PURPOSE: To enable the collection of cocoon in high efficiency without damaging boundaries of a frame of paper boards crossing rectangularly for putting cocoons, by changing the shape of a piece for pushing out cocoons.

CONSTITUTION: The piece 6 for pushing out cocoons is not directly attached to the revolving shaft 5, a cylindrical piece having a shape obtained by cutting a pipe or round rod is used as the piece 6 for pushing out cocoons, and the piece is connected to the revolving shaft by using a laminar or cylindrical connecting rod. The connecting rod 4 has a shape and size wherein the piece is not brought into contact with the top c of the side of the boundaries of the frame 3 made of paper boards crossing rectangularly for putting cocoons when the piece 6 for pushing out cocoons is introduced into the frame 3.