Patent GB-152343-A (GB)
Title: Improvements in printing telegraph apparatus
IPC: H04L17/24
Filed: 1920-10-11
Abstract: 152,343. Morkrum Co., (Assignees of Krum, C. L., and Krum, H. L.). Oct. 13, 1919, [Convention date]. Void [Published under Sect. 91 of the Act]. Electric type-wheel machines. -A printing telegraph operated by combinations of code units (as described, a five unit code is used, the units being periods of current and no current, or of positive and negative impulses) has selector plates, means for re-setting the selector operating mechanism (which can be effected before the printing operation is completed), means for rotating the type wheel to the selected position, means for effecting the case-shifting, printing, letter-spacing and linespacing movements, and relay devices for controlling the various operations in predetermined sequence. Type-wheel actions; case-shift mechanism.- The types are arranged in two rows on a typewheel 38, the upper row containing letters and the lower row figures, punctuation marks, &c. The type-wheel is secured to a spindle 39 slidable in a hollow shaft 40 journaled in an arm 41 pivotally mounted on a carriage 44. A collar 61 surrounding, and slidable upon, the shaft 40 is connected to the spindle 39 by a set-screw 62 which passes through a slot in the shaft 40. A fork 64 engaging this collar is normally held in lower position by a spring 193, but is raised when required to bring the lower row of types to the printing position by a plunger 63 operated by a link 66 pivoted to one arm of a bell crank lever 67, the other arm of which has a roller bearing against a pivotally-mounted bar 69. The bar 69 is swung to control the case-shift by a pivoted lever 194, Fig. 5, urged to raise the type-wheel by the core 199 of a solenoid 197 when the latter is energized. The type-wheel is maintained in the raised position by a spring-catch 201 engaging the lower end of lever 194. This catch is released to lower the type-wheel by the core 200 of a solenoid 198 engaging a tail-piece on the catch. Shaft 40 is connected by a universal joint 45, Fig. 1. with a vertical shaft 46, Fig. 3, which is rotated in one direction or the other to bring the selected type to the printing position by bevelwheels 57, 56, the latter slidable upon, but rotated by, a square shaft 54. The shaft 54 has a pinion 73, Fig. 5, meshing with a toothed sector 74 on a shaft 75. The shaft 75 has an arm 78, Fig. 3, connected to two opposed springs. 79, one of which has a tension-adjusting screw 80, which serve to hold the sector 74 in the central position shown. The shaft 54 is also held in central position, or restored thereto after small displacement, by pivoted dogs 123 engaging a shouldered member 122, Fig. 10. The shaft 75 is rotated in one direction or the other by one or other of the cores 82 of two solenoids 83, the cores hearing against a cross-arm 81 on the shaft. The shaft 40 is thus rotated to bring the selected type into printing position. To ensure rotation of the type-wheel 38 with the shaft 40, a projection 65 secured to the shaft passes through an eccentric hole in the typewheel. Rotation of the shaft 40 is limited so as to bring the required type into position, by pins selectively projected into the path of an arm 98, Fig. 6, on shaft 54. The selection is obtained by four selector plates 96 mounted side by side for limited oscillation on a hub, and normally held with a pin 101, which passes through slotted ears 103 on all the plates and limits movement of the plates, at one end of the slot, as shown in Fig. 10. The plates are variously perforated, and in normal position the perforations do not register, so that no pins can be projected through the plates. Under these conditions, rotation of the shaft 54 is limited by a fixed tongue 121 extending through slots in the plates into the path of arm 98. When the plates are selectively oscillated, holes register to allow predetermined pairs of pins to pass through the registering perforations into the path of arm 98. The pins 97 are slidably mounted in a drum having end-plates 111, 112 spaced apart, springs 115 surrounding the pins between the plates and bearing against collars on the pins, holding the pins so as to project beyond plate 111. When the selector plates have been set, the drum is moved bodily towards them, the selected pair of pins passing through the registering perforations. Movement of the drum is effected by a pivoted arm 117 operated upon by a plunger 119 secured to the armature of an electro-magnet 120. The plates are operated by corresponding arms 104 on shafts 105 and urged to hold the plates in normal position by springs 108. The rods 104 are selectively operated to move the plates from normal position by plungers 88 actuated by springs 94, and normally held retracted with the springs 94 in compression by catches 86 tripped bv the cores 93 of corresponding solenoids selectively energized by the code impulses. The two pins 97 projected through the plates 96 retain the plates in the set position, so that the plungers may be re-set. This is done by a pivoted plate 132, the lower edge of which engages collars 95 on the plungers, the plate being rocked to re-setting position by the core 135 of a re-setting magnet 136. The shaft 54 is locked against rotation from central position by pivoted dogs 126, Fig. 5, engaging arms on a member 127 and knocked out of engagement by upward movement of a lever 130 operated when the pin drum is moved towards the seelctor plates. The arm 41 is swung about its pivot to effect the printing bv a link 60 connected with an arm 59 slidable along, but rocking with, a square shaft 55. Shaft 55 is rocked by an arm 145, Fig. 3a, connected by an adjustable link 144 with the pivoted armature arm 143 of a magent 142. Alining for impression.-A cam-operated finger 71, Fig. 3. engages a notched wheel 70 to lock the type-wheel during printing. Letter-spacing and carriage-returning mechanism; carriage-releasing arrangements, - The type-carriage 44 slides along a preferably cylindrical guide 48 and has a roller 51 running along a second guide 52 and retained in contact therewith by a keeper 53. Wheel 56 and arm 59 are carried by the carriage and move freely along the squared shafts 54, 55. Carriage 44 is attached to a cord 170 passing over a pulley 171 to a spring drum 172 which tends to move the carriage to the left. Movement to the right is effected by two rack bars 157, 158, the former fixed and the latter movable longitudinally. A detent pawl engages the fixed bar and prevents movement of the carriage to the left. A similar pawl 161 on the carriage engages rack 158. Rack 158 is moved one letter-space to the left by a plunger 168 engaging a pivoted arm 163 and operated by a magnet 169 which is energized simultaneously with the printing magnet 142. When the magnet 169 is deenergized, rack bar 158 is returned to the right, carrying with it the carriage 44, by a spring 166 acting on arm 163. The pawls are knocked out of engagement with the rack bars, to allow return of the carriage under the action of spring drum 172, by means of a bar 173 having guide slots 175 working over fixed pins 174. Bar 173 engages lugs on the pawls, and is raised by a lever 177 acted on by a plunger 180 when magnet 179 is energized. Line-spacing mechanism.-The paper passes over a cylindrical platen 13, being guided by guides 17, 18, 19 and a scale 23 with guide-fingers 24. The platen spindle has a ratchet-wheel 25, Fig. 4, which is stepped round to effect single or double line spacing by a pawl 26 on a lever 27 operated by a plunger 30 secured to the armature of an electro-magnet 31. A roller detent 37 prevents accidental movement of the ratchet-wheel, and a projection 36 is provided on lever 27 to prevent overthrow. The throw of lever 27 is limited by a projection 32 on a pivoted arm 33 which can be set by hand to either of two positions, and is held in either position by a spring catch 35.