Gee you lot are nuttier than me!!!
I do like some of the suggestions though.:biggrin: I also have one on the drawing board that will remove the coupler on a closed ended cap, but this one IS for removing a pressed in coupler. Particularly on a closed ended pen.
The reason it is so long is for the cuts in the 'jaws'. With long cuts, the springyness allows the jaws to be pushed through the coupler (without damaging them ) and to spring open again once inside the tube.
Turning the big knurled nob simply pulls the part out.
The small knob ( was the yellow one ) serves only a minor purpose.
I filed a flat surface on a section of the steel shaft. The small knob simply screws down far enough to prevent the shaft from rotating while trying to tighten it up.:biggrin:
When I get some time I'll make a little pictorial. There are no special tools required. The jaws are shaped with a file and the slots can be cut witha thick bladed hacksaw.
Manny, please PM me with your address. Just give me a little time to make one:biggrin: