US 11,738,509 B2
Extruders and printing machines for 3D metal printing
Krzysztof Wilk, Mysłowice (PL); Filip Turzyński, Sopot (PL); Bartosz Janus, Piekary Śla̧skie (PL); Robert Olesz, Piasek (PL); and Piotr Jop, Pawłów (PL)
Filed by Krzysztof Wilk, Mysłowice (PL); Filip Turzyński, Sopot (PL); Bartosz Janus, Piekary Śla̧skie (PL); Robert Olesz, Piasek (PL); and Piotr Jop, Pawłów (PL)
Filed on Jul. 31, 2020, as Appl. No. 16/944,256.
Prior Publication US 2022/0001608 A1, Jan. 6, 2022
Int. Cl. B29C 64/209 (2017.01); B29C 64/118 (2017.01); B29C 64/295 (2017.01); B29C 64/241 (2017.01); B33Y 30/00 (2015.01)
CPC B29C 64/209 (2017.08) [B29C 64/118 (2017.08); B29C 64/241 (2017.08); B29C 64/295 (2017.08); B33Y 30/00 (2014.12)] 1 Claim
OG exemplary drawing
 
1. An extruder for a 3D printing machine that is adapted to print with metallic filament substrates, which comprises:
(a) two rotating elements, each of which is at least partially cylindrical, wherein the two rotating elements are positioned parallel to each other, with a first of the rotating elements being configured to rotate in a first direction and a second of the rotating elements being configured to rotate in a second opposite direction;
(b) a transmission that is operably connected to at least one end of each of the two rotating elements, wherein the transmission is configured to drive rotation of the rotating elements in the first direction and the second opposite direction;
(c) a metallic filament contact zone located in a cylindrical area of each of the two rotating elements; and
(d) a flexible coating that at least partially covers the metallic filament contact zone, wherein the flexible coating is configured to be removed and replaced by an operator of the 3D printing machine, wherein:
(i) the two rotating elements comprise two cooperating knurled gears, which are made of a material selected from the group consisting of plastic, metal, and metal alloys, wherein the metal alloys are selected from the group consisting of steel, hardened steel, brass, and bronze;
(ii) the metallic filament contact zone of at least one of the rotating elements exhibits a reduced diameter area, wherein the reduced diameter area is dimensioned to create space between an exterior surface of the metallic filament contact zone and the flexible coating;
(iii) the flexible coating (A) exhibits a hardness between 20D and 70D, as measured on a Schore scale and (B) comprises a material selected from the group consisting of polyurethane, elastomers, vulcanized rubber, rubber, polyvinyl chloride, ethylene copolymer, and combinations of the foregoing materials; and
(iv) the extruder is (A) operably connected to a print head that includes a channel, heating block, and a conical-shaped nozzle and (B) configured to advance metallic filament substrates towards the print head, wherein the metallic filament substrates are between 50% and 85% metal.