Patent GB-430449-A (GB)
Title: Improvements in the mechanical solution of vector problems
IPC: B64D43/00
Filed: 1934-02-26
Abstract: 430,449. Calculating - - apparatus. LEVKOVITSCH, P. GOUDIME-, 31, Beauchamp Place, Brompton Road, London. Feb. 26, 1934, No. 6249. [Class 106 (i)] A device for the mechanical solution of vector problems comprises four spaced arms or equivalents connected in pairs in such manner that the ends of each pair of arms will be equidistant from a central point on the connection between each pair ; one pair of arms is adjusted in accordance with the magnitude and direction of the known vector quantities to position the central point while one arm of the other pair of arms is adjusted to the known third vector and the other arm is manipulated to register the central point of the connection with that of the first pair whereupon the remaining unknown quantities are ascertained. The device may be used as a course computer for aircraft operating at sea in conjunction with a moving base or as a calculator for determining the direction and velocity of the wind by the double drift method. The setting and indicating units ensuring the related movements of the arms are similar to those described in Specification 395,806. As shown in Figs. 3 and 4, a panel has mounted thereon four units 1-4 each with an adjustable arm 5 the opposite arms of which are connected by opposing racks 6, 7 engaging pinions 8 loosely mounted in a central guide 6<a>. The panel is provided with a central glazed aperture 30 through which the central guides are viewable. One of the guides has an aperture with cross wires 33 and the other has a centre mark 34 which can be brought into register with the wires. The sliding arms 5 have scales 10 representing ground speed, speed of ship, air speed, and wind velocity and the dials 12 can be rotated to set the directions of these vector quantities, the setting being read on scales 19 against index wires 21 for the true course or against adjustable wires 22 for the magnetic variations. A typical vector problem is set out in Fig. 1, for the case of an aircraft desirous of rejoining a moving ship. The ship's course and speed is represented by ED, the velocity and direction of wind by BD, the ship's bearing by AE, and the air speed by AB. The direction of AB will give the course which the aircraft must steer. The principle underlying the invention is shown in Fig. 2. The arms Ss and Ww are set to correspond to the sides ED, BD, whereupon the centre point f will be set at a distance from a central point F such that Ff represents in length and direction half of the side EB. If now the arm Gg is set to correspond to the side AE and the arm Cc is adjusted to bring the point f into coincidence with the point f the position of the arm Cc will correspond to the side AB. To find the velocity and direction of the wind by the double drift or bearing method the procedure is for the aircraft to fly over the ship on a given course and speed; after a time the tail bearing of the ship is observed, the aircraft then changes course and flies over the ship a second time when the tail bearing is again noted. For this purpose the central aperture 30 is provided with annular rims 31, 32 graduated in time and distance and the glazed cover with an index line 37 is rotatable by means of a knob 36. The various adjustments necessary are set out in the Specification. Instead of using racks and pinions the arms 6 and 7 may carry equivalent devices such as steel bands passing round rollers which replace the pinions.