[lambda]

The quote from "Surely You're Joking Mr. Feynman" explains it better. This Wikipedia article is pretty bad.

  One mechanical engineer at Frankfort was always trying to
  design things and could never get everything right. One 
  time he designed a box full of gears, one of which was a 
  big, eight-inch- diameter gear wheel that had six spokes. 
  The fella says excitedly "Well, boss, how is it? How is it?"

  "Just fine!" the boss replies. "All you have to do is 
  specify a shaft passer on each of the spokes, so the gear 
  wheel can turn!" The guy had designed a shaft that went 
  right between the spokes!

  The boss went on to tell us that there was such a thing as 
  a shaft passer (I thought he must have been joking). It was 
  invented by the Germans during the war to keep the British 
  minesweepers from catching the cables that held the German 
  mines floating under water at a certain depth. With these 
  shaft passers, the German cables could allow the British 
  cables to pass through as if they were going through a 
  revolving door. So it was possible to put shaft passers on 
  all the spokes, but the boss didn't mean that the machinists
  should go to all that trouble; the guy should instead just 
  redesign it and put the shaft somewhere else.

So, a shaft passer really does exist, and really has been used. But for this example, of someone designing a machine that has one axle going through another wheel, the better solution is just to move that axle, rather than trying to actually build a wheel with a shaft passer on each spoke.

[PhasmaFelis]

I'd like to see a reliable source, and ideally a photo/video of the device in action. I won't say it's impossible, but it seems like it would be hard to make sure the gear rotates smoothly instead of binding, and "Feynman says that a guy he worked with heard about it" isn't as convincing as it might be.

[onetwofiveten]

The shaft passer shown here has never been used in real life. The mechanism that's on each of the spokes of the cog has been used in real life to allow cables to pass each other (just imagine one of the spokes and the obstructive shaft are actually cables).

[acjohnson55]

You should consider editing the Wikipedia page. This would make it much better.

[lambda]

I considered it; I've done a good bit of Wikipedia editing in the past. The problem is, I have a hard time figuring out how to phrase it better without just including the Feynman quote. That's the only source, and it seems that the Wikipedia page is merely trying to re-phrase what Feynman said; there really isn't anything to the page other than Feynman's quote and the diagrams. As such, it's hard to do a good job rephrasing it rather than simply quoting Feynman.

If you can find other sources than Feynman on the shaft passer (and blog posts and forum discussion that are merely discussing Feynman don't count), I'll consider updating it with an improved description and reference to the other sources.

[if_by_whisky]

And yet, nobody has improved it..