Fastening device and hook part

1. A fastening device in which an attachment part and a hook part are rotatably coupled around a rotational axis, the hook part comprising:

a hook main body;

a latch for closing the hook main body; and

a coupled portion to which a base end of the latch is integrally coupled, the coupled portion extending away from the hook main body along the rotational axis such that coupling between the attachment part and the hook part is ensured, wherein

the latch comprises:

a spring portion provided closer to the base end of the latch, the spring portion being elastically configured to enable urging of the latch away from the hook main body; and

a latch main body coupled with the coupled portion via the spring portion, and wherein

a connection point of the latch and the coupled portion is farther from the hook main body along the rotational axis than a connection point of the hook main body and the coupled portion,

wherein the hook main body is coupled to a lower end of the coupled portion, and the base end of the latch is coupled to a portion between the lower end and an upper end of the coupled portion.

2. The fastening device according to claim 1 in which a left-right direction is defined as a direction orthogonal to a plane in which the latch pivotally moves around the spring portion to open/close the hook main body, wherein

one of the hook main body and the latch comprises at least one restricting portion to restrict displacement in the left-right direction of the other of the hook main body and the latch.

3. The fastening device according to claim 2 , wherein the restricting portion is configured to sandwich the hook main body or the latch in the left-right direction.

4. The fastening device according to claim 3 , wherein the restricting portion is engageable with the hook main body or the latch so as to restrict displacement of the latch in a direction away from the hook main body.

5. The fastening device according to claim 3 , wherein

the restricting portion provided on the hook main body comprises at least one first lug,

the latch comprises at least one second lug,

the second lug is shaped to protrude in the left-right direction, and

the first lug extends in a direction other than the left-right direction so as to be engageable with the second lug.

6. The fastening device according to claim 3 , wherein

the restricting portion provided on the latch comprises at least one first lug,

the hook main body comprises at least one second lug, and

the first lug and the second lug to be interlocked one another are oppositely projected in the left-right direction.

7. The fastening device according to claim 3 in which the restricting portion comprises a left restricting wall and a right restricting wall arranged in the left-right direction so as to sandwich the hook main body or the latch, wherein

the fastening device further comprising:

a first lug provided on at least one of the left restricting wall and the right restricting wall; and

a second lug engageable with the first lug, wherein

interlocking between first lug and the second lug restricts displacement of the latch away from the hook main body.

8. The fastening device according to claim 3 in which the restricting portion comprises a left restricting wall and a right restricting wall arranged in the left-right direction so as to sandwich the hook main body or the latch, wherein

the latch main body comprises a latch distal end that engages with the hook distal end of the hook main body, and

a thickness of the latch distal end along the left-right direction is greater than a thickness along the left-right direction of a portion of the latch main body sandwiched by the left restricting wall and right restricting wall.

9. The fastening device according to claim 1 , wherein the coupled portion is provided with a recess and a base end of the spring portion is coupled with a surface of the recess.

10. The fastening device according to claim 9 , wherein a notch extending through at least the coupled portion from the surface of the recess toward the hook main body is provided, and the notch is able to partially accommodate the latch.

11. The fastening device according to claim 1 ,

wherein the hook part further comprises a rest between the coupled portion and the hook main body, the attachment part being able to sit on the rest and wherein

the connection point of the latch and the coupled portion is farther from the hook main body than the rest along the rotational axis.

12. The fastening device according to claim 1 ,

wherein the hook part further comprises a rest on which the attachment part can sit, and

the latch is shaped to provide a rest surface for the attachment part together with the rest.

13. A hook part that is attachable to an attachment part in a rotatable manner around a rotational axis, the hook part comprising:

a hook main body;

a latch for closing the hook main body; and

a coupled portion with which a base end of the latch is integrally coupled, the coupled portion extending away from the hook main body along the rotational axis such that coupling between the attachment part and the hook part is ensured, wherein

the latch comprises:

a spring portion provided closer to the base end of the latch, the spring portion being elastically configured to enable urging of the latch away from the hook main body; and

a latch main body coupled with the coupled portion via the spring portion, and wherein

a connection point of the latch and the coupled portion is farther from the hook main body along the rotational axis than a connection point of the hook main body and the coupled portion,

wherein the hook main body is coupled to a lower end of the coupled portion, and the base end of the latch is coupled to a portion between the lower end and an upper end of the coupled portion.