Patent ID: 8647098

Claim:
A liquefier assembly for use in an extrusion-based additive manufacturing system, the liquefier assembly comprising: a downstream portion comprising a first end and a second end opposite of the first end along a longitudinal length of the liquefier assembly, wherein the downstream portion has a first average inner cross-sectional area; an upstream portion disposed adjacent to the first end of the downstream portion, the upstream portion being configured to receive a consumable material, wherein the upstream portion includes a hollow liner having a second average inner cross-sectional area that is less than the first inner cross-sectional area, and wherein the hollow liner defines a shoulder between the first inner cross-sectional area and the second inner cross-sectional area, the shoulder being configured to restrict movement of a melt meniscus of the consumable material; an external heat transfer component extending around the downstream portion between the first end and the second end of the downstream portion, the external heat transfer component being configured to conduct heat to the consumable material within the downstream portion; and an extrusion tip disposed at the second end of the downstream portion.