Patent GB-226997-A (GB)
Abstract: 226,997. Fairweather, W. C., (Underwood Computing Machine Co.). Feb. 5, 1924. Adding and subtracting apparatus; differential mechanism; for monetary values.-In a combined typewriting and computing machine of the Underwood-Hanson type, as described in Specifications 3390/12 and 165,175, a modified form of mechanism is described for computing according to the British monetaty system. The numeral keys 13, Fig. 1, in the known manner actuate appropriate type carriers 18, and through stems 31 rock the corresponding shafts 33 that are connected to the usual pin-setting linkages and bars 38. Each bar 38 is adapted to project a pin 41 on an actuating rackbar 40 when the rack-bar is moved forwardly by the usual denomination-selecting mechanism 48, 50 associated with the typewriter carriage. An operation of the main handle causes a main operating universal bar 53 to engage the ends of the set pins 41 and to drive the actuating rack-bars 40 through distances proportional to the value of the keys depressed and to transmit this movement to the totalizer numeral wheels 30. For sterling currency the totalizer is divided into three sets of numeral wheels, pounds, units and tens of shillings, and units and tens of pence The tens-of-shillings rack-bar 70, Figs. 2 and 5, has a single pin 72 adapted to be set by the " 1 " numeral key; the units of shillings rack-bar 68 is identical with those for the pounds. Two rackbars 73, 74, Figs. 3, 5, and 6, are provided for adding pence, the units bar 74 being utilized from " 1 " to " 9." When it is desired to add 10d., the rack.bar 73 is moved to bring a projection on the lever 76 under the bar 38 for the " 1 " key, the depression of which rocks the lever 76 about the pivot 77 so as to move a cooperating stop lever 80 into the path of the main actuator 53. The main actuator is normally displaced two digit spaces from the nearest key-stop pin, whereas the nose 82 of the stop lever 80 is arranged so as to be engaged by the actuator at the commencement of its forward stroke. If no key is depressed in units-of-pence position a lateral extension 85 of a pin 86 on the rack-bar 74 is engaged, after an idle movement of one unit, by a projection 84 on the bar 73 so as to cause the bar 74 to actuate the corresponding numeral wheel ten steps. If the " 1 " key is depressed in the units position it causes the lowering of a stop pin 90 so as to set a second extension 91 in the path of the projection 84, which extension is one step in advance of the extension 85 and consequently adds eleven to the numeral wheel. The numeral wheels 57<a>, 57<b> for the units and tens of pence are rigidly connected to each other and bear numerals from " 0 " to "11," and the corresponding rack-bars are connected by a bolt 94 fixed to the bar 74 and passing through a slot 95 in the bar 73, a head 96 being provided to prevent separation of the bars. In setting the machine for subtraction depression of the subtraction key 97 effects the substitution of a second set of connections between the numeral keys and the pin-setting bars 38 and at the same time through the usual setting bail 118 sets the " 9 " pins 116 on the various rack-bars. The bail 118 also sets the various levers 120 - - 122, 124 - - 127, of the associated racks and complementary bars from the normal position, Fig. 3, to that shown in Fig. 5. Assuming that it is desired to subtract 1d., the depression of the " 1 " key operates the pin-setting linkage of complementary value, i.e. the " 8 " pin 136 of the units bar 74; as the complement in the pence position' is " 11 " this amount is added to the appropriate numeral wheel by a ten-step movement of the units bar 74 and '' 1 " is added by means of a " complement " bar 123. This movement is effected through the medium of two other " auxiliary " bars 128, 129; the bar 128 is driven by the actuator 53 which engages a nose on the lever 126 and at the same time a projection 138 on the bar 128 engages the set " 8 " pin and advances the rack-bar through ten spaces. The bar 129 is also driven by the engagement of the actuator with a nose on the lever 127 and a projection 141 on the bar engages the set pin 156 of the " complement " bar 123, which is thereby moved through ten spaces to impart one rotation to a blank wheel 142 of the totalizer so as to transfer a unit to the units wheel of the totalizer. When subtracting " 0 " in the pence position, the " 9 " pins remain set, consequently the pence numeral wheel makes a complete rotation. To subtract 9d., " 2 " is added by the rack-bar 74 and " 1 " by means of the bar 123 as above described. When the bar 74 is moved to pin-setting position and the '' 9 " key depressed the pin-retracting linkage 146 engages the end of a lever 148 on the tens-of-pence rack-bar 73 and rocks it about the pivot 150 so that the other end thereof engages and rocks a lever 145 about the pivot 77 and causes the depression of the pin 86. The link 146 at the same. time, through the lever 121, retracts the " 9 " pin 116 of the units-ofpence bar 74 and withdraws the nose 82 of the lever 80 from the path of the actuator 53. For this purpose the lever 121 has a projection 151 which engages a projection 152 of a lever 153 connected by a pin and slot to the lever 80. Operation of the actuator 53, through the levers 126, 127 of the auxiliary bars 128, 129, which remain set, cause the said bars to move. The bar 128 moves idly until the projection 138 engages the set pin 86 to cause a two-step movement of the bar 74. The bar 129 is actuated as above-described to transfer , " 1 " to the units wheel. To subtract 10d., when the " 1 " is typed the " 9 " pin retracting linkage 146 engages the, lever 148 toactuats the lever 145 and to depress the pin 157. At the same time the complementary " 8 " pinsetting linkage is operated to set a lever 158 pivoted at 150 on the bar 73 and the link 146 depresses the lever 153 so that the projection 152 thereon engages the projection 160 on the lever 121 to retract the " 9 " pin 116 and thereby withdraw the lever 80. Aftar typing the " O " in the units position the actuator drives the bars. 128, 129 to transmit a one-step movement to the units rack-bar 74 and to the units numeral wheel. To subtract 11d., it is necessary to add " 1 "; the " 1 " in the tens-of-pence position is typed,. whereupon as previously stated a lever 158 is set, and, through the engagement of a projection 162 thereon with a slot 163 in a member 132 associated with the denomination selecting mechanism,. is effective to withdraw the onset 134 of the member 132 from engagement with the units bar- 74 and into operative position with an abutment 164 on the auxiliary bar 128. In the units position when the '' 1 " is typed the bar 128 is moved and the " 8 " pin-setting bar 38 rocks a lever 166 to withdraw the nose of the lever 126 from the path of the actuator 53 and so render the bar 128 ineffective. The numeral wheel is advanced one unit by the bar 129, as previously described. The rack-bars and auxiliary bars are restored to normal by the actuator engaging heels 172 thereon and the set pins and levers are restored by means of a platform 92, Fig. 1. The " 1 " pin of the tens of shillings bar 70 is set when the machine is performing subtraction by means of the bail 118 which rocks the lever 124 and through a pin and slot connection rocks an intermediate lever 188 to depress the pin 72. Under certain circumstances the pin 72 is restored by the " 9 " pin retracting linkage to render it ineffective. When subtracting only in the pounds denominations the addition of unity to the numeral wheel of lowest order is ejected by the auxiliary bar 129, which causes " 1 " to be carried over to the pence wheel and thence through the " 9 " pin and the " 1 " pin settings of the units and tens of shillings rack-bars causes " 1 " to be carried into the units of pounds wheel.