Connectors for use in frames for holding circuit cards

Claim 1

A frame for holding circuit boards, which comprises a metal back plate, pairs of opposed, channel-section guides, disposed at right angles to and extending forwardly from the back plate, for receiving the edges of circuit boards, connectors mounted on the front of the back plate for establishing electrical contact with circuits on the boards fitted into the guides, each connector including a plastics moulding, having a plane rear face and a recess on its front surface for cooperation with a board and carrying metal contact pins which project from its rear face through holes in the back plate, and an insulator disposed between the rear face of each connector and the back plate, the insulator consisting of at least one strip of plastics material having at least one row of holes to receive said contact pins on the connector and tubular extensions which surround the portions of said contact pins which extend through the holes in the back plate, said plastics material and the tubular extensions being adapted to be removed enabling electrical contact to be established between said metal contact pins and said metal back plate by removal of the intervening plastics material, and each connector has fitted to each rear face an insulator including a plurality of differently colored strips of plastic material which abut end to end.