Patent GB-382313-A (GB)
Title: Improvements in printing telegraph apparatus
IPC: H04L17/24
Filed: 1931-07-24
Abstract: 382,313. Type printing telegraphy. CREED & CO., Ltd., Telegraph House, Croydon.-(Teletype Corporation ; 1400, Wrightwood Avenue, Chicago, U.S.A.) July 24, 1931, No. 21149.. [Class 40 (iii).] In a printing telegraph receiving apparatus, a number of independent selector members is simultaneously operated by the received code impulses to condition a movable stop member carried with a rotatable type-wheel to engage with a stationary, toothed, stop-member to arrest the yieldingly driven type-wheel by the engagement of the movable stop-member with aligned notches in the selector members and with a notch in the stationary toothed member. The selecting cams and the type-wheels are carried on shafts 10, 88 respectively, which, when released, are rotated by gears 29, 94 driven by a motor supplied with driving current over separate lines from the transmitting station. The impulses controlling the startstop mechanism and character selection operate an electromagnet 3 effecting longitudinal movement of the cam shaft 10 in accordance with the polarity of the received impulses, the start impulse being arranged to move the shaft 10 longitudinally disengaging a stop-pin from a fixed abutment whereby the shaft 10 is set into rotation by the engagement of a driving extension on the shaft of the gear wheel 29 with a member secured to the cam shaft 10. During the remainder of the revolution, the shaft 10 is moved longitudinally in accordance with the received impulses so that the selecting cams 35 .. engage either selector bars 42 or the extensions 49 of latching members 47. When a bar 42 has been depressed on engagement with a selecting cam, the latch member 47 engages a lateral extension of the bar and holds the bar in the operated position. When a cam does not engage its associated bar 42, it resets the bar to its upper position by engaging with the latching extension 49, if the bar has been operated in accordance with the previous signal. At the end of the selecting impulses, a cam 65 engages a roller 64 on a pivoted bent lever 62 carrying pivoted rockers 59 having lugs 57, 58 one of which engages with one of two lugs 40, 44 on the selector bars 42, according to the raised or lowered position of the selector bars. By the engagement of the corresponding lugs the members 59 are simultaneously rocked accordingly to position a set of internally notched selector rings 69 which are latched in their selected positions by a lever 73 with a lug 78 engaging aligned locking slots 79 in the rings. Secured to the shaft 88 of the type-wheels 96, 97 is an arm 85 carrying a pivoted, spring-controlled seeker lug 86 which, in the printing position of the type-wheels, lodges in one of the notches 83 of a fixed stop-ring 82 and in the aligned notches, corresponding to the selected character, formed on the inner side of the selector rings 69. On the operation of the rockers 59, the stopmember 86 is moved outwardly by the movement of any of the rings 69, and the type-wheel shaft 88 is released for rotation until the lug 86 finds the set of aligned notches corresponding to the signal combination set up on the rings 69, when the type-wheel is again arrested for the printing operation. Printing operation ; letter and figure shift. The characters are carried on two type wheels 96, 97 and printing is effected by one of two hammers 103, 104 selectively operated by mechanism controlled by a sixth impulse. The shift bar 121, operated similarly to the selector bars 42, carries a pin 123 which, on the depression of the bar, rotates a shaft 125 carrying a bifurcated member 127 so arranged that one of the forks 128, 129 is in an abutting position with respect to a hammer selecting and operating member 134, mounted on a printing lever 111, when the shift bar 121 is actuated. During the selecting period the lever 111 is rocked on a shaft 112 which is rotated by a member 114 with a nose 115 engaging the cam so that the member is brought downwardly into engagement with the forked member 127 set by the shift bar 121. The printing operation is effected when the nose 115 drops into a depression in the printing cam 22 allowing the lever arm 111, carrying the member 134, to raise the selected hammer 103 or 104 and the tape against the selected character on the corresponding type-wheel 97 or 96. To prevent the occurrence of the printing operation during a space between words, the type-wheel shaft is rotated by the spacing signal combination to a position, in which it is latched, such that a projection 143 engages a lug 142 on the lever 141 fixed to the shaft 112, and limits the movement of the printing lever 111 so that the hammers are unable to force the tape against the type-wheels. Paper-feed. After a character has been printed, a feed-cam 21 operates levers 156, 158 controlling a pawl 154 which steps forward a ratchet wheel 153 on the shaft of the tapefeed roller 151, latched against reverse movement during the return stroke of the pawl 154 by an auxiliary pawl 158<1>. Inking of the type-wheels 96, 97 is effected by a roller 161.