DE69317177T2 - Shielding a surface mount electrical connector - Google Patents

Description

The present invention relates to a shielding sleeve made of folded sheet metal for receiving an electrical connector for attachment to the surface of a printed circuit board.

US-A-5 017 156 discloses a metal shield for an electrical connector which is formed from a metal plate which has been folded to form a housing with an open seam defined by the inwardly projecting end portions of the shield. The seam faces a circuit board when the shield is assembled with an electrical connector and mounted on the surface of the circuit board. The seam faces projecting connecting portions of the terminals of the connector. The connector is held in the shield by locking pawls which project from said end portions along the seam and engage an opening in a dielectric housing of the connector. Since the seam faces the circuit board, electromagnetic induction radiated from said connecting portions can leak through the seam directly onto the circuit board and interfere with the circuits thereon. In any case, when the connector is mated with a mating connector, the seam opens due to thermal changes and distortions of the shield.

According to US-A-4 637 669, a shielding sleeve made of folded sheet metal and open on both sides is secured around an electrical connector for mounting on the surface of a printed circuit board by means of inwardly facing projections on opposite side walls of the sleeve, said projections engaging between locking pawls on a terminal carrier of the connector and proximate walls of the terminal carrier. A lower wall of the shielding sleeve has a mounting post which is bent downwardly therefrom.

US-A-4 842 555 discloses a shield sleeve made of folded sheet metal for receiving an electrical connector for mounting on the surface of a printed circuit board. The connector is secured in the sleeve by means of inwardly turned flanges depending from a top wall of the shield sleeve and recesses in side walls of the sleeve which anchor the sleeve to the body of the connector. Mounting posts project from lower edges of the side walls of the shield sleeve.

US-A-5 017 156 discloses a shield according to the preamble of claim 1.

According to the present invention there is disclosed a folded sheet metal shield sleeve for receiving an electrical connector for mounting on the surface of a printed circuit board (PCB), the shield sleeve being folded from a single piece of sheet metal material and including an upper wall, a lower wall positioned proximate one side of the circuit board when the connector is mounted on the circuit board, first and second side walls connected to the upper and lower walls and cooperating therewith to define a tubular housing for receiving said connector, at least one post depending from the shield sleeve below the lower wall for connection to a ground terminal conductor on the printed circuit board (PCB), characterized in that the second side wall has two parts cooperating to define a seam extending along the length of the shield sleeve, and the lower wall is seamless.

Thus, if the seam is slightly opened as a result of thermal changes or as a result of the connection of the connector to a mating connector, then any electromagnetic field emitted by the connector's terminals can only escape from the shield laterally and therefore not in the direction of the circuit board.

A mounting flange for use in attaching the connector and its shield to a panel may be arranged to clamp around the shield so as to keep the seam closed under all conditions.

The mounting flange can clamp multiple shields from multiple corresponding connectors. Previously, multiple fasteners were required to attach multiple shields to a panel. The mounting flange can itself be attached to a panel, reducing the number of fasteners previously required. The mounting flange continues to clamp the multiple shields, not only to keep the shields closed, but also to mount the multiple connectors side by side in a compact grouping that eliminates the space previously required for fasteners between the shields.

If the shield and connector assembly is not to be mounted on a panel, a flange may be provided depending from the upper wall of the shield sleeve and overlapping the seam, the flange having a tongue projecting beneath and engaging the lower wall of the shield sleeve so as to provide some inhibition of the opening of the seam if it is desired to reduce the lateral leakage of said induction.

The first side wall projects rearwardly beyond the second side wall, and a cantilever flange connected to the upper wall provides a rearward extension of the second side wall. The cantilever flange has a locking member formed therein in the connector and is resiliently bendable away from the first side wall.

Below the bottom wall of the sleeve, a mounting post hangs from the cantilever flange for connection to a ground conductor on the circuit board.

The bendability of the boom flange ensures that when the connector is inserted into the shielding sleeve, the locking element of the connector can engage with the locking opening of the boom flange with a snap action without distorting the side walls of the shielding sleeve, and that the connector can be easily inserted into the sleeve.

A tongue may extend from the boom flange under the lower wall of the sleeve to facilitate the guidance of the boom flange as it is deflected away and subsequently moves resiliently. Conveniently, the mounting post may depend from a crosspiece connected to the tongue and flange, the crosspiece being bent up to lie in an opposite cutout in the boom flange.

Where the second side wall defines the seam of the folded shield sleeve, which seam could open, for example as a result of thermal changes, so as to allow the escape of electromagnetic induction from the sleeve when the connector is in use, the second side wall and thus the seam is preferably overlapped by the cantilever flange, and the cantilever flange cooperates with the tongue to restrict the opening of the seam.

For additional safety, the boom flange and the first side walls can have rearward-projecting tabs for bending against the rear part of the connector.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is an isometric view of a metal shielding sleeve according to a first embodiment of the invention for an electrical connector for mounting on the surface of a printed circuit board;

FIGS. 2 and 3 are a front isometric view and a rear isometric view, respectively, of an electrical connector assembly with the shield sleeve attached to the connector;

FIG. 4 is an isometric view showing two superimposed electrical terminals of the connector;

FIGS. 5 and 6 are an isometric front view and an isometric rear view, respectively, of an insulating housing of the connector;

FIG. 7 is a longitudinal cross-sectional view of the electrical connector assembly mounted to the circuit board;

FIG. 8 is an isometric view of an electrical connector assembly having a shielding sleeve according to a second embodiment of the invention in connection with a mounting flange for use in securing the connector assembly to a mounting plate;

FIG. 9 is an isometric view showing the connector assembly of FIG. 8 attached to the mounting flange in conjunction with the mounting plate; and

FIG. 10 is an isometric view showing two electrical connector assemblies as shown in FIG. 8 attached to a common mounting flange in conjunction with another mounting plate.

The first embodiment of the invention will now be described with reference to FIGS. 1 to 7. An electrical connector assembly 2 for attachment to a printed circuit board PCB comprises a metal shielding sleeve 4 against electromagnetic interference and an electrical connector 6 received in the sleeve 4.

The sleeve 4, which is stamped, formed and folded from a single piece of sheet metal material, provides a four-sided, generally rectangular cross-section tubular housing for the connector 6. The sleeve 4 includes seamless planar upper and lower walls 8 and 10, respectively, a planar seamless first side wall 12 and a second side wall 14. The side wall 14 includes substantially identical upper and lower portions 16 and 18, respectively, which cooperate to define a longitudinal seam 20 formed upon folding of the sleeve 4. The side wall 14 is bent outwardly from the sleeve 4. The sleeve 4 has an open front end 22 and an open rear end 24. The side wall 12 extends the full length of the sleeve 4 and has a rear edge 26 which projects rearwardly beyond the upper wall 8 and slopes downwardly and rearwardly therefrom. The side wall 12 includes at its lower rear end below the edge 26 a connector anchor tab 28 which projects behind the sleeve 4 in coplanar relationship with the side wall 12 prior to assembly of the sleeve 4 with the connector 6. A substantially square latch opening 30 is formed in the side wall 12 near the rear edge 26. A mounting post 32 having side hooks 34 depends from a crosspiece 33 which is received in a cutout 35 in the side wall 12, the crosspiece 33 being connected at each end to the lower edge of the side wall 12. The mounting post 32 is located between the tab 28 and the opening 30. The lower wall 10 of the sleeve 4 is formed with a rectangular, elongated, three-sided cutout 36 which is located forward of the rear edge 33 of the upper wall 8. The cutout 36 is open at its end remote from the side wall 12 near the rear edge 40 of the side wall portion 18. The cutout 36 has a front edge 42. The upper wall 8 has a rear part 44 which projects laterally beyond the side wall 14 and from which depends at right angles to the upper wall 8 a bent-down planar flange 46 having a front edge 47 which overlaps a rearwardly extending seam 48 of the side wall 14 and thus overlaps the rear end part of the seam 20. A tongue 50 extends from the sleeve 4 inwardly from and perpendicular to the lower end of flange 46 and extends slightly below and engages the lower portion 18 of side wall 14. Rearwardly of its seam 47, flange 46 is formed with a generally square detent opening 52 which is aligned with the opening 30 in side wall 12. A mounting post 54 identical to mounting post 32 depends from a crosspiece 55 which is received in a cutout 57 in flange 46. Crosspiece 55 is connected at one end to tongue 50 and at its opposite end to the lower edge of flange 46. Flange 46 has a rear edge 56 which slopes downwardly and rearwardly from upper wall portion 44 into alignment with edge 26 of side wall 12. An anchor tab 58 projects rearwardly of flange 46 below its rear edge 56 and faces male tab 28 of side wall 12. As shown in FIG. 1, male tab 58 projects rearwardly from side wall 46 in coplanar relationship therewith prior to assembly of sleeve 4 with connector 6. At their forward ends, walls 8, 10, 12 and 14 of sleeve 4 have outwardly turned guide flanges 60, 62, 64 and 66, respectively, for guiding the interconnect shield of a mating connector (not shown) into sleeve 4. Seam 20 bisects flange 66. Outwardly convex dimples are formed in walls 8 and 10 of the sleeve for snap-fit engagement with complementary bosses of said mating connector shield. The connector 6 comprises a one-piece molded dielectric housing 70 having a body 72 in the form of a substantially rectangular flat block. The terminal protection shoes 74 project rearwardly from opposite side edges of the body 72. Each shoe 74 has a downwardly inclined rear surface 76, the length and inclination of which are identical to those of the rear edge 26 of the side wall 12 and the rear edge 56 of the flange 46. From the A vertical rear tongue stop surface 78 depends from the lower end of each rear side 76 of each shoe 74. Each shoe 74 has a flat lower surface from the rear portion of which a rear spacer lug 82 depends. Each of two flat opposite outer sides 84 of the housing 70 is formed with a detent member 86 having a rear stop shoulder 88 extending perpendicular to the side 84 and a front cam side 90 sloping forwardly from the shoulder 88 toward the side 84. The body 72 has a flat top 92 and a flat bottom 94 stepped slightly above the bottoms 80 of the shoes 74. A spacer front lug 96 depends from each end of the bottom 94. The body 72 has a front side 98 and a rear side 100. Projecting rearwardly from the lower portion of the side 100 is a terminal end spacer comb 102 which defines a single row of terminal end receiving notches 104. Upper and lower rows of terminal receiving through cavities 106 and 107, respectively, open into both sides 98 and 100. Projecting horizontally from the front side 98 is a terminal retaining plate 108, the upper surface of which is formed with an upper row of terminal receiving grooves 110 and the lower surface of which is formed with a row of lower terminal receiving grooves 112. Each groove 110 communicates with a corresponding cavity 106 and each groove 112 communicates with a corresponding cavity 107. In addition, each of the grooves 110 and 112 communicates with a corresponding channel 114 opening into the front end of the retaining plate 108.

The connector 6 further comprises a plurality of upper and lower electrical terminals 116 and 118, respectively, which are best seen in FIG. 4. Each terminal 116 and 118 comprises a straight connecting portion 120 having a locking lip 122 at its front end, an intermediate portion 124 which is provided with locking tabs 126 and 128, and a contact end having a horizontal portion 131 and a vertical portion 133 depending from portion 131 and terminating in a soldering foot 132. As best seen in FIG. 7, the connecting portion 120 of each upper terminal 116 lies in a corresponding groove 110, with the intermediate portion 124 of the terminal lying in a corresponding cavity 106. The connecting portion of each lower terminal 118 lies in a corresponding groove 112, and the intermediate portion 124 of the terminal is received in a corresponding cavity 107. Each terminal 116 and 118 is held in position by the engagement of its locking lip 122 in a corresponding channel 114, the engagement of its locking tongue 126 against the front 98 of the body 72, and by the engagement of its locking tongue 128 against a shoulder located just forward of the rear 100 of the body 72. The contact ends 130 of the terminals lie between the protective shoes 74 of the housing 70, the parts 133 of the contact ends being received in corresponding ones of the notches 104 of the comb 102, and the soldering feet 132 of the terminals being located under the bottoms 80 of the shoes 74.

The connector 6 is assembled with the shield sleeve 4 by inserting the connector 6 with its terminal carrier 108 forwardly through the open rear end 24 of the sleeve 4 until each latch member 86 of the housing 70 is snap-received in a corresponding latch opening 30 or 32 of the sleeve 4. During insertion of the connector 6 into the sleeve 4, the cam sides 90 of the latch members 86 deflect the flange 46 away from the tapered rear portion of the side wall 12 of the shield 4 until the stop shoulders 88 of the latch members 86 pass corresponding rear edges of the openings 52, thereby snapping the flange 46 and the tapered rear portion of the side wall 12 back into their initial positions so that the connector 6 from withdrawing from the sleeve 4. Forward movement of the connector 6 into the sleeve 4 is restricted by the abutment of the spacer ridge 102 against the rear edge of the tongue 50 and the rearmost edge of the bottom wall 10, as best seen in FIG. 2. In the fully inserted position of the connector 6, the top 92 and bottom 94 of the housing body 72 snugly rest against the inner surfaces of the top and bottom walls 8 and 10, respectively, of the sleeve 4. The connector 6 is further secured in the sleeve 4 by bending the tabs 28 and 58 to engage the abutment surfaces 78 of corresponding ones of the shoes 74 (FIG. 3).

The finished assembly 2 thus provided is mounted to the surface of the PCB as diagrammatically shown in FIG. 7, with the mounting posts 32 and 54 resiliently engaged by means of longitudinal slots therein in holes in the PCB, the hooks 32 of the mounting posts securing them from withdrawal from the holes. The lugs 82 and 96 engage against the top of the PCB to keep it spaced therefrom, with the soldering feet 132 of the terminals abutting against printed conductors on the PCB. When the assembly 2 has been thus mounted to the PCB, the soldering feet 132 are soldered to the printed conductors, which are connected to electronic circuits on the PCB, and the posts 32 and 54 are soldered to the ground terminal conductors G on the PCB.

When the connector 6 is connected to a matching shielded electrical connector on another circuit board and/or due to temperature changes, the seam 20 of the sleeve 4 tends to open, although it is held thereto to some extent by the engagement of the flange 46 and its tongue 50 with the side wall 14 of the sleeve 4. Since the seam 20 is defined by a side wall of the sleeve 4, electromagnetic induction radiated from the connector 6 is not directed toward the printed circuit board PCB so as to disturb the electronic circuits thereon.

The second embodiment of the invention will now be described with reference to FIGS. 8 and 9, in which those parts already described above with reference to FIGS. 1 to 7 bear the same reference numbers, and parts similar to these bear the same reference numbers but additionally have a prime symbol.

The connector assembly 200 shown in FIGS. 8 and 9 differs from the connector assembly 2 in that it is designed for attachment to a metal plate P. For this purpose, the upper wall 8' and the lower wall 10' of the sleeve 4' are each formed with a pair of forwardly projecting tabs 204, the walls 8' and 10' also each being formed with a pair of extended resilient stops 202. The tabs 204 are divided into two halves by the longitudinal axis X-X of the sleeve 4'. The stops 202 of each pair are equidistant from this axis, and each stop 202 of the upper wall 8' is arranged opposite a corresponding stop 202 of the lower wall 10'. Each stop 202 has a forwardly curved stop surface 206 which projects away from the sleeve 4'. Each tab 204 is straight and, as shown in FIG. 8, is coplanar with its corresponding wall of the sleeve 4' from which the tab 204 projects. The connector in this embodiment is identical to the connector 6 described above and is assembled with its shielding sleeve in a similar manner.

The assembly 202 is provided with a stamped metal flange 208 for attachment thereto in order to attach the assembly 2 to the plate P. The Flange 208, which is in the form of a substantially rectangular flat plate, has a central cutout 210 sized to snugly receive the sleeve 4'. Flange 208 has a threaded hole 212 through it on each side of the cutout 210. Flange 208 also has a pair of opposed recesses 214 formed in its upper and lower seams, each opening into the cutout 212 and into a respective edge of flange 208.

The flange 208 is assembled with the sleeve 4' by inserting it with the tabs 204 forward through the cutout 210 until the stop surfaces 206 of the stops 202 engage the rear of the flange 208. The tab 204 of the upper wall 8' is then bent upward into the upper recess 214 while the tab 204 on the lower wall 10' is bent downward into the lower recess 214 (see FIG. 9). The flange 208 is thereby securely fastened to the sleeve 4' with the stops 202 resiliently engaging against the rear of the flange 208. Since the sleeve 4' is snugly contained in the cutout 210, the seam 20 is held firmly closed. The connector 6 can be assembled with the sleeve either before or after the sleeve 4' has been assembled with the flange 208.

The plate P, which is shown only in fragmentary form, has a cutout 216 with opposed side extensions 218 for receiving corresponding screws 220. To attach the connector assembly 200 to the plate P, the flange 208 on the assembly 200 is engaged against the rear of the plate P with each of the threaded holes 212 of the flange 208 aligned with a corresponding extension 218 of the cutout 216 of the plate P. The screws 220 are then screwed into corresponding ones of the holes 212 until the heads of the screws 220 are firmly seated in the front of the plate P. Due to the flange 208, the seam 20 cannot open at all due to temperature changes and/or when connected to a mating connector. Only the two screws 220 are required to attach multiple connectors, whereas previously each connector required its own fastener to be attached to the plate P and to a common mounting flange 208' (FIG. 10).

As shown in FIG. 10, a plurality of connector assemblies 200 may be mounted in juxtaposed relationship to a common plate P' having a pair of juxtaposed cutouts 216' each having a lateral extension 218', with these extensions facing each other. To enable the assemblies 200 to be mounted to the plate P', they are secured to a common flange 208' having a pair of juxtaposed cutouts 210. Each assembly 200 is secured in a corresponding cutout 210 in the flange 208' in the manner described above with reference to FIG. 9. The flange 208' engages against the rear of the plate P' with each hole 212' in alignment with the extension 218 of a corresponding cutout 216' of the plate P', and screws 220 are inserted through the extensions 218' and screwed into the threaded holes 212'.

The tabs 204 not only serve to secure the sleeve 4' to the flange 208 or 208', but also provide an electrical path through the sleeve and flange to the metal plate. The tabs 204 securing the sleeves 4' to the common flange 208' overlap sides of the respective cutouts, but not on sides of the cutouts located between the electrical connectors, to allow the electrical connectors are located in close proximity to one another on the mounting flange.

Claims (10)

1. A folded sheet metal shielding sleeve (4) for receiving an electrical connector (6) for mounting on a printed circuit board (PCB), the shielding sleeve (4) being folded from a single piece of sheet metal material and comprising an upper wall (8), a lower wall (10) positioned near one side of the printed circuit board when the connector (6) is mounted on the printed circuit board, first and second side walls (12, 14) connected to the upper and lower walls (8, 10) and in cooperation therewith defining a tubular housing for receiving said connector (6), at least one post (32) depending from the shielding sleeve (4) below the lower wall (10) for connection to a ground connection conductor (G) on the printed circuit board (PCB), characterized in that the second side wall (14) two parts (16, 18) which cooperate to define a seam (20) extending along the shielding sleeve (4), and the lower wall (10) is seamless. 2. Shielding sleeve according to claim 1, wherein the said parts (16, 18) of the second side wall (14) are substantially identical and the seam (20) is arranged in the middle of the height of the second side wall (14). 3. Shielding sleeve according to claim 1 or 2, wherein the second side wall (14) is bent laterally out of the shielding sleeve (4) and the seam (20) is arranged in the middle of the height of the second side wall (14). 4. A shielding sleeve according to claim 1, 2 or 3, wherein a flange (46) extending from the upper wall (8) overlaps the seam (20), a tongue (50) extending from the flange (56) to below the lower wall (10) and engaging the latter. 5. A shielding sleeve according to claim 1, 2, 3 or 4, wherein said walls (8, 10, 12, 14) have a forwardly open end (22) for receiving an electrical connector, wherein a first deformable tab (204) projects forwardly from the upper wall (8) beyond said open end (22) and a second deformable tab (204) projects forwardly from the lower wall (10) beyond said open end (22), the upper and lower walls (8, 10) each having at least one resilient outer stop (202) located behind and proximate to said open end (22). 6. Shielding sleeve (4) according to claim 1 for surface mounting on a printed circuit board (PCB), with the following: a forward open end (22) for receiving a suitable shield and an open rear end (24) for receiving said connector (6), the first side wall (12) extending behind the second side wall (14); a cantilever flange (46) connected to the upper wall (8) and providing a rearward extension of the second wall (14), wherein a latching opening (52) is formed in the cantilever flange (46) for latchingly receiving a latching member (86) on the connector (6), wherein said flange (46) is elastically bendable away from the second side wall (14); and a mounting post (54) depending from the cantilever flange (46) below the lower wall (10) of the sleeve (4) for connection to a ground connection conductor (G) on the printed circuit board (PCB). 7. A shielding sleeve (4) according to claim 6, wherein a tongue (50) projects from the cantilever flange (46) below the bottom wall (10), the mounting post (54) projects from a crosspiece (55) separated by a gap (57) from a vertical portion of the cantilever flange (46) and having a first end formed integrally with the cantilever flange (46) and a second and opposite end which is formed integrally with the tongue (50). 8. Shielding sleeve (4) according to claim 6 or 7, wherein the cantilever flange (46) projects from the top wall (8) in overlapping relation with the second side wall (14), said first side wall (12) being formed with a latching opening (30) which is aligned laterally of the shielding sleeve (4) with the latching opening of the cantilever flange (46). 9. Shielding sleeve (4) according to claim 8, wherein each latching opening (30, 52) is rectangular and has a rear latching edge. 10. A shield sleeve according to claim 6, 7, 8 or 9, wherein a first connector anchor tongue (28) coplanar with the cantilever flange (46) extends from a rear edge thereof and a second connector anchor tongue (58) extends from a rear edge of the first side wall (12) in coplanar relationship therewith and in alignment with the first anchor tongue (28) laterally of the shield sleeve (4).