Patent GB-734435-A (GB)
Title: Facsimile recorder
IPC: H04N1/00
Filed: 1953-01-30
Abstract: 734,435. Copying-telegraph receivers. CREED & CO., Ltd. Jan. 30, 1953 [March 29, 1952], No. 2738/53. Class 40(3). Facsimile receiving apparatus comprises an endless belt upon which are mounted a number of stylus units, a first guide member arranged in supporting engagement with the underside of one edge of the belt, a second guide member mounted parallel to, but out of contact with, the other edge of the belt and having a straight edge arranged to engage said stylus units during their scanning travel, and spring means arranged to exert a constant pressure on each stylus while in the scanning position to hold the stylus units in uniform pressure contact with the second guide member during the scanning period. The belt 70 carrying the stylus units passes over a metal pulley 46 keyed to the shaft of a motor SM and over a similar idler pulley 52 adjustably mounted in a bracket 56. Each stylus holder 82 is secured to a block 22 secured by rivets to the belt, and in the zone where the styli 84 engage the recording paper the rear edge of the belt 70 engages the top edge of a rail 120 secured to a steel bar 110 which is itself secured to an insulating block 104 mounted on a supporting member 20. The stylus mem. bers 84 engage the top edge of a steel rail 116 also secured to the steel bar 110 and a leaf-spring 126 mounted on a block 122 secured to the bar 110 engages the upper surface of the stylus holders 82. A modified form of stylus holder and mounting is described in connection with Figs. 22-24 (not shown), and the stylus may be adjusted within its holder, Figs. 22A, 22B (not shown). In a modification, Fig. 24A (not shown), a double leaf-spring engaging spaced points on the stylus holder is employed. The setting of the styli relative to the recording paper is facilitated by a gauge member comprising an arm 140 rotatable to a fixed position and carrying an adjustable anvil member 152, the inner end of which acts as an abutment against which the point of the stylus 84 is set. Paper - feed arrangements.- The recording paper 212 is fed from a roll 181 through a guide channel comprising plates 214, 216 terminating adjacent a platen 236 which comprises a pivoted aluminium bar having bent-over guide-plates and a groove 248 opposite the line of traverse of the stylus 84. A spring 250 stretched between brackets, one of which is shown at 252, Fig. 4, holds the paper 212 against the platen 236 which is normally urged forwardly to its recording position by a spring 270 carried in a block 272<SP>1</SP> secured to a rod 275 having a lever 276 biased in a clockwise direction by a spring 278. Retraction of the platen from the operative position is effected by a lever 290 biased clockwise by a spring 294, and in operation a small motor rotates the lever 290 anticlockwise so that a cord 284 allows the platen 236 to move to its operative position under the action of the spring 270. The feed roller 226 is driven by separate motors at normal and run-out speeds through gears 312, 314, Fig. 32, and oneway clutch mechanisms housed in flange portions 308, 309 formed as extensions of hubs 306, 307 carrying a steel tube 304 in which the rubber roller 302 is mounted. Metering, severing and delivery of recorded paper.-A pinion 356, Fig. 37, on the feed roller shaft, engages a gear 366, Fig. 8, secured to a hub 372 having flanges. 376, 377 forming an annular groove for the coil 378 forming part of a magnetic clutch comprising a clutch armature 394 secured to a hub 390 by screws 395 and a switch cam 396 clamped between the armature and the hub. A stop-arm 400 is clamped to a sleeve portion of the hub 390 and carries a stoppin 402, whose position relative to the lobe of the cam 396 can be adjusted. When the clutch is energized the stop-pin 402 of arm 400 moves away from a pin 410 carried on a stop-disc 370 until the lobe of cam 396 actuates the arm 406 of a two-plunger switch 408 to stop the fast-feed motor. On de-eriergization of the magnetic clutch, the cam and armature assembly are returned to their normal position, with pins 402, 410 in engagement, 'by a band 412, Fig. 37, attached at one end to the hub 390 and at its other end to a spring-actuated drum 416. The setting of the stop-disc 370 is effected by a pulley 434, Fig. 4, in two portions 438,'444 relatively adjustable and carrying bands 436, 437 secured to adjacent portions of the stopdisc 370. When the wheel 432 is set to the position R to feed out a predetermined'length of blank at the end of the message, an operating lever in the path of a pin carried by the hand wheel 432 operates a switch so that the magnetic clutch is energized at the end of the message. The paper is severed at the end of the paperfeed operation by a fixed blade 480 and a movable blade 484, one end of which is attached to a bar 486, which rides on a bar 482 and two similar bars support the opposite end of the blade 484. Parallel movement is given to the moving blade assembly by a rack 498, engaged by a toothed segment 500 in conjunction with a similar rack and segment, mounted on a rocker shaft 502 connected by a crank 504 and slotted link 506 to a pin 509 on a sprocket wheel 510 driven through one revolution by a motor energized by the action of a micro-switch 408. The rotation of the wheel 510 through chain 538 and gears 534, 532, 530, 528 rotates a delivery feed roller 524, and a pair of spring-loaded rollers, one of which is shown at 540, attached to the moving blade 484 urges the severed sheet against the delivery roller. The slot 508 in the ink 506 allows a " dwell " period when the roller 540 and the second roller are in their forward position to ensure that the severed sheet is fed to the delivery roller. An indication that the supply roll is nearing exhaustion is provided by a spring-biased roller engaging the underside of the roll and carrying a rod 566 which in its upper position engages the arm 570 of a micro switch 572 which operates a signalling circuit and also prevents a new cycle of recording until the paper supply has been replenished. Circuit arrangements, Figs. 42, 43.-At the end of the stand-by signal of 12.5 kc., the current flow in valve 587 is increased and relay EMD is energized. The stylus motor SM is initially operated over the A.C. supply. Relay EMD completes a circuit for a tube 622 with a delay provided by elements 625, 626, and the firing of the tube 622 operates a start relay ST by which the driving circuit of the motor SM is transferred to a synchronous power amplifier 604. The start of the phasing signal which follows the standby signal energizes a timer circuit 634 which after a predetermined time, e.g. 2¢ seconds, closes contacts 636, energizing a " rur " relay RR. The contacts 636 are opened at the commencement of the facsimile signals and relay RR brings into operation the platen advance motor 296 and the normal feed motor 330. Operation of relay RR also energizes fast-feed relay FF which locks up over contacts 677, 678 of the switch 408. The endof-message signal, comprising a short pulse of 12.5 kc., causes relay EMD to release, opening the circuit of relay RR which removes power from motors 296, 330. The release of the relay ST is delayed to ensure continued operation of the stylus motor SM between messages transmitted in quick succession. If the switch 470 is in the fixed length position, the magnet 378 of the paper-feed motor is energized when relay RR is released and after the desired amount of paper has been fed by the fast-feed motor 348, cam 396 opens contact 678 of switch 408, releasing relay FF which removes power from motor 348 and clutch magnet 378. The operation of switch 408 closes contacts 696, 697 completing the circuit of knife relay KNF which locks up over knife switch 518. Relay KNF energizes knife motor 514 which operates the movable blade 484 and the cut-message deivery mechanism. After the completion of the operation, switch 518 is opened, releasing relay KNF and removing power from motor 514. If the switch 470 is set to the fixed-length position, the magnet 378 is energized at the start-of-message reception when relay FF operates. When the end-of-message signal is received, the fast-feed motor is brought in, and after the requisite total length of paper has been fed, the cam 396 opens contacts 697, shutting off the fast motor and initiating the knife cycle as before. When message transmission ceases, the stand-by tone holds relay EMD de-energized for sufficient time to allow ST to release and the motor will be disconnected from its two sources of power. When the " low-paper " switch 572 is operated, D.C. is supplied over conductor 602 to a signal lamp 705 and the energizing circuit of relay EMD is opened so that a new recorder cycle cannot be initiated. Specifications 680,661 and 717,726, [Group XL (c)], are referred to.