Patent ID: 8096212

Claim:
A two-section tool joint comprising: a first rod including a receiving groove in one end thereof, on an inner surface of the receiving groove being equidistantly provided six engaging protrusions, between each two neighboring engaging protrusions being defined an engaging groove; a second rod received in the receiving groove of the first rod and including a driving portion and a hexagonal ball along an axis thereof; a limiting element being disposed at an opening of the receiving groove of the first rod for preventing the hexagonal ball from disengaging from the receiving groove; an engaging element including a bottom and six support arms that are equidistantly arranged around a circumference of the bottom; the engaging element being disposed in the receiving groove of the first rod, the bottom of the engaging element abutting against a bottom surface of the receiving groove, the support arms being located in the respective engaging grooves; the engaging element being characterized in that: each of the six support arms including a first inwards-bent engaging portion and a second outwards-bent engaging portion the first and the second engaging portions being allowed to restore to their original shapes after being deformed under pressure; the hexagonal ball including six upper abutting surfaces and six lower abutting surfaces that are arranged around the axis, the respective lower abutting surfaces being located farther from the driving portion than the upper abutting surface, the hexagonal ball being disposed in the receiving groove of the first rod and movable along the axis, when the second rod is pushed back into the first rod to a retracted position, the respective first engaging portions of the engaging element will be pressed against the respective upper abutting surfaces of the hexagonal ball to hold the hexagonal ball between the bottom surface of the receiving groove and the first engaging portions, and when the second rod is pulled outwards relative to the first rod to an outward-extended position the respective second engaging portions of the engaging element will be pressed against the lower abutting surfaces of the hexagonal ball to hold the hexagonal ball between the second engaging portions and the opening of the receiving groove; the first and the second engaging portions of the engaging element define a compression space with respect to the inner surface of the receiving groove, when the first and the second engaging portions are deformed under pressure, the compression space will disappear, and when the first and the second engaging portions restore to their original shapes, the compression space will be formed.