| 摘要 |
PROBLEM TO BE SOLVED: To provide a connecting method in keeping certainty and coaxial property of a seed rod and an extending rod. SOLUTION: A taper shaft 51 is formed at the tip of a seed rod 5 coaxially with a central axial line of the rod 5 and a taper hole 31 having a taper the same the taper shaft 51 and a root diameter slightly smaller than the root diameter of the taper shaft 51 is formed at a bottom end of an extending rod 3 to be connected to the seed rod 5 in coaxially with the central axial line, then pin-piercing holes 32 and 52 having the same diameter in the direction crossing to the axial line are respectively pierced in the taper hole 31 and the taper shaft 51, thus the taper shaft 51 is engaged with the taper hole 31 and a connecting pin 41 having a suitable slope or a taper on one face is commonly pierced into both of the pin-piercing holes 32 and 52 to a point on which the pin is stopped. |
