US Patent 11559113 Plug for buckle, and buckle

A plug for a buckle includes an attachment portion configured to be attached to the predetermined members; a pair of leg portions protruding in the same direction away from the attachment portion; extending portions extending in a direction from tip end portions of the pair of leg portions toward base end portions of the leg portions; a coupling piece coupling the base end portions of the pair of leg portions; a first restricting portion that is located at an intermediate portion of the coupling piece and faces extending ends of the extending portions; and second restricting portions that protrude from two sides in a longitudinal direction of the coupling piece in a manner of sandwiching the first restricting portion, extend in a protruding direction of the leg portions, and face inner side surfaces of the leg portions.