Method of manufacturing a filter cartridge
AssigneeFilter Technology Australia Pty Ltd.
InventorsJosef Winter, Harold Thomas Krelle
Life of this patent
Estimating the term…
Abstract
An injection moulding assembly includes a male moulding member surrounded by a female moulding member forming a void between them that upon injection of molten plastics into the mould a container can be formed. The moulding assembly includes a guide rod and ejection flange and a pair of ejection flange guide rods, an air vent valve and an injection passage. The male member includes in this embodiment eight grooves unevenly spaced so that the partially hardened container formed in the injection mould can be pushed from the mould using the ejection flange while the container is sufficiently green to enable the ribs formed in the grooves to move over the surface of the male mould during the ejection process.
Claims9
A method of constructing an internally ribbed injection molded hollow tube for a filter element, the method comprising steps of:
- providing a generally cylindrical male mold member having longitudinally spaced ribs defining grooves and a free end;
- providing a female mold member adapted to overlay the male mould member in closely spaced relation and define a tube shaped void between the mold members;
- injecting molding material into the void, said molding material providing a solid-walled substantially rigid tube when cured;
- removing the female mold member from the male mold member while the tube is in a green state, the grooves in the male mould member retaining the tube in position on the male mould member;
- and
- subsequently forcing the tube from the male mold member while the tube is still in a green state to form an internally ribbed injection molded solid-walled hollow tube having an open end,
- wherein the grooves are not uniformly spaced on the male mold member and further comprising the step of progressively sliding the tube off the male mold member, so that once the initial release of the tube from all of the grooves takes place, ribs formed in the grooves do not all encounter grooves at the same time.
Dependencies are inferred from the claim text.