GB380326A - Improvements in navigational calculating apparatus - Google Patents

Abstract

380,326. Plane-trigonometry calculators. AKT. - GES. C. P. GOERZ, OPTISCHE ANSTALT, Pressburg, Bratislava, Czecho- Slovakia. Jan, 1, 1932, No. 95. Convention date, Jan. 3, 1931. [Class 106 (i).] A calculating device for use in solving aerialnavigation problems comprises a base 1 within which is rotatably mounted a ring 2 having scales 2b. Within the ring can rotate a disc 3 with a scale 3b and a pointer 3a and having a radial slot in which moves a slide 4. To the slide is attached a disc 4b graduated to indicate the wind direction and also a pointer 4a indicating the still-air velocity. A pin passes through the slide and a rule 11 graduated in wind velocities may be coupled to it by a nut 5. When so coupled the rule is caused to move parallel to itself, when the disc 3 is rotated, by bevel gears 6, 8, the latter being slidably carried by a shaft 7 having a bevel gear 9 meshing with a fixed gear 10. A coverplate 12 is rotatably arranged outside the base 1, its upper part being cut away along a diameter. A scale 12c on this diameter indicates actual aircraft velocities. The three rotatable members may be locked in position by thumbscrews. In use, the disc 3 and ring 2 are set to the direction of the aircraft axis by the aid of a pointer 1a. The slide 4 is set radially to the still-air speed and the diametral scale 12c to the angle between the craft axis and its course. The rule 11 is adjusted until it intersects the scale 12c at the actual speed, whence the wind speed may be read off the rule and its direction off the disc 4b. The results of changes in the course can then be calculated.