Finish for injection blow molded container

Abstract

An injection molded finish portion of a container preform has an annular wall with an end sealing surface. A set of ratchet teeth are located at a lower end of the annular wall on a flange having upper and lower surfaces including radially inward edges coterminous with the annular wall. A threaded portion is located below the sealing surface and above the ratchet teeth that includes sets of inclined threads extending part way around the annular wall, the threads having crest portions that terminate at planes tangent to the annular wall along parting lines on opposite sides of the finish. Lugs project outward from the annular wall in the vicinity of the parting lines to ensure correct interaction between the ratchet teeth and a cooperating flexible closure.

Description

BACKGROUND [0001] 1. Technical Field [0002] The present invention is directed generally to neck structures of containers and preforms that are particularly adapted to receiving flexible closures that include a tamper indicating band. [0003] 2. General Background [0004] Flexible closures that include a tamper indicating band are commonly employed on extrusion blow molded plastic jugs typically used in the dairy industry. Closures of this general type are disclosed, for example, in U.S. Pat. Nos. 3,980,195; 5,480,045 and 6,003,701. Another similar closure in common use is a Super Quad ASP-100 available from Blackhawk Molding Co., Inc., of Addison, Ill. Closures of this general type are typically made of low density polyethylene and are therefore very flexible and unsuitable for use to contain carbonated beverages. Such closures generally include an end panel having an interior surface that can include various sealing elements. The end panel is surrounded by a skirt having an interior ...

AI Technical Summary

Benefits of technology

[0012] One feature of a finish portion molded in accordance with the present invention is the termination of the crest portions of the threads in planes tangent to the parting lines so that the threads are not deformed by the outwardly moving mold surfaces upon release of the finish portion from the corresponding mold.

[0014] A further feature of a finish portion molded in accordance with the present invention is the placement and configuration of the ratchet teeth so that interaction with the tamper indicating band in maximized.

Problems solved by technology

Closures of this general type are typically made of low density polyethylene and are therefore very flexible and unsuitable for use to contain carbonated beverages.

Any attempt at a straight reproduction of the exterior finish geometry of a given extrusion blow molded container into an injection blow molded container would result in a very heavy, and thus overly expensive, finish, probably containing flaws due to the general inability of the injection molded finish to flex as the molded article is removed from the mold.

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