An evaporable foam pattern assembly for use in a process of casting a
one-piece article in a mold filled with flowable particulate molding
material. A first foam pattern section includes a first recess pattern
portion and an adhesive surface pattern adapted to be joined to an
adhesive surface pattern of a second foam pattern section having a second
recess pattern portion that is registered with the first recess pattern
portion to define the article when the adhesive surface patterns of the
first and second foam pattern sections are adheringly joined. The
registered first and second recess pattern portions define an outer
shaped surface pattern of the article, and an inner shaped surface
pattern of the article. An inlet end section of a tubular passageway
cavity pattern forms a fluid flow path from the inner shaped surface
pattern through an outlet end section of the tubular passageway cavity
pattern that extends openly and outwardly through the outer shaped
surface pattern. A structural configuration at the inlet end section is
effective to enhance movement of particulate molding material into the
passageway cavity pattern during the casting process to form a passageway
fluid connection section within the article. Molten material poured into
the mold evaporates and replaces the evaporable pattern assembly to
produce the article. The invention more specifically produces a novel
one-piece brake caliper casting having a cast-in tubular passageway
having an inner surface diameter of less than about 6.0 mm. The unique
casting design minimizes the time required to machine and assembly the
finished disc brake caliper of the invention.