721,725. Selective punching machines. MAUL, M. Oct. 16, 1952 [Nov. 17, 1951], No. 25978/52. Class 31 (2). A key-actuated machine for punching code perforations in record cards having a plurality of decks of perforations comprises a set of punches 12 for each deck disposed below the card path, a matrix bar 52 disposed above the card path, a single set of key levers common to all the sets of punches, a set of punch selector bars 11 associated with each set of punches and constructed as code selector bars, means effective upon the actuation of any key lever to condition for operation in each set of selector bars that bar or bars representing in code the character corresponding to the actuated key lever, and means for selectively rendering effective the conditioned selector bars in any one of the said sets so as to establish an operative connection between the punch operating means and the selected punches of the selected set. The machine is in many respects similar to that described in Specification 710,928 wherein, upon the depression of a character key 30, a card carriage 62 is moved one step to punching position over a transverse line of punches 12 arranged in sets each corresponding to the deck of a card, and appropriate selector bars 11 are then longitudinally displaced to render effective the desired punches of the selected set. Instead, however, of providing a single set of selector bars which can be moved bodily to co-operate with the set of punches corresponding to the chosen deck, a set of selector bars is provided under each set of punches. For punching a card having three perforated decks, three similar sets of selector bars 11 are arranged under the corresponding sets of punches 12, as shown in Fig. 4. Each set of selector bars is associated with an electromagnet W1, W2, W3 which, when energized, acts as in the above-mentioned Specification, through springs 32 to displace longitudinally such of the bars as are not locked against such movement by one of a plurality of locking bars actuated by the character keys 30. In this displaced position, the ends of the bars are disposed over a punching yoke which is subsequently rocked automatically to raise the displaced bars and so force the corresponding punches through the card. The lower edges of the selector bars are toothed, the arrangement of the teeth in the bars of each set being such that each locking bar, when raised by depression of a key 30, locks a different combination of selector bars against displacement and therefore provides a different combination of operative punches. Deck selection is effected by two switches u1, u2, Figs. 4 and 13, controlled by three keys 13, each of which when depressed has the effect of including one of the three electro-magnets W1, W2 or W3 into a circuit for subsequent energization when a character key 30 is actuated; the three keys 13 are so interconnected that only one key can be actuated at one time. A further key 14 disposed adjacent each of these keys is arranged so that, on being depressed, it actuates its neighbouring key 13, and also acts through linkage to release a locking pawl from a rack on the underside of the card carriage which is then moved to starting position by a spiral spring. After insertion of a card in the carriage when the latter is in its fully-advanced position, the deck to be punched is selected by depressing the corresponding key 14, which, as described above, permits the card carriage to move to its starting position and by actuating the adjacent key 13 selects the electromagnet W1, W2 or W3 appropriate to the selected deck. Depression of a character key 30 then operates the corresponding locking bar (which locks the desired selector bars in all the sets), and by closing a switch g, Fig. 13, energizes both the feed magnet T to move the card carriage one step and the selected one of the selector magnets W1, W2 or W3 to displace the free selector bars 11 of that set to operative position over the punching yoke. Closure of a switch tII by the feed magnet T then energizes the punching magnets S1, S2 which rock the yoke upwardly for the punching operation. Actuation of a key 13, instead of a key 14, effects deck change without moving the card carriage to starting position. The constructional details of the card carriage feed, punching mechanism, and means for locking the selector bars are the same as those described in Specification 710,928, and the skip, release, and back-space keys are similarly operated.