Band winding apparatus for forming a bead core

A band winding apparatus for forming a bead core comprising a winding device which is composed of

• a drum capable of expanding and contracting a diameter of the drum, rotatably supported by a support shaft, and having a peripheral surface on which a band for forming a bead core is wound, and
• holding means installed in the drum and having a holding surface capable of detachably holding a start end of the band on the drum, wherein
• said holding surface is arranged approximately flush with the peripheral surface of the drum
• said drum includes a diamond shaped central portion mounted on the support shaft and four semi-circular expanding pieces each having a partially circular shape so as to form the peripheral surface of the drum and each expanding piece having a rectilinear side, the rectilinear sides of said expanding pieces being arranged along four sides of the diamond shaped central portion,
• an adjacent two of said expanding pieces comprising a first pair and being pivotally secured to a first pin therebetween and a second two of said expanding pieces comprising a second pair and being pivotally secured to a second pin therebetween;
• said first and second pins being located at opposite corners of said diamond shaped central portion;
• at least one toggle means interconnecting said first and second pairs of expanding pieces so that movement of said toggle means will pivot said expanding pieces to expand and contact the diameter of said drum.