Patent GB-830479-A (GB)
Title: Printing telegraph system
IPC: H04L17/00
Filed: 1957-03-29
Abstract: 830,479. Selective printing. TELETYPE CORPORATION. March 29, 1957 [March 29, 1956], No. 10358/57. Class 100(4) [Also in Group XL(b)] A page-printing telegraph receiver (see Group XL(b)) comprises a continuously rotating type wheel provided with circumferential rows of printing characters with chemical means controlled jointly by the rotating type wheel and the received signals for selecting the particular character an the type corresponding to the received signal and for causing the selected character to be printed during the rotation of the type wheel by the appropriate one of a series of print-hammer devices facing the rows of printing characters opposite an intervening sheet or strip on which printing is to be effected. Printer operation. Printing is effected on a sheet 103, Fig. 10, guided around the type-wheel 101 comprising the character type rings 104, equal in number to the characters in a line, and associated with an equal number of printing devices, each provided with a spring-biased hammer 107 engaging an inking ribbon 106. When printing is to take place the corresponding magnet 121 is energized and its armature 118 moves to the right a lever 117 engaging a rod 116 articulated to a print hammer pawl 111 which is brought into operative relation with an impeller wheel 113 rotated in conjunction with the type wheel 101 and provided with teeth 113 spaced to correspond with the spacing of the characters on the rings 104. The pawl 111 engaged by a tooth 115 is rapidly moved to the left to engage the extension 122 of the print hammer 107 to press the ribbon 106 and paper 103 against the selected character in the type-ring 104. During its return stroke, the pawl 111 is rapidly withdrawn from engagement with the impeller 113 by the action of springs 119, 127. Paper-feed; line-spacing. The paper 103, Fig. 9, from a supply roll 151 is fed around a roller 159 on a spring-biased arm 161 having a shaped cam slot 162 engaged by a pin on a spring-biased lever 158 carrying a brake-shoe 156 engaging a drum 154 mounted on the shaft 152 of the paper roll. When the roll 151 is complete or unused. the arm 161 is in the position 161<SP>1</SP> so that the shoe 156 is pressed against the drum to retard the rate of rotation of the roll 151, and as the arm 161 moves towards the position 161<SP>2</SP>, the pressure of the shoe 156 on the drum 154 is gradually reduced so that the feed of the roll 151 is accelerated. When. printing ceases, the reduced tension in the sheet 103 allows the lever 161 to rotate clockwise to apply the shoe 156 to the drum 154. The paper 103 is fed over guide rollers 164, 166, in front of the typewheel 101, and to a feed roller 169 associated with pressure rollers 171, 172 carried by a lever 174. The roller is secured to a gear wheel 177 engaged by pawls 176 eccentrically mounted on a shaft connected to a gear driven from the type wheel shaft and released for one sixth of a revolution by a six-position clutch 178 when the linefeed magnet 181 energized by the appropiate signal rocks the clutch detent arm 183. Ink-ribbon mechanism. The ribbon is carried by spools 128, 129, Fig. 11, which can be individually rotated by gear wheels 133 or 134 in engagement with gear 144 or 145 on a shaft 136 splined for rotation with a gear wheel 137 driven, for example, from the type-wheel shaft. Bifurcated actuators 149 engaged by the reversing cyclet on the ribbon close the associated switch 148 to energize an associated magnet 142, 143 operating on armature 138 having a yoke connection at 139 with the shaft 136 which can be moved longitudinally. In the position shown when the eyelet reaches the left-hand actuator 149 switch 148 is operated to energize magnet. 143 moving the shaft 136 to the left so that gears 133, 144 are separated and gears 134, 145 brought into engagement to drive the spool 129. The shaft 136 is held in its operative position by a spring-biased detent 146 engaging a roller 147 carried by the yoke 139. Specifications 676,779 and 799,699 are referred to.