Gyroscopic instrument

Claim 1

A gyroscopic instrument comprising: a gyro case having incorporated therein a gyro: a first means for supporting said gyro case in neutral equilibrium with three degrees of freedom, said first means having a horizontal shaft about which said gyro case is substantially inclined, said horizontal shaft extending substantially at right angles to a spin axis of said gyro; a second means for establishing a mounting having an axis on said horizontal shaft inclined about the axis of said horizontal shaft in proportion to a differentiated value of inclination of the spin axis of said gyro from the horizontal plane; and a third means mounted on said second means for producing a torque about the axis of said horizontal shaft in proportion to the inclination angle of said mounting axis about said horizontal shaft axis, said torque being applied to said gyro through said horizontal shaft, said third means having a pair of containers spaced from each other in the direction of said mounting axis, a pipe interconnecting said pair of containers at their lower ends, and a liquid contained in one part of each of said pair of containers and in said pipe, and said containers mounted such that when the fluid in the containers is at the same level with respect to both containers no torque is produced but said torque is produced when the fluid in said containers is not at the same level, whereby the spin axis of said gyro precesses about an axis orthogonal to said spin axis and said horizontal axis with a period of not longer than about 24 hours with respect to the earth, said precession being damped in accordance with time lapse, and the spin axis settles in a position parallel to the axis of the earth.