SWITCHES WITH SELECTION BY CO-ORDINATES

1,222,463. Electric selectors. P. LUCAS, A. SAUTEL, and S. CHOUPIK. 22 July, 1969 [26 July, 1968], No. 36806/69. Heading H1L. In a mechanically latched cross-bar switch having two sets of orthogonal bars X, Y, each X bar 11 of one set 10 carries a plurality of spaced fork contacts 110 which normally rest on an insulating side 29 of respective bars of the other set 20 and each of the latter Y bars has a number of notches 211 through which a fork can pass after selective movement of one bar in each set so that the fork eventually rests on a conducting side 21 of the moved Y bar. Insulating plates 26, 25, 24 are spacedly located between each composite conductive/insulating bar of the Y set. Since all movements of an X bar cause its forks to resiliently engage a bar or a plate vibration of the contacts is very heavily damped. With the crosspoint shown, three contacts are simultaneously operated. The X bar 10 comprises three subsidiary bars 11, 12, 13, each of which carries a plurality of forks of which only one for each bar can be seen at 110, 120, 130. Each subsidiary bar and its forks are formed by cutting and bending a single metal sheet (Fig. 2, not shown). The forks of the three subsidiary bars are aligned and potted in a dielectric (e.g. polycarbonate) block 14. The top of the block is saw-toothed such that each fork has more freedom of movement in the X direction than in the other direction. The blocks are L-shaped at one end and T-shaped at the other, the one arm of the L and the two parts of the bar of the T carrying pegs which slide in apertures in the switch frame, such that transverse movement of a bar is prevented (Fig. 3, not shown). The Y bar 20 comprises three subsidiary composite bars 21/211, 22/221, 23/231, which are notched as at 211 ... 232 to allow passage of the tines of the corresponding forks. In operation bar 20 is moved to the left so that tines 131, 121, 111 become aligned with notches 231, 221, 211, respectively (and similarly for tines 132 &c. and all the other tines pertaining to not-shown X bars). Then X bar 10 is moved to the left so that the tines of forks 130, 120, 110 pass through the notches and abut against insulating plates 24, 25, 27, whereafter bars 20 and 10 are restored in turn so that contact is made between the tynes and the conductive faces of their respectively co-operating subsidiary Y bars. In order to release the connection, the Y bar is moved to the left momentarily whereby the resilient tines emerge from the n