Improvements in electric selector switches

802,437. Keyboard switches. MINISTER OF SUPPLY. Nov. 19, 1956 [Nov. 19, 1955], No. 33178/55. Class 38 (5). A selector switch comprises two spaced groups of contact carrying members, one group crossing the other, the members of the first group being movable lengthwise to and fro and those of the other group being movable out and back so as to close selected contacts by a combination of movements of the appropriate members of the two groups. In one, form, one group 11 ... 18 is horizontal and the other group 21 ... 28 is vertical, each member of each group having a contact spring, e.g. 114, 241 where it crosses the members of the other group. In order to complete a circuit, e.g. between members 11 and 24, the latter is moved in direction a, Fig. 1, into the position of Fig. 4a, member 11 is then moved in direction b, Fig. 1, 24 is moved back in direction c, Fig. 1, into the position of Fig. 4c, and finally member 11 is moved in direction d, Fig. 1, into the position of Figs. 4d, 5d to engage contacts 114, 241. In order to prevent disengagement of these contacts on subsequent downward movement of member 24, contact 114 may be formed as a spring wire 199 and contact 241 as a channel-shaped member 291, Figs. 6d, 6e, 7d. The form of contacts 199, 291 may be reversed. The backs of one or both of the sets of contacts may be insulated to prevent undesired contactmaking in the Fig. 3 position. The members of one group may be " folded back " upon themselves, Fig. 8, to give three rows of contacts 311 ... 316, 317 ... 322, and 323.. 328 co-operating with three rows of contacts 411 ... 461, 471 ... 521, 531 ... 581.