GB105280A - Improvements in or relating to Apparatus for Indicating the Direction of Travel of an Aeroplane or other Moving Body by the Sun. - Google Patents

Abstract

105,280. Woodward, C. D. June 5, 1916. Solar compasses.-Apparatus for use on an aeroplane or other moving body for indicating its direction of travel comprises a disk 1 which is graduated with compass bearings in reverse order, and is rotated uniformly at the rate of one revolution in 24 hours, and also a style 5 the shadow of which cast by the sun gives the indication. The disk is rotated by clock-work operating through a toothed wheel 20, this wheel rotating once in 12 hours and being geared by wheels 21, 22 to a flexible shaft 23, which turns the disk 1. The whe@ 20 bears two rings of graduations reading from 0 to 179 and 180 to 0 respectively, the readings being observed through windows in a cover-plate which are marked A.M. and P.M. respectively, and being used in setting the disk 1 to its proper position. The wheel 20 is geared to the clockwork by wheels 18, x, 19, Fig. 3, the wheel x being frictionally mounted on the spindle 34, so that it may be turned by a finger-piece 35 to adjust the wheel 20 and the disk 1 independently of the clock-work. The clock-work is also provided with two sets of hour and minute hands 11, 30, and disks, the hands 11 indicating Greenwich time, and the wheels 16, 17, through which the hands 11 are operated, being carried on an arm 26 pivoted at 27, so that they can be turned out of mesh with the clock-work mechanism to permit adjustment of. the hands 11 to the local time. The disk 1 may be semi-transparent, so that its markings may be read from below. The apparatus may be modified by the omission of the wheel 20 or of the hands 11. Examples of the methods of using and setting the apparatus are described in the Specification, the original adjustment of the compass being made by observation of objects having known bearings, or of heavenly bodies with employment of Burdwood and Davis' azimuth tables.