| 摘要 |
<p>A boat speedometer of the type wherein a vane extends into the water from a torsion arm and speed is determined by the deflection of the arm, wherein the arm is at least partially hollow and the indicator mechanism is actuated by a shaft through the hollow arm. The arm is substantially surrounded by a water chamber and is supported at fixed points so that no motion is transmitted through a moving seal. This permits the torsion arm to be completely sealed to the water chamber so that the leakage problem normally associated with moveable seals is obviated.</p> |
