Patent GB-519843-A (GB)
Title: Improvements in or relating to counters
Filed: 1938-09-30
Abstract: 519,843. Calculating - apparatus. BRITISH TABULATING MACHINE CO., Ltd., and KEEN, H. H. Sept. 30, 1938, No. 28522. [Class 106 (i)] A counter comprises a driving member, means for rotating the driving member through a plurality of steps, bringing it to rest, rotating it through a single step and again bringing it to rest, all during each cycle of the counter, a number of counter-wheels, means for coupling each counter-wheel to the driving member for a number of steps of movement of the latter equal to a digit to be added by that wheel, and a separate carry device associated with each counter-wheel except the lowest, each of which devices is controlled by the counter-wheels for lower den ominations and arranged, when a carry is to be made to its associated wheel, to cause its wheel to be, or to remain, coupled to the driving member during the first rest period of the latter and to be uncoupled therefrom during the second rest period. The counter shaft 26 is power driven by a mutilated gear wheel so that it makes eleven steps rests for two steps, makes a further step and again rests for two steps in each cycle. Shaft 26 carries for each denomination, a sun wheel 32 driving compound planet wheels 142 carried by a spider 37 and meshing with a sun wheel 34 loose on shaft 26. Brushes reading perforations in cards energize  magnets CM at the appropriate part of the cycle to withdraw pawl 42 from spider gear 37 and to lock ratchet 36 attached to sun wheel 34. This causes gear 37 to rotate at half the speed of shaft 26 and in the reverse direction to drive readout gear 55, until shaft 26 comes to rest for the first time. Each readout device comprises a common segment 59 and ten digital segments 60 wiped by plungers 56 carried by the gear 55, to record the total in known manner in the counter. Transfer mechanism.-If, when the shaft 26 has stopped, the cam disc 38 secured to spider 37 has reached or passed zero position, a projection 91 lifts arm 92 which is then latched to connect contact SC to brush 96 connected to magnet TM of the next higher denomination through cam operated contacts L3 (not shown). If disc 38 of this denomination comes to rest on the " 9 " brush 96 is connected to contact LC connected to magnet TM for its own denomination, in which case the first transfer energises the second magnet TM also. At the end of the first rest period, cam 82 on shaft 20 rocks arm 79 to depress bail 76; at the end of second rest period, cam 83 (not shown) depresses bail 77. When magnet TM has not been energized, bail 76 engages interposer 73 to rock lever 75 to move pawl 47 away from ratchet 36 and to lock gear 37 by pawl 42. This prevents movement during the extra step of shaft 26. When magnet TM is energized, lever 71 is released to move interposer 73 under bail 77. Pawl 47 therefore continues to hold ratchet 36 and gear 37 makes the extra step. Bail 77 arting on interposer 73 in the second rest period then releases pawl 47 and applies pawl 42. When no significant digit has been added during the first movement of the shaft 26, it is necessary before transfer can take place to couple the shaft 26 to the gear 37. This is done by lever 71 opening contacts BC and closing contacts TC to energize magnet CM during the first rest period. Cams 82, 83 restore parts to their original positions through bails 85, 105 at the beginning of the new cycle. When subtraction by adding the nines complement is to be done, the brush 96 for the highest denomination is connected to the magnet TM for the units to account for the fugitive unit. A modification for subtraction is illustrated in Fig. 13 (not shown) in which the gears 37 are set into motion at the " 9 " point, in the cycle and are stopped when subtracting magnets encounter the holes in the card. The result is to add the nines complement.