| 摘要 |
PURPOSE:To make bearing base lines easy to see at measurement when they are matched to longitude and latitude, by setting the center of a bearing plate to a moving plate having a parallel moving parts with a bearing plate attaching shaft and making the bearing plate rotatable to eliminate read error. CONSTITUTION:Upper side faces of a transparent linear ruler 4 are projected to provide moving plate receiving parts 13, and both ends of a moving plate 2 are bent into an L shape to form parallel moving parts 11, and their tips are bent inside slightly, and the center of the bearing plate 1 is set to the center part of a moving plate supporting part 12 by a bearing plate attaching shaft 3 so that the bearing plate 1 can be rotated. A center line 6 is provided in positions coincident with the center of the bearing plate 1 on the linear ruler 4, and a stopper (b) is provided in one end, and a hook hole (c) is provided in the other end, and length graduations 5 and loran time difference graduations (a) are provided in the front part, and true bearing graduations 8 are provided on the outside circumference of the bearing plate 1, and magnetic bearing graduations 7 are provided on the inside of them. Bearing base lines 9 and 10 connecting angles 0 deg. and 180 deg. are angles 90 deg. and 270 deg. are drawn, and the linear ruler and the bearing plate are interlocked with each other. |
