Automotive and Aerospace Materials in a Continuous, Pressurized

Mold Filling and Casting Machine

The invention achieves pressurized filling and pressurized solidification

of moving molds at selectable and different pressures.

SUMMARY OF THE BENEFITS OF THE INVENTION

A manager of a permanent mold, alloy wheel foundry has said:

"Whoever invents a way to cast wheels on a vertical green sand molding machine will own this business!" The Herron, Continuous, Pressurized, Casting Process is the way!

Pressurized bottom filling of molds enables use of fine grain, high density mold media, the pressure overcoming the low mold permeability. Economical sand of any mineral may therefore be used to chill cast wheels, rather than, expensive and slow, permanent molding. The fine grain sand produces exceptional surface finish when the pressure is controlled and minimized to fill the mold, yet not penetrate or burn into the molding sand. The Herron Casting Machine controls pressure.

Pressurized solidification enables improved feeding of solidification shrinkage in any mold orientation, irrespective of the gravitational feeding direction. Alloy wheels, normally cast horizontally, may thus be cast in the higher speed, vertical orientation. The Herron Casting Machine increases the pressure as needed to produce high integrity, high strength alloy wheels.

Vertically parted green sand molding machines may reach production speeds of 500 molds per hour. To enable such productivity, current pouring and filling methods must complete their operation within the short cycle time. Even at 250 molds per hour, this rapid pouring, or filling, violates fluid flow principles for lamellar, non-turbulent flow. Scrap rates are excessive and elaborate methods to filter metal or fill the mold often raise the cost of casting. Generally, the molding machine production rate must simply be reduced. The Herron Casting Machine solves this problem by filling slowly and continuously during the rapid movement of molds.

Exceptional quality in alloy wheels traditionally comes at a high price. Permanent mold tooling is expensive and pressurized solidification dramatically limits productivity. Now, with this invention, the Herron Casting Machine achieves the same or better quality and properties in economical, expendable mold media. The weakest link in foundry technology, the interface between modern molding and modern melting, the filling operation, has now been automated and refined. The pressurized filling and feeding of continuously moving expendable molds is now possible.

TWO WHEELS CAST VERTICALLY

TWO WHEELS PER MOLD, CONTINUOUSLY CAST, HORIZONTAL OPTION

OPERATION OF THE INVENTION

The novel invention operates simply and with very few moving parts. The system is quiet, clean and contained. Hard sand molds, with or without binders, float on a pressurized bath of liquid metal. A restraint device resists rupture of the mold and presses the mold onto the filling/feeding chamber to seal against runout or leakage. The molds are pushed through the unit, maintaining connection as long as desired, even until solidified. Various methods may be used to enhance the seal. Simple to complex furnace designs allow any degree of time, temperature and pressure control.

At extreme quality requirements, molds must be of fine media with low permeability and thus require pressurized filling. Pressurized, solidification shrinkage feeding has been identified as necessary for finest dendritic grain structure, essential for high elongation, ultimate strength, aluminum castings. To meet this quality level, the invention achieves pressurized filling and pressurized solidification of moving molds, at selectable and different pressures. This quality level is possible at high speeds with the dramatic cost improvements of consumable mold media. High quality aluminum alloy wheels may be produced at up to 1000 pieces per hour. The invented method is detailed in FIGS. 36-38 of the patent application.

BUSINESS OPPORTUNITIES

Licensing is currently available for foundries to build their own custom equipment and operate the process under license. Preferred licensing terms or exclusive licensing is available to early participants in prototyping.

Certain patent pending methods to other castings and metals, such as engine cylinder heads and brake parts are also available. A new method of treating ductile iron is incorporated in the process. Please write, call, or E-mail for an executive summary on these other applications.

We are in process of negotiation on rights to manufacture and market components of the machine. Engineering firms and OEMs are invited to consider strategic partnership with Herron Casting Services, P.O. Box 3403, Barrington, IL 60610. Phone: 312-261-0229

THE VACUUM AND PRESSURE CONTROLLED FILLING AND FEEDING VESSEL

WITH MOLD SUPPORT/RESTRAINT DEVICE

This machine comes is single or multiple chamber configurations. Automated controls allow precise and consistent pressures, mold after mold, for filling and for feeding. The furnace is replenished at will, at one location, achieving the energy and environmental benefits of complete containment. Precise temperature control, mold after mold, means consistent casting integrity including hardness and other mechanical properties. Quiet, clean, and safe mold processing with no pour-off labor, no under-pours, no over-pours nor any spilled metal results with proper operation.

The two business products together achieve higher mold utilization with reduced or eliminated risering. Inclusions are eliminated by the clean practices: the bottom filling, the filtration, and the controlled quiescent velocity and pressures of the flowing metal.

CAST ALUMINUM WHEELS ACCORDING TO THE HIGH INTEGRITY,

HIGH SPEED, CONTINUOUS, PRESSURIZED, CASTING MACHINE

A primary goal in the development of the Herron Casting Machine was to automate the casting of aluminum wheels into high speed vertical green sand molds or lost foam. Pressurized filling and pressurized solidification are essential to achieving the necessary properties.

Plain wheels may be produced with normal core sand at the required strength with the casting machine equipment invented. Highly popular, esthetic wheels can also be made using special purpose facing cores. These may be fine grained silica, with or without a core wash or coating. Olivine, zircon or other minerals may be used. Semi-permanent cores of graphite or other material may be used. Even reusable metal dies may be used as the special purpose core riding inside the vertical green sand molds.

This special purpose core, for esthetic appearance, or for rapid, high quality, chilled solidification, is of one piece construction, in the preferred embodiment, forming the face for two wheels. The common gating is either drilled, machined, or formed by mandrels, through the special purpose core (199). At shakeout (880) the gating (108) breaks from the wheel's (995) center hub and the hub of the wheel (995) is drilled out, leaving no marks from the gating (108).

The outer rims of the wheels (995) are formed by two identical conventional cores (122) of high quality. The bulk of the inside of the wheels (995) is formed by the economical green sand (101 or 111). The early solid metal shell (650 in other drawings), discussed elsewhere, protects the surface finish sufficiently from the higher pressure over the secondary solidification feeding chamber (414).

Wheels may also be produced in loose sand molding. The cores may be bound together by consumable lost foam patterns.

A lower rim gate (108) may be employed for completely gentle, bottom filling of the wheels. By multiplying this assembly (38, see FIG. 38), four wheels may be made in a mold, at four wheels per cycle of the molding machine, for near 1000 wheels per hour.

THE NEXT STEP

Several independent programs to prototype the invention are under discussion. We expect to have a working prototype available for visitation and tour within six months. A small and simple embodiment is sufficient to prove the principles of operation.

I would like to present a full disclosure and business plan to any interested parties, particularly foundries and equipment manufacturers. The period of disclosure with trade secrecy is now ending, so we are now widely disseminating the information. Many positive endorsements are in hand.

Preferred licensing arrangements will be available to those willing to build a prototype open to outside visitors. Exclusive partnerships to build and market the equipment are also available. Venture funding opportunities are welcome.

Please E-mail DHerron@HerronCasting.com to schedule our complete presentation. Thank you.

U.S. Patent #6,637,497

International PCT Patents Pending