The first truly efficient and functional automatic filling system based on the compression of a rubber tank was the famous crescent filler, designed by Roy Conklin' who patented it in 1901 (nº US-685258), which was introduced to the market by the company of the same name founded by him, the first example of the success of a brand due to the invention of an innovative filling mechanism.
The crescent filler is based on the realization of a particular pressure bar on which a metal crescent shaped bow is welded (from which derives the name given to the system by its inventor). The bow comes out of the body of the pen through a side slit made on the shaft of the same. By pressing on the headband you can directly compress the sac and thus quickly and easily fill the pen.
To avoid accidentally pressing the crescent filler the pens were also equipped with a ring retainer that went to fit into the slot under the bow, so that it was locked in an open position outside the pen. When it was necessary to load the pen it was enough to rotate the ring, cut on one side, to bring the position of the cut in correspondence of the slit, so that the bow could go down.
The system was simple and effective, and also allowed for better filling than the later lever filler, as the rubber tank could be completely compressed. Despite its technical superiority, however, the projection of the bow from the body of the pen was quite unpleasant from an aesthetic point of view, and this decreed its inexorable decline.
- Patent n° US-685258, of 1901-10-29, requested on 1901-07-12, of Roy Conklin, Conklin Pen Manufacturing Co.. Self-filling fountain pen.
- Patent n° US-745481, of 1903-12-01, requested on 1902-07-21, of Roy Conklin, Conklin Pen Manufacturing Co.. Self-filling fountain-pen.
- Patent n° US-756778, of 1904-04-05, requested on 1904-03-04, of Roy Conklin, Conklin Pen Manufacturing Co.. Self-filling fountain-pen.
- Patent n° US-758930, of 1904-05-03, requested on 1903-11-30, of George S. Parker, The Parker Pen Company. Fountain-pen.
- Patent n° US-772467, of 1904-10-18, requested on 1903-11-16, of Rhodes G. Lockwood, Sterling Fountain Pen. Self-filling fountain-pen.
- Patent n° US-799777, of 1905-09-19, requested on 1905-04-05, of Roy Conklin, Conklin Pen Manufacturing Co.. Self-filling fountain-pen.
- Patent n° US-814520, of 1906-03-06, requested on 1905-09-11, of Roy Conklin, Conklin Pen Manufacturing Co.. Fountain-pen.