GB312821A - A new or improved printing telegraph receiver - Google Patents

Abstract

312,821. Cook, F. W. June 14, 1928. Type-printing telegraphs.-A printing telegraph receiver comprises a type-carrier 2 with associated stops, Fig. 4, means for placing a detent 5 into operative relation with successive sets of the stops, means responsive to the character of each signal element for operating the detent selectively, and means responsive to the successive selective operations of the detent for positioning the type carrier progressively during the arrival of a signal. The first incoming signal of a fiveunit code causes attraction of a non-polarized armature 22 and thus trips a ratchet clutch 13, 14 into engagement. A shaft 10 then rotates, in synchronism with the signals, a snail cam 7, which raises the escapement 5 step by step, and a notched cam 8, which releases the escapement for one blade, and thus one stop on the type wheel 2, after each step of the snail cam, provided a catch 24 is withdrawn from an extension on a lever 18 by the attraction of a polarized armature 23. A stop on the typewheel is thus released or not according to the polarity of the received signal, and, if released, the typewheel is arrested by the next stop in the concentric row to which the escapement has been raised. As each successive row of stops halves the angular permissible movement of the typewheel for the preceding row, any one of 32 characters is selected and brought into position over a printing-anvil 25. A cam, not shown, on a sleeve 9 actuates the anvil to print the character on a paper tape 26 just before the return of the escapement to normal, and the return of the printing-anvil moves the tape forward. The clutch detent automatically disengages after one revolution, and the escapement, dropping to the zero position, withdraws from the last engaging stop and allows the typewheel to return to the zero position where it is arrested by the single stop of the innermost row. A figure-shift device is fitted to the typewheel by carrying the printing-character on a separate ring which is free to move, relatively to the disc carrying the stops, a distance equivalent to a quarter of the distance between consecutive stops in the outermost row. To reduce the time interval between signals required for the typewheel to return to rest, the rows of stops may be carried on separate rings which mutually engage through locking-stops and the width of the escapement reduced to that of one row (Figs. 5-7, not shown). According to a modification, adapted for operation on the Morse-code, the printing- characters are arranged on the surface of a drum, the detent is withdrawn by a dash, which is distinguished from a dot by its length and from a space by its polarity, and the printing-anvil is actuated immediately after the receipt of a signal (Figs. 8-12, not shown).