Patent ID: 7699256

Claim:
A spool comprising: a base plate in the form of an elongated rectangle having a central portion and end portions and capable of changing its posture between a folded posture in which the base plate is bent at the central portion so that the end portions are opposed to each other and an expanded posture in which the end portions depart from each other symmetrically; a pair of thread retaining members disposed on the end portions of the base plate in such a fashion as to be opposed to each other when the base plate is in the folded posture, each of which is in the form of a column with the peripheral surface being in the form of a circular arc; and, an auxiliary plate being provided on each of end faces of the thread retaining members that are opposed to each other when the base plate is in the folded posture, wherein the auxiliary plate has flange portions and fixing portions, the flange portions being fixed to the end faces of the thread retaining members and one end of each of the fixing portions being formed continuously from the flange portion; and, each of the fixing portions extends from the flange portion in a longitudinal direction of the base plate so that the other end is fixed to the central portion of the base plate, a length of each of the fixing portions in a direction orthogonal to the longitudinal direction of the base plate being reduced gradually toward the center of the base plate.