Patent ID: 7473067
Filing Date: 2009-01-06
Classification: E02F

Abstract:
1. An attachment coupler comprising: a first arm and a second arm, each of the first arm and the second arm including a U-shaped portion provided on a lower end and having a U-shaped cross section and a pivot shaft provided on an upper side of the U-shaped portion, and upper portions of the first arm and the second arm being swingably connected by a swing shaft; an expansion-contraction tool of which one end is rotatably supported by the pivot shaft of the first arm and the other end is supported by the pivot shaft of the second arm, and which opens and closes the first arm and the second arm around the swing shaft as a fulcrum due to expansion and contraction; a locking member which moves rotationally around the pivot shaft of the second arm along with rotation of the expansion-contraction tool, is rotationally biased in a rotational direction around the pivot shaft of the second arm during contraction of the expansion-contraction tool, and includes a cam formed in a peripheral portion; and a hook which includes a base end rotatably supported by the second arm, a free end which advances toward and retreats from an opening of the U-shaped portion of the second arm, and a cam follower which is provided on a peripheral portion between the base end and the free end and contacts the cam; wherein a state in which the free end of the hook is removed from the opening of the U-shaped portion of the second arm is maintained by engagement of the cam and the cam follower during contraction of the expansion-contraction tool; and wherein the cam follower is driven by the cam along with rotation of the locking member during expansion of the expansion-contraction tool, thereby causing the free end of the hook to advance toward the opening of the U-shaped portion of the second arm.