| 摘要 |
A method of producing a valve includes the steps of: providing a mold comprising a pair of mating mold halves, with each of the mold halves including a mold cavity; providing a valve member-stem unit comprising a valve member of substantially circular cross-section attached to a stem, with the valve member including a passageway extending therethrough in a direction generally normal to the stem; inserting a mold core into the passageway of the valve member-stem unit to form a mold insert assembly; positioning the mold insert assembly within the cavity of a first of the mold halves; positioning a second of the mold halves in adjacent contacting relationship with the first mold half such that the mold insert assembly is located within the mold cavities of the first and second mold halves; injecting a polymeric material into the mold half cavities such that a valve casing forms around and captures the valve member-stem unit; and removing the valve casing, the valve member-stem unit and the mold core from the mold halves. With this method, the casing of the valve can be formed around the ball-stem unit during molding so that the product of the molding steps is ready for use. |
