Abstract: An extrusion head for a three-dimensional printer is disclosed including a feed tube, a heater, a cooler, and a bridge. The feed tube can be made of metal and has an inlet for receiving a forwardly driven filament of solid deposition material, an outlet, a downstream portion adjacent to the outlet, an upstream portion upstream from the downstream portion, and an internal passage extending from the inlet to the outlet. The heater is thermally coupled with the downstream portion of the feed tube for heating a filament to provide softened fluid deposition material. The cooler is thermally coupled with the upstream portion and spaced generally axially from the heater to define a generally axially extending gap traversed by the feed tube. The bridge traverses the gap and provides a rigid mechanical connection between the heater and the cooler.

Abstract: An extrusion head for a three-dimensional printer is disclosed including a feed tube, a heater, a cooler, and a bridge. The feed tube can be made of metal and has an inlet for receiving a forwardly driven filament of solid deposition material, an outlet, a downstream portion adjacent to the outlet, an upstream portion upstream from the downstream portion, and an internal passage extending from the inlet to the outlet. The heater is thermally coupled with the downstream portion of the feed tube for heating a filament to provide softened fluid deposition material. The cooler is thermally coupled with the upstream portion and spaced generally axially from the heater to define a generally axially extending gap traversed by the feed tube. The bridge traverses the gap and provides a rigid mechanical connection between the heater and the cooler.