Improvements in slide rule calculators, other scale devices, and direction drawing instruments

摘要

468,257. Scales ; drawing-appliances. BOARDMAN, H., CLAYTON, A. E., NAYLOR, F. S., and THORNTON, Ltd., A. G. Feb. 25, 1936, No. 5590. [Class 97 (iii)] [Also in Group XIX] A scale device or drawing- appliance.is provided with a group of scales representing angles and the inverse trigonometrical functions corresponding to the angles whereby on a single setting of a cursor the various values can be ascertained. The scales may be logarithmic or otherwise and conform to the equation f(alpha)=Sin-1x=Cos-1y=tan-1(z). The scale device shown in Fig. 1, comprises a strip of wood, metal, or other material grooved to carry a cursor K and having marked thereon a uniform scale E representing angles, and scales F, G and H, graduated in accordance with inverse sine values, inverse tangent values, and inverse cosine values respectively. Scales for the other trigonometrical values cotangent, secant, &c. may also be provided. An adjustable set square is shown in Fig. 2, with the scales as described arranged on a quadrant plate x secured to an arm Z and passing through a cursor K1 secured to the triangular shaped arm Y. The arms Y, Z are mounted on a pivot W and a set screw V enables the arms to be adjusted to a given angle or given trigonometrical function.