Patent GB-216156-A (GB)
Title: Improvements in gyroscopic apparatus
IPC: B63G13/00
Filed: 1924-05-16
Abstract: 216,156. Sperry Gyroscope Co., (Assignees of Carter, L. F., and Bassett, P. R.). May 16, 1923, [Convention date]. Gyroscopic apparatus.-Apparatus for providing a base line for use in fire control on ships comprises a gyroscope having three degrees of freedom and controlling an indicator, and a clockwork device adapted to impress on the indicator an azimuth movement equal to the apparent movement in azimuth of the gyroscope due to the earth's rotation, so that the indicator remains fixed in azimuth with respect to the earth. The gyroscope is prevented from turning in altitude by torques applied around the vertical axis by means controlled by a level device on the gyroscope. The gyroscope 1, with a horizontal axis of rotation, is mounted on pivots 2, 3 in a vertical ring 4 supported in bearings 5, 6 in a followup member 7 from which it is suspended. The member 7 has an upward extension 7<1> journaled in bearings 8, 9 and the ring 4 also has an upward extension 14 carrying a bracket 15 to which is secured the mechanism 18 for correcting the apparent azimuth movement of the gyroscope. This mechanism consists of a slotted arm 19, Fig. 7, pivoted at 20 and rotated from clockwork 22 by gearing 21, 23. The slot is engaged by a pin 24 on a pivoted arm 26<1>, which also engages in a slider 25 which can be displaced along a latitude scale 26. The arm 26<1> is connected to a pivoted arm 28 which is connected by a link 29 to an arm 31 secured to a shaft 32 to which is also secured the indicator 33, which thus remains fixed in azimuth when the slider 25 is set for the latitude. For indicating tilting of the axis of the gyroscope and operating means for annulling the tilt, vessels 60, 61, Fig. 2, containing mercury &c. are mounted on opposite sides or the casing and are connected by a restricted tube 62. To prevent disturbances of the mercury due to acceleration of the ship the tube 62 may be formed with a number of reverse bends 63 arranged either vertically as shown or horizontally. Alternatively, the tube may be provided with an adjustable restriction or with a displaceable membrane around which the liquid passes; or a valve may be provided in the tube 62 adapted to be operated by an electromagnet controlled by a pendulum on the gyroscope so that the valve is closed when acceleration occurs. Mounted within the containers 60, 61 are floats 93, Fig. 3, carrying contacts 94 terminating adjacent to adjustable contacts 96. For compensating for the effects of temperature variations on the mercury, the contacts 96 may be mounted on posts formed of hard rubber, or they may be in the form of curved bimetallic strips. The contacts 94, 96 control the circuits of electromagnets 100, 101 mounted on the ring 7 and adapted to attract cores 102, 103 on the ring 4. Completion of the circuit of one of the magnets thus causes a torque to be exerted around the vertical axis of the gyroscope. To reduce static friction in the vertical bearings, the follow-up ring may be continuously oscillated in the known manner, while in the case of the horizontal bearings the oscillation is produced by pairs of electromagnets 43, 44 arranged to oscillate arms 42 secured to the trunnions, the magnets being controlled by the contacts which operate the followup member. Means for observing the indicator 33 and for transmitting its indications to a distance comprise an optical device consisting of a fixed part 104 mounted on a bracket 103<1>, and a part 105 rotatable around an axis 106, .prisms 107, 108, 109 being included in the optical system. An illuminated scale 114, Fig. 8, is provided adjacent the indicator, a scale 115 in the part 104 and an index 118 on the rotatable part. The part 105 can be turned by a handwheel 110 operating a worm 111 gearing with a wheel 112, the wheel being turned until the image of the pointer 33 is in alignment with a cross-bar 122, Fig. 9. The .wheel 112 operates three transmitters which are driven at different speeds and are connected to three receivers which may be graduated in degrees, minutes, and seconds respectively.