Patent ID: 7275585

Claim:
A process for the manufacture by lost wax moulding of a part that includes at least one cavity, comprising, forming a core in a ceramic material to reproduce said cavity, inserting the core into in a wax mould, placing at least one element on the core thereby forming a spacer between the core and an internal wall of the wax mould, forming a wax model of the part with the core by injecting wax into the mould, forming a shell mould in ceramic material from the wax model, removing the wax, pouring casting metal into the shell mould, and dissolving said at least one element with the casting metal during said pouring of said casting metal, wherein said dissolving of said at least one element is performed such that an outer surface of said part is free of protuberances at a location where said at least one element was placed, and wherein the element is of elongated form and placed on the core in a laying position such that the element is flush with an outer surface of the wax model formed by injecting wax into the mould.