Patent GB-452451-A (GB)
Title: Improvements in or relating to record-card-controlled printing mechanism
IPC: B41J9/44
Filed: 1935-02-22
Abstract: 452,451. Typewriters &c. BRITISH TABULATING MACHINE CO., Ltd., Victoria House, Vernon Place, Southampton Row, London. Feb. 22, 1935, No. 5782. Convention date, Feb. 23, 1934. [Class 100(iv)] Relay type-wheel actions; hammerimpression arrangements.-In recordcontrolled mechanism of the kind comprising a set of types moving continuously across the printing line, and a hammer operated at a time determined by the position of a hole in a column, a selecting-device for enabling the mechanism to print letters as well as numerals is adjustable in accordance with the position of the holes in an additional part of the column, and delays operation of the hammer while one or more types cross the printing line. In the mechanism shown in the Figure, a drum 30, making one revolution per cycle, is provided with circumferential rows of letter and numeral types 31, every fourth type in a row being a numeral type, and each row being associated with a hammer 123, and operating-means therefor constructed in the following manner. A hammer-operating lever 115 carries a coupling-link 121 having a tooth 118 for engaging a toothed driving-roller 120, engagement being normally prevented by a latch 138. The coupling-link is depressed, to effect engagement, by means of a dog 116 on a lever 112 normally restrained by a latch 111 in connection with the armature 109 of one of the magnets 12 which are in circuit with the brushes read by the 0 .. 9 holes during the second cycle. A disc 97, secured to a shaft 81 making a half-revolution per cycle, is provided with a selecting-device comprising a pair of segments 86 formed with notches 98 which pass a finger 114<a> on the link 121 in synchronism with the passage of the numeral types across the printing line. The segments have pin- and-slot mountings on the discs and are held in normal position by springs 86a, latches 101 being provided for retaining the segments when displaced. Each segment is provided with a lug 95 for co-operation with steps 94<a> on a bell-crank 87 having notches for engaging a tooth 93 on a lever 92 normally restrained by a latch 90 in connection with the armature 88 of one of the magnets 8 which are in circuit with the brushes read by the 0, 11, 12 holes during the first cycle. A universal bail 84, operated by a cam on the shaft 81, allows the set of bell-cranks 87 to rock clockwise during the reading of the 0,11,12 holes. When a numeral is printed, the magnet 12 only is energized, and the finger 114<a> can drop into one of the notches to permit co-operation of the link 121 with the driving-roller for the purpose of operating the hammer. For printing a letter, the magnets 8, 12 are energized in successive cycles. In the first cycle, the bellcrank 87 is differentially arrested by the tooth 93, and one of segments 86 is displaced one, two, or three steps by means of one of the steps 94<a>. In the next cycle, the finger 114<a> rides initially on the periphery of the displaced segment, and engagement with a notch and consequently operation of the hammer are delayed while one, two, or three types cross the printing line, the delay selecting one of the three types. The levers 112, 92 and latches are restored by means of bails 131, 105 and 100.