Plastic article or earthenware shaping or treating: apparatus – Female mold and charger to supply fluent stock under... – With means to heat or cool
Reexamination Certificate
1998-12-31
2001-03-06
Heitbrink, Tim (Department: 1722)
Plastic article or earthenware shaping or treating: apparatus
Female mold and charger to supply fluent stock under...
With means to heat or cool
C264S328140
Reexamination Certificate
active
06196830
ABSTRACT:
FIELD OF INVENTION
The present invention relates generally to a water jacket for injection molding apparatus, and more specifically, for heterocavity injection molding machines.
BACKGROUND OF THE INVENTION
In the field of thermoplastic injection molding, thermal regulation is critical for efficient production. Typically, plastic resin must be heated to a temperature where it flows freely as a liquid. The liquid plastic is then injected into a pre-shaped mold. When the mold is cooled, the plastic solidifies in the shape of the mold and the part is ejected. Thermoplastic materials have the tendency to stick to hot surfaces in the mold. Good thermal regulation reduces cycle times, prevent sticking, and aids in part ejection. Water is most commonly used to cool or heat the mold apparatus, although other fluids may be utilized.
An object of this invention is to provide a thermal regulating mechanism for injection molds, particularly heterocavity systems. A heterocavity injection mold machine has the ability to utilize a variety of different molds during operation. This permits operators to efficiently produce output for a plurality of clients. In addition, the heterocavity system allows the owners of different molds to share in the costs of the production run. Heterocavity systems provide significant cost and production benefits to the injection mold business. However, in heterocavity systems it is often necessary to change one or more molds used in the machine between runs. By minimizing the time consumed during these changeover periods, greater overall efficiency can be achieved.
A further object of this invention is to provide a quick-change feature for heterocavity mold system which utilize a variety of locking-key mechanisms to secure each individual mold within the mold base. In certain locking-key arrangements, even though only one mold may require changing before a production run, every mold is unlocked in the process. Although the other molds may stay in place within the mold base, they are not sufficiently secured to prevent leakage of the cooling fluid that circulates throughout the mold apparatus. Furthermore, new locking mechanisms may rely on the actual compression of the “A” and “B” plates during the molding process to form a tight fluid seal. However, while the “A” and “B” plates are separated, the individual molds are not completely rigid within the mold base, thereby causing some leakage of the cooling fluid.
Current systems such as that described in U.S. Pat. Nos. 5,647,114 and 4,828,479 to Pleasant ('114 and '479 patents) provide a circulation channel for fluid to cool or heat an injection mold assembly. However, fluid must be drawn out of the apparatus before the molds are changed. This delay slows down the production cycle of current molding systems which routinely swap various molds according to production needs.
Consequently, there is a need in the art for a water jacket apparatus which maintains the fluid barrier during mold changes, yet provides the requisite thermal regulating abilities for injection mold systems.
There is a further need in the art for a mold interface which provides a secure fluid inlet and outlet channels for fluid circulation within the mold itself.
SUMMARY OF THE INVENTION
The present invention solves significant problems in the art by providing a water jacket apparatus which does not require the fluid circulating around the perimeter of the mold to be drained when a mold is changed. The water jacket is preferably constructed of an oxidation-resistant material which has good heat conducting properties, such as AMPCO 940, a copper-beryllium alloy.
The water jacket comprises a sleeve dimensioned to receive a mold within the inside perimeter of the sleeve. The inside perimeter of the sleeve and the outside perimeter of the mold are designed to fit flush to provide the maximum amount of surface area contact. A conduit is beveled into the outside perimeter of the sleeve forming a circulation channel through which fluid, usually water, flows to either cool or heat the apparatus. The water jacket is rigidly fixed to a mold base through which a sleeve fluid duct provides a channel to transfer fluid to the circulation channel in the sleeve. Fluid-impermeable gaskets are sandwiched on either side of the circulation channel to prevent leakage of fluid into the mold base. One or more mold fluid ducts are provided in the mold base to circulate fluid throughout the mold itself.
It is also preferable to have a separate fluid circulation system directed to the actual mold inserted within the sleeve. This may be accomplished using a fluid input plug and fluid output plug extending from the mold base inside the perimeter of the sleeve. Rather than using
0
-ring gaskets which may fail to seal if the mold is not completely secured within the base, resilient, tapered plugs are received by opposing apertures in each mold to provide fluid circulation. In a preferred embodiment, the plugs are located towards the top of the mold base so that during changeovers, a minimal amount of fluid drains from the internal molds fluid channels when separated from the plugs.
Accordingly, it is an object of the present invention to provide an apparatus that permits operators of injection mold systems to quickly change one or more molds without requiring the operator to drain fluid from the fluid circulation channel surrounding the mold.
These and other objects, features, and advantages of the present invention may be more clearly understood and appreciated from a review of the following detailed description of the disclosed embodiments and by reference to the appended drawings and claims.
REFERENCES:
patent: 4622001 (1986-11-01), Bright et al.
patent: 4828479 (1989-05-01), Pleasant
patent: 5423670 (1995-06-01), Hamel
patent: 5647114 (1997-07-01), Pleasant
patent: 5935621 (1999-08-01), Gellert et al.
Cohan Norman H.
Foltuz Eugene L.
Gomez Enidio A.
Heitbrink Tim
Lott & Friedland, P.A.
Security Plastics Inc.
LandOfFree
Water jacket apparatus for injection molding systems does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Water jacket apparatus for injection molding systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Water jacket apparatus for injection molding systems will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2441298