GB537495A - Improvements in type-printing telegraphy - Google Patents

Abstract

537,495. Type-printing telegraphy. CLAYETTE, C. J. Feb. 5, 1940, No. 2228. Convention date, Feb. 15, 1939. [Class 40 (iii)] The characters are arranged upon the type carrier as shown in Fig. 1, one half only of the carrier being utilized. Selection of a character can thus be effected by transmitting first a number of pulses corresponding to the smaller of the two co-ordinates determining the character and then a number of pulses corresponding to the difference between the two co-ordinates in question. Instead of using two sets of pulses varying in number, two pulses varying in duration may be used. The type carrier is cylindrical and the first set of pulses produces a combined linear and rotary (i.e. helical) movement of the carrier, the second set of pulses producing a rotary movement only. In the system described, each character is represented by two sets of pulses, the last pulse in each set being prolonged to effect the necessary change-over and printing operations respectively. The first pulse received by magnet 1 allows the cylindrical cam 7 to rotate through half a revolution, thereby permitting the lever 10a on a sliding member 9a to engage the thread of a rotating screw 12. If the pulse is a short one, the member 9a moves until the lower end of the lever 10a engages an abutment 14a and raises projection 29 to permit the shaft 16 to rotate one step, thereby giving a helical movement to the type carrier 17 owing to the engagement of a lever 30 in the screw-threaded groove in sleeve 27. Succeeding pulses, if short, act similarly through sliding members 9b, 9a in turn. When, however, a long pulse is received, member 9a (or 9b) moves far enough to engage a catch 15a (or 15b), thereby allowing a shaft 32 to rotate half a revolution, and withdraw lever 30 from sleeve 27, so that the next short pulse acting through members 9b (or 9a), 29, and shaft 16 allows the carrier 17 to rotate without moving axially. Further short pulses do the same, the final long pulse causing 9a (or 9b) to engage 15a (or 15b) to allow the shaft 32 to rotate to effect the printing operation by roller 42, and restore all parts to normal.