| 摘要 |
A hollow hub has around its exterior a plurality of apertures for individually receiving a respective cylindrical inner end portion of one of a plurality of axially rotatable propeller blades. Additionally, the hub has around its exterior a plurality of arcuate recesses for (a) individually receiving an inner portion of one of the respective propeller blades when the cylindrical inner end portion of that blade is received in one of the apertures, and (b) accommodating arcuate movement of the blade inner portion upon axial rotation of the cylindrical inner end portion of the blade.
|
