Patent GB-720475-A (GB)
Title: Improvements in or relating to type bar checking interpreter for record controlled printing machines
Filed: 1951-10-18
Abstract: 720,475. Record-controlled printing machines. INTERNATIONAL BUSINESS MACHINES CORPORATION. Oct. 18, 1951 [Dec. 4, 1950], No. 24321/51. Class 100 (4). [Also in Group XIX] In a record card controlled typebar machine in which rows of sliding type-bars 45 are selectively moved to print on record cards 24 previously sensed, the setting of the typebars is checked by the comparison of two circuits one of which is set up by the position of the type-bars and the other by a supplemental sensing station 90, 91 positioned between (i) a normal sensing device 31, 32 effecting the setting of the bars; and (ii) the printing position 81: the circuits are concurrently set up and non-agreement suppresses printing. The machine is similar to that described in Specification 535,740, but has the supplemental sensing station comprising sensing brushes 90 and a co-acting common strip 91. These brushes set up the first comparison circuit at two points of a machine cycle later than sensing by the type-bar setting brushes 31. A complete machine cycle comprises thirty-two points. The detection of a perforation by a brush 90 increases the potential on the grid of a thyratron 95, Fig. 6, by a circuit from supply line 92, cam contacts CB1, CB2, closed by cams on a shaft of the driving mechanism, cam, contacts CC3 (closed), contacts R44c which are closed when the machine is running and when record cards are passing through the machine, strip 91, brush 90, and contact R11d to the thyratron. The increased potential fires the thyratron and relay R9 is energized and operates contacts R9b in a circuit at the top of Fig. 6a, which, if completed by contacts R11b controlled by the second comparison circuit set up by the position of type-bars, arranges for a hammer impression to be made. Figs. 6, 6a show the arrangement for four columns only and agreement of all four pairs of contacts is necessary for printing. The second comparison circuit is operated by the type-bars 45, Fig. 1, moved to left by a crossbar 47 until a pawl 59 (released by a magnet 58 operated from the sensing brushes 31) engages a notch 60. Continued movement of the cross-bar 47 causes a pawl 46 to ride down a cam surface 163 and so depress a plunger 160 to operate a T-shaped lever 164 carried by parallel links 165 and close type-bar contacts 168a arranged in staggered formation for adjacent columns. The time delay between the sensing by brushes 31 and the closing of contacts 168a is two points of a cycle so that they operate simultaneously with the sensing of the card by the supplemental sensing device. Contacts 168a in the various columns, four of which are shown at the foot of Fig. 6, effect the operation of a relay R11 whose contacts R11b, Fig. 6a, complete a hammerrelease solenoid circuit. With both contacts R9b, R11b (or the equivalent) of all columns operated, cam contacts CC5 are short-circuited so that, when these contacts open, a relay R45 is maintained operative. Relay R45 is operated by a circuit associated with the starting and running of the machine motor, and if the two circuits do not compare, relay R45 is released when cam contacts CC5 open and cause the machine motor to stop. With relay R45 operative, a test impulse is sent from cam contacts CC7, R44b (operated), R45b (operated) to a solenoid 89, Figs. 1 and 6a, unlatching the hammer 72 for operation. If relay R45 had been released, the test impulse could not operate solenoid 89. Circuit arrangements also prevent printing, if (a) supplemental sensing relay R9 be energized before the normal sensing relay R11; (b) relay R 11 is energized before R9; (c) a record card is out of alignment with the sensing brushes; (d) the hammers have not actually been released by the solenoids 89 for cam operation; (e) no perforations in any column in the 1-9 index point positions are sensed; and (f) a card is punched with a zero in all columns. Specification 656,485 also is referred to.