RORFORBINDNINGSDEL ELLER DYLIKT SAMT FORFARANDE OCH VERKTYG FOR DESS FRAMSTELLNING

摘要

A hard outer member generally centered on an axis and having a concave inner surface is injection molded of a relatively hard synthetic resin to have on its inner surface at one end a recess formed with a radially throughgoing passage. Parts of the mold in which this member is molded are then displaced before the resin has time to cure and another softer synthetic resin is injected through this radially throughgoing passage to form in the recess a relatively soft seal having a sprue extending through the passage. The seal therefore adheres in surface contact with the inner surface at the recess and the sprue further ensures excellent holding of the seal on the member.