GB1196941A - Currency Calculator - Google Patents

Abstract

1,196,941. Currency conversion and change calculator. JAMES COOMBES & CO. Ltd. 8 July, 1968 [6 July, 1967], No. 31163/67. Heading G4B. A currency conversion and change calculator comprises two concentric discs, centrally connected and rotatably movable relative to each other, each disc having thereon a uniform centrosymmetric scale corresponding on the first disc to the units of one currency and on the second disc to the units of a second currency, the outer edge of the scale on one disc extending adjacent to the inner edge of the scale on the second disc. In use the calculator converts shillings and pence to new pence and vice versa, and also by relative rotation of the discs indicates change for transactions in either currency. In a preferred calculator a paper or cardboard disc marked with one scale is e.g. glued on to a similar sized plastics disc. A second scale is marked on a transparent disc of plastics material or celluloid of the same size as the paper or cardboard disc. The two resulting discs are then joined rotatably together at their centres, the two scales being visible through the transparent plastics disc. Alternatively, the disc carrying the inner scale may be of smaller diameter than the disc carrying the outer scale. The discs may be of polystyrene, card, metal &c.