Patent GB-575846-A (GB)
Title: Improvements in or relating to printing mechanisms
IPC: G06K15/08
Filed: 1944-04-14
Abstract: 575,846. Typewriters. B R I T I S H TABULATING MACHINE CO., Ltd. April 14, 1944, No. 6950. Convention date, April 21, 1943. [Class 100 (iv)] A typewriting machine, which is especially applicable for use with record-controlled tabulating machines as described in Specification 375,889, [Group XIX], is constructed with a reciprocating type-carriage 81 containing a row of type members 90, Fig. 6, from which impressions are taken on a sheet 440, Fig. 5, which may be divided into as many as 109 columns. The type members comprise three complete sequences of 43 type characters and 22 additional type in the same sequence. The sheet passes over a platen 56 which is moved for line spacing in a known manner, and the ink ribbon 49 arranged and driven by conventional means. The types are moved to print by means of hammers 100 which are retracted by a shaft 120, Fig. 8, having a flange 121 engaging shoulders on the hammers. All the hammers are withdrawn simultaneously, and a selected number are held in cocked position by means of dogs 123, 124 which engage notches 127, 128 in the hammer under control of latching bars 130, 130a, operated by levers 136, 140, under control of selective storage mechanism comprising bars 160-1, 160-2... 160-6, Fig. 22, mounted in frames 160, 161 which are oscillated in unison with the operation of the hammer shaft 120. The storage mechanism controls the printing operations in the next cycle of machine operations. There are a number of sets of storage bars, and by the energization of electric magnets 240 certain of the bars, e.g. 160-1, 160-4 in Fig. 22 are raised above the other bars by the action of cam pro - jections on toes 193 of the bars which are brought into engagement with the cams by the lowering of stirrup 170 upon energization of the magnets 140. The whole machine is driven by an electric motor under control of a hand-switch, and the drives of the printing mechanism, and the means for feeding and delivering the tabulating cards which control the selective printing are controlled by electromagnetically operated clutches. The tabulating cards and the circuits which they control are similar to those described in Specification 523,832. Only the raised bars 160-1, 160-4, engage the levers 136, 140 to actuate the latching-bars 130, 130a. There are a series of latching bars arranged alternately. The bars 160-1 &c. are formed with transverse bars 160a-1, 160a-2 &c., and the raising of bars 160-1, 160-4 brings the bars 160a-1, 160a-4 into position to engage the pins 390-1, 390-4, of a control device for releasing selectively the printing hammers. The pins are associated with a permutation bar 300, Fig. 6, which is reciprocated in a direction parallel to the axis of the roller 56, and is connected to and moves with the type carrier 81, being reciprocated by a pair of shafts driven in opposite directions and fitted with grooved spiral cams in which can engage a roller connected to the permutation bar. The permutation bar is also given vertical movements as it reciprocates, and a lost-motion device connects the type carriage to the bar 300. This bar comprises a central web 301 on each side of which are projections 302-1, 302-2 &c. of substantially triangular section, and the bases are formed with series of inner grooves 382, Fig. 33, and outer grooves 381 connected by flat portions 380. The pins 390-1, 390-4, which effect the control of the printing, are moved by the bars 160a-1 &c., so that their heads 395, 396, 397 &c. move into adjustment with the grooves 382, and the other heads engage normally with the flat portions 380 except at certain times when a clearance is to be effected. Associated with the ends of the pins 390-1 &c. are yokes 400 which are raised and lowered by the action of the grooves 382 and 381. The yokes 400 are connected to spring-controlled hooks 405 which tend to engage shoulders 408 on the latches 123, 124, but are prevented from such engagement while any of the heads of the pins 390 engage a flat portion 380, and the yokes only rise when all the pins of a series engage with either the control recesses 382 or clearance recesses 381. The consequent engagement of a hook 405 over the shoulder of a latch is followed by a depression of the yoke and hook with release of the latch and operation of a printing-hammer 100 by means of a spring lever 105 the movement of which is controlled by a stop device 114 acting upon an arm 113 of lever 105. The bars 160-1, 160-2 &c. are re-set by means of a projection 420 R, Fig. 16, on a shaft 421 R, and the other set which controls the storage pins on the lift side of Fig. 6 are re-set by means of a similar projection 420F on a shaft 421F. The type members 90 are operated against the action of restoring springs 91, and to prevent blurring the types can move about vertical pivots 95 to compensate for the longitudinal movement of the types relatively to the platen 56. The types are re-set so as to start normal to the platen by the engagement of tapered sides with slots in the type casing. The storage device may be set from record cards in which the data to be printed are recorded in either a 12-point or a six-point code. The control pins are re-set at each cycle of operations by means of cam surfaces 430, Fig. 33, on the permutation bar 300 when this is given a vertical movement. The machine is constructed so that the character spacing can be adjusted on the record sheet by changing the time of release of the hammers by their latching dogs. By operation of a detent 490 the control of the printing of zeros may be made dependent upon the occurence of a significant digit to the left.