Patent GB-1055334-A (GB)
Title: Gyroscopic apparatus
IPC: G01C25/00
Filed: 1964-03-18
Abstract: 1,055,334. Gyroscopic apparatus. SPERRY RAND CORPORATION. Mar. 18, 1964 [Mar. 28, 1963], No. 11360/64. Heading G1C. Tranportable gyroscopic and power supply equipment for providing an output which may be used for aligning a compatible navigation equipment in a navigable craft comprises a directional gyro 14 having a housing 15 orientable to a known azimuth position e. g. by placing it on a fixed alignplate, a ring 26 mounted in the housing with rotational freedom about a vertical axis 27 an electrical pickoff 28, a frame 34, with a rotor 31 spinning about a normally horizontal axis 32, mounted on the ring with rotation freedom about a second horizontal axis 35 perpendicular to the spinning axis, an electrical power supply 37, and means for connecting it to the pickoff 28, a motor 40 responsive to the pickoff output for exerting a torque about the axis 35 of the frame 34 to orientate the ring 26 in relation to the housing 15, an integrator 76 for intergrating the pickoff output when the gyro is being orientated to its known azimuth position, the integrator being electrically disconnected from the pickoff 28, whilst maintaining its established output, when the equipment is transported for use on the craft, the output being fed to a motor 41 to exert a drift compensating torque about the axis 35 of the frame 34. The gyro 14 is mounted on a base 17 provided with a vertical mounting plate 19 and bent pin 20. The base 17 is mounted on the fixed aligning plate at an airfield or other establishment, the aligning plate having a known azimuth position, and the plate 19 serving to align the base 17 with the fixed plate. Suitable cables connect the gyro with a receptable 22 (Fig. 4) containing the power supply. The electrical circuiting shown in Fig 4 is described in detail in the Specification, but the equipment has three modes of operation controlled by rotation of a switching knob 65. From the "off" condition the switch is set to "orient" and the rotor 31 speeds up driven by a motor 36. The output from the pickoff 28 is used to apply signals to the motor 40 to torque the rotor case 34 and bring the ring 26 into alignment with the case 15. In this condition the only pickoff output will be due to draft caused by the effect of the Earth's rotation and this component is sensed and fed to the integrator 76 which comprises potentiometer slides 86, 87 feeding the motor 41. This motor thus applies a torque about the axis 35 to compensate for this drift. The pickoff output will then be zero as indicated by a meter 66. The equipment is then switched to "integrate" and the equipment functions automatically to maintain the orientated condition. When it is desired to use the equipment it is switched to the "free" position and the cable 45 (Fig 4) is disconnected, thus disconnecting the pickoff 28. The motor 40 is also disconnected but the motors 36 and 41 are still energized as previously. The equipment is transported to the craft and mounted on an alignment plate therein, which plate is aligned with longitudinal axis of the craft. By use of a correcting table the pickoff 28 is used to feed an alignment signal to the computible navagation equipment in the craft.