Patent GB-190408540-A (GB)
Title: Improvements in Printing Telegraph Receivers.
Inventor: SWIFT FREDERIC JOSEPH
Filed: 1904-04-13
Granted: 1904-09-08
Abstract: 8540. Swift, F. J. April 13. Telegraphs.-Relates to the receiving instruments in page-printing telegraphs. Fig. 1 shows the apparatus in side elevation. The type-wheel I is carried by a shaft which rotates with the tubular shaft H, but can be raised by means of the electromagnet T and lever 78 for change of " case." The electromagnet U serves to release the latch 80 and to allow the type-wheel to fall after it has been raised by the electromagnet T. The shaft H tends to rotate under the impulse of a spring drum and suitable gearing, which includes bevel-wheels l, o. The spring is continually being rewound by means of ratchet gearing operated by an electromagnet which is energized whenever a character is printed. The shaft H bears an arm G which is arrested by means of pins E, one of which is lifted whenever one of the letter-selecting magnets D is energized. The pins E are guided in fixed plates s, F between which is a plate u capable of a limited rotary movement. The plate u is provided with perforations of such size as to allow the collars x on the pins E to pass. Normally the plate u is turned sufficiently to lock the pin E, which has been lifted, against return, and to lock all the other pins in their normal or depressed position. Whenever one of the letter-selecting electromagnets D is energized, the electromagnet P is also energized, and a rod 2 with coned head 3 shifts the plate u sufficiently to allow the new pin to be lifted and the pin previously raised to return. The impression is made by means of a hammer J which turns about a shaft 19. When the " printing- " magnet " Q is energized, the armature 13 is attracted and the rod 15 pushed forwards, rocking the arm 18 and shaft 19 and allowing the hammer to make the impression under spring tension. The hammer is positively withdrawn when the rod 15 returns. The paper-carriage P<1> is advaoced through one letter-space, after each impression has been made, by means of a pawl 28 and ratchetwheel 29, the gear 35 transmitting the movement to the carriage rack 36. At the end of a line, the electromagnet R is energized and the armature 37 and clutch-piece 39 depressed, a spring which has been wound up within the drum 31 serving to return the carriage in readiness for the commencement of a fresh line. The inking-ribbon spools are carried on shafts 47 actuated by the pawl 42 and gearing 45, 46. The paper is held between a feed roller 53 and an idle roller 54. The feed roller has a ratchet connection with a pinion 63 gearing with a rack 60, actuated by a bar 59 overhung by the hooked end of a lever 57. By means of a "line-spacing" electromagnet, the link 56 can be pushed forward and the bar 59 depressed. To prevent overthrow of the feed roller in line spacing, a locking-pawl controlled by the bar 59 is adapted to prevent the ratchet-wheel on the feed roller from advancing more than one tooth when the pinion 63 is turned. The printing-wheel is locked at the instant of impression by means of a pawl 70 actuated by a finger 69 extending from the arm 18. A dash-pot cushions the return stroke of the carriage. It consists of a cylinder 72, Fig. 15, containing a plunger 73 which is pushed in by the plunger rod 74 on the carriage, and is engaged by the hook 76 for a sufficient portion of the return stroke to bring it back to the position shown in the Figure. A " spacing electromagnet " is provided for locking the hammer J so as to allow the carriage to be spaced forward without an impression being made. The instrument may be operated through any suitable circuits and connections.