Patent GB-481443-A (GB)
Abstract: 481,443. Cash registers. NATIONAL CASH REGISTER CO. Sept. 10, 1936, No. 24651. Convention date, Sept. 13, 1935. [Class 106 (i)] [Also in Group XVI] Hammer-impression arrangements.-In a cash register or similar accounting machine, means are provided automatically to lock the actuating arm of a printing hammer after a driving spring therefor has been tensioned by the first lobe of the usual multi-lobed cam, such locking means being disabled automatically to allow the last lobe at least, to be effective to operate the actuating arm and cause an impression to be made. Differential mechanism.-The number of impressions to be made on an inserted slip is controlled by the differential mechanism of a special bank containing two keys 11, 12, Fig. 1, and a zero stop pawl 26. This mechanism comprises a differential arm 23 to which is pivoted a latch 21 co-operating with a driver 14 that receives a constant clockwise and counterclockwise excursion from a cam 18 at each operation. The latch is broken by the contact of a pawl 24 with the stop pawl or the stem of a depressed key, the pawl being pivoted to thelatch to enable the clockwise movement of the latter to be unimpeded. The stop pawl is controlled by the keys through a detent plate in usual manner. The differential arm is connected through gearing to a type-wheel 37, Fig. 2, that impresses the record strip and inserted slip with a mark indicative of the number of impressions made. Printing on inserted material.-The inserted slip receives one, two or three impressions from a hammer 44, Fig. 2, rockable about a shaft 39 and actuated by a three-lobed cam 40 through a bell-crank 43 that is urged clockwise by a spring 42 and is adapted to strike a rod 44a on the hammer. The first lobe 40a of the cam 40 is always effective to rock the bell-crank 43 and stress the spring, and the last lobe 40c always releases the bell-crank to effect printing. The first and second lobes 40a, 40b effect, or do not effect printing according as to whether the bellcrank is free, or restrained by the abutment of a stud 46 thereon with a blocking arm 45 of a shaft 48. The blocking arm is normally held in ineffective position against the action of a spring 54, Fig. 3, by a cam 55 that, through levers 50, 49 and shaft 48, releases the blocking arm, for a period during each operation, to the control of a disc 60 angularly positioned by the differential of the special bank, Fig. 1. Pivoted on a stud 62 and co-operating with the periphery of the disc are two feeler arms 53, 70, of which the first (53) is connected through levers 52, 49 to the blocking arm, while the second (70) is connected to the first by a spring 63 attached to a downward extension. When key 12 is depressed, a lug 60a on the disc 60 is positioned beneath the feeler 53 whereby the blocking arm, when released by the cam 55, is still maintained in ineffective position and the hammer makes all three strokes. When key 11 is depressed, the lug 60a rocks the feeler 70 clockwise to position a roller 71 on its downward extension in the ;path of a shoulder 72 of the cam 55. Now as the cam 55 rotates, the lever 50 rocks clockwise to suppress the first stroke of the hammer, after which the shoulder 72 acting through the roller 71 restores the lever 50 to enable the hammer to make two strokes. When no key is depressed, the hammer makes only one stroke, the first two strokes being suppressed by the clockwise rocking of the lever 50. Slip-feed mechanism.-The slip is fed between impressions by successive rockings of a pair of sectors 87, Fig. 5, that are raised during the machine operation to compress the slip against discs 90. The sectors are pivoted on a rod 86 carried by a pair of arms 85 that are rockable about a shaft 39 and connected by a spring 89 to a lever 80 actuated by cams 81, the arrangement being such that the sectors are raised at the beginning of each operation and lowered to release the slip after the last impression has been made. The feeding movements of the sectors are controlled by a cam 91 coaxial with the cams 81 and acting through bell-cranks 94, 99 and link 100 to rock the sectors to full extent clockwise before they engage the slip and subsequently clockwise one step after each impression.