Abstract: An apparatus for forming a moulded article includes a stationary mould core with an external threaded surface. A female mould surrounds a portion of the mould core including the threaded surface in a mould closed condition to define a mould cavity between the mould core and the female mould. Molten plastic is injected into the mould cavity to form the moulded article. A rotatable sleeve surrounds the mould core and engages with the moulded article formed in the mould cavity. The sleeve carries a gear wheel which meshes with a pinion. A rack is associated with the pinon and is moveable linearly to impart rotation of the pinion and in turn the sleeve. A lead screw on the sleeve engages a lead screw nut to cause the sleeve to displace axially along the mould core as the sleeve rotates. Lugs on the sleeve engages the moulded article and causes it to rotate with the sleeve so that the moulded article unscrews from the mould core allowing it to be ejected from the apparatus.

Abstract: An insert for providing a seal at the junction of axially aligned bores extending through two adjacent segments of material. The insert is of a rigid material, has an inner diameter equal to the diameter of the bore, and comprises a retaining portion with a frusto-conical outer surface and a stem portion with a cylindrical outer surface. The insert is retained in a co-axial recess which extends inwardly from the face of one of the segments of material. In this manner, the retaining portion of the insert and the walls of the recess define a groove for retaining an O-ring. Also described is a method of providing a seal at the junction of axially aligned bores extending through two segments of material. The method includes the steps of boring a recess in one of the bores, introducing the insert into the recess, retainably inserting an O-ring into an annular groove defined between the insert and the recess, and bringing the segments together.