leverfiller

The leverfiller is a type of fountain pen filling mechanism. It uses a lever inside the pen barrel to operate a pressure bar that presses against a rubber sac. When the lever is pushed down, the pressure bar compresses the sac, expelling air. Releasing the lever allows the sac to expand, creating a vacuum that draws ink into the pen through the nib.

This filling system was popular in the early to mid-20th century and is still found in vintage fountain pens. Leverfillers are generally considered reliable and easy to use, though the rubber sac will eventually degrade and require replacement. To fill a leverfiller, the nib is dipped into ink, the lever is pressed down, held briefly, and then released. The process can be repeated a couple of times to ensure the sac is fully filled.

The lever filler mechanism is distinct from other filling systems like piston fillers, vacuum fillers, and eyedroppers, each offering different advantages in terms of ink capacity, ease of filling, and maintenance. Its simple mechanical action contributed to the widespread popularity of fountain pens during their heyday.