GB646399A - Calculating instrument for the simultaneous conversion of weights, volumes, prices and currencies - Google Patents

Abstract

646,399. Calculating-apparatus. SBERNADORI, P. Jan. 26, 1948, No. 2319. Convention date, April 4, 1947. [Class 106(i)] A slide-rule for converting weights, volumes and prices for a plurality of units of measure and exchange comprises two similarly graduated logarithmic fixed scales A, B for reading weights and volumes respectively spaced apart to allow two slides C, D to move therebetween relative thereto and to each other. The slide D bears a logarithmic scale of specific gravities cooperating with an arrow F on the slide C, scale and arrow being marked in black, while the slide C bears an appropriate scale of A.P.I. gravities co-operating with an arrow G on the slide D, both marked in red and represented by small black triangles in the drawings. The slide C has marks labelled with units of weight in various systems, while the slide D has marks appropriately disposed and labelled with units of volume in the same systems, both sets being marked in black, so that by setting the black scales C, D relative to one another according to the specific gravity of a liquid corresponding weights and volumes may be read off in any system by moving the slides together as set to appropriate positions relative to either of the fixed scales. Similar conversions between price per unit volume may be made by using the red A.P.I. gravity scales in conjunction with red labels of price on slides C and D. Scale plates U and V, logarithmically graduated, are provided for money conversions between dollars and sterling by setting according to the rate of exchange, and may be replaced by similar plates for other currencies. Conversion scales for conversions between different temperature scales may be provided. Mechanical means for effecting relative movement between the movable slides C, D comprise a screw turning in bearings fixed to the slide D and co-operating with a nut T on an arm W fixed to the slide C. Alternatively, the arm W may be pivoted at an intermediate point to the nut T and at its ends to arms R, S, see Fig. 3, pivoted respectively to the slides C, D so as to give an amplified movement to the scales.