| 摘要 |
A direction indicator comprising a direction pointer arranged to pivot about a fulcrum and a flight mounted on the direction pointer that is capable of interacting with a fluid flow, the flight having a resistive portion resistive to fluid flow in a direction parallel to a longitudinal axis of the direction pointer, the resistive portion being substantially effective to cause the direction pointer to pivot about the fulcrum and thereby align the fli ht with the direction of the fluid flow. |
