Patent ID: 6749414
Filing Date: 2004-06-15
Classification: B29C,B33Y

Abstract:
A modeling machine of the type which builds three-dimensional objects by depositing thermally solidifiable modeling material as a road of molten material having a height h into a build environment having a temperature lower than an extrudate temperature of the material, and from an extrusion head that moves at a known speed in a predetermined cross-sectional pattern, comprising:a first supply of a first thermally solidifiable modeling material, in the form of a continuous filament; a second supply of a second thermally solidifiable modeling material, in the form of a continuous filament; a first thermally conductive dispenser carried by the extrusion head and having an inlet for receiving the first supply of the first thermally solidifiable modeling material and a tip for dispensing roads of the first material in molten form, the tip of the first dispenser having a downward face positioned in approximately a z-plane; a second thermally conductive dispenser carried by the extrusion head and having an inlet for receiving the second supply of the second thermally solidifiable modeling material and a tip for dispensing roads of the second material in molten form, the tip of the second dispenser being maintained in a fixed vertical position relative to the tip of the first dispenser, and having a downward face spaced apart a distance s from the face of the first dispenser and positioned in approximately the same z-plane as the face of the first dispenser; a thermally conductive body in which the dispensers are carried; a thermal insulator positioned in the body so as to provide thermal separation between the dispensers; a means for heating the first dispenser to a temperature at which the first material is flowable; and a means for heating the second dispenser to a temperature at which the second material is flowable; wherein the distance s is great enough that a road deposited by one of the tips will shrink due exclusively to cooling during a minimum transit time &Dgr;t between the tips such that the other one of the tips does not drag across and smear the road.