Patent GB-580882-A (GB)
Title: Improvements in or relating to printing telegraph apparatus
Inventor: SALMON REGINALD DENNIS
IPC: H04L17/24
Filed: 1944-01-15
Abstract: 580,882. Printing telegraphs. CREED & CO., Ltd., and SALMON, R. D. Jan. 15, 1944, No. 803. [Class 100 (iv)] [Also in Group XL] A printing-telegraph receiver comprising a type-wheel provided with a plurality of rows of type normally out of the printing position to leave the printed characters visible as described and claimed in Specification 524,342, incorporates means effective for every printing operation to bring the selected row of type into and out of the printing position, in a motion which is approximately simple harmonic. The appropriate row of type is selected by the actuation of one of a number of levers having different ratios and corresponding to the rows of type. The axis of the type-wheel is approximately at right-angles to the axis of the platen and is mounted in a carriage which is traversable parallel to the axis of the platen for letterspacing. The receiving selector arrangements are mainly similar to those described in Specification 228,842, [Class 100 (iv)], the received signal being successively applied to selector members 21 through cams 16, 17, a pin 13 and striker lever 19 reciprocated by a cam 18. The movements of the members 21 are transferred to selector bars-23 positioning discs 28 so that a stop member 29 drops into aligned slots to arrest the type wheel in the appropriate position. The type wheel 41, Fig. 1A, mounted on shaft 42 is driven from the shaft 40 coupled to shaft 33 through a clutch 34 and shockabsorbing coupling 39 as described in Specification 563,221. Between the hub 38, Fig. 2, and sleeve 52 carrying gear wheel 53 meshing with bevel gear 50 on the type wheel shaft is interposed a self-aligning coupling, Fig. 4, comprising a thin sleeve 55 with keyways 56, 57 engaged by keys 59, 58 on sleeves 54, 52. The interior of sleeve 54 is filled with lubricating material 60. The printing magnet 69 releases a cam sleeve 70 having its cam groove 71 in the form of a sine-curve and through lever 73, extension 75 of a frame 76 bail 77 and lever 78 raises the type-wheel to the printing position. Case-shift; inking mechanism. For a lowercase character, the lever 103 is released by the magnet 100, 101 and transmits greater movement to the. extension 75 whereby the typewheel is lifted to'bring the lower ring of characters into the printing position. At the same time a lever 73 moves a lever 80 and shaft 81 which through levers 82, 83 engage the ends of a frame 84 carrying the inking ribbon 85. Cam 86 on sleeve 70 moves lever 87 and printing bail 89 which operates lever 90 and printing hammer 91 to move the corresponding type against the inking ribbon and paper 93 carried on platen 61 as described in Specification 559,466, [Group XL]. A lever 98 engaged by a lever 83 reciprocates a pawl 99 of an ink ribbon feeding and reversing mechanism constructed as described in Specification 457,821. Letter spacing. A magnet 110 controls a cam sleeve 112 which moves a slidable rack 114 engaged by a pivoted pawl 115 attached to the type-wheel carriage and a further pawl 116 engages a fixed rack 117 to hold the carriage in position. A steel tape 118 is attached to a post 119 on the carriage and to a drum 120, Fig. 1. Carriage release mechanism shown in Fig. 3, comprises a cam 121, operated by a carriage release magnet (not shown) which moves a bar 122, arranged between the racks 114, 117, Fig. 1A, and carried on pins 123, 124 located in inclined slots 125, 126. When bar 122 is moved to the right and upwardly, the pawls 115, 116, are raised, allowing the carriage to return and the bar 122 is released to return to its normal lower position by a member 136 on the type-wheel carriage striking the arm 128 of a latch member pivoted at 129. Carriage return is cushioned by the engagement with a lever 133 connected to a dashpot 135. Line-feeding mechanism is controlled by a magnet 137 which releases a cam 138 to actuate a pawl 140 and ratchet wheel 141 on the shaft of platen 61. The provisional specification describes a typeprinting telegraph receiver identical with that described in Specification 563,221. Specification 545,317 also is referred to.