GB392961A - Improved means for auxiliary signalling in printing telegraph systems - Google Patents

Abstract

392,961. Type-printing telegraphy. CREED & CO., Ltd., Telegraph House, Croydon.-(Teletype Corporation ; 1400, Wrightwood Avenue, Chicago, U.S.A.) Nov. 27, 1931, No. 32918. [Class 40 (iii).] In a printing-telegraph system using a code having a starting element followed by a series of permutation elements of operative or non-operative character, a bell or other auxiliary signal is selected for operation on the receipt of a blank signal in which all the per-. mutation elements are of non-operative character. The bell &c. is actuated by the next code signal if of predetermined character, say that for effecting line feed, but by no other. In the system described, the permutation signals are distributed to five magnets 2, Figs. 1 and 2 (two only being shown), printing being effected by a magnet 21 (its armature 22 only being shown in Fig. 1), energized by a locally produced impulse. Arms 5 attached to the armatures 4 of magnets 2 co-operate with the notched ends of latches 9 connected by pin and slot to a common release bar 14 in such a way that when, during a normal signal, one or more magnets 2 are energized, the corresponding armatures are locked by the ends of the latches 9 and the bar 14 is moved to the right. A lug 33 on the bar 14 unlocks the armature 22 of the printing magnet 21 so that this is attracted in due course, engaging lug 31 to move the bar 14 to the left, thereby unlocking the armatures of the magnets 2 ready for the next code signal'. If, however, a blank signal is received, so that none of the magnets 2 is energized, the bar 14 is not moved to unlock the armature 22, so that the energization of magnet 21 at the end of the signal is without effect. A magnet 35, Fig. 3, in parallel with magnet 21 is, however, energized over contact 38, which is closed since the bar 14 has not been moved. The magnet 35 moves the member 47, Fig. 4, into the position shown in dotted lines, where it is held by a latch 56, the forked end 52 of the member 47 moving from beneath the member 61 to beneath the member 62. The members 61, 62 are both operated in response to the same code signal, say that for effecting line feed, but whereas the member 62 effects the line feed the member 61 only-controls the bell signal. If, therefore, the line feed signal is received immediately after the blank signal, i.e. when the magnet 35 has been energized and its armature is held in its attracted position by the latch 56, the member 62 is blocked by the forked end of the member 47 and the line feed mechanism is inoperative, but the member 61 is operated to ring the bell. If, however, the line feed signal is received at any other time, the member 47 blocks the member 61 to prevent actuation of the bell but frees member 62 to actuate the line feed. The latch 56 holding the member 47 is tripped by an arm 71 which rotates when the armature of the printing magnet 21 is attracted. The bell signal is thus only given when the blank signal is followed by, say, the line feed signal.