Patent GB-902931-A (GB)
Title: Improvements in or relating to telegraph printers
IPC: H04L17/26
Filed: 1958-12-09
Abstract: 902,931. Printing-telegraph receivers. TELEPRINTER CORPORATION. Dec. 9, 1958 [Dec. 13, 1957], No. 39685/58. Class 40 (3). In a telegraph printer having a type-cylinder moved axially by selector pulleys and a first cable and rotated by a second cable and selector pulleys, mechanism for the special functions comprises two slides, each formed with a plurality of transverse notches, one slide being moved longitudinally by the first cable and the second slide moved longitudinally by the second cable, and a number of probes selectively and transversely moved into aligned notches of the slide members. The mechanism is incorporated in a printing-telegraph receiver, operating generally as described in Specification 799,956 and shown diagrammatically in Fig. 24 in which the type cylinder 12 embraced by a yoke 32 is moved axially by a cable 34 connected to the notched slide 38 which is connected by a cable 42 to a sprocket 58 coaxial with a pulley member 54 rotated by pulleys 44, 46, 48 whose supports are moved in response to three impulses of a code combination. The rotary position of the type cylinder 12 is controlled by rotation of a splined shaft 30 by a cable 36 passing over pulleys 120 . . . 126 and a pulley 116 to a fixed support 118. The pulley 124 is attached to the slide 106 connected via cable 108 to pulleys 112, 114 which are moved in accordance with the remaining two impulsers of the 5-unit code. The pulley 116 is secured by an arm 128 to a sleeve 130 rocked in response to the case shift signals, the figure shift signal effecting rotation of the type member 12 through 180 degrees so that lowercase and upper-case characters are included in, and printed from opposite halves of the member 12. The character feed of the type head 12 is achieved by passing the cable 34 over a pulley 60 to a character-feed drum 64. A continuation of the cable 34 is passed over pulleys 68, 74 to a take-up drum 70. The simultaneous movement of the printing member 14 is effected by a cable 86 connected to the feed drum 64 and take-up drum 70, whilst a cable 96 passing over pulleys 100, 102 ensures identical movement of the drums 64, 70. The pulley 74 around which the cable 66 passes is resiliently mounted by the arm 78 and spring 76 so that the rapid character-selecting axial movement of the cylinder 12 are taken up by movement of the support arm 78. The slides 38, 106 which have three and five notches respectively in their lower edges are slidable on a support plate 148 provided with guide notches for the probes in line with the pairs of aligned notches corresponding to the various functions. The notched slide plates are not moved directly by the pulley systems, but are operated by intermediate members 164, 174 which are attached to the chains 42 and 108 and carry the pulleys 50, 124 provide a resilient lost-motion connection with the actual slides. The probes such as 182, Fig. 4, are pivotally mounted at 184 on lever members 198 formed in most cases with an arm 202 controlling a clutch member 204 permitting connection of a function arm to the shaft 138. A pusher member 192 oscillated by a shaft 194 during the reception of each code combination of pulses moves inwardly after the slides 38, 106 have been set by the signal pulses, and the probe 182 if allowed to move upwardly by aligned notches, is moved to the right. The probe during its rightward movement rocks the lever 198 which through its arm 302 releases the clutch member 204, and also by the engagement of its cam surface 212 with a fixed rod 210 is depressed so that it returns to the left, but is held under the lateral extension 190 of the pusher 192 until the latter has been restored to its left-hand position so that the slides 38, 106 can be freely set by the subsequent code combination. The upward movement of a probe also depresses a rod 260 which through a detent arm 256 obstructs an arm 254 so that the printing shaft 248 cannot be rocked by the follower 250 operated by the printing cam 252 on the shaft 138 driven from the main cam-shaft 234 by a half revolution clutch controlled by a detent lever 226 operated by a lever 230 rocked by a cam 232 driven through one revolution during the reception of a code combination and carrying sequence cams which in response to the received code impulses move the frame carrying the pulleys 44, 46, 48, 112, 114 which determine the axial and rotary motions of the type cylinder 12 together with the positioning of the slides 38, 106. Character-feed and spacing operations.-With the normal printing of a character, the rocking of the shaft 194 through a lever moves downwardly a feed pawl 270, Fig. 2, engaging the teeth of a ratchet 268 mounted in the shaft of the retaining character-feed drum 64 and held by a spring-biased pawl 272. For the " spacing " operation of the probe 182 allocated with this function depresses the rod 260 which is effective to suppress the printing operation, but does not operate a clutch control member, corresponding to the arm 202 of Fig. 4, to connect a function cam on the shaft 138. The function shaft 194 is rocked so that a normal character spacing is effected without printing. Character-feed suppressions.-The clutch control members operated by the function probes except that responding to " space " operate an overlying yoke member 280 secured to a shaft 286, which is rocked by all the function signals except " space " and through a pin 290 rotates a retractor 294 which disengages the feed pawl 270 from the ratchet 268 to suppress character feed. As this action is only of momentary duration in relation to the normal feed operation by the feed-cam on the shaft 194, the retractor 294 is latched by a detent 296 which is released by a pin 302 on the feed-pawl 270 when the latter has been depressed to the full extent by the feed-cam. Carriage-return and line-feed.-When the probe corresponding to carriage-return has been operated a full revolution clutch on the shaft 138 is operated and a cam 312, Fig. 8, operates a follower 314 to rotate shaft 286 which rocks the retractor 294 and moves downwardly a link 292 engaging a pin 318 on the retaining pawl 272 which is held away from the ratchet 268 for a period corresponding to two complete 5-unit signals. For the line-feed operation the selected probe releases a cam on the shaft 138 operating a cam follower connected to a shaft 322 which through links 324, 326 actuates an integral pawl 328 to stop a ratchet 332 on the shaft carrying the roller over which the paper is fed. Case-shift operations.-The probes actuated in response to the " letters " and " figures " signals operate clutch control members similar to 198, Fig. 4, whose latching fingers similar to the arm 202, are associated with two discs controlling a cam-shaft and each provided with a stop tooth and the teeth displaced 180 degrees apart. The cam has high and low parts at diametrically opposite points and through a cam follower 308 rocks a hollow shaft 130 which, as indicated in Fig. 8, operates the frame carrying the pulley 116 to rotate the typecylinder through 180 degrees to bring the " letters " or " figures " half section opposite the printing hammer 14. Operation of signal bell.-The bell comprising a freely-suspended bar 396, Fig. 19, struck by a hammer 398 is operated by the upper case of the letter S. When the letter S is received for printing, the cam 306 in the position shown holds the lever 308 so that the latch 414 on the arm 410 by engaging the tail 389 of the probe 388 prevents it from rising. When, however, the " figures " signal has been received the rotation of the cam 306 rocks the lever 308 so that the latch 414 does not prevent the probe 388 from rising when the code-signal for " S " is received. The rightward movement of the probe 388 by the pusher rocks the lever 390 so that its arm 386 impacts the hammer 398 against the bar 396. Automatic carriage-return and line-feed.-If the signals for these functions have not been received when the end of a line has been recoded, a pin within the character-feed drum, Fig. 9 (not shown), engages an extension on one arm of a pivotal lever rocking a shaft 354 which moves downwardly a rod 366 engaging the extended tail 368 of a probe 372 provided with a cut-away portion 374 opposite the lower surfaces of the slides 38, 106. The rocking of the probe 372 allows it to be engaged by the pusher so that its rightward movement operates a clutch controlling the cam which effects carriage-return. The downward movement of the rod 366 also allows a second long-tailed cut-away probe to be actuated by the pusher and to control the release of the cam controlling the line-feed operation. Local manual control of printer.-Carriagereturn line-feed and " figures " may be controlled by push buttons, such as 421, Fig. 11, which in operation engage a downward projection, such as 426, of the clutch lever associated with the corresponding probe. In the case of the " letters " button 423 a strip 433 has a sideways offset 435 engaging the bent portion 436 of a spring having a verticallymovable free end portion 437 bearing against the lower surface of a cut-away probe 440 connected to the arm 442 controlling the letters shift clutch. The arm 442 is also actuated by a probe engaging notches in the slide plates. Normally, when the button 423 is moved inwards the end 437 of the spring is raised and the probe 446 is moved to the right on the next inward stroke of the pusher 190. If the button 423 should be actuated when the pusher 190 is above the cut-away portion of the probe 440, the portion 437 yields when the pusher returns to the left, and subsequently raises the probe 440 to be engaged by the next forward movement of the pusher. In lieu of the buttons 421 . . . 423 and a fourth button for " figures " indicated in Fig. 7 (not shown), the strip 433, or a strip such as 431, Fig. 11, can be moved by a lever 444 pivoted at 446 and having a concave surfac