This is how the filling system adopted by the Pilot for its Super line is called, by the shape of the knob that activates filling. As can be seen from the relevant patent (nº US-2871825), this is a system based on the same principle as the button filler, in which a I-bar is flexed by actuating a sort of switch at the bottom of the pen. The system is very similar to the bottom lever filler of the Aurora, in particular to the variant with ball used on the Superna; unlike this, however, the operation is done by removing the shaft of the pen to access the internal mechanism.
- Patent n° US-2871825, of 1959-02-03, requested on 1956-01-18, of Ryujiro Uchida, Chuji Kurihara, Pilot. Fountain pen.