Neck finish for a container and mold for forming the container

Details Neck finish for a container and mold for forming the container Neck finish for a container and mold for forming the container

1999-11-16

2002-05-14

Davis, Robert (Department: 1722)

Bottles and jars

Neck

Structure to receive a particular closure

C425S525000

Reexamination Certificate

active

06386380

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to a neck finish on a container having an anti-thread distortion feature and more particularly relates to a neck finish for a container having a clearance designed into a bottle thread to allow horizontal withdrawal of bottle thread molding surfaces during manufacture.
Currently, in the forming of containers of plastic, glass, or other known materials, an extruded parison or injection molded preform is initially formed. In the use of plastics, materials such as polyethylene terephthalate (PET) or High Density Polyethylene (HDPE) are most commonly found. In the blow molding process for a container, the preform is positioned within a mold cavity which is defined by the coming together of two mold halves and the preform is held in place by the neck finish between the mold halves. In the molding process the preform is longitudinally stretched, usually by a push rod, and then laterally expanded by injection of a blowing gas or fluid into the interior of the preform. Upon completion of the molding process the mold halves are moved apart horizontally and in many instances during the separation of the mold surface, and particularly in the neck finish, the molding surfaces pull, tear, or rip the helically-shaped formed bottle container neck threads. A common problem found in the forming of containers utilizing steep-pitch threads is distortion of the threads upon removal of the container from the mold.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a neck finish for a bottle container including an anti-thread distortion feature.
It is another object of the present invention to provide a neck finish for a container which includes a clearance designed into a bottle thread to allow horizontal withdrawal of the bottle thread molding surfaces during the molding operation of a container without pulling, tearing, ripping, or otherwise deforming threads on the neck of the container.
It is yet another object of the present invention to provide a neck finish for a container which allows for the use of steep-pitch threads.
In accordance with the present invention, a blow molded container is formed from a parison. The neck finish of the container has been modified to assist in the separation of the mold upon the completion of the formation of a container without deforming the container thread profile. The neck finish is provided with a pair of recesses on opposed sides of the neck and also of the mold, each recess being disposed within a thread of the neck and in alignment with the direction of movement of the axially moveable mold sections which make up the container forming mold.
More particularly, the present invention provides a container with a neck portion having a first open end and an opposed second end opening into a body portion of the container. A helical thread of the type such as a steep-pitch helical thread or the like encircles the neck. The helical thread is provided for engagement with mating threads of a closure or container cap. A pair of recesses are provided within the helical thread wherein the recesses are spaced 180° apart. The recesses are formed by fingers in at least two axially movable mold sections. When the mold sections are joined together they form a mold cavity from which the container is formed.


REFERENCES:
patent: 1499612 (1924-07-01), Hammer
patent: 1577020 (1926-03-01), Hammer
patent: 1841980 (1932-01-01), Plattring
patent: 1866770 (1932-07-01), Hilgenberg
patent: 2169686 (1939-08-01), Fabrice
patent: 2589005 (1952-03-01), Welhart
patent: 3511403 (1970-05-01), Braun
patent: 4007848 (1977-02-01), Snyder
patent: 4084717 (1978-04-01), King
patent: 5366774 (1994-11-01), Pinto et al.
patent: 5423441 (1995-06-01), Conti
patent: 5431291 (1995-07-01), LaBombarbe, Jr.
patent: 5553727 (1996-09-01), Molinaro
patent: 100 375 (1984-02-01), None
Injection Molding Handbook, Rosato et al, pp. 198 and 199 and figure 7-24, Von Nostrand Reinhold Company, Inc, 1986.

Affiliated with

Also associated with

Rating

Neck finish for a container and mold for forming the container does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Neck finish for a container and mold for forming the container, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Neck finish for a container and mold for forming the container will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2906233