GB1137533A - Improvements in or relating to matrix switches - Google Patents

Abstract

1,137,533. Electric selectors. BRITISH TELECOMMUNICATIONS RESEARCH Ltd. 8 March, 1967 [8 March, 1966; 12 Jan., 1967], Nos. 10142/66 and 1789/67. Heading H1L. In a matrix switch having at each cross-point at least one fixed and one moving contact, the commoning between contacts of a row or a column is provided by conductive strips mounted upon an insulating surface, such as by moulding the strips into an insulating board or by printed circuit techniques, the commoning strips for a row of moving contacts being upon one insulating surface and those for a column of fixed contacts being upon another insulating surface. The two surfaces may be upon separate insulating boards or on opposite faces of the same board. In one arrangement (Fig. 1), where there are four pairs of contacts at each cross-point, the columns of fixed contacts 31 are mounted upon one side of boards 32 and make contact through the board with commoning strips upon the underside. The moving contacts are not shown, but are wires (Figs. 3 and 4, not shown) mounted upon the cross-members 36, into which boards 32 are slotted, and at one end are bent to overly the respective fixed contact and at the other end pass through the cross-member to connect with row commoning strips 42 mounted upon the upper side as shown, or alternatively the lower side of the boards 43. The four moving contacts at a cross-point are mechanically bridged so that they may be operated together, such as by a fluid or electromagneticallyoperated cross-bar system. The ends of the moving contact wires may be kinked to engage the fixed contact or the latter may have a V-shaped contact block. In another arrangement (Fig. 6), again having four contact pairs per cross-point, the row and column commoning strips are on opposite faces of the same board 50. So-called columns of fixed contacts 59 upon the upper side of the board connect through the board with their commoning strips 53, 55 upon the underside. So-called rows of moving contacts, not shown here, are supported by horizontal cross-members which overly the row commoning strips 56 mounted upon the upper side; the moving contacts are connected to their respective strip at the tags 57. Each row commoning strip 56 is connected through the board to one conductor 52, 54 mounted upon the underside alongside the column commoning strips 53, 55, thereby enabling outside connection to the whole matrix switch to be made along one edge of the board.