| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to positively fit a sprue part to a specific split mold during mold opening without allowing the spool part to fit to another split mold by providing a second sprue lock to the outer face of a protrusion with a tapered sprue lock which is formed as an undercut in the inner face. SOLUTION: A second sprue lock 11 of an annular recessed shape is formed on the outer face of an annular protrusion 9 with a tapered sprue lock 10 which is formed as an undercut on the inner face. Therefore, the fitting strength of a sprue part (b) to the second spool lock 11 is added to the fitting strength of the sprue part (b) to the spool lock 10. Consequently, if the fitting strength of the sprue part (b) to the sprue lock 10 is reduced by setting the inclined angle of the taper of the sprue lock 10 at a comparatively lower degree, this angular insufficiency can be compensated for by the addition of the fitting strength of the sprue part (b) to the second sprue lock 11. Thus, it is possible to positively fit the sprue part (b) to a stem 4 during mold opening. |
