Patent GB-1254898-A (GB)
Title: Electrical connector
Inventor: SCHULTZ HAROLD ROBERT
IPC: H01R13/7197
Filed: 1969-01-30
Abstract: 1,254,898. Electrical connector filter arrangements. HUGHES AIRCRAFT CO. 30 Jan., 1969 [12 Feb., 1968 (2)], No. 5131/69. Heading H1R. [Also in Division H2] An electrical connector for carrying signals between the outside and inside of an electrical equipment enclosure is provided with a filter and R.F. shield to effect attenuation of stray or extraneous R.F. by reflecting back or by-passing such energy. The connector, Fig. 1, for carrying signals to electronic equipment enclosed by frame 26 comprises an electrically insulating connector body 21 having a protruding boss section 21a which extends through aperture 54, a conductive gasket 22, an R.F. interference metal shielding enclosure 23, a filter support and isolation block 24 of non-conductive material and filter socket connectors 29 or pin 70, see Fig. 5, connectors. A complementary similar arrangement is provided on the opposite side of frame 26 only connector body 57 being shown in Fig. 1. The connector is assembled by first fastening the connector body 21, gasket 22 and connector body 24 together by means of jackscrew 25 and then bolting shield 23, gasket 22, and connector body 23 to earthed frame 26. Finally the filter connectors 29, 70 are positioned in the aligned apertures. The gasket 22 is formed of a yieldable rubber or elastomer material impregnated with conductive particles so that under compression it is very conductive to A.C. noise of certain frequencies or is formed of alternate layers of such material and metal coatings or foil, Fig. 10 (not shown). The gasket 22 is so dimensioned and compressed by means of jackscrew 25 and bolts that unwanted frequencies are by-passed through the filter to the conductive gasket and grounded via shield 23 and frame 26 and if made of the proper thickness or includes a metal layer reflects back other frequencies. In order to eliminate noise at high frequencies conductive layer 31 must be used or the gasket is in the form of Fig. 10. The provision of metal layer 31 also results in the shortcircuiting to ground or reflection of undesired signals passing through the jackscrew 25. Filter connector.-Fig. 2 shows a filter connector contact socket 29 and Fig. 5 a pin filter connector of similar construction. The filter comprises a plurality of ferrite beads 47 strung over tubular section 41 and two capacitors formed by coatings of silver 63, 64 on the outer and inner surfaces of dielectric tube 62, the arrangement being such as to form a pi network. The filter structure 59 is retained in place by solder sections 48, 49 and a dielectric coating 56 is provided so as to leave only the centre of coating 63 exposed to contact gasket 22. To allow the filter connectors to be removed clips 46 are provided having a deformable flared portion 66, the removal being effected by a tool, not shown. The diameter of the filter 59 is greater than the corresponding apertures 37 in the gasket 22. In an alternative embodiment, Fig. 6, a filter connector section 121 is used with a standard (no filter) socket connection 122 and a standard (no filter) pin connector section 123, the three sections being clamped together by jackscrew device 125. The filter connector section 121 includes filter 106 and is provided with a pair of insulating blocks sandwiching deformable gasket 100 which has its outside in contact with a metal floating ground shell 99. The shell 99 is bolted to equipment enclosure frame 102 and is slidably disposed along the filter connector section 121, its position being determined by the thickness of frame 102. Retaining clip 112 and reduced aperture 111 are provided as in the first embodiment.