Cap bands

[DumDum]

Simon says he cannot find any information on how cap bands were fitted to the cap of a fountain pen.

Simon asks if anyone can shed some light on this subject.

Simon says TIA.

[Deb]

I don't know how they were fitted originally. Loose cap bands are swaged back on.

[Chrissy]

What's with the Simon says game?
How a fountain pen is made?

[Deb]

Thank you Chrissy. Very interesting.

[DumDum]

Simon is my name! Intro

Have read the linked site (thanks, Chrissy), Simon is none the wiser. Presumably the cap band is applied to an already completed cap that has a recess for it. How then is the band made to shrink to fit this recess? Looking at a couple of pens with cap bands, Simon cannot discern any obvious break (tho' me old eyes may just not be up to the task, suggesting the band is all one piece.

What is Simon missing here?

[Farmboy]

They are swaged in place.

Some pen caps are made from multiple pieces and assembled as sandwich.

[DumDum]

Okay, okay. Simon says that a video on the Tube explained how swaging can be used to fix two tubular structures together. This makes sense with respect to cap bands that actually form part of the cap lip. Simon, tho', remains in the dark as to how cap bands can be fitted when they are beyond the lip of the cap and do not form part of it - like the thin rings sometimes seen on both vintage and modern pens. If the cap is one piece, how does a cap ring fit over the lip and then magically shrink into a recess beyond the lip?

Simon says he is very confoozled.

[DumDum]

Simon knows that his words have been doubleplusungood.

After appropriate mental correction, Simon will conform to the tenets of IngSoc and thence engage only in duckspeak, thus avoiding the ignominy of becoming an unperson.


B-B! . . . B-B! . . . B-B!








edit: spent me whole life as a piddling little drone. Now in me autumn days... well, what hair is left is getting let down a bit!


Edit 2: this was a tongue in cheek response to a post by another member, a post that has now vanished into the aether.

[Farmboy]

Okay, okay. Simon says that a video on the Tube explained how swaging can be used to fix two tubular structures together. This makes sense with respect to cap bands that actually form part of the cap lip. Simon, tho', remains in the dark as to how cap bands can be fitted when they are beyond the lip of the cap and do not form part of it - like the thin rings sometimes seen on both vintage and modern pens. If the cap is one piece, how does a cap ring fit over the lip and then magically shrink into a recess beyond the lip?

Simon says he is very confoozled.

Ahhh, those cap rings. They are swaged in place.

[DumDum]

Yeah, but how? The inner diameter of the rings has to be the same diameter as the outer surface of the cap. How then does one compress the ring into a recess? Obviously there is something I'm overlooking or not understanding here. Does anyone either know precisely how it is done, or can explain it in simple terms to someone (me) who is not a machinist?

[Deb]

There's a Wikipedia article which will explain swaging for you.

[Chrissy]

There's a Wikipedia article which will explain swaging for you.

There's also a very good FPN article about cap band swaging written by "fountainbel."

[Chrissy]

^^^^
FAQ....Reading & Posting Messages.....Editing and Deleting your posts

[DumDum]

Read the Wiki page. Problem is that I don't really understand the process it is describing. It is unclear to me. That's why I looked for a video, but there are none that I could find that show the process of putting rings on a cap, only how to mate two pipe ends.

[DumDum]

Ah! Read the FPN article (had to find out what FPN was first). The reason why it was confusing to me is that the wikipage suggest making something smaller without taking away any material. The other article is more clear on this such that in order to make the rings tighter they must be deformed laterally (if I've understood it right). So, presumably the recess cut into the cap material starts off a little wider than the cap ring.

Does that sound right?

[although]

I'm gonna guess that it's the cap bands (being relatively soft and malleable brass) that get swaged down to size to fit in the cap grooves. Not unlike the process of resizing brass cases for rifle/handgun cartridges.

I've only ever heard of swaging as a process for mechanically squishing metal things from a bigger size to a smaller size, without use of heat. I don't think the resins and such used in pen caps is malleable enough to be swaged.

Just a guess tho, I've never worked in a fountain pen factory

[Farmboy]

Swage ing is essentially squeezing the ring in place.

Now think about how you start with a flat sheet and end up with a cap without welding.

[Farmboy]

The metal band is swaged not the plastic cap.