I didn’t cover all the filling system types in my previous post but that wasn’t really my intention. However, I might pick up some of the others now. There are several sac fillers that find other means of depressing a pressure bar apart from the usual lever or button. There’s the coin filler which has a slot in the barrel above the pressure bar. It’s of the right dimension for a common US coin. The match filler is similar; it has a small hole over the pressure bar for the insertion of a match. A variation of the match filler is the clip filler: the clip protrudes from the bottom of the cap and is the right size for insertion in the hole in the barrel.
A close relative of these is the crescent filler, too well known to need detailed description here. I would say that the various others were just step-gap measures, abandoned as soon as a way to circumvent Sheaffer’s patent lever filler could be found. The crescent filler was actually a competitor to lever and button fill pens. It attracted a strong following and remained in production by Conklin for quite a long time. There have been various Japanese versions. I like the crescent filler.
Rob reminded me of the glass cartridge pen. The first version was by Eagle. It was cheap and sold well. You exchanged your empty cartridge for a full one supplied by Eagle. Those pens have bad nibs and though one can find cartridges for them they do not seal well now. Waterman’s later version of the glass cartridge filler was much better. The pens themselves are excellent. Cartridges are still occasionally available though the seals have perished now. A new seal can be made using a normal latex sac. The cartridges are large and hold a lot of ink.
Another filling system that was moderately popular, especially in Germany, was the blow filler. A sac was fitted in the usual way but there was no pressure bar. There was a small hole in the end of the barrel. One blew into the hole and the pressure deflated the sac. The sac reflated with the pen in the ink. The system worked well enough and was cheap to implement but crouching with one’s face over an ink bottle was not a very popular way to fill a pen.
The basic syringe filler was another cheap method of filling an ink reservoir. The problem with it is that to achieve a good fill of ink would require a very long barrel! The simple squeeze filler doesn’t take very much ink onboard either. Parker’s improvement, called the Aerometric filler employs the addition of a tube which enables several depressions to be applied, each adding ink to the sac until it is full.
Again, the simplest form of bulb filler is inefficient but the inclusion of a vacuum tube allows the barrel to be completely filled. The Langs and Mentmore versions are very good pens. The addition of a metal depressor makes for a better action than squeezing the bulb. To my mind this makes for a better filling system than the over-complicated Parker Vacumatic.
Sheaffer’s Vac, Touchdown and Snorkel are two well-known to need explanation here. Others, such as the Onoto plunger filler and the Ford Patent Pen sophisticated version of the syringe filler were tremendous successes.
I’m sure there are others, old and new, that I’ve forgotten about. The Chinese have been producing various very good ink-in-the-barrel pens. I have one or two of those myself.