Inner bobbin case holder of a fully rotating hook

摘要

A bobbin case holder body and a track projection portion are made of steel. A coating member of a liquid crystal polymer is integrally molded to the outer surface of the track projection portion so as to have a thickness t which is selected to be 0.3 to 0.5 mm. A part of the coating member is fitted into a groove formed in the track projection portion, thereby preventing the member from peeling off. In a loop spreading portion, the track projection portion made of steel is exposed from the coating member so that a so-called thread handing area is prevented from being formed. Therefore, wear resistance and durability are improved.