Patent GB-585700-A (GB)
Abstract: 585,700. Calculating - apparatus. ARENCO AKTIEBOLAG. July 5, 1944, No. 12862. Convention date, July 6, 1943. [Class 106 (i)] In fire control instruments &c., triangle-computing mechanism comprises two computing members pivoted on parallel axes adjustable transversely to a distance representing one side of a triangle, the computing members being intercon. nected by a slidably adjustable pivot, the distance of which to each axis is adjustable, by members for introducing values, to represent the other two sides of the triangle, and is characterized by the provision of safety means for rendering a driving connection between the triangle-computing mechanism and the value - introducing members inoperative when a computed minimum value, corresponding to the distance between the pivot and one of the axes, is obtained. In Fig. 1, F represents a target, M an observation post and B a gun position. The range 8, angle of elevation # and angle of traverse alpha, obtained by instruments at M, are entered into the triangulation apparatus, Fig. 2, to obtain corresponding factors for the gun position, i.e. s<1>, # and gamma. An arm 1, Fig. 2, rotatable on a hollow shaft 2, and with a slide 6, Fig. 3, and pin 7 adjustable along the arm by a threaded rod 5 rotated by a bevel gear 4 from a shaft 3 passing through the hollow shaft 2, represents the side s of the right-angled triangle MFFo, Fig. 1, the distance between the pin 7 and the shaft 3 representing the range s and the inclination of the arm representing the angle #. The pin 7 engages a vertical slide 8 slidable in depending members 9 integral with a horizontal slide 10, so that the setting of the arm 1 moves the slide 10 a distance representing a, the horizontal projection of the range #. A bracket 40 depending from the slide 10 carries a shaft 39 supporting an arm 37, interconnected by a pin 41 to a further arm 36 journalled on a stationary shaft 38. Thus, the displacement of the shaft 39 from the shaft 38 being equal to that of the slide 10, is-equivalent to the distance a in Fig. 1. The angular setting of the arm 36, controlled by a hand wheel 80, represents the angle of traverse alpha, and the effective length of the arm to the pin 41, controlled by a hand wheels 82, operating bevel gears and screwed rod 45, represents b, the distance, between the observation post and the gun position. The third side a<1> of the triangle MBFo is therefore represented by the arm 37, the angular position of which is transmitted by bevel gears to a pinion 50 engaging a pinion 51, while the effective length of the arm 37, representing the value a<1>, is transmitted by a rack 54 attached to a slide 53 forming a bearing of the pin 41, which rack rotates a pinion 55 on a shaft passing through the hollow shaft 39 and carrying a further pinion 57 engaging a rack 58 attached to a slide 22 upon which is journalled a shaft 23 carrying an arm 21. As the displacement of the slide 22 represents the distance a<1>, the angular position of the arm 21 represents the angle #<1> and its effective length the side s<1> in the triangle BFFo, Fig. 1. The angle #<1> of the arm 21 is transmitted through a sector 24 and pinions 25, 26 to a pinion 27, while the effective length of the arm s<1> is transmitted through a rack 30, pinion 29, bevels 32, &c. to the pinion 35. The values y (=alpha- 8), a<1> and #<1> are transmitted to the gun battery by electrical means. To correct for a possible difference in level between the observation post M and the gun position B<1>, the pins 7 and 12 (Fig. 3) can be displaced laterally by an amount equivalent to BB<1> by a handle 18 (Fig. 2) operating a splined and threaded rod 14 through a worm gear 15. To arrange that the movements of the rack 58 represent only changes in the effective length of the arm 37, an epicyclic gear is included in the drive between the shaft 56 and the pinion 57. Similar epicyclic gears are provided between the shaft 3 and the gear 4 and between the shafts 44 and 48. To prevent the triangulation members 36, 37 from assuming an unstable position, e.g. when shafts 38 and 39 are collinear and the effective length of arm 37 approaches zero, an abutment 68 is provided to arrest the pin 41 and a yielding interconnection is provided between the arm 1 and the shaft 2. Furthermore, a spring coupling 81 is provided between the shaft 44 and its control handle 82. The apparatus can be employed in solving other triangulation problems, e.g. for ascertaining the line of aim at a moving aerial target or for ascertaining the position of an aircraft detected by a sound locator (assuming the target to fly in a straight course at constant speed and altitude). Specification 582,815 is referred to.