| 摘要 |
The propeller for a model airplane having an electric motor or an internal combustion engine is releasably attached to the motor or engine shaft by an overload coupling which disconnects it when any of its blades is struck in the longitudinal direction of the airplane, e.g. when it lands badly and the propeller blade strikes the ground. The motor or engine shaft end carries an end plate, whilst the propeller nave has a corresp. end plate which, with the aid of centering and driver pins, can be fitted against the shaft end plate in a correct driving position, with the overload coupling fitted between the two plates. - The first plate is magnetic and the other is of steel, so that magnetic force holds them together until a predetermined break force on the propeller blade is surpassed. The centre pin can be replaced by a press button or similar in the one plate which can snap-engage in a corresp. central aperture in the other plate. |
