Karl Kristian Masden

Inventor of a semi-automatic arc welding machine and method

Karl Kristian Masden was the inventor of a semi-automatic arc welding machine and method.

Patent US2470178A of 16 March 1945 (Denemark) and 17 May 1949 (USA)

The electrode (8) was clamped to an articulated arm (7) moving downwards by gravity and conventionally supplied with welding voltage via a cable (9). Using two pins (4), one of which is not visible, the foot (3) was moved along the butt weld so that the electrode was always guided at right angles to the weld seam.

The method was later called "gravity welding" because the patent specification describes that "the tip of the electrode core is maintained at arc-striking distance from the workpiece by gravity or by other suitable means."
In a process variant described in the patent specification, the method can also be used to produce fillet welds.
Karl Kristian Masden applied for the patent on 16 March 1945 Denmark. It was published in the USA on 17 May 1949 as US2470178A, and not in 1938, as often claimed.
In the 1960s, the process gained popularity for a short time when it became successful in Japanese shipyards, but after that it was only used in isolated applications.


Lomas de Zamora F. C. S.

Karl Kristian Masden was living in Lomas de Zamora F. C. S. in Argentina at the time of the patent application. The acronym behind the place name in the patent application is probably intended to clarify that this was the place with the railway station on the railway line of Ferrocarril del Sud. The patent was granted to the public limited company ESAB in Copenhagen, Denmark. 

Lomas de Zamora railway station of the Ferrocarril del Sud (F. C. S.) in Argentina

© Argentinische Nationalbibliothek, 1902