Improvements in Navigational Instruments.

Abstract

Abstract 1024. Elphinstone, G. K. B. Jan. 14. Angle-measuring instruments. - An instrument for use on board ship for determining the inclinations to the ship's course and to the meridian of the line joining the ship to a distant object consists of two cylindrical scales 11, 13, the former set electrically from a gyrocompass, and the latter fixed to the ship; both these scales are visible through the eyepiece 3 of a telescope 5, which can turn about the axis of the two scales without moving either. The scale 11 is connected through gearing 9, 8, 7 to a motor 6 actuated by a gyro-compass, and is graduated from 0 to 360 degrees. The scale 13 is attached to the fixed pillars 12, and is graduated to 180 degrees each side of zero. At the commencement, the telescope is pointed fore and aft, whereupon the zero of the scale 13- should coincide with the line 4 in the field of view; the division on the scale 11 coinciding with this line should be equal to the angle between the ship's course and the meridian. The scale 11 can be set to the required position by raising the pinion 18 into engagement with the wheel 19 and rotating the pinion. Attached to the scale 11 there may be a compass card 16, over which is stretched a fore-and-aft line 15, so that the inclination of the course to the meridian can be obtained without using the telescope. In a modification, the scales are horizontal and are projected into the field of view by right-angled prisms. The scales may be illuminated if required.

Inventors

• 👤 George Keith Bulle Elphinstone

Bibliographic Details