Patent GB-191200442-A (GB)
Title: Improvements in or relating to Adding or like Machines.
Inventor: BOULT ALFRED JULIUS
Filed: 1912-01-05
Granted: 1913-01-06
Abstract: 442. Boult, A. J., [Burroughs Adding Machine Co.]. Jan. 5. Adding and subtracting apparatus.-Means for enabling an adding- machine to perform operations in subtraction and to print totals, sub-totals, and ' negative ' totals, representing, for instance, the amount by which a bank depositor has overdrawn his account, are exemplified in connexion with the ' Pike ' adding - machine described in Specification 3259/03. In the present arrangement, an additional series of receiving-wheels E, Fig. 6, is provided, adapted to engage with the usual adding-racks alternatively with the receiving- pinions 385, but there is only one set of numeralwheels 313. The wheels E are disposed in front of the wheels 385 and are not in the same vertical planes; both series of wheels, however, are always connected with each other through pairs of toothed wheels A, B. The whole totalizer can be moved transversely with respect to the racks 405, by means of a lever F, Figs. 1 and 3, link H, cam-plate H<2>, and pin h<1>, so as to enable either the additive receiving-wheels 385 or the subtractive receiving-wheels E to engage with the racks and thereby turn the numeral wheels 313 in opposite directions. The totalizer carriage is adapted to undergo a vertical movement to enable the pinions to engage with the racks as usual, but the sequence of engagement and disengagement of pinions, no matter which series of receiving - wheels is operative, is preserved as described in the Specification referred to. Transfer mechanism for additive and subtractive operations. The pinions E are provided with a series of transfer-cams C<1>, Fig. 7, set at an angle relatively to the cams 311 attached to the additive pinions 385 and to the numeralwheels. These cams are adapted to engage lugs 303<d> on the transfer-levers 303, with which they co-operate in a similar manner to the cams 311 and lugs 303<a>, to disengage the projections 303<b> from lugs 405<a> on the racks, thereby allowing the racks to undergo the usual additional movement. This movement takes place in the same direction whether for addition or subtraction. Interlocking. - Interlocking - means J<2>, J<3>, Fig. 1, are provided for the selecting-lever F and the operating-lever. These means become operative before the transverse movement of the totalizer-carriage commences. Printing totals and sub-totals.-The depression of the total or sub-total keys 702, 702
 results as usual in the printing of totals &c. when the additive pinions 385 are in gear with the rack. If the subtractive pinions E are in gear, the depression of the keys results in the printing of the complements of the total or sub-total. In order to print a negative total, however, the total key is depressed when the subtractive pinions E are in engagement with the racks; negative totals thus printed are always one cent short. In printing totals or sub-totals, the projections 303<d> and 303<a> on the transfer levers co-operate with the transfer-cams C', 311, respectively, in the usual manner, thus acting as zero stops.