Patent GB-464528-A (GB)
Title: Improvements in and relating to printing telegraph apparatus
IPC: H04L17/24
Filed: 1936-02-29
Abstract: 464,528. Typeprinting telegraphy. NATIONALE TELEPHON - UND TELEGRAPHENWERKE G E S . Feb. 29, 1936, No. 6189. Convention date, March 2, 1935. [Class 40 (iii)] A printing-telegraph receiver comprises a set of code discs and a type wheel rotated therewith and a group of testing members which are set by power supplied by the receiving motor, the receiving magnet not being called upon to provide any substantial force. The receiver is of the type described in Specification 421,227 and has two groups of selecting members, one being set while the printing operation is carried out for the other which has been adjusted by the preceding signal. The selecting members are moved axially into one of two positions, to co-operate with the code discs 193-196, Fig. 1, by levers 157 which are set by a lug 156 on a rotating arm 152 attached to a drum 153, Fig. 7, which is axially movable on the driving shaft against a spring 155. A fixed drum 141, has cams 149 round its circumference which act on lugs 151 on the distributer arm 152 to cause axial movement of the drum 153 and its separation from the drum 141 which separation is maintained ,by a marking signal or released by a spacing signal as follows. A pivoted extension 147 of the armature 148 of the receiving magnet 150 is interposed between the drums 141, 153 by the cams 163 on cam disc 160 acting on the member 164 fixed to the armature, once per signal element, the armature 148 being at the same time brought up to the magnet pole 165. If the magnet is energized by a marking signal the armature is retained in this position, the drums 141, 153 being held apart by the member 147 and the corresponding selecting member set to the marking position by the arm 152 attached to the drum 153. If the magnet is de-energized when the member 164 is released, the armature drops back, the member 147 is removed from between the drums 141, 153 which close so that the arm 152 does not operate the next selecting member. The levers 157 are all placed initially in the spacing position by a cam 238 on a disc 162 fixed in advance of the lug 156 on the arm 152. The phase position of the selecting mechanism relative to the start-stop shaft may be adjusted by rotation of the member 142, Fig. 1, which adjusts the angular relation of the drum 153 relative to the start-stop shaft. Start-stop mechanism, Fig. 3. The sliding member 131 of a dog clutch is coupled to the driving wheel 114 for half a revolution for each signal combination, the coupling being effected by a pawl 133 the curved end of which normally projects into one of two diametrically opposite openings 171 in the drum 131 which are so shaped that the clutch members are disengaged. A check pawl 177 engages the opposite opening to prevent backward rotation. The spring 176 tends to withdraw the pawl 133 from the opening 171 but is normally prevented by an extension 175 of the pawl which engages the cranked end 185 of a pivoted member 183, Fig. 6, the arm 182 of which is tripped by the start signal which operates the end 181 of the receiving magnet armature. Shortly before the end of one half revolution of the drum 131, one of the cams 179 thereon engages an extension 174 of the pawl 133 to move the latter into one of the apertures 171 disengaging the clutch and bringing the selective mechanism to rest. Control of printing mechanism, Fig. 15. Cam discs II ... V, rotated for one third of a revolution by a dog clutch 260, 262 from the shaft 107, for each character, operate the printing hammer, paper and ribbon feeds, or switching operations. The clutch is engaged by the withdrawal of a double pawl 257, 258 from one of three diamond-shaped projections 259 on the clutch member 260, the pawl being controlled by a rod 240 which is normally held by one of the two members 249, 250. One of the selecting mechanisms, having selected a character for printing, operates the appropriate rod 246 or 247 to move a pin 252 for the release of the appropriate locking member 249 or 250.