Fountain Pen Filling Mechanisms

Fountain pens come in a variety of filling mechanisms

This list is approximately sorted by how common they are. Most filling systems in vintage pens work by compressing a rubber ink sac which takes in ink as it reinflates (like the bulb of an eyedropper).

Cartridge

Common
modern cartridges

The pen fills from a disposable plastic cartridge. Something pointy in the end of the section pierces the cartridge on insertion. When the pen runs dry, throw away the cartridge and insert a new one.

The earliest popular cartridge pen was the Waterman CF, released in 1954 by Waterman's French subsidiary JiF-Waterman. Sheaffer cartridge pens were produced by the millions and millions in the Sixties and are still being produced (in different forms) today.

There are relatively few cartridge types in current production and they haven't changed much since they were invented decades ago, so your chances of finding a cartridge that fits is very good. Pictured from top are International Standard (fits most European pens), International Standard Long, Parker, Sheaffer standard, Sheaffer slim, and Cross.

If no modern cartridge fits your vintage cartridge pen, you can refill an existing vintage cartridge. Ask your local pharmacist (nicely!) for needles and syringes and use them to refill the cartridge from bottled ink. Some people say to pretend to be diabetic or the like, but I have never failed by flat-out telling the pharmacist that I needed the needles for pen purposes (it may help to dress up and look respectable when doing this). Specifically, Waterman CF and Esterbrook cartridges are incompatible with modern cartridges, requiring measures like this.

Converter

Common
modern converters

Many cartridge pens can be fitted with a device called a converter. The converter plugs into the place the cartridge would go and acts as a filling mechanism, allowing you to draw ink from a bottle. This "converts" the cartridge pen into a bottle-filling pen. A typical scenario is pictured to the left; a Parker piston converter installed in a Parker 45 pen.

Converter
in a Parker 45

The two most common types are piston (screw thingy) and aerometric (squeezable press bar), which work like their proper vintage counterparts. Naturally, you can only use a converter that fits your pen and they are not terribly interchangable between pens that use different cartridge types.

Pictured here are some of the more common converter types. From the top are Waterman (International Standard), Parker piston, Parker slide, Parker aerometric, Sheaffer standard aerometric, Sheaffer slim aerometric, and Cross piston.

Compared to pens with built in filling mechanisms or the larger cartridges, converters typically have fairly small ink capacities, requiring frequent refilling if you write a lot.

Piston

The piston mechanism is the most common mechanism in modern non-cartridge pens. Historically, it seems to be much more prevalent in Europe than in the US. German pens are usually piston fillers, including modern Pelikans and MontBlancs.

Playing with the screw at the end of the pen moves a plunger down. Playing with it the other way moves it back up, drawing in ink. The ink is stored directly in the barrel.

I wouldn't try to repair one unless you really know what you are doing. There's some pretty precise engineering going on here.

Lever

Lever in an
Esterbrook SJ

Sheaffer patented the lever filling fountain pen in 1908 and was the first company to successfully market it. Most pen makers adopted the lever fill soon thereafter, where it remained dominant until the postwar era.

The lever filler is very simple in operation. A lever on the outside pushes a springy bar on the inside. The bar compresses the rubber ink sac. When the lever is released, the ink sac reinflates, drawing ink into the pen in much the same manner as an eyedropper.

Assuming the lever is intact, lever fillers are very easy to repair if you can get the section off. You'll have to replace any crumbled ink sac (simple enough for trained chimpanzees to do) and possibly a pressure bar if the existing one is snapped or rusted. The hard part is in the initial disassembly.

Touchdown

Touchdown plunger extended in a Sheaffer Valiant TM

The Sheaffer proprietary Touchdown filling mechanism was first introduced in 1949. This is somewhat more complex than a lever filler in operation, but Touchdown pens are usually very easy to service.

The Touchdown pen contains a flexible rubber ink sac inside a metal frame. There is a blind cap at the end of the barrel that screws out to pull out a large shiny metal plunger. When the plunger goes down, air pressure compresses the ink sac. When the plunger reaches the end, it moves past a seal and allows air to escape the pen (look for the tiny pinholes). As the pressure is released, the ink sac reinflates and sucks ink.

Most Touchdown parts simply screw together and thus disassemble very easily without tools. Replacing the ink sac is utterly trivial. However, the pen depends on airtight seals to function, so if the interior O-rings are bad, they must also be replaced. This is only somewhat trickier.

Snorkel

Snorkel with tube extended in a Sheaffer Admiral M2

The Snorkel (introduced in 1952) is another Sheaffer proprietary system and is perhaps the most complex filling mechanism ever made. The principles of operation are largely the same as the Touchdown, except that a long thin tube extends from the pen. Only this needle-like tube needs to go into the ink. When the pen is done filling, turn the screws the other way to retract the snorkel. This eliminates the need to wipe the nib after filling the pen.

The complexity of the system and its many moving parts have serious Geek Value. It is also the best pen to use as a water weapon due to the syringe-like needle.

Vacumatic

This system is commonly seen on Parker pens from the 40s and 50s.

A blind cap at the end screws off to reveal a plunger-like button. Pressing this repeatedly turns a rubber diaphragm inside out and back. The pressure changes pump ink into the pen with each press.

Typically the only work needed is replacement of a rotted diaphragm. However, many of these Parkers don't disassemble as nicely as we'd like and require custom tools (which are widely available). The actual mechanics aren't too scary if you know where the parts are.

Aerometric

Aerometric filling system on a Parker 21

This system was widely used by Parker in the postwar era until cartridges ate everything. Many converters work on the same principle.

The aerometric system is basically an eyedropper bulb attached to the insides of the pen. Unscrewing the barrel reveals an ink sac encased in a metal frame with an exposed pressure bar. Press the pressure bar a few times to fill the ink sac.

The Parker-built aero fillers are extremely durable (they used nylon or some plastic instead of rubber for the sac) and are more often than not in perfectly good condition even after 50 years of use.

Vacuum Plunger

The back unscrews and is connected to a thin metal plunger rod. Pull it all the way up and push it down. As the plunger goes down, it creates a vacuum behind it. When it reaches the wider end of the barrel, the vacuum is released and ink fills in behind the plunger. This mechanism was used in the Onoto pens and a whole boatload of 40s-vintage Sheaffers.

This design has some nasty problems with back pressure building up behind the plunger, which means you shouldn't play with the fill mechanism too much for fun. I've never tried to play with the plunger while the pen was still full of ink, but I can't imagine it being healthy for the pen (liquid doesn't compress, y'know). It is also nontrivial to repair the right way, as there are a whole bunch of pressure seals.

Button

The button filler (commonly seen on vintage Parker Duofolds) works much like the lever filler. A blind cap unscrews to reveal a button; pressing the button engages the metal pressure bar and squeezes the ink sac.

Eyedropper

The simplest filling mechanism is a non mechanism. Simply unscrew the section, get an eyedropper, and fill the barrel directly with ink. Screw back together and write.

Assuming the pen screws apart, there is simply nothing to repair. However, most of us wouldn't be entirely comfortable with the potentially leak-prone nature of this system

Rare and Exotic Mechanisms

Pelikan Level

This is used on the modern Pelikan Level 1 and Level 5 pens. The pen's rear mates with a specially designed ink bottle and you basically just dump ink into the pen. Some thingies prevent leakage and use when the little dots don't line up. Weird. Has to be seen to be believed. See Pelikan's own explanation.

Safety pen

This Rube Goldberg contraption is an eyedropper filler with retractable nib. Think of it as a small vial of ink that happens to have a nib inside. When you open the vial, it looks like a normal vial and you can fill it with ink. Turn the dial on the end and a nib comes out and seals against the section, after which you can use it like a normal fountain pen. Compared to the slip cap pens of the time, what made it "safe" was that they could not leak while closed in the pocket (since it is just like a small vial with a seal in the cap. After uncapping it, you must remember to fully extend the nib while holding the thing in the upright and locked position or you will spill a lot of ink.

Safety pens were mostly abandoned after the inner cap and comb feed were invented. The inner cap seals against the part where the nib meets the section and prevents runaway ink from getting on the rest of the section where it might leak out or get on your fingers. The comb feed provided much more surface area for ink to adhere to. Together, these developments solved the early leak problems and made safety pens obsolete.

Safety pens have a couple of advantages that allowed them to linger on well after they had been made obsolete. Since the nib was kept immersed in ink when not in use, you could use far nastier ink (including India ink, if you're careful) that would clog ordinary fountain pens. Waterman actually marketed some as art pens because they could be used with India ink. Also, since the entire ink chamber is exposed when you uncap it, air pressure remains equalized and the pen is immune to problems from atmospheric pressure, making it popular for aviation use before hidden collectors and pressurized cabins were invented.

Coin and matchstick filler

These look like lever fillers without levers. You use some thin object, like a coin or matchstick, to press the bar that would have been pressed by the lever.

Crescent filler

The crescent filler was developed by Conklin in 1898 and was a predecessor to the lever filler. It looks like some monstrosity with a dial and a half-moon crescent sticking out of the middle of the pen. Turn the dial to line up with the crescent and press the crescent to compress the ink sac. The dial turns to act as a safety; we wouldn't want to squirt ink by accidentally pressing the crescent. The crescent sticking out of the side also makes it uncomfortable to write with, although it won't roll off any tables.

How they managed to come up with this instead of using the obvious lever escapes all rational minds. Walter A. Sheaffer must have found it hilarious.

Blow filler

These pens have holes in the barrel. Put your mouth over the holes, stick the other end in the ink bottle, and blow. The pressure from your breath compresses the ink sac. I don't know about you, but blowing on one end of a pen with the other end in a bottle is a good way to get a faceful of ink.

In addition, huffing and puffing on a pen in an ink bottle doesn't exactly look very dignified.

Sleeve filler

This is kind of like an early aerometric filler. However, instead of unscrewing the barrel, you move a sleeve on the pen, which reveals a cutout exposing the ink sac and attached pressure bar. Push to fill. I believe this was introduced by Waterman in 1910, but they soon figured out that Sheaffer's lever was a much better idea.

Twist filler

This is what we call a Bad Idea. The ink sac is attached to a spindle at the end, which is revealed by unscrewing a blind cap. Turn one way to twist and deflate the sac; turn the other way to return it to normal (and draw in ink).

It doesn't take a rocket scientist to see that you'll be putting a lot of stress on that rubber ink sac. For whatever reason, Swan made these pens well into the Thirties, after everyone else had gone over to levers.

Accordion filler

Another Bad Idea. These pens use a special accordion-shaped ink sac; play with the end to get it to pump ink, accordion-like. Good luck finding such a replacement sac today.

Capillary fill

Yet another Bad Idea, but this time from a reputable manufacturer, Parker. The Parker 61 originally incorporated a wick thingy attached to the section. Unscrew the end, dunk the back of the pen in the bottle, and wait. Ink automatically fills via capillary action. If you have trouble picturing this, visualize a cylindrical sponge (it isn't, but a sponge is in the same spirit) inside the pen, filling from an exposed rear. No moving parts!

You don't have to be brilliant to figure out that this is utterly impossible to clean, and should it ever clog, it is almost a lost cause (you'll need ultrasonic cleaners and other fancy things). Due to customer complaints, Parker dropped this mechanism and began replacing existing 61s under warranty with cartridges. Working examples are rather rare today, and should you find one, it's probably best to leave it be.

Hatchet filler

These things were used by some companies to get around Sheaffer's patent on the lever filler. They come in several variants, but the idea is that some large chunk of the pen pivots (say, the entire blind cap), lever-like, to press the ink sac. There's another variant where a shaped bar would be flipped 180 degrees to expose a protrusion that then presses the end of the pressure bar.

Who said that patents weren't good for innovation? Rube Goldberg would be proud.