| 摘要 |
A coupler includes: a hook portion; a stem portion extending from an end portion of the hook portion in a first direction; a slide bar closing and opening the hook portion by reciprocating in the first direction; a connection ring rotatably connected to an end of the stem portion with respect to the first direction, having a predetermined contour, and extending in a second direction perpendicular to the first direction; at least one projection extending from an outer circumferential portion of the connection ring in the second direction by a predetermined length; and an operation member connected to the slide bar and extending toward the connection ring. The operation member abuts only the projection when being moved in the first direction. |
