US 11,883,914 B2
Contact tip for arc welding with a channel having a stellate, multi-lobular cross-section with convexly rounded sides
Carsten Hune, Wallenhorst (DE); Jörg Schönfeld, Ibbenbüren (DE); Frank Böert, Wallenhorst (DE); Reinhard Hintemann, Osnabrück (DE); Hans-Günter Wobker, Bramsche (DE); and Stephan Meyer, Stemshorn (DE)
Assigned to Cunova GmbH, Osnabrück (DE)
Appl. No. 16/755,456
Filed by KME Germany GmbH & Co. KG, Osnabrück (DE)
PCT Filed Oct. 8, 2018, PCT No. PCT/DE2018/100832
§ 371(c)(1), (2) Date Apr. 10, 2020,
PCT Pub. No. WO2019/072338, PCT Pub. Date Apr. 18, 2019.
Claims priority of application No. 10 2017 123 749.6 (DE), filed on Oct. 12, 2017.
Prior Publication US 2020/0238422 A1, Jul. 30, 2020
Int. Cl. B23K 9/173 (2006.01); B23K 9/29 (2006.01); B23K 9/12 (2006.01); B23K 9/26 (2006.01)
CPC B23K 9/173 (2013.01) [B23K 9/295 (2013.01); B23K 9/123 (2013.01); B23K 9/124 (2013.01); B23K 9/26 (2013.01); B65H 2701/36 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A contact tip for arc welding, comprising a channel passing through the contact tip for receiving a welding wire and having a crosssection which is non-round and has in cross-section a stellate, multilobular profile with convexly rounded sides and at least 5 corners which define corners of an imaginary polygon, said convexly rounded sides being configured in crosssection at least partially as circular arcs which are defined by a radius which extends from a center point located outside the polygon, said convexly rounded &des including a central region which is convexly rounded, and edge regions adjoining the central region tangentially and configured as straight lines, said edge regions being sized each shorter than the central region wherein pockets, which are rounded in their lowest point, are arranged between adjacent convexly rounded sides of the multi-lobular profile, wherein the radius is in a range from 0.5 to 4 mm, the rounded sides of the multilobular profile define radially innermost points which delimit an inner circle defined by a diameter which is greater by 15 to 20% than a diameter of the welding wire, and the radius of the circular arcs is greater than a radius of the inner circle.