| 摘要 |
<p>The warning sign is placed in the open, near roads, to give a visual indication of icing conditions. It consists of a triangular sheet (6) with a warning signal portrayed on it. It is pivoted about a horizontal axis (2, 3, 4) so that more surface area lies to one side (8) than the other (6). A counterweight (7) on the smaller side normally holds the sign in a horizontal plane against a stop. When icing conditions occur, the greater weight of ice forming on the larger side (8) overcomes the counterweight and the sign swings into a vertical position. The edge of the base of the triangle (9) is turned up to form a rim to prevent the sheet of ice sliding off.</p> |
