FILTERED SH IELDED CONNECTOR ASSEMBLY The present invention relates to an electrical connector assembly and in particular to a filtered electromagnetic shielded electrical connector assembly. Controlling electromagnetic emissions from electronic equipment is of great concern in the design of highly sophisticated electronic equipment. The Federal Communications Commission has recently expanded the scope of its rules governing electromagnetic interference emissions from electrical equipment to include computing devices used in the home as well as in commercial , industrial or business environment.
Means for achieving electromagnetic compatibility include shielding , filtering and grounding. Shielding is used to minimize electromagnetic radiation. Filtering the system protects against conducted interference and protects low frequency communication signals by excluding high frequency noise. A proper grounding system is important particularly where there are multiple and electrically different power outlets used within the system . Improper grounding can adversely affect the equipment as well as create potential safety hazards .
Although shielded connectors and filtered connectors have been available for a number of years , there has been a recent increase in demand for these types of connectors and interconnecting devices. Separate shielding means and filtering means are used in many of today's equipment systems .
In addition there has been a demand for means to convert standard connectors into the type that can be used to make a shielded interconnection with a shielded connector and a cable. U .S. Patents 4,337 ,989 and 4 ,386 ,814 disclose means for attaining such a conversion .
The filtered shielded connector assembly disclosed herein provides both filtering and shielding capabilities in a single unit, thus eliminating the need for separate devices. Furthermore, the invention provides a means for obtaining a greater number of terminals per given area than is possible with converted
standard connectors . The invention also provides a grounding means directly through the connector. The herein disclosed invention provides an economical connector in terms of both space and cost savings. A filtered shielded connector assembly is comprised of an insulated housing member , a plurality of pin terminals , a filtering means and a shielding means. The housing has a front face having one or more connector receiving openings therein , an oppositely facing back wall with a plurality of apertures therein , oppositely facing side walls , and oppositely facing end walls. The side walls and end walls extend from the front face to the back wall . The housing has one or more connector receiving cavities extending inwardly from said front face toward said back wall . The shielding means is comprised of two members , a metal front face plate and a metal shell . The face plate has one or more openings therein , the number of openings being equivalent to the number of cavities in the housing . Each opening in the plate has one or more spring fingers which project rearwardly from the plane of the face plate. The metal shell has a rear wall with a plurality of terminal receiving apertures therein , opposing side walls and opposing end walls. The shell rear wall extends between the shell - side walls and shell end walls, said walls defining a housing receiving cavity. The face plate and shell are dimensioned to surround the housing member when the assembly parts are joined. The assembly has a plurality of pin terminals. The terminals have first and second ends , the first end passes through the apertures in the housing back wall and into the connector receiving cavities. The second terminal end extends rearwardly from the housing back wall , passes through a filtering means and the apertures in the shell's rear wall , and extend rearwardly from said shell wall . Fastening means are provided to join the parts of the assembly , thus forming a filtered shielded unit. The spring fingers on the shield face plate extend into the connector receiving cavities to provide shielding continuity with shielded plug connectors .
A better understanding of the invention is obtained by way of example from the following description and the accompanying drawings.
Figure 1 is an isometric view of the filtered shielded connector assembly disclosed herein .
Figure 2 is an exploded isometric view of the connector assembly of Figure 1 .
Figure 3 is a top plan view of the assembly of Figure 1 mounted to a printed circuit board and panel . Figure 4 is an isometric view of the connector assembly of
Figure 1 exploded from a printed circuit board and panel .
Figure 5 is an isometric view of the connector assembly of Figure 1 mated with a plurality of known shielded plug connectors , with one plug connector exploded therefrom . Figure 6 is a cross-sectional view of one cavity of the assembly of Figure 5 with a portion of the mating plug therein.
Figure 7 is a cross-sectional view similar to Figure 6 showing an alternative embodiment of the herein-disclosed connector assembly. Figure 8 is a side elevation view of an alternative embodiment of the invention .
Figure 9 is a top plan view showing an alternative embodiment of the assembly .
Referring now to Figures 1 and 2 , a filtered shielded connector assembly 10 is comprised of an insulating housing member 12 , a plurality of pin terminals 36 , a filtering means 42 , and shielding means 43. The housing member 12 is comprised of a front face 14 and an oppositely facing back wall 18 , oppositely facing side walls 22 , and end walls 24. The front face 14 has one or more connector receiving openings 16. The housing 12 contains a plurality of connector receiving cavities 26 which extend from openings 16 in front face 14 inwardly toward the back wall 18. The back wall has a plurality of terminal receiving apertures 20 therein. The back wail further has a
plurality of standoff legs 34 extending rearwardly therefrom . Side walls 22 have mounting means 28 extending therefrom.
Shielding means 43 is comprised of a face plate 44 and a metal back shell 58. in the preferred embodiment the face plate 44 and back shell 58 are stamped and formed metal . The face plate 44 has one or more openings 46 therein , the number of face plate openings 46 being equivalent to the number of connector receiving openings 16 in front housing face 14. Each face plate opening 46 has one or more spring fingers 48 which extend rearwardly from the plane of plate 14. When plate 44 is joined to housing member 12 these spring fingers 48 extend into the cavities 26 and are used to engage shielded mating plug connectors 90 as shown in Figures 5 and 6. Inwardly facing dimples 50 on the spring fingers 48 interconnect with the plug retaining means 94 on the mating connector 90. Referring again to Figures 1 and 2 face shield 44 has one or more mounting tabs 52 extending therefrom. These mounting tabs are recessed from the plane of the face plate.
Metal back shell 58 is comprised of a rear wall 60 oppositely facing side walls 64 and end walls 66. These walls 60 , 64 and 66 define a housing receiving cavity 67. The rear wall 60 has a plurality of terminal receiving apertures 62 therein . The rear wall 60 also has a plurality of stand-off openings 68 therein. The rear wall 60 further has one or more grounding extensions 74 stamped therein. Extensions 74 extend rearwardly from the rear wall 60 and away from said housing receiving cavity 67. The grounding extensions 74 are offset from the center of the shell to provide polarization for the assembly when it is mounted to a printed circuit board as is shown in Figure 3. Figures 2 and 6 show that a plurality of pin terminals 36 having a first end 38 and a second end 40 extend through the apertures 20 in the back wall 18 so that first end 38 extends into cavity 26. The second end 40 extends rearwardly from the back wall 18 of the housing 12 and through apertures 62 in rear wall 60 of shell 58. In the preferred embodiment each pin
terminal 36 has individual filter sleeves 42 mounted intermediate the ends 38 , 40 of the terminals. The filter sleeves 42 extend through apertures 62 in rear wall 60 of shell 58 , so that a portion of the filter sleeve 42 extends on each side of wall 60. The filter sleeves are of the type disclosed in U .S . Patent No. Re. 29258 , the disclosure of which is incorporated herein by reference .
When manufacturing the assembly , filter sleeves 42 are mounted on the terminal pins 36. These filtered terminals are inserted through the apertures 62 in the rear wall 60 of the shell 58. Housing 12 is then inserted into the metal shell . The first end 38 of pins 36 are aligned with and inserted into corresponding apertures 20 in the back wall 18 of housing 12. As the parts of the assembly are joined, the standoff legs 34 enter the standoff openings 68 in the rear wall 60 of the shell 58. The standoff legs have enlarged portion 35 which rests against the rear wall 60 of the back shell 58 , providing space to protect the portion of filter sleeves 42 that extend into housing receiving cavity 67. The standoff legs 34 have a smaller sized portion 33 which pass through openings 68 and extend outwardly from rear wall 60. As shown in Figures 3 and 6 , the ends of standoff portions 33 rest on the printed circuit board 80 to provide space for the portions of filters 42 t it extend to the rear of the assembly. Referring again to Figures 1 and 2 , side walls 64 of back shell 58 have shield fastening extensions 70 extending therefrom . These fastening extensions 70 enter corresponding slots 32 in housing mounting extension 28 and slots 54 in face plate mounting tab 52. After joining the parts , extensions 70 are bent over the recessed mounting tabs 52 on the face plate 44. The tabs 52 are recessed sufficiently so that the fastening extensions 70 lie essentially in the same plane as the face plate 44 as is shown in Figure 3. Face plate mounting tabs 52 , housing mounting extensions 28 and fastening extensions 70 have holes 56 , 30 and 72 respectively for mounting assembly 10 to a
panel 84 with mounting means 78. Mounting tabs 52 and fastening extensions 70 provide grounding for the assembly when panel 80 is made of a conductive material . Figure 3 also shows the location of the grounding extension 74' when the assembly is mounted to printed circuit board 80.
The assembly has the capability of being grounded through either the ground extension or through fastening extension 70 and face plate mounting tab 52 if the assembly is mounted to a metal panel . Figure 4 is an exploded view of Figure 3 which shows assembly 10 exploded from printed circuit board 80 to the rear and panel 84 from the front. Panel 84 has a plurality of connector openings 86 and a plurality of openings 88 for mounting means 78. The pattern of said openings 86 corresponds to that of the assembly 10. In addition to terminal apertures 82 , printed circuit board 80 has at least one aperture 75 for ground extension 74.
Figure 5 shows assembly 10 mounted to printed circuit board 80 and panel 84 mated with a plurality of known shielded plug connectors 90. The mating plug connector 90 is preferably of the type disclosed in U . S. Patent No. 4,337 ,989 , the disclosure of which is incorporated herein .
Plug connector 90 is connected to shielded cable 92. Connector 90 has at least one plug retaining means 94 which cooperates with dimples 50 in spring fingers 48 to retain plug 90 within cavity 26 as is seen in Figure 6. Cavities 26 are profiled to provide polarization for the plugs 90.
Figure 7 is a cross-sectional view of an alternative embodiment of assembly 10. In this embodiment, terminal pins 36 are inserted into a planar filter 142 , rather than individual filter sleeves as is shown in Figure 6. In the alternative embodiment, planar filter 142 is contained between housing back wall 18 and shell rear wall 60. The planar filter 142 has a plurality of apertures for receiving a plurality of terminals 36.
Figure 8 shows a further alternative embodiment in which the filter pins 136 are bent intermediate the second ends 140 for systems requiring right angle mounting .
Figure 9 shows another embodiment 310 of the filtered shielded connector assembly . This embodiment is designed to be mated with plug-type connectors (not shown) instead of being mounted to a printed circuit board. Assembly 310 is comprised of an insulated housing member 96 attached to and extending from the back of filtered shielded connector assembly 10. Housing 96 has at least one plug connector receiving cavity 98 therein . Pin terminals 36 extend from cavity 26 in assembly 10 and into cavity 98.
It is thought that the shielded filter connector assembly of the present invention and many of its attendant advantages will be understood from the foregoing description. It will be apparent that various changes may be made in the form , construction and arrangement of the parts thereof without departing from the spirit or scope of the invention or sacrificing all its material advantages. The form herein described is merely a preferred or exemplary embodiment thereof.