主权项 |
1. A flight unit that is a part of a dart comprising a shaft and a flight, wherein
the shaft has an axis direction and comprises a shaft body, a protrusion provided at one end of the shaft body, and a flight connector provided at the tip of the protrusion, the flight comprises a hollow cylinder in which the protrusion is slidably fitted, vines at the bases of which the hollow cylinder is provided, and an open cavity adjoining the hollow cylinder and in which the flight connector is slidably fitted, the open cavity is provided to the vines and comprises no exterior walls, the hollow cylinder is provided rotatably with respect to the protrusion of the shaft, wherein a projection projecting in the axis direction of the shaft where said projection is formed on one of the shaft and the flight, and a recess, in which the projection is fitted, said recess being formed in either the shaft or the flight. |