| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a synthetic-resin-made screwable cap capable of reducing a resin quantity for molding, having good mold releasability after the molding, and with excellent washability. <P>SOLUTION: The synthetic resin cap has a top wall 2 and a skirt wall 3 and screws over an external thread formed on the outer peripheral surface of a container mouth for sealing a container. An upper surface and a lower surface in at least the axial direction have screwing protrusions consisting of hemispheres 5 having a curved surface to screw with the thread of the container mouth dotted with intervals longer than at least the length in a lead angle direction of the hemisphere in accordance with screw pitches of the container to screw with the inner peripheral surface of the skirt. The screwing protrusions are shifted circumferential direction so that the positional relation between the axially and vertically adjacent screwing protrusions is such that the centers of the protrusions do not overlap in the axial direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
