GB1324560A - Plug-in electrical component assemblies - Google Patents

Abstract

1324560 Electronic component assemblies STANDARD TELEPHONES & CABLES Ltd 23 Nov 1971 54292/71 Heading H1R A box for housing and screening a printed wiring board having components mounted thereon comprising a metallic frame in which the board is mounted parallel to the top and bottom of the box, the top and bottom being formed separately by sheet-metal lids held to the box by bosses on the frame which engage with slots in the lids both at the front and the back, each lid being fitted and removed by means of a bias spring, a contact spring on each lid ensuring good contact between lid and frame. A flange 11, Fig. 1, is provided in the diecast aluminium frame 10 such that the printed wiring board 20 may be mounted as described above and secured to the box by means of screws. Channelshaped contact springs 21 with fingers 211 on one side are fixed to each edge of the board to provide a good contact between the box and the copper surface of the printed wiring board. The two lids 30 and 31 are fitted with plate contact springs 32, said springs having fingers 35 bent away from the lid which press against the periphery of the frame. Each lid has a lip at the front, back, and sides, and slots 33 in the front and 34 in the back are provided to accommodate bosses 12 and 13 respectively, formed integrally with the frame, to hold the lids to the frame. Bowed springs 14 situated between the frame 10 and the inside of the rear lips of the lids press the lips in a rearward direction away from the frame when the lids are in the rest position. Each lid can be removed by pressing in a forward direction against the bias of the spring, the ends of the spring passing through holes 15 until the slots 33 in the front of the lid disengage the bosses 12. Fins 16 are provided on the sides of the frame to allow easy mounting in an equipment rack. An aluminium cover-plate 40, adapted to clip over the front of the box and thereby cover any controls, is fitted by means of latch springs 18 on the frame which engage with recesses 431 in plastic moulded strips 43 which are force fitted into grooves 44 on the cover-plate 40. In order to remove the panel a hole 45 is provided which allows access to the latch 18. A multiple box may be formed by stacking boxes together and joining the lids to form a link member. If access between two printed wiring boards is necessary the inner area of the connecting lids is removed, contact springs attached to the link member ensuring good contact between the frames.