GB520339A - Improved deflection indicator or deflectometer - Google Patents

Abstract

520,339. Measuring inclination of ships and other structures. TAYLOR, T. U. Oct. 18, 1938, No. 30078. [Class 97 (ii)] An instrument for measuring the heel and/or trim of a ship, or the inclination of any other object or structure on which the instrument is mounted comprises a fluid reflector and a projector for projecting an imageon to an indicator screen after reflection from the fluid surface; or alternatively comprises an illuminated indicator screen which may be observed against the hair line of a telescope after reflection of the light from the fluid reflector. As shown in Fig. 2, light from a lamp within a hood 7 passes through a triangular orifice in an adjustable slide 8 and is projected by a lens 5 on to a mercury, oil or water &c. reflector 32 and thence on to an elongated ground glass screen 4, Fig. 4, which may be graduated from a central zero. The glass screen is viewed through a slot 20, or in a mirror 39. An apertured masking blind may be adjusted along the slot 20, or over a slot 41, to exclude unwanted light. Two sliding indexes 21 may be provided to mark the extreme positions of the reflected image so that a mean may be taken. The projector 2 and screen box 3 maybe adjusted about hinges 12, 17 by means of screws 13, 17A. Screens 37, 38 may be provided. In a modification for indicating inclinations in any direction, the image 16B, Fig. 4B, is projected on to a square screen and the unwanted light is masked off by two slotted blinds adjustable at right angles to one another over a square viewing aperture replacing the slot 41, Fig. 2. The apparatus may be modified by illuminating the scale on the indicator screen 4 and observing the same against the hair line of a telescope (replacing the projector 2) after reflection at the fluid surface.