Patent GB-803969-A (GB)
Abstract: 803,969. Calculating-apparatus. REMINGTON RAND, Inc. May 9, 1955 [May 12, 1954], No. 13371/55. Class 106 (1). In a pin-carriage machine for performing short-cut multiplication having, in addition to the usual multiplicand keys, a set of multiplier keys each of which when depressed causes an operation to take place in which a previously entered multiplicand is multiplied by the corresponding multiplier digit, no multiplier key can be depressed until a multiplicand has been entered, a depressed multiplier key is locked until the completion of the digit multiplication, another multiplier key can be depressed only on the release of the previously depressed multiplier key, and depression of a multiplier key from " 0 " to " 5 " is prevented when any multiplier key from " 6 " to " 9 " has been partially depressed and released. The invention is applied to the machines described in Specifications 681,271 and 718,412 and comprising a pin carriage 40, Fig. 5, settable by a tenkey keyboard 37, set pins controlling differential slides 45 co-operating with adding racks 46 for a totalizer 48. The invention provides a set of multiplier keys 58 (see also Fig. 8) by which multiplier digits are set and which control the machine for the appropriate number of add cycles. Operation by " 2 " to " 5 " multiplier keys.- The stems 68, Figs. 8 and 9, of these keys engage levers 76 on a shaft 80 and engaged with slots 84 of a comb 85 also carried by the shaft. Depression of one of these keys rocks the lever 76 and comb clockwise, an arm 86 of the comb rocking a motor control bell-crank 88 clockwise. The bell-crank 88 thrusts a link 120 rearwardly so that a roller 122 thereon trips a latch 123 on a bail 128 clear of a roller 125. This releases the bail 128 so that a key lock bail 129, connected therewith by a link 119, is moved by a spring 130 to engage over an arm 71 of the key stem to hold the key depressed. The bellcrank 88 also lowers the nose 116 of a link 117 to engage a roller 118 on the link 119 so that the link 117 also moves rearwardly and trips a latch 131 to release a motor control arm 132 for clockwise spring movement, the arm operating to start the motor through connections 134-137 and by means of the mechanism described in U.S.A. Specification 2,237,881. Another arm 87 of the comb 85, when rocked by the depressed key, actuates a multiply non-print bell-crank 89, Fig. 10, which moves a slide 92 rearwardly to withdraw an ear 93 from a lever 108, so permitting a spring 98 to engage a latch pawl 97 with ratchet teeth 96 on a slide 79 adapted to be advanced stepwise during successive cycles by means of a pawl 148 actuated through bevel gears 141, 142 from a cyclically oscillated main shaft 127. This slide controls the number of repeat cycles according to the multiplier digits, the key-actuated lever 76 having arms 77 spaced in the direction of movement of the slide according to the digit values of the " 2 " to " 5 " keys. During the penultimate cycle, an ear 78 on the slide abuts the arm 77 associated with the depressed key and shifts the arm and lever 76 laterally clear of the key stem so that the lever and comb 85 return counterclockwise. The bellcrank 89 returns with the comb 85 so that the latch pawl 97 frees the slide 79 which thereupon is spring returned. A cyclically engaged latch (not shown) prevents restoration of the motor control bell-crank 88 at this stage, although released by the comb arm 86, so that the motor continues operation for the concluding cycle, during which the latch releases the bell-crank 88 to stop the motor and restore the key-lock bail 129. Means are provided which then positively raise the depressed multiplier key. Operation by " 6 " to " 9 " multiplier keys. These keys operate by the short-cut method. The carriage is step shifted for an initial add cycle to multiply by ten, whereafter the carriage is returned, the totalizer engaged for subtraction and repeat actuation continued until the total number of cycles executed is the elevens complement of the multiplier digit. The levers 76, Fig. 13, of these keys engage over lugs 178 of a bail 179, key depression rocking the bail causing a pawl 180 thereon to actuate a member 183 which depresses a spacer stop of the pin carriage, so that the carriage is advanced by one denominational step. The levers 76 of these keys have no arms 77, but are connected by bails 83 to the levers 76 of the " 2 " to " 5 " keys, so that the mechanism is conditioned for the complemental number of cycles of operation. The bail 179 also controls the totalizer add/subtract mechanism and subsequent operation of a back space pawl 41 to return the carriage, as described in Specification 718,412. Operation by " 0 " and " 1 " keys.-The levers of these keys are connected together by a bail 83 (see Fig. 8) formed with a single stop arm 77 common to the two keys. This arm co-operates with a further lug 78 on the cycle control slide 79 in order to release the lever 76 and bail 85 from the depressed " 0 " or " 1 " key during the first cycle, as when the " 2 " key is operated. To prevent the second cycle of the latter key, the " 0 " and " 1 " keys have studs (not shown) adapted to rock a transverse shaft which disables the cyclically engaged latch, referred to above, so that the motor control bell-crank 88 is restored during the first cycle. Known " non-add " mechanism is brought into operation when the " 0 " key is depressed. Multiplier key locks.-The bail 129 retains a depressed multiplier key during the ensuing machine cycles in the manner already described. The arm 71 of the depressed key enters between a row of rollers (not shown) preventing depression of another key until the operative key has been released. When the pin carriage 40 is in home position, prior to entry of the multiplicand, the carriage back-space rack 400, Fig. 19, displaces a key lock slide 401 to the right by means of a lug 399 thereon and a resilient pawl 433 on slide. In this position of the slide, ears 434 thereon block the keys, e.g. the " 9 " key shown, against depression. Upon entry of the multiplicand, the lug 399 moves away from the pawl 433 and the slide 401 is moved to the left by a spring 439 to release the keys, a finger 440 on the slide coming to rest against a lug 441 on a carriage control slide 185. When a " 6 " to " 9 " key is depressed, the resultant denominational shift of the carriage slide 185 and lug 441 permits further movement of the key lock slide 401 such that ears 434 adjacent the " 0 " to " 5 " keys, which are broader than those adjacent the " 6 " and " 9 " keys, again block the former keys against depression.