Methods for forming faucets and fixtures

Abstract

This invention provides methods for forming stainless steel, single-piece, multi-chambered water faucets and fixtures with a single one-body construction. A variety of stainless steel products can be formed with a main body having an internal hollow region and a plurality of dividing chambers. The main body may be constructed using high temperature resistant ceramic cores in combination with a lost wax investment casting process. The stainless steel products formed from a single piece construction can eliminate the need for additional time-consuming manufacturing steps, such as parts welding, screw assembly, or precision press fitting. In addition, water faucets and fixtures can be provided that are substantially lead-free, non-verdigris, and non-toxic in compliance with environmental regulations and lead / toxic limits.

Description

CROSS-REFERENCE[0001]This application claims the benefit of priority to U.S. Provisional Application No. 61 / 269,609 filed Jun. 26, 2009, which is incorporated by reference herein in its entirety.FIELD OF INVENTION[0002]The invention relates to investment casting (“IC”). More particularly, the invention relates to processes and structures formed from ceramic core patterns for lost wax investment casting that are capable of producing single-body metal structures formed with single or multiple interior chambers.BACKGROUND[0003]Environmental concerns around pollution and current economic development are forcing changes to the design and manufacture of water faucets that traditionally have been constructed of soft metal alloys containing lead (Pb). For more than hundred years, this traditional manufacturing process has been improved from sand casting to shell molding, even permanent mold casting. This process typically utilizes low-temperature metal alloys that require casting temperatur...

AI Technical Summary

Benefits of technology

[0011]The manufacture process of may include the use of ceramic cores, precise positioning of the ceramic core, and one or more wax injection processes to form a complete one-body construction wax pattern with internal structures, such as multiple hollow center chambers or chambers with hollow internal portions. A wax pattern can be subjected to a pattern tree assembly process that includes one or more of the following processes: slurry dipping, coating to build up the outer shell, lost wax, shell sintering, melt stainless steel pouring to complete a hollow center, and one-body construction stainless steel faucet body after the removal of the internal ceramic cores.

[0014]Another aspect of the invention provides stainless steel faucets and water fixtures that are substantially lead-free, non-verdigris, non-toxic. Such products may be manufactured to comply with EPA regulations and imposed lead / toxic limits, while also saving manufacturing costs by eliminating additional welding or machining expenses. Other aspects of the invention combine also the use of CIM processes and cores with investment casting techniques to produce a variety of products, including single body construction stainless water fixtures such as faucets that are made with less hazardous metals such as stainless steel.

Problems solved by technology

Thus the composition of the alloy can be detrimental to humans.

These heavy metal elements will accumulate beyond the tolerance or load of human body and organs that will eventually lead to or cause various types of known toxic metal lead poisoning that impacts the nervous systems, mental capacity, skeletal, muscular and cardiovascular systems.

These conditions are particularly harmful to young children, pregnant women and older adults.

If human beings drink such water for a long or extended period of time, this will be harmful to their bodies and cause damage to their brains, nervous systems, kidneys and red blood cells.

In particular, if pregnant women and children drink such water, then the consequences are unthinkably miserable.

However due to the complexity and small size of the internal passages, construction of a water faucet main body, there are many drawbacks in using current manufacturing processes and investment casting techniques to form water faucet main bodies.

These include, but are not limited to, the following: the lack of a de-molding-able support to produce hollow chambers within a wax pattern; the difficulties of homogenous slurry dipping and coating when dipping to build up the layers with adequately necessary shell strength for a subsequent process of shell sintering and pouring of melted stainless steel; and the internal shell removal from or out of a casting body.

Consequently such substantial limitations in various stages of an investment casting process fail to produce a sophisticated casting body constructed with the internal complexity of one or more hollow center chambers at an industrial scale with economics that matches the low-temperature alloys.

This description generally represents the current level of investment casting available today for making stainless steel utility faucets with serious limitations in the formation process which not only limits the functionality and aesthetics of the unit, but requires expensive and complex secondary processes such as welding, multiple part assembly and other steps that may introduce oxidation, corrosion, points of failure and / or un-necessary manufacturing expenses.

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