Patent GB-1306072-A (GB)
IPC: H01H67/26
Filed: 1969-05-01
Abstract: 1306072 Electric selectors GENERAL ELECTRIC CO Ltd 1 May 1970 [1 May 1969] 22285/69 Heading H1L In a cross-bar switch comprising a plurality of parallel tiers of co-ordinate row and column bare-wire conductors, each vertical set of crosspoints (i.e. one from each tier) is located in an individual housing which interlocks with other such housings in a same column direction. The switch is basically the same as that disclosed in Specification 1,216,186 which provides connections between 10 inlets and 30 outlets (all four wire) with the aid of three so-called level switching rows and in which each vertical set of contacts is operated by a comb-like interposer which is moved in a direction normal to the planes of the tiers after the movement of a select bar parallel to three planes whereafter the operated set is mechanically or magnetically latched. Fig. 3 depicts a column of plastics housings 4 which are provided at their upper and lower front faces with spigots 10 that mate with corresponding recesses 11 in the housings on their right. The assembly is held together by end bars (not shown) which extend normal to the plane of the paper, each spigot having a bore for a locking bolt which passes therethrough. Vertical conductors 3 in the form of hairpins are threaded through apertures formed in the back plates 6 of each housing at the level of each tier, these conductors being physically-but not electrically-terminated in the end terminal housing 14. The teeth at the end of the comblike interposers 26 are provided with a U-shaped slot 33 for accommodating row wires 2, the front (right as shown) of the slots being closed by a forwardly projecting bar 15 on the adjacent casing 4. Each comb 26 (Fig. 5) is retained in its respective housing by upper and lower slots 21, one of which has a depression 31 for receiving a stop member 30 of the comb (lateral movement of the combs is of course prevented by the adjacent housings). The teeth stand slightly proud of their back piece 27 to allow row wires (not shown) to be threaded therebetween and to be then guided by the shaped teeth (34, 35) into the slots 33. It should be noted that the threading of the row and column wires is effected after the formation of the full matrix assembly. An exception is made however in the case of the wires 18 for the level switching rows 1, 2, 3, these wires being fed through apertures 17 in the back wall 6 of the housing in the same manner as the column wires 3 are subsequently fed through apertures 16 when the full column is interlocked together. The comb is maintained in a generally downward direction by co-operating resilient teeth 22, 23 on the housing and comb respectively. Reverting to Fig. 3, the wrapped joints 41 represent the multipled inlets to the level switching rows, the outlets from the remaining rows being taken from a similar terminal block behind the column shown. Considering now Fig. 2, each inlet is multipled to four different tiers 18 in rows 1, 2 and 3. In completing a connection, one of the interposers in one of these three rows is operated so as to connect the inlet to one 4-wire set of column wires 3, whereafter an interposer in one of rows 4-13 is operated to connect this set of column wires to one set of row wires 2, the connection then remaining held after the select and bridge magnets release.