Patent GB-213023-A (GB)
Title: Improvements in gyroscopic apparatus
IPC: G01C19/42
Filed: 1923-01-03
Abstract: 213,023. Henderson, Sir J. B. Jan. 3, 1923. Gyroscopic apparatus.-In apparatus for indicating the angular velocity of a moving body such as an aircraft, and of the kind in which a gyroscope is so mounted on the body as to be subjected to precessional torque when angular movement occurs, the gyroscope is retained in a substantially constant position in relation to the moving body by the application of torque of sufficient magnitude to prevent the occurrence of precession. Figs. 1, 2 and 3 show an instrument for indicating angular velocity about the vertical axis. The gyro-casing 2 is pivoted in a casing 1 on fore-and-aft trunnions 3, 4, to the latter of which is secured a crank 5 connected at its lower end by springs 8, 9 to a toothed sector 6 freely pivoted around the trunnion and gearing with a pinion 16 on a shaft 18 which is rotated through gears 14. 15 by a reversible motor 13. A disc 24 secured to the motor shaft rotates with a small clearance in a drum 25 connected by springs 26, 27 to the casing 1, and carrying contacts 28, 29 between which extends an arm 30 secured to the trunnion 3. The motor circuit is completed by contact of the arm 30 with one of the contacts 28, 29, and the viscous forces on the drum 25 cause the circuit to be broken sooner than it would be if the drum were fixed, in order to prevent hunting of the motor. The shaft 18 carries an indicating dial 19 and the motor shaft carries a transmitter 23 for distant indication. Fig. 4 shows an arrangement in which a single gyroscope is used to indicate velocities about two axes at right-angles to each other. The gyro-casing is mounted on vertical pivots 35, 36 in the ring 37 mounted on the fore- and-aft trunnions 3, 4, the crank 5 being secured to the trunnion 4 and operating as described above. The drum 25<1> is fixed to the casing 1 and the disc 24' is driven through gears 38, 39 by the motor 13 and is connected by a crank 40 and cantilever spring 41 to the contact arm 30'. The gyro-casing is also mounted on pivots 46, 47 in a ring 45 which is pivoted in a vertical ring or half ring 48, itself pivoted about the vertical axis 49, 50 in the casing 1. Secured to the trunnion 49 is an arm 55 connected by springs to a gear sector 56 operated by a motor 53. The motor 53 also drives the drum 59 of a viscous brake, the disc 61 of which is connected by a crank 62 and cantilever spring 63 to a rearward extension of the arm 55. The gyro-casing carries a horizontal contact-arm 65 extending between contacts 66, 67 fixed to the casing. These contacts control the motor 13 and the arm 30' with its associated contacts controls the motor 53, so that these motors are started up on the occurrence of yawing and rolling motions respectively. the velocities of these movements being indicated on dials 19, 62. Transmitters 23, 52 are associated with the motors. Fig. 7 shows an indicator or automatic controller for steering. The torque applied to the trunnion axis 3, 4 is transmitted through springs 60<1>, 61<1> in a box 62' which is connected by the shaft 65' to the brake discs 64<1> in the drum 63' geared to the motor 13. The motor driven a dial 71 and the discs 64<1> drive a dial 73, a fixed pointer 74 indicating on both dials. The angular velocity is indicated on the dial 73, whilst the displacement of the dial 71 has two components, one proportional to angular velocity and the other to angular displacement. The transmitter 75 may operate a servo-motor for the automatic, control of the tiller.