Patent ID: 8783777

Claim:
A headrest support structure, comprising: a stay extending downward from a headrest in use; a bracket configured to be coupled to a backrest so as to be formed in a tubular shape, and extending in an upward-downward direction in use; a tubular portion having an insertion hole in which the stay is inserted, the tubular portion being fitted into the bracket, and extending in an upward-downward direction in use; a first projection portion projecting from an outer peripheral surface of an upper part of the tubular portion, and facing to an inner surface of the bracket; a second projection portion projecting from the outer peripheral surface of a middle part in a longitudinal direction of the tubular portion, and facing to the inner surface of the bracket; a third projection portion projecting from the outer peripheral surface of a lower part of the tubular portion, and facing to the inner surface of the bracket; a first connection portion located between the first projection portion and the second projection portion, the first connection portion being configured to contact and connect the first projection portion and the second projection portion; and a second connection portion located between the second projection portion and the third projection portion, the second connection portion being configured to contact and connect the second projection portion and the third projection portion, wherein the first and second connection portions project outwardly from the outer peripheral surface of the tubular portion.