Patent GB-468839-A (GB)
Title: Improvements in or relating to printing hammers for type printing telegraph apparatus and the like
IPC: H04L17/18
Filed: 1936-01-13
Abstract: 468,839. Printing-telegraphs. CREED & CO., Ltd., and SALMON, R. D. Jan. 13, 1.36, No. 1080. [Class 100 (iv)] Hammer-impression arrangements ; web-guiding arrangements; ; letterspacing mechanism.-In type - printing telegraph and like apparatus, a printing-hammer, carried by a lever extending parallel to the axis of the type-wheel and to the upright direction of the characters carried thereby, is placed above the type-wheel, an ink ribbon and paper strip are interposed between the hammer and type with the paper next to the type, and the ink ribbon and paper strip are moved at rightangles to one another. The type-wheel 81, Fig. 1, slides on a square shaft 82 and is set by the action of detent-levers and a train of sun and planet gears described in Specification 466,815 [Group XL]. After the type-wheel detent-levers have been operated, the levers 2, Fig. 4, are operated and permit a pawl 45 to engage a rotating wheel 46. The disc 47 on which the pawl is mounted makes a half-turn before the pawl is disengaged by the second lever 2. During this motion and while the type-wheel 81 is still rotating, a cam 42 operates a lever 41, whose other end is forked at 62, Fig. 1, to engage a roller 61 on a lever 79, pivoted at 80. The lever 79 is connected by a spring 70 to a lever 97, Fig. 5, also pivoted at 80 and carrying, by means of a pivot 87 a hammer 86 which is also connected to the frame by a link 77. The lever 97 is at first restrained by a pawl 74 engaging a projection 75 on the frame, but, after an interval, the pawl is cammed back by an adjustable cam 71 on the lever 79, and the lever 97 then flies forward and an anvil 88 on the hammer 86 makes impression in a direction perpendicular to the type face. The pivot 85 of the link 77 is adjustable round the pivot 80 and the pivot 80 is carried on a bracket adjustably mounted on a pivot 93, in the plane of the type-face. The lever 41 also raises, by means of a springily connected link 20, Fig. 4, a lever 24 which carries a corrector 22. As soon as the type-wheel comes to rest the corrector engages a wheel 68 secured to the shaft 82 of the type-wheel. The paper strip 102, Fig. 1, is fed over the type-wheel by a roller mounted on an axle 31, Fig. 4, and driven by a ratchet-wheel 30. A blade 106 separates the paper from the type-wheel after impression. A trunnion-block 5 on the lever 41 moves loosely in a slot in a lever 39 to which is pivoted a pawl 18, pressed into contact with the ratchetwheel 30 by a spring 38. The lever 39 is pivoted between spring-pressed collars so that it will lag behind the trunnion 6. During the return movement of the lever 41, after lost motion at the slot in the lever 39, the pawl 18 feeds the paper strip. An overthrow stop 19 and a detent pawl 35 are provided. Mounted on the axle of the sun-gear 100 are three notched discs 50. During certain operations, the pointed end 7 of a lever 12 falls into a notch on one disc 50 and a depending tail 17 is placed in the path of an abutment on the lever 97 and prevents impression. Case-shift mechanism.-The type-wheel is slidden on the axle 82 for case-shift by a lever 83, Fig. 1, connected through a link 66 to a bell-crank 13 pivoted on a boss 53, Fig. 4. The lever 13 is actuated by a link 9 pivoted to a rotating disc. During case-shift in either direction, one or other of two cams on the boss 53 engage one or other of two levers 54, which have pointed ends engaging in notches on two of the discs 50. Whichever of the levers 54 is allowed to fall into its respective notch by the boss 53 engages a lever 57 and thereby moves a lever 59. The lever 59 engages a pin 32 on the pawl 18 and disables the paper-feed. A link 8 prevents too great extension of the spring 38 during disablement of the pawl 18, so that on its release it will engage the correct tooth of the wheel 30.