Evaporable foam pattern for use in a casting process and having load

Abstract

An evaporable foam pattern for use in casting a metal part, such as an engine block. The pattern includes a first evapoable foam section having an outer peripheral rim and an internal wall which is spaced from the rim. The pattern also includes a second pattern section having a rim disposed in abutting engagement with the rim of the first section and having an internal wall spaced from the rim and disposed in abutting engagement with the internal wall of the first section. A third pattern section is disposed outwardly of said second section and has a rim disposed in abutting engagement with the rim of the second section. A layer of adhesive or glue is disposed between the abutting rims and between the abutting internal walls. Load transmitting members interconnecting the outer surface of the second pattern section with the inner surface of the third pattern section and are located in load transmitting alignment with the abutting internal walls so that an external clamping force applied to the outer surface of the third section during the gluing operation will be transmitted through the load transmitting members to the abutting internal walls to maintain the walls in tight bearing engagement. The clamping forces are thus resisted by direction compression of the thin foam walls rather than by bending of the foam.