RETENTION AND GROUND PLANE CONNECTOR CLIP

Abstract: A metal clip (30) is described which retains a modular insert (60) containing an insulator body (26) with contacts (30) thereon, in a shell (12) of a connector (10), while also providing a ground plane and shield against electromagnetic interference. The clip (30) includes a flat middle portion (32) that extends across most of the width of the connector (10) and a pair of opposite ends (36, 38) bent out of the plane of the middle portion (32) and having edges (44, 46) that abut shoulders (40, 42) formed on the shell (12) and that press against shell surfaces (74, 76) lying adjacent to the shoulders (40, 42). The flat middle (32) portion lays facewise against a face of the insulator body (26) of the connector (10) to prevent movement of the insulator body (26) and contacts (30) therein. The middle portion (32) of the clip (30) spans most the area within the shell (12) to provide an electromagnetic shield that is electrically terminated to the shell (32).

Description: The present invention relates to electrical connectors. In IBM Technical Disclosure Bulletin Vol. 22 No. 6 November 1979, pages 2309-2310, there is shown a connector in the form of a plug having a base plate and a housing. A plurality of contact pins extend from the base plate through an insulating plate and a ground plate and into the housing. The ground plate has resilient tongues which serve no purpose in the plug per se but are only useful when a number of connectors in the form of plugs are mounted in a device frame to form a multi-plug arrangement. The individual parts of a plug are presumably held together by projections on the base plate engaging corresponding recesses in the housing, but this is not clearly shown or described. According to the present invention there is provided a connector comprising a shell of electrically conductive material having a pair of opposite sides and forming a shoulder at each said side and clip-engaging surfaces immediately rearward of said shoulders, a body of insulative material within the shell, a plurality of contacts mounted in the body and a clip of electrically conductive material having a substantially planar middle portion and having opposite ends bent relative to said planar middle portion and each abutting a respective shoulder, the body, contacts and clip forming an insert module, characterised in that the ends of the clip are bent to a degree less than 90° from the plane of the clip so that they tend to flex in an outward direction and resiliently engage the clip-engaging surfaces, the ends of the clip forming edges that abut said shoulders to thereby retain the module within the shell. The clip can extend across most of a cross sectional space within the shell to serve as an electromagnetic interference shield when the connector is unmated from another connector. The bent clip ends make electrical contact with the shell near where the clip ends abut the shell shoulder. The clip can allow the insulative body and the contacts mounted therein to "float" so as to move laterally by a small amount which is necessary during mating of a pair of connectors. The clip can be permanently installed in an insert module which includes the insulative body and contacts therein, for rapid mounting in a shell or withdrawal therefrom. Constructional embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, wherein:- Figure 1 is a partial perspective view of a connector constructed in accordance with the present invention; Figure 2 is a view taken on the line 2-2 of Figure 1, and also including a sectional view of a removal tool; Figure 3 is a more detailed sectional view of the connector of Figure 2, shown with another mating connector in proximity thereto; Figure 4 is a view taken on the line 4-4 of Figure 3; Figure 5 is a plan view of the clip of Figure 2, but showing it prior to bending of ends of the clip out of the plane of the middle; Figure 6 is a partial plan view of the clip of Figure 5, shown after bending of an end thereon; Figure 7 is a view taken on the line 7-7 of Figure 6; and Figure 8 is a view taken on the line 8-8 of Figure 7. Figure 1 shows a connector 10 which includes a shell 12 of rectangular shape, which has pairs of opposite short sides 14, 16 and a pair of opposite longer sides 18, 20. The shell forms a space 22 of rectangular cross sectional area when viewed along a forward direction 24, or rearward direction 25, along which the connector respectively mates and unmates from a corresponding second connector. These directions each may be referred to as mating-unmating directions, or as vertical directions (when the connector is in the illustrated orientation with its opposite sides horizontally spaced). The shell shown has several of such spaces 22 that each can hold a module containing numerous contacts. As shown in Figure 2, the connector includes a body 26 of electrically insulative material having a substantially flat rearward face 28 and a plurality of electrical contacts 29 held in the insulative body and which can mate with corresponding contacts on another connector. A clip 30 formed of sheet metal extends between opposite sides 14, 16 of the shell. The clip has a substantially flat middle portion 32 which lies in a plane 34 and facewise against the rearward body face 28. The clip also has a pair of opposite ends 36, 38 that are bent out of the plane 34. The shell forms a pair of shoulders 40, 42 facing in the rearward direction 25. The ends of the clip form edges 44, 46 that abut the shoulders 40, 42, at least when the clip is pulled in the forward direction 24. It is possible to embed the clip in the insulator body. The shell 12 includes slots 50, 52 at its opposite sides 14, 16, that extend across locations otherwise occupied by the shoulders 40, 42. Each slot extends rearward (direction 25) of the corresponding shoulder 40, 42. This allows a removal tool 54 to be positioned with a pair of elements 56, 58 against the opposite ends 36, 38 of the clip. The elements 56, 58 can be moved together to deflect the clip ends inwardly off the shoulders 40, 42 to release the clip from the shoulders so that it and parts attached to can be removed from the shell 12. As shown in Figure 3, the insulative body 26 and contacts 29 can form part of an insert module 60 that can be readily removed and replaced from the shell 12. The insulative body 26 of the insert module includes several insulative layers 62, 64, 66 which are bonded to one another and to the clip middle portion 32. To insert the module 60 into the shell 12, wires or other termination means (not shown) connected to the rearward ends of the contacts 29 are passed through the space 22, and the module 60 is pressed rearwardly until the clip ends 36, 38 snap into positon behind the shoulders 40, 42 of the shell. The shell also forms a pair of forwardly-facing shoulders 70, 72 lying rearward and inward (in the direction of arrows 25 and I) of the forward shoulders 40, 42. The end portions 32c of the clip middle portion rest against the shoulders 70, 72 to limit rearward movement of the module. Thus, the clip holds the module within the shell, preventing both forward and rearward movement of the module to hold it in place, and yet the clip ends can be moved together to readily release the module from the shell. When the module is replaced, the clip (as part of a new module) is also automatically replaced. The clip 30 provides an electrically grounded plane or ground plane, covering most of the cross sectional area of the space 22 within the shell. The ends 36, 38 of the clip form spring fingers that are preloaded so they tend to flex in an outward direction indicated by arrows O against clip-engaging surfaces 74, 76 of the shell that lie immediately below, or rearward, of the shoulders 40, 42. The shell 12 is, in the usual practice, electrically grounded. The fact that the middle portion 32 of the clip extends over most of the space 22 of the shell, results in the clip serving as an EMI (electromagnetic interference) shield that limits the induction of unwanted interference in the wires leading to the contacts 29 when the connector 10 is unmated from another connector and therefore the space 22 is open. It may be noted that the clip middle portion 32 has numerous perforations 80 around the contacts 29 to avoid grounding of the contacts (except for those contacts which are intentionally grounded as by providing a solder connection between the contact and the clip middle portion). Although the position of the insert module 60 is closely controlled, it is still necessary that the module "float", by a distance such as 0,254 mm (0.010 inch) in a lateral direction (indicated by arrows L in Figure 4). Such "floating" is necessary to enable the contacts 29 to align themselves with contacts 82 of a corresponding second connector 84 when the connectors mate, and to allow for displacement between the two connectors after mating, for example because of clamping of a heat sink. The ends 36, 38 of the clips provide a low friction sliding surface. It is also necessary to allow the module to "float" by a distance such as 0,1016 mm (0.004 inch) in a longitudinal direction (indicated by arrows M in Figure 3) to allow contact alignment during mating. The ends 36, 38 of the clip can bend sufficiently to permit such longitudinal movement of the module. The second connector 84 is formed with a shell 86 and an insert module 88 that include an insulative body 90 and the contacts 82 mounted in the body. The insert also includes a combined ground plane and retention clip 92 having a middle portion 94 lying facewise against faces 96, 98 of insulative layers 100,102 of the insulative body. The clip also has ends or fingers 104, 106 preloaded outwardly against the shell and forming edges 108, 110 that can abut corresponding shoulders 112, 114 on the shell. In this embodiment of the invention, the abutment of the clip ends against the shoulders prevents movement of the insert in a rearward direction 116 relative to the second connector 84. As shown in Figure 4, one of the insulative layers 102 forms a pair of ledges 118 at its opposite longer side 120, 122 that abut corresponding shoulders 124 on the shell to prevent movement of the forward portion of the insert 88 in the forward direction 126. Figures 5-8 illustrate details of a clip 30 constructed by applicant for a connector. Figure 5 shows the configuration of the clip 30A prior to bending of the ends 36, 38 out of the plane of the middle portion 32. The middle portion is preferably substantially flat so its ends 36,38 lie substantially in a common plane 34, but it is possible to include bends in the clip middle portion. As shown in Figure 7, the ends are bent at an angle A of 84° from the plane 34 of the middle clip portion, so that the ends extend at an angle B of 6° from the forward direction 24 and the edges 44, 46 are further spaced apart than the end portions 32c of the middle portion. In a preferred form the length L of the middle portion 32 of the clip (at the outside of the bends connecting it to the ends) is 27.432 mm (1.080 inches), while the length C between the outside of the ends is 28.346 mm (1.116 inches). The distance between the surfaces 74, 76 (Figure 3) against which the clip ends make contact, is separated by less than 28.346 mm (1.116 inches), such as 27.635 mm (1.088 inch) to bend each clip end by about 0.3556 mm (14 mil; one mil equals one thousandth inch). This assures that the clip ends remain bent when located in the shell and can "float". The clip has a thickness D of 0.2032 mm (8 mil), and is constructed of stainless steel. It is formed with eighty perforations 80 for use with a module-insert having that number of contacts. The shell 12 (Figure 1) has four spaces 22 to receive four of such module inserts. Thus, the invention provides a connector having a clip which serves several functions, all in a simple and reliable construction. The clip has a middle portion which bears against an insulative body that holds contacts, and has ends that couple to the connector shell. The insulative body and contacts are part of an insert assembly that is designed to be readily removed and replaced in the connector shell. The clip ends are bent by more than 60° and preferably close to (within 15° of) 90° from the clip middle portion, with the middle portion preferably being substantially planar. The clip ends form edges that can abut corresponding shoulders on the shell to prevent removal of the clip and the insulative body coupled thereto. The clip ends are preferably preloaded so they are slightly bent when installed in the shell, to insure contact with the shell so as to ground the clip to the shell. The clip preferably covers most of the space within the shell to provide an electromagnetic interference shield. It may be noted that the multiple holes in the clip through which contacts extend are of small size and prevent the passage of most electromagnetic energy past the clip. Where each contact is a coaxial contact, the outer conductor of each contact can be directly soldered to the interference shield. The bent ends of the clip can bend slightly more, to permit the module to "float" so as to move longitudinally by a small amount which is necessary to permit mating of contacts of a pair of connectors. The clip ends can also slide to permit the module to "float" laterally. In one embodiment of the invention, the ends of the clip middle portion bear against another pair of shoulders formed on a shell which extend further inwardly than the shoulders against which the edges of the clip ends bear. In such a construction, the clip prevents movement of the insulative body in both forward and rearward directions.

Claims: A connector (10;84) comprising a shell (12;86) of electrically conductive material having a pair of opposite sides (14,16) and forming a shoulder (40,42; 112,114) at each said side and clip-engaging surfaces (74,76) immediately rearward of said shoulders, a body (26;90) of insulative material within the shell (12;86), a plurality of contacts (29;82) mounted in the body and a clip (30;92) of electrically conductive material having a substantially planar middle portion (32;94) and having opposite ends (36,38;104,106) bent relative to said planar middle portion (32;94) and each abutting a respective shoulder, the body (26;90), contacts (29;82) and clip (30;92) forming an insert module (60;88), characterised in that the ends (36,38;104,106) of the clip (30;92) are bent to a degree less than 90° from the plane of the clip so that they tend to flex in an outward direction (O) and resiliently engage the clip-engaging surfaces (74,76), the ends (36,38;104,106) of the clip forming edges that abut said shoulders (40,42;112,114) to thereby retain the module (60;88) within the shell (12;86). A connector as claimed in claim 1, characterised in that the ends are bent by more than 60° relative to the planar portion. A connector as claimed in claim 1 or 2, characterised in that the ends are bent to within 15° of 90° relative to the planar portion. A connector as claimed in claim 1, 2 or 3, characterised in that the middle portion of said clip has end portions (32c) adjacent the ends (36, 38) and the shell (12) has a second pair of spaced shoulders (70, 72) at a distance from said first pair and engaged by said end portions (32c) to prevent movement of the module relative to the shell in a direction (25) in which the ends of the clip could move away from said first pair of shoulders (40, 42). A connector as claimed in claim 1, 2 or 3, characterised in that the body (90) has a pair of ledges (118) which abut corresponding shoulders (124) on the shell to prevent movement of the module (90) relative to the shell in a direction (126) in which the ends of the clip could move away from said spaced shoulders (112, 114). A connector as claimed in any one of claims 1 to 4, characterised in that the shell (12; 86) has slots (50, 52) to receive a tool (54) whereby the ends (36, 38; 104, 106) of the clip (30; 92) can be moved to disengage the clip ends from the shoulders (40, 42; 112, 114) which they engage so that the module (60; 88) can be removed from the shell (12; 86).

Inventors: WELSH, DAVID EDWARD, WILSON, ALBERT HUEAL
Applicants: ITT INDUSTRIES INC.
Application year: 1988
Main classification: H01R13
IPC codes: H01R13