A long time ago the Sheaffer Snorkel pens became my favorite pens, for its ingenious mechanism and the clean fill concept. They are also great writers I used one to take class notes through secondary school, (a lifetime ago).
This interest lead me to investigate the origin and evolution of pneumatic fountain pens and in this post I am going to try and identify the key milestones in their evolution.
First I will attempt a definition of a pneumatic filling system. A pneumatic filling pen has a rubber sac enclosed in a barrel where air pressure can be introduced which collapses the sac and when the air pressure is released, if the nib is immersed in ink the sac will recover its original shape drawing ink into it. There may be a better definition and I would appreciate the input.
The earliest such pen I am aware of is the Crocker blow pen, introduced in 1901. It has a hole at the end of the barrel. You have to blow through it and release the pressure when the nib and feed is immersed in ink. The cap also has a hole, so this can be done with the cap posted which may be more comfortable.
The next improvement to the concept was in 1924 with the Chilton touchdown pen. This model had a tube sealed with waxed twine, with a hole at the barrel end. To fill, you have to extend the tube, cover the hole with your finger and push it in a rapid stroke. When the finger is removed the sac expands and fills with ink
It was in 1948 that Sheaffer came up with the Sheaffer Touchdown model. It worked very much like the Chilton above, except that there was no need to block the hole with the finger. This was achieved with a hole near the top of the barrel that would relieve the pressure in the up stroke. The availability of o-rings probably enabled this solution. Sheaffer continued to use this filling system for many decades in a variety of models. At this time I don't have a picture to show this pen
So it was in 1952 that the Sheaffer Snorkel was introduced to the market. Probably one of the most complex pens ever. It filled like the touchdown, except that the nib didn't have to be immersed in the ink bottle, just the snorkel tube that is extended to fill and then retracted afterwards without the need to wipe the nib. The Snorkel system was also used later on on the PFM model and then discontinued in favor of the Touchdown system, probably because of the complexity of the Snorkel mechanism.
The last pen design iteration came in 1995 with the Sheaffer Legacy. This model included a touchdown converter that enabled the pen to be filled with a cartridge or if the converter was used as a touchdown pen.
As indicated above, I just attempted to list significant milestones, I am aware that there were some French pneumatic pens. Perhaps members of the community could help to fill in the blanks in this story.
All the best,
Edited by sztainbok, 27 September 2019 - 16:29.