Adjustable core pin for vial molding

Abstract

An adjustable core pin for molding vials for use in levels and those vials molded using the adjustable core pin are disclose. The core pin includes an elongate rod with a crest at its cross section with the greatest diameter and a rod retainer with a cavity which receives the rod such that the distal end of the rod projects from a rod retainer distal opening, the rod being adjustable in relation to the rod retainer so that the crest can be adjustably placed at a preferred position in a molding cavity for vial molding.

Description

RELATED APPLICATION [0001] This application claims the benefit of the filing date of copending U.S. patent application Ser. No. 10 / 060,503, filed Jan. 30, 2002, and incorporates the disclosure of which herein.FIELD OF THE INVENTION [0002] This invention relates generally to molding processes using core pins, and in particular, to a process of molding barrel-shaped vials for use with levels. BACKGROUND OF THE INVENTION [0003] The molding process for making barrel-shaped vials or other tube-like items with elongate cavities typically utilizes injection molding around a core pin. Injection molding of plastic materials is well known in the art and is well suited for forming a large number of discrete items such as vials. [0004] During the injection molding process, a core pin is inserted into a molding cavity such that the space between the pin and cavity defines the shape of the intended product mold. When the pin is positioned in the cavity, a plastic material, such as acrylic, polyca...

AI Technical Summary

Benefits of technology

[0010] It is an object of the invention to provide an improved core pin which can be adjusted after fabrication to allow the centering of its largest cross section.

Problems solved by technology

While such grinders typically allow for great precision, in practice it is extremely difficult to fabricate core pins having the proper positioning and alignment of the largest cross section.

Compounding that difficulty is the fact that the measurement of the position of the largest circular cross section on the core pin is extremely difficult to obtain.

Therefore, verification of the position of the largest cross section on the core pin is practically impossible.

Because the position of the core pin's largest cross section is so difficult to determine, core pins used for molding barrel-shaped level vials are inherently imprecise.

If the position is determined to be too close to the distal end, the core pin is defective and cannot be used.

If the position is determined to be too far from the distal end of the core pin, the core pin can be ground further to center the position; however, this process is expensive and does not always result in a more precise core pin.

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