are secured in the passages by the securing clips 32 (FIG. 2) .

Two alternate embodiments for the contact member 4 will now be described in greater detail with reference to FIGS. 6 and 7. FIG. 6 shows a first alternate embodiment of the contact member 104, having a stamped and formed contact 110 which has a compliant section 116, a right angle tail 118, and a contact tip 140 which is rolled to form a pin at the mating end. The tail 118 is overmolded with an insulative material 120 and an insulative cap 125 is fit over the contact tip 140 abutting the insulative overmolded material 120. This entire assembly is then placed into the outer conductive member 10 as in the embodiment of FIG. 2. The advantage of this embodiment is that the entire contact 110 may be stamped and formed from a single sheet of material thus reducing the number of parts necessary to form the contact member 4.

Referring now to FIG. 7, a second alternate embodiment of the contact member 204 will now be escr e n greater eta l. Much l ke the f rst two embodiments, this embodiment also has a compliant section 16 at the board mounting end and extending therefrom is a right angle tail 18. Similar to the embodiment of FIG. 2, this right angle tail 18 is received into a socket 24 of the contact 30. The assembled contact is then overmolded with an insulative material 220 and may then be inserted into the outer conductive member 10 like the earlier embodiments of FIGS. 2 and 6. The advantage of this embodiment is that it reduces the number of insulative parts and allows for overmolding both contact sections in a single process step.

It should be noted that the singular overmolding technique described in FIG. 7 may also be applied to the singular stamped and formed contact of FIG. 6. However, care must be taken to insure that the overmolded material does not enter the area of the seam in the tip 140. Referring now to Figures 8-10, an alternate shell embodiment will be described. Referring to Figure 8, it can be seen that the contact assembly 102 consists two shell subassemblies. The first shell subassembly is defined by the shell members 140 and 160. The second shell subassembly is defined by shell members 160a and 140a. Each of these shell subassemblies receive one half of the coaxial contact elements 4 which in this example comprises three such contact elements 4.

Figure 9 shows the shell 102 as viewed from the top. The first subassembly consisting of top and bottom shell members 140,160 will first be described. The bottom shell member 160 features a plurality of studs

166 extending from its top surface 163. Also formed in the top surface 163 are a series of complementary partial channels 168 which extend from the front face

167 rearward to a series of respective openings 162 which pass from the top surface 163 to a bottom surface 165. A partial annular groove 170 is formed in each of the complementary partial channels 168 near the front face 167. This channel and annular groove es gn s similar to that of the previous embodiments shown in Figures 3 and 4. The top shell member 140 is profiled to have a plurality of stud-receiving openings 146 which pass from a bottom surface 148 to the top surface 149. A series of partial channels 143 (Fig. 10) are formed in the bottom surface 148 and are aligned with the complimentary partial channels 168 of the bottom shell member 160. Similarly, a series of partial annular grooves 42 are formed in the partial channels 143 near the front face 147. The second shell subassembly, consisting of shell members 140a and 160a, is similarly joined by a plurality of studs 166a cooperating with a plurality of stud-receiving openings 146a. Also, a plurality of partial channels 158 are formed in a top surface 159 and extend from the front face 167a rearward to an opening 157. The opening 157 extends from the top surface 159 to the bottom surface 151. The top shell member 140a contains similar features to the shell member 40 described with reference to Figures 3 and 4. Therefore, this shell member 140a will not be described in further detail.

This contact assembly l has been shown by way of example to contain six contacts arranged in a series of rows and columns, but it should be understood that larger arrays of contacts in a right angle stacked orientation could be created using these same concepts.

The present invention offers significant savings in manufacturing of this contact assembly 1 by reducing the number of parts necessary as compared to the modular designs of known connectors. The required number of assembly steps are also greatly reduced thus reducing labor costs involved with assembling the connector.

Claims

We Claim:

1. An electrical connector contact assembly for being mounted inside an insulative housing, the assembly having a plurality of coaxial contact elements being arranged in at least one row disposed parallel to a board mounting face and a plurality of columns, the contact elements being secured in respective contact receiving passageways extending from a front face to a board mounting face such that an outer conductor of each contact element is electrically connected to a shell of the assembly, the assembly shell being characterized by: a plurality of shell members 40,50,60 being joined to each other along an axis extending parallel to the board mounting face 65, at least one shell member

40,50,60 having a partial channel 43,53,58,68 extending inward from a front face 67 to an opening 57,62 extending through the shell member 50,60 and being approximately perpendicular to the partial channel, at least one other shell member 40,50,60 having a complementary partial channel 43,53,58,68 being aligned with the partial channel to form the a portion of the contact receiving passageway being continuos with the opening 57,62.

2. The contact assembly as recited in claim 1 wherein one shell member 60 has a stud 66 extending perpendicular to the partial channel 68 toward the other shell member 50 such that it passes through a stud receiving opening 56 of the other shell member 50.

3. The contact assembly as recited in claim 1 wherein the partial channel 43,53,58,68 has an annular groove 42,54,70 formed therein proximate the front face 67.

4. The contact assembly as recited in claim 3 wherein the outer conductor 10 of the contact element 4 has an annular shoulder which cooperates with the annu ar groove , , o secure e con ac e eme to the shell.

5. The contact assembly as recited in claim 1 wherein the coaxial contact elements 4 each comprise a contact having a contact tip 28, and a tail 18 having a bend.

6. The contact assembly as recited in claim 5 wherein the contact element 4 is stamped and formed such that the tail 18 is bent at a right angle and the contact tip 28 is rolled.

7. The contact assembly as recited in claim 5 wherein the contact tip 28 is formed on a socket contact 30 having a socket 24 at a first end which receives the tail 18 and a tip 28 at a second end.

8. The contact assembly as recited in claim 5 wherein the tail 18 is overmolded with a dielectric material 120.

9. The contact assembly as recited in claim 8 further comprising a cap 125 which is formed of a dielectric material being disposed over the tip 28 and in contact with the overmolded dielectric material 120 on the tail 118.

10. The contact assembly as recited in claim 7 wherein the both socket contact 30 and tail 18 are overmolded with a dielectric material 220 subsequent to the tail 18 being received into the socket 30.