| 摘要 |
A directional arrow (6,6a,6b) is marked on the baseplate (1) which has a cut-out area (8) to accommodate the thumb of a user. This area (8) is broken by the directional arrow in such a way that when the user with the hand holds the compass pressed against a chart, the latter is located beneath the baseplate between the thumb and fingers. The cut-out area (8) is formed in the direction of travel of the baseplate (1) in front of the compass capsule (2). The compass capsule (2) is pivotably fitted on the baseplate (1), and above it is marked a line (5) to permit the desired direction to be maintained. The edge of the cut-out area (8) is formed so that at the same time as the thumb presses the compass against the chart it is supported on that edge. The required direction can be 'memorised' using the line (5) marked on the compass capsule (2) which is pivoted so that the indicator (4) remains exactly beneath the line (5). |
