US 7,066,338 B1Granted

Filter element with anti-tracking ribs

AssigneeFilter Technology Australia Pty Ltd.

InventorsJosef Winter, Harold Thomas Krelle

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Abstract

An injection moulding assembly (10) comprising a male moulding member (11) surrounded by a female moulding member (12) forming a void (13) between them that upon injection of molten plastics into the mould a container can be formed. The moulding assembly includes a guide rod (14) and ejection flange (16) and a pair of ejection flange guide rods (17 and 18), an air vent valve (15) and an injection passage (19). The male member (11) includes in this embodiment eight grooves (20) unevenly spaced so that the partially hardened container formed in the injection mould can be pushed from the mould using the ejection flange (16) while the container is sufficiently green to enable the ribs formed in the grooves (20) to move over the surface of the male mould (11) during the ejection process.

Claims18

Dependent claims

A filter element comprising:

a rigid injection moulded generally cylindrical canister formed about a male mould member, the canister having an internal diameter, an open end and a side wall, the side wall having an outer surface and an inner surface;
and
a paper roll as filter media,
wherein at least five spaced anti-tracking ribs project from the inner surface of the side wall a distance sufficient to enable the canister to be removed from the male mould member during a moulding process and while still sufficiently flexible, at least five of said ribs being unevenly spaced such that there is a unique distance between every two immediately adjacent ribs,
the paper roll has a marginally greater diameter than the internal diameter of the canister prior to insertion into the canister, and
the canister is sufficiently rigid and the paper roll is sufficiently tightly wound that the paper roll, when inserted into the canister using a press, is substantially compressed to the internal diameter of the canister without distortion of the canister.

3 more elements

Dependencies are inferred from the claim text.