Patent GB-331956-A (GB)
Title: An improved gyroscopic device
IPC: G01C19/38
Filed: 1929-04-23
Abstract: 331,956. Berglund, G., H. F., April 23, 1929. Gyroscopic apparatus.-Apparatus for use on a moving body for determining the geographical position of the body and its velocity in relation to the earth's surface comprises an arrangement of one or more gyroscopes so'disposed that the axis of each gyroscope makes a fixed angle with the vertical direction and that the vertical plane containing the axis of the gyroscope, or the axes of the gyroscopes, makes a fixed angle with the meridian plane. To maintain these axes so adjusted, external moments are applied about axes at right-angles to the axes of rotation of the gyroscopes, these moments requiring to be varied as the apparatus is moved over the earth's surface, and the required values of position and velocity being deduced at any time from the instantaneous values of the moments. Three forms are described; one consisting of a single gyroscope with its axis maintained horizontal at right angles to the meridian, a second form consisting of two gyroscopes one of which has its axis horizontal in the meridian plane and the other has a vertical axis, while the third form comprises two gyroscopes having their axes in the meridian plane and equally inclined in opposite directions to the vertical. A construction according to the first form is shown in Figs. 6 and 7. A frame 1 mounted in a cardan suspension on the vessel and provided with a stabilizing gyroscope 2 carries a container 3 rotatably mounted therein on vertical pivots 4, 5. Mounted in the container 3 on vertical pivots 15, 16 is a ring 17 within which the gyroscope 19 is supported on horizontal pivots 18. To maintain the ring 17 in the vertical plane the bob 8 of a pendulum 7 mounted on the vessel 3 co-operates with contacts within a sleeve 9 to control the operations of motors 11, 12 which are adapted to displace masses 13, 14 to apply stabilizing torques to the gyroscope 2. The vessel 3 is maintain in a fixed azimuth in which the ring 17 normally lies in the meridian, by a motor 25 operated by transmssion from a gyro-compass, &c. and connected to the vessel by gearing 26. The pivot 15 is provided with a horizontally-extending arm 20 provided with contact members 21, 22 cooperating respectively with pairs of contacts 23, 24 carried by the vessel 3. Movement of the gyro-axis in azimuth relatively to the vessel 3 brings the member 21 into contact with one of the contacts 23 and so causes rotation in one direction or the other of a motor 27 mounted on the gyroscope 19 and adapted to displace a mass 28 which exerts the torque necessary to annul the said azimuth movement. A larger azimuth movement causes the member 22 to abut against one of the contacts 24 and so complete the circuit of one of the electromagnets 30 supported by the ring 17 and acting on an armature 31 carried by the gyroscope. In this way a relatively large temporary moment is exerted which limits the amplitude of the relative azimuth movements. The gyroscope carries oppositely-extending horizontal arms 31, 34 at right-angles to the plane of the ring 17, these arms being provided with contact points 35 dipping into mercury cups 33 supported by the ring. Movement of the gyroscope about the axis 18 causes one of the points 35 to make contact with the mercury to complete the circuit of a. reversible motor 36, rotation of which displaces a sleeve 37 from which is suspended a pendulum 38 the bob of which extends into a recess 39 at the end of an arm 40 extending from the pivot 15. Displacement of the pendulum thus produces a torque about the axis 15, 16 to annul the movement of the gyroscope about the axis 18. The two moments utilized for determining the position and velocity of the moving body are those exerted about the axis 15, 16 and the axis 18 by the above-described means. The centre of gravity of the gyroscope and attached parts coincides with the point of intersection of the said axes. The vessel 3 is partly filled with a suitable liquid to relieve the bearings of load. Specification 331,972 is referred to.