Patent GB-435353-A (GB)
Title: Gyroscopic pendulum for crafts
IPC: G01C19/44
Filed: 1934-10-12
Abstract: 435,353. Gyroscopic apparatus. BOYKOW, J. M., 2A, Fontanestrasse, Lichterfelde, Berlin. Oct. 12, 1934, No. 29258. Convention date, Oct. 14, 1933. [Class 97 (iii)] Two gyroscopes with horizontal spinning axes at right angles to each other and means for compensating for the effect of the earth's rotation are each mounted with freedom for precession about one axis only in a common frame which is suspended by a cardan system and indicates the horizontal, the precession of the two gyroscopes indicating the overground speed of the supporting craft. As shown, a frame R is pendulously mounted by horizontal pivots Z<1>-Z<1>, lying athwart the craft in a ring r which pivots in turn on a fore-and-aft axis Z<2>-Z<2>. The two gyroscopes K\ K<2> are pivoted on vertical precessional axes in the ring R and have horizontal spinning axes normally parallel and perpendicular respectively to the fore-and-aft line. A " Deprez-coil" acting on the precessional axis of the gyroscope K<2> is energized by a current dependent upon the angular velocity of the earth and the craft's course so that the gyroscope will not experience a directive force unless it is moved over the earth's surface. In the latter case the spinning axis of the gyroscope K<2> will move to a position transverse to the direction of movement of the craft relative to the earth. If, due to drift, the craft does not move over the earth in the direction P of the fore-and-aft axis, the spinning axis of the gyroscope K<2> deviates from its position perpendicular to the direction P and a pointer b on the precessional axis may indicate the drift on a scale b<1>. A spring f, attached at one end to a lever d on the precessional axis of the gyroscope K<1> and at the other end to a slide el adjustable on a circular guide e is adapted to compensate for the directive force due to the earth's rotation and a predetermined speed of the craft over the earth so that the gyroscope K<1> only precesses against the tension of the spring f when the fore-and-aft speed of the craft deviates from the predetermined speed. These deviations are indicated by a pointer g and scale g<1>. During turning of the craft a moment is applied to the frame R either through the pivots Z<1>-Z<1> at D or by displacing a weight K causing the gyroscope K<1> to precess and follow the turning of the frame R. The distance of the centre of gravity of the pendulum below the plane of the pivots Z<1>, Z<1>, and Z<2>, Z' is adjusted by displacing a weight so that the moment due to centrifugal force is sufficient to cause the gyroscope K<2> to precess and follow the frame R. In a modification the supports S<1>, S<2> for the pivots Z<2>, Z<2> are carried by a disc turned by a repeater compass to maintain the pivots Z<2>, Z<2> in the N-S direction. Each gyroscope has an electromagnetic device to compensate for the directive force due to the earth's rotation and is constrained by springs, the gyroscope K<1> with its spinning axis in a N-S direction and the gyroscope K<2> with its spinning axis in an E-W direction. The gyroscopes K<1>, K<2> tend to set their spinning axes transverse to the direction of motion of the craft and indicate by their precessions the N-S speed and E-W speed of the craft respectively. In order to ensure stabilization of the frame R the spinning axes of the gyroscopes are preferably maintained substantially perpendicular by suitably adjusting the anchorages of the constraining springs and the zeros of the scales g<1>, b<1>.