Patent GB-605132-A (GB)
Title: Improvements in or relating to record-controlled printing mechanisms
Filed: 1945-12-14
Abstract: 605,132. Typewriters &c. BRITISH TABULATING MACHINE CO., Ltd. Dec. 14, 1945, No. 33967. Convention date, Dec. 23, 1944. [Class 100(iv)] [Also in Group XIX] Record-controlled type-wheel machines, type-wheel actions.-A printing-machine in which a type-wheel carrying groups of type characters is rotated, while printing means are operable to print from a selected type character of a group, and in which record cards having two group selections holes 1 to 9 and type selecting holes O, X, R are analysed, is characterised by means for storing a representation of the type group selecting holes analysed and, at a later time in the cycle, for starting rotation of the type wheel at a time under control of the stored representation, and means, operable during rotation of the type wheel, to start operation of the printing means at a time determined by the time of analysis of one of the type selecting holes. The type wheel 60, Fig. la, comprises numeric, alphabetical, and special symbol type arranged in groups of four in accordance with the code shown in Fig. 7. It is in mesh with a gear-wheel 70 which is adapted to be clutched to a constantly-rotating, fluted tube 68 by a spring- urged arm 76 having a single engaging tooth 77. The sensing of a card hole in the 9-1 range determines the time of engagement of this clutch which takes place about 130 degrees later in the cycle. The type wheel is then rotated until the selected group of type reaches the printing position when. by cam controlled means, the type wheel is slowed down so that the four type pass the printing position at a reduced rate. When a second hole (if any) is sensed in the card, a clutch 87, Fig. la, is released by a lever 88 to couple up a cam disc 85 with a constantly-rotating, fluted tube 86, and during the presentation of the selected type group at the printing position a rise 83 on the cam engages an arm 84 integral with a member 81, pivoted at 82, which carries the type wheel 60. Thus, the type wheel is rocked into contact with the.platen 90, its rotary movement being momentarily counteracted by its rolling over the gear 70 so that the selected type meets the platen squarely. Where no type-selecting hole is provided, the clutch 87 is released automatically to select the fourth type in the selected group. Absence of both type-selecting holes causes printing of $ sign, if desired. The means for storing representations of the type group selecting holes and, at a later time in the cycle, operating the clutch mechanism 76, comprises four cams 100AD, Fig. 1b, co-operating with members 110A-D to control the movement of a link 63, Fig. 1A, which is hooked to co-operate with a three-armed lever 64 normally withholding the clutch arm 76 from engagement. The cams 100A-D have low, medium and high sectors, the last raising the members 110A-D to such an extent that, if a magnet 61 is energised concurrently, pulling a bar 116 longitudinally and rocking pawls 106, the rocked pawls become latched by the hooked ends 112 of any of the members 110 which are in their highest position. In the high and medium positions a shoulder 108 on a member 110 is clear of a lug 109 on the link 63, so that, when all four members 110 are in either of these positions and a cam follower 118 is opposite a groove in a cam 125, the link 63 is moved longitudinally by a spring 114 and releases the clutch arm 76, Fig. 1a. The second energisation of magnet 61 (by the sensing of an O, X or R perforation) again causes the link 116 to move longitudinally, rocking a three-armed member 124 to bring a notch 126 therein into a position which allows a spring-pressed pawl 88 to release the clutch arm 87 for engagement. This action is prevented during the sensing of the 9-1 holes by a cam 137 co-operating with the pawl 88. Notches 120a and a lower part 120c in a cam 120 allow movement of the member 124 upon energisation of the magnet 61, the rises 120b providing a positive restoring means for the armature 115 and link 116. The first energisation of the magnet 61 and consequent movement of the member 124 removes a projection 179 on the member from the path of a spring- urged lever 173 thus causing contacts 166, 165 to be transferred. The means for driving the type wheel 60 at a reduced speed during the presentation of the selected type group at the printing position includes a plate 46, Fig. 6, slidable diametrically in slots 44, 45 on a gear wheel 40 under the control of a roller 47 cooperating with a cam groove 48 in a fixed plate 49. The plate 46 has a lug 52 with a pivot 53 for a square block 54 sliding between guides 55 on a driven wheel, and this arrangement provides the desired speed variation. The printing of zeros to the left of the highest significant figure is prevented by the circuit arrangement in which the completion of a circuit to each print control magnet 61 for zero printing is dependent upon the previous analysis of a digit hole in a higher order.