Patent GB-825773-A (GB)
Title: Improvements in or relating to cross bar switches for communication arrangements
IPC: H01H67/26
Filed: 1956-11-13
Abstract: 825,773. Cross-bar switches. LEHNER, C. L., [trading as FERNSPRECH-U SIGNALBAU LEHNER & CO. K.G.]. Nov. 13, 1956 [Nov. 18, 1955; April 20, 1956 (2)], No. 34657/56. Class 40 (4). In a switch an array of adjacent groups of sets of contact springs is provided in which the sets of each group are arranged side by side in a row, a selecting finger being chosen and operated by actuation of one of a number of selecting members and one of a number of switching members to actuate a particular set of contact springs. In the embodiments two arrays of adjacent groups of contact springs are disposed facing each other with the selecting and switching members lying between the arrays. As shown in Fig. 1, each set of contacts has four contact blades 1 mounted in a block 12 and prestressed to make contact with four transverse conductors 6. A spring blade 14 holds the blades 1 off the conductors 6 by pushing on one end of an operating post 2. Ten sets of contacts mounted side by side form a group and the contact bank has five such groups side by side making contact with one set of conductors 6 and a further set of five groups mounted oppositely and in alignment to make contact with a second set of conductors 6. For each of the oppositely arranged pairs of groups two selecting fingers are carried by each of five selecting rails 7 so that a selecting finger lies between each pair of adjacent contact sets in each group and by operation of one of the magnets Z1 to Z10, to reciprocate a selecting rail one way or the other, selecting fingers may be aligned with the operating posts of the corresponding contact sets of each group. Between the selecting fingers provided for each opposite pair of groups lies a pivoted bar 8 controlled by a lever 25 and, for the groups illustrated, magnets E1 and E2 which displace the bar 8 upwards or downwards to operate the selected contact set in one or the other group. Four other pairs of magnets E3 to E10 operate the bars 8 serving the remaining four opposite pairs of groups. To avoid the use of ten magnets E1 to E10 the arrangement of Figs. 2 and 3 has magnets M1 to M10 which by means of magnets D and E are coupled to drive rails 7 to select a wanted group and to drive rails 8 to select a wanted set of contacts in the group, a magnet A then actuating the contacts. From each of the rails 8 extend selecting fingers to lie between the operating posts of upper and lower groups of contacts and between the selecting fingers associated with an upper group and the fingers associated with its opposite lower group lies a pivoted bar 9 from which projects operating arms 27 and 28. To each pivoted bar 9 corresponds a rail 7 carrying selecting fingers 47 such that if an upper contact group is required a rail 7 is moved to the right to underlie an arm 28 with a first selecting finger while to select a lower group a rail 7 is moved to the left to overlie an arm 27 with a second selecting finger. The selecting fingers are separated by a cam shaft 11 which when twisted by magnet A spreads the fingers apart to deflect a bar 9 upwards or downwards to displace the selecting fingers associated with the rails 8 and the selected group, and in particular to deflect that one finger placed in alignment with the operating post of a wanted contact set. The setting of rails 7 or 8 is effected by energizing the magnet D or E to deflect bars 117 or 118 downwards to engage pawls 102, carried on the ends of armatures 93, with notches in the rails. Limbs 142 on the bars 117 and 118, each deflect a locking bar 134 which normally secure the bars by engaging the central one of three slots in each rail. The armatures 93 are pivoted on blocks 94 with centre-restoring springs 108 and are each associated with a pair of the magnets M1 to M10 such that one magnet deflects a rail 7 to the left and the other magnet deflects it to the right, while acting conversely to deflect the rails 8. When a rail 7 has been set in accordance with a tens digit to select corresponding contact sets in each group, the magnet D is released to uncouple the displaced armature 93 and lock the rail in its set positions by means of the locking bar 134. The magnets M1 to M10 are now free to set a rail 8 in accordance with a units digit and the armatures are coupled for this purpose by energizing the magnet E which, when released, leaves the set rail locked by its locking bar 134 and permits release of the energized M magnet. The selected contact set is now actuated by energizing magnet A to rotate cam-shaft 11. The switch is released by de-energizing magnet A and momentarily energizing magnets D and E to release the locking bars 134 and permit the rails to return to their normal positions under the action of restoring springs which for rails 7 are shown as flat springs 69 controlling lever cams 68, and for rails 8 are shown as vertical spring wires 56 extending across the rails in slots 55. The switch of Figs. 2 and 3 is described in greater detail with reference to Figs. 4 to 10, not shown, in which the contact groups are mounted on a rail so that. the selecting and operating mechanism may be slid into position and be detachably secured between and to one side of the upper and lower contact groups. An arrangement in which ten banks of ten groups of contact sets may be mounted, each with their own A, D and E, magnets and with one set of magnets M1 to M10 in common to drive five shafts 94 which extend across the banks, is shown in Figs. 12 and 13. Here, the rails 7 or 8 of each bank are coupled as required to an associated one of the shafts 94 by the magnets D or E and pawls 102 carried on arms of the shaft. Each shaft is oscillated to set a rail to left or right by one pair of the magnets M1 to M10.