Navigational instruments
OwnerRichard Creighton Kinginventor
Life of this patent
Estimating the term…
Abstract
A portable navigational instrument has edge portions which are adjusted so that the instrument's orientation with respect to a vessel can be maintained constant in different positions within the vessel's wheelhouse. Bearings of objects are determined by a sighting arrangement which co-operates with a scale which is set in accordance with the vessel's steering compass bearing, corrected for deviation, whereby the need for a compass on the instrument is avoided. The sighting arrangement can comprise a single visible sight, and/or three such sights enabling horizontal angles between objects to be determined from a further scale, and/or a radio direction finding aerial.
Claims18
A portable navigational instrument comprising a supporting body having a plurality of edge portions which form extremeties of the instrument and are angularly adjustable to angles which correspond to a plurality of walls of a vessel, said walls having arbitrary angular orientation with respect to the fore and aft axis of the vessel, and means for holding said edge portions at the angles to which they are adjusted, whereby when said edge portions are so adjusted the instrument may be placed against each one of said walls of the vessel without its orientation with respect to the vessel changing, and means supported by the supporting body for determining the bearing of the object.
Dependencies are inferred from the claim text.