Why are fountain pen reservoirs reverse threaded?

I’ve got a couple of fountain pens–I like 'em. They’re classy. And after using them, reloading them, cleaning them, etc. over the course of five years, I’ve learned to write with them and not get ink all over my hands.

That being said, of the four fountain pens I own, I use the refillable cartridge and bottles of ink. And it occurred to me today, “Righty tighty, lefty loosey–so why do I have to twist right to draw the plunger back and ink into the cartridge?” For Engineers, the threading does not follow the ‘right hand rule.’

Is there some historical reason for this? Everything else I own, right twists force a product out. Not on these four pens; there are three manufacturers involved, so I suspect this is an industry-wide thing.

Tripler
This sigline includes a flourish with good penmanship.

On everything you own, right twist of the inner (male) screw forces it out.

These fountain pen converts also have the standard thread screws. It’s just that the part you grab and rotate is the female (outer) screw; the plunger is connected to the male screw. Basically, you are turning the nut, not the bolt. So when you turn it clockwise, it pulls the plunger towards you.

When I was young I had a beautiful fountain pen with iridescent stripes all over the body. That was a neat thing about fountain pens, they came in so many artful designs.

The filler was different, and maybe some here have seen ones like this. It had a lever on the side that you pulled out to squeeze the rubber ink-filled balloon inside. Then when you put the lever back down, it sucked ink in.

Pictures:
(1) In normal use: Note the silver-ish strip along the side that looks not-quite-like a pocket clip. It’s a lever that lays flat or slightly retracted in the side of the pen.

(2) You pull it out like this and then let it back down to fill the pen.

No twisting anything.

Is this so? Does it depend on which end of the screw or bolt you’re looking at when you twist the screw or bolt (or nut)?

I’m thinking of lug nuts on car tires. You twist the lug nut right (clockwise) to tighten it, if I remember right. (It’s been so long since I’ve had to change a flat. :slight_smile: ) In this case, you’re looking at the bolt from the “end” end, not from the “head” end. If you were able to look at the bolt from the other end, you’d be turning the lug nut counter-clockwise to tighten it.

When I think of twisting a screw clockwise to turn it into the bolt, that seems the opposite at first thought – but then, I’m picturing looking at the screw from the head end.

Does a left twist remove the whole cartridge?

On some cars and most trucks, the lug nuts on the left side are left-hand threaded.

Wow. I never thought to picture it this way. Put this way, the rule works for either piece (nut or bolt) AND whichever end of the bolt you are looking at.

Oh, thanks to this thread I now have a a Lamy Z28 converter and a bottle of J.Herbin Eclat to Saphir ink on its way via Amazon. If I don’t like it Imma gunna blame Y’All. :smiley:

OK, everyone gets a praline chocolate chip oatmeal cookie! The converter and ink arrived and… it’s brilliant! The ink is smooooth and dries way more quickly than the stock Lamy ink, and the converter is super easy to use. Call me a convert! Now I may have to go shopping for another pen, or see if I can find my vintage Waterman or Cross pens somewhere in the dregs of the basement.

I dropped my open fountain pen today onto some tile. Not a good result.

Uh, oh. What have we done?

Whatever you do, don’t go to a pen show or a brick and mortar pen store (if you can find one).

p.s. can you make one cookie without pralines? Allergic.