Patent GB-289071-A (GB)
Title: Improvements in or relating to printing mechanism, particularly applicable to record-card-controlled statistical machines
Filed: 1928-04-21
Abstract: 289,071. British Tabulating Machine Co., Ltd., (Assignees of Carroll, F. M.). April 22, 1927, [Convention date]. Statistical machines.-In a selective-printing mechanism, particularly for recordcontrolled statistical machines, comprising, as described in Specification 204,676, a rotary carrier supporting pivoted typebars, each type-bar is provided with a number of type and means, for instance platen-shift mechanism, is provided for selecting any of the types. The printing-mechanism may be controlled by record cards, and when cards of the Peirce type are employed, the card-reading means may be arranged to transmit one or more impulses to a translator which is adapted to synthesize the impulses in a single timed impulse for the selection of a type. The cards may control accumulating mechanism adapted during re-setting to transmit the amount to the printing-mechanism. In the mechanism shown in Fig. 14, type-bars 265 pivoted on a rotary drum 61 are, as described in the above-mentioned Specification and in Specification 280,580, selected for impression on a platen 62 by means of devices comprising rotary cams 267, and a hook-lever 270 which is normally retained by a lever 287 engaging a latch 278 operated by a magnet 269. The type-bars are now provided with three types 266 and the platen is mounted in a pivoted frame 290 which can be depressed in opposition to a spring 291 by means of a cam 294 engaging a lever 292. The cam has three dwells of different radii corresponding to the normal and two shift positions of the platen. The cam is clutched, under control of a magnet 295, to a shaft 296 making one revolution during three cycles of the machine, and during these cycles the platen occupies the normal and two shift positions respectively. The drum 61 rotates once during each cycle, and a. type-bar is selected during each cycle, the normal or shift types being selected according to the position of the platen. The printing-mechanism may be controlled by Peirce cards having six hole-positions in a column, the characters being represented by one, two, or three holes. The cards are read by upper or control analyzing- and lower or adding analyzing- brushes. Two fields of perforations may be placed one below the other on a card of the usual size, the brushes being duplicated to read simultaneously from both fields so that items in the two fields can be transmitted to different accumulators and printers. The cards control translators, Figs. 4 and 7, each arranged to receive one or more impulses from a brush and to synthesize these impulses in a. single timed impulse for typeselection. The translator comprises a set of six notched discs 300 which make one revolution during every three cycles. The discs and interposed friction-discs 303 are mounted on a sleeve 301 and are clamped between a plate 326 and a flange 326, the sleeve being revoluble on a stud 302. Studs 327, passing through holes and short slots in the disc 303, 300 respectively, permit of slight relative movement of the discs 300. Associated with the set of discs 300 and revolving synchronously therewith is a set of discs 299 mounted as a unit on a stud 306 and each having a projection 307. The translator is controlled by a magnet 310 which is energized momentarily when the brush enters a hole in the card. The pivoted armature 316 of the magnet engages loosely with freely mounted levers 313 each having a lug 314 co-operating with one of the projections 307, and a lug 319 which normally disengages a pawl 320 from the associated disc 300. When the hole-positions in the card pass the brush, the corresponding levers are raised by the projections 307, and if holes occur, the magnet is energized and the levers fulcrum on the armature and are rocked to release the pawls. The released pawls ride on the discs until they enter deep notches 323, whereupon a bell-crank 328, operated by a projection 329 rotating with the discs 300, rocks a pivoted member supporting the pawls. Thereby the released pawls compel the associated discs 300 to shift slightly relatively to the other discs, and the discs then present a combination of six aligned notches corresponding to the character represented by the holes in the card. For any character, the notches on the discs that are not shifted in the selection of the character are normally in alignment. During the further rotation of the discs, a spring-urged feeler or selecting-member 342 pivoted on a rocking arm 341 enters the aligned notches and a finger 340 on the feeler rocks into engagement with a stop. Thereupon the arm is rocked and by means of a rod 346 closes the contacts 347 of the magnet 269, the energizing of the magnet causing the selected type-bar to be operated. The discs 299, 300, drum 61, and cam 294 are so timed that the type-bar is selected during the cycle in which the platen is in proper position to receive the type represented by the aligned notches. When the discs 300 have almost completed a revolution, a pawl 350 is rocked by a rotating projection 351, and an arm 352 of the pawl enters notches 353 and restores the shifted discs to the normal position. The notches in the discs 300 are so arranged that the combinations of six aligned notches representing the characters are divided into three groups corresponding to the upper types and shift types on the type-bars, the first group containing all the numerals. The record cards are fed from the bottom of a magazine by means of a reciprocating picker and are moved past upper and lower reading-brushes by means of feed-rollers. The cards are then diverted by a reciprocating arm to other feed-rollers and are delivered to a stack which is arranged directly beneath the magazine to facilitate access. The feeding-mechanism delivers one card at every third cycle of the machine, but is so arranged that when the machine is started and no card is under the upper brushes, the first card is fed to the upper brushes during the first cycle, and from the upper to the lower brushes during the next cycle. The driving-shaft 191, Fig. 18, for the card-feeding mechanism is driven through a clutch C from a shaft 195 which is driven through a clutch A and equal gears 193, 192 from a shaft 190, making one revolution during each cycle. The shaft 195 also drives a shaft 201 through a clutch B and gears 200, 199, the shaft 201 running at one-third the speed of the shaft 195. The clutch A consists of a fast disc 198 provided with a spring-urged pawl 212 which is normally prevented from entering a notch 211, Fig. 21, in a disc 196 on the loose gear 193 by means of a latch 213 engaging the tail of the pawl. The latch is mounted on an arm 225 on a shaft 231 provided with a spring-urged hook 215 normally engaging a hook 217<a> on the pivoted armature 217 of a magnet 218. The arm 225 has pin-and-slot engagement with an arm 234 on a shaft 262 provided with a spring-urged arm 227 having a bevelled end for engaging the tail of the pawl. When the magnet 218 is energized, the hook 215 is released and the pawl is permitted to enter the recess 211, the tail of the pawl snapping over the arm 227. The tail then abuts on the arm and a cam surface 220 in the recess turns the pawl and causes the disc 198 and shaft 195 to start without shock and turn with the disc 196. When the shaft attains the same speed as the disc 196, the pawl abuts on an undercut part 233 of the recess, and a second pawl 221 enters the recess and abuts on a shoulder 222. For declutching the shaft 195, the disc 198 has a pin 223 which, once in each revolution, rocks the hook into position for engaging the hook 217a, the armature being connected by a link 237 to a lever 238 engaging a disc 239 on the shaft 201. After the first and second revolutions of the shaft 195, following the starting of the shaft 201, projections 241, 242 on the disc 239 lift the lever 238 and prevent the hook 217 from being caught. Towards the end of the third revolution however, the hook 215 is latched by the hook 217<a>, and the tail of the pawl rides over a spring 233<a> on the arm 234, the pawl being thereby released from the disc 196, and the shaft 195 being de-clutched. The shaft then moves by momentum until a projection 243 on the disc 198 engages a spring-pressed braking-arm 228, and thereupon the tail of the pawl is caught by the latch 213. The arm 228 then rides on the projection 243 and forces the tail of the pawl into firm engagement with the latch 213, the shaft 195 being thereby held in the next position. The clutch B is controlled by a magnet and is similar to the clutch A, but the loose disc 202 has three notches for engaging a pawl on a fast disc 203. The clutch C is similar to the clutches A, B, but is controlled by a cam 252 on the shaft 201, the clutch hook 247 co-operating with a pivoted hook 249 which is connected by a link 250 to a lever engaging the cam. The circuits of the brushes and magnets are arranged in the manner described in the above-mentioned Specification 280,580. If the machine is started with no card under the upper brushes a circuit is established for two cycles by a timing-device, the magnet 218 is energized, and the shaft 191 makes two revolutions with the shaft 195 to feed a card to the lower brushes. The magnet of the clutch B is then energized and the clutch starts the shaft 201, so that the cam 252 is effective through the clutch C to arrest the shaft 191 during the next two cycles. Thereafter, control of the magnet 218 is transferred to an automatic-control circuit, and, so long as the shaft 201 continues to rotate, the cam 252 causes the clutch C to drive the shaft 191 through one revolution during one of three cycles. If the machine is started with a card under the upper brushes, a circuit is established through another timing-device, and the magnet of the clutch B is energized slightly after the magnet 218, so that when the card has been fed to the lower brushes,