Patent GB-379273-A (GB)
Title: Improvements in or relating to printing telegraph apparatus
IPC: H04L17/24
Filed: 1931-05-14
Abstract: 379,273. Type-printing telegraphy. CREED & CO., Ltd., Telegraph House, Croydon.-(Teletype Corporation; 1400, Wrightwood Avenue, Chicago, U.S.A.) May 14, 1931, No. 14255. [Class 100 (iv).] Relay type-wheel actions; case-shift mechanism; hammer-impression arrangements.-In a printing-telegraph receiving-apparatus, a selectormember which is normally in rotation is arrested whilst effecting its selective functions in accordance with the received combination of electrical conditions representing a character. The selector-member, which comprises a shaft formed with a number of helically arranged selector cam-pins 51 .. 56 and a shutter-ring campin 58, is normally rotated by the engagement of a cam-pin 57 with a driving-projection 82 on a flange 17 secured to a shaft 9 constantly rotated by a motor 2 through gears 3, 4, 7, 8 and carrying a rigidly mounted type-wheel 16. The initial impulse of a signal combination operates the line magnet 75 so that the shaft 59 is moved to the left, Fig. 3, disengaged from its driving connection, and brought to rest by a brake band 87. In accordance with the signal impulses, the shaft 59 is moved longitudinally so that the stationary cams are sequentially in engaging or non-engaging position with respect to a number of selecting- fingers 37a .. 37f mounted on a spindle 36 secured to the rotating flange 17. The fingers 37a .. 37f which are individual to a shift-ring 23 and to the selector-rings 24 .. 28 are normally in engagement with shoulders 40 formed on the rings. In the actuated position, the fingers are moved out of engagement with the shoulders 40 into engagement with shoulders 41 and are latched by members 45a .. 45f mounted on a shaft 46 secured to the flange 17. The rings 21, 22, 23 and the selectorrings 24 .. 28 are mounted on rollers carried on shafts 18 secured to the flange 17 with respect to which their movement is limited by a stop member 32 extending across slots 33. The shutter and cam rings are secured together and a stop member 30 extends across slots 31 in the rings 23 .. 28 to limit their relative movement. At the end of a signal combination, a finger 37g invariably trips the shutterring 22, and the actuated rings 23 .. 28 are moved under their individual springs 34 and a bail 37h locks the rings in their selected positions. The slight rotations of the selectorrings bring peripheral notches into alignment in accordance with the corresponding positions of the characters on the type-wheel 16. The latches 45b .. 45f, of which only one is shown, are arranged in relation to the cam-pins so that the unlatching of the actuated fingers 37b .. 37f in either position of the cam-shaft 59 is effected by the cams 52 .. in advance of the reception of the subsequent signal combination being received. The latch 45a is restored by the start cam-pin 57 simultaneously with the restoration of latch 45b by cam 52. The flange 17 and shutter-ring 22 are formed with peripheral notches corresponding to the positions of characters on the type-wheel 16, and relatively arranged so that until the tripping of the shutter-ring 22 at the end of a code combination, the seekers 94, 95 are prevented from moving inward to initiate the printing operation. The printing-mechanism is selectively controlled for letters or shift characters by the operation of the shift-ring 23 and is set into operation by seekers 94, 95, one or both of which fall into the aligned notches after the operation of the shutter-ring. The mechanism is arranged so that for letters the seeker 95 alone is operated, whilst for the shift characters, the seekers 94, 95 are brought into action simultaneously. For the printing of a letter when the rings and type-wheel have rotated to the position in which the seeker 95 falls into the aligned notches in the selector-rings and in the cam ring 21 and flange 17, a lever 112 is tripped, and causes a bell crank 119 to rotate a shaft 120 carrying the platens 153, 154, a hammer anvil 125, and the tape-feed mechanism. The rotation of shaft 120 and depression of a member 129 raise the platen levers 130, 131 and, as shown in Fig. 12, an extension 160 on the platen arm 131 engages the extension 127 of the hammer anvil 125, preventing the upward movement of the platen 154, and allowing the platen 153 to press the tape 152 against the type-wheel 16. For the printing of a shiftcharacter, the shift-ring 23 will be rotated so that its notches align with those of the flange 17 and of the rings 21, 22, but the arm 114 is prevented from movement until the seeker 95 has found the aligned notches of the selectorrings and freed the arm 116 which normally holds 105, 114 latched. On the operation of seeker 95, the shift-seeker 94 falls into a set of aligned notches and trips a lever 105, which releases a bell crank 114 to rotate the shaft 115 carrying the hammer anvil 125 into the position shown in Fig. 13. As in the case of letter printing the shaft 129 is depressed, but the surface 158 of the extension 157 of platen member 130 is arrested by the anvil 126, so that platen 154 is pressed against the tape 152. The restoration of the cam and selector rings forces the seekers 94, 95 outwards, resetting the latch members 105, 112, which return the shaft 129 and step the tape by a ratchet wheel 139 engaged by one of two pawls 143, 144 pivoted to the members 130, 131. Specification 218,643, [Class 100 (iv), Typewriters &c.], is referred to.