Patent attributes
An upper through hole is formed in a support base, a lower end of the upper through hole being opened in an upper-side sliding contact surface of the support base, the upper through hole being configured to receive insertion of an upper portion of a pivot shaft; a lower through hole is formed in a rockable section, the lower through hole and the upper through hole being provided on the same axis, an upper end of the lower through hole being opened in contact with the upper-side sliding contact surface, the lower through hole being configured to receive insertion of a lower portion of the pivot shaft; an enlarged diameter hole section is provided in the lower through hole, the enlarged diameter hole section being configured to accommodate a needle bearing having a cylindrical shape, the needle bearing being fit to an outer side of at least a lower shaft portion of the pivot shaft; and the needle bearing having the cylindrical shape bears the lower shaft portion of the pivot shaft.
