Patent GB-571492-A (GB)
Title: Improvements in or relating to punching machines for perforating statistical record cards
Filed: 1944-02-22
Abstract: 571,492. Selective punching machines. BRITISH TABULATING MACHINE CO., Ltd. Feb. 22, 1944, No. 3266. Convention date, Feb. 24, 1943. [Class 31 (ii)] A machine for perforating statistical record cards is constructed so as to produce perforations in record cards corresponding to perforations in a master card, and other perforations may be formed in columns of the record cards under control of settable elements actuated by a typewriter keyboard, or a numerical keyboard, and in producing the record cards the punches thereof are controlled by the master card when a hole in the master card is sensed, but if no hole is sensed the punches are controller solely by the settable elements. The master card M, Fig 13, is attached to a card carriage which is advanced intermittently under control of an escapement mechanism, and the cards to be perforated are fed from a stack to this carriage by a picker 11, the general arrangement of the machine for punching the cards being of a construction such as is described in Specification 362,529 for producing a number of similar copies from a master card. The present machine is adapted to reproduce on a series of cards C, Fig. 23, perforations in columns b, e which correspond to the perforations in the columns b, e of the master card M, and also to produce perforations in other desired columns such as a, d, g of card I and a, f of card II, and a, c of card III which are distinctive for each card and are controlled by the operation of typewriter keyboard selective device 131, and a numerical selective keyboard 117. The keyboards are fitted with keys for effecting such operations as "release," "skip," or correction of error. The key 135, 124 which are indicated diagrammatically in Fig. 24, control the setting of blades 228 on a drum 223, Fig. 1, the blades 228 being shown diagrammatically in Fig. 24a. The setting of the blades can be actuated to a limited extent in advance of the control of the perforations by the master card, and can continue independently of the control of the perforations by the set-up blades during the production of the record cards. The blades 228, Fig. 1, are insulatedly mounted in a drum 223 fitted with a wheel 222 which is advanced intermittently through a thirtieth of a revolution by a pin 271 on a shaft 208 driven by a one-revolution clutch comprising a spring- pressed radial tooth which engages a constantly driven internal ratchet under control of an electro magnet, and is released by cam action. The blades 228, Fig. II, are normally engaged by hooks 227a on similar blades 227 as shown to the right in Fig. II, and so do not engage contacts 290 on a read-out bar 286. Under the action of magnets 237, Fig. I, the blades 228 are released, and then they cause the operation of magnets 154, Fig. 24a, which operate the perforating devices 159, Fig. 14 not shown, which control the perforations as described in Specification 362,529. Means are described for resetting the blades 228 after they have effected their control, and also for back-spacing and eliminating errors. The blades are re-set by a cam 239, Fig. I, on the shaft 208 which engages a roller 240 on a lever 241, and causes operation of a pair of levers 244, 246 connected by a link 250 fitted with fingers 249 which re-set the blades 228. The armatures of the magnets 237 are reset by pins on the link 250. The read-out mechanism comprises a tubular rod 286, Fig. I, supported by arms 287, 288 carrying contacts 290 which coact with the set blades 228. The arms are advanced at the same rate as the drum when receiving entries but can be moved independently of the drum. The read-out operations may begin at any time after the rod 286 has left a given position, and the rod steps back toward this position while the entering continues. The rate of receiving entries is controlled, and at a given point no further entries can be received until operation of the readout devices. The electric circuits for controlling the operations are shown in Figs. 24, 24a, 24b, and when the main switch is closed the main driving motor N' is permanently energized. In Fig. 24a are shown the circuits connected with the contacts 101 which sense the perforations in the master card, and make contact with a roller 105, and also the circuits connected with the storage drum blades 228 and the contacts 290 of the bar 286, and also the arrangement of the punch control magnets 154. Fig. 24 shows the circuits connecting the magnets 237 and the keyboards 124, 135, and Fig 24b shows the various switches and relay devices for controlling the operation of the magnets, The switching over of the control from the brushes 101 and the perforations in the master card M, to the control by the storage drum blades and the contacts 290 on rod 286 is effected by a high speed electronic relay arrangement, and operates as follows. As brushes 101 encounter the first perforated position of a column of card M, which takes place before the floating cam contacts 149 close, positive voltage from line 312 is applied to the starter and main plates of a valve 328 of the gas-filled relay tube. The valve ionises and impresses a positive voltage thrust on the grids of valves 330, 331 which become conductive and energize relays R51, R56 in their respective plate circuits. Relay R51 opens contacts R51a to open the circuits of the read-out escapement magnets 300. The floating cam contacts 149, 149a close soon after the above action and put a negative voltage on the plates of valve 328 which then stops conducting. A condenser resistor network 322 acts to put a lag on the application of the negative pressure and so maintains relays R51, R56 energized as long as the columns in the master card M are perforated. When no perforation is sensed in the card M the relays R51, R56 are de-energized and the negative bias is imposed and the contacts return to the position in which the perforating magnets are controlled by the storage drum blades.