Posts Tagged ‘variations on vacumatic mechanisms’

Odd ducks

Friday, September 23rd, 2011

I’ve been impressed with the infinite number of creative ways to fill a pen.  There were of course serious motivations to avoid someone’s patent while coming as close as possible to copying another manufacturer’s ideas.  Tom Zoss says that people followed the latest developments in pen technology just as much as we do with  our smart phones today.  Lawsuits abounded because big money was invested in each new development, and the manufacturers fiercely protected their “intellectual property.”

Once in a while you come across an odd duck that came out of someone’s evasive tactics.    This past week I had an Osmia 94 cross the bench.  I haven’t been able to find any documentation on the pens (yeh, repair guys read other repair guys books and web sites) but careful examination gives you some clues to how the pen was put together and how it fills.

Exhibit 1:

If some of the parts look familiar, may I suggest looking at a Parker Vacumatic pump?  Rod down the middle, cone that slides over a rod, blind cap nut/nipple that fits over the cone, and a pin that goes through the back side of the cone to keep it in place on the rod.  No evidence of a spring inside though,  and the design in general precludes a spring up the middle of the rod as with a Vacumatic.   The spring fits into the cup at the end of the rod,  and the rod is held in the blind cap by the threaded brass nut.  Even the angle of the taper on the cone matches that found on a Vacumatic pump.  Inside the barrel, there should be a ring for the cone and diaphragm to seat against.

Like a Vacumatic, the 94 has a breather tube sticking out of the end of the feed, and the pen fills with successive strokes of the filler, the section screws in, and is sealed with a rosin based thread sealant.

So, how did it go together?  Exhibit 2:

This view shows you the diaphragm in place – note the notch for the end of the diaphragm and the pellet to go through.  The pin is in place, and rides down a slit on the other side of the rod.  The only thing not attached yet is the blind cap.  The diaphragm gets talc on the outside, and is folded back over the cone as with a Vacumatic.  A spanner is used to screw the brass nut into the blind cap, and the blind cap nipple into the barrel.

Without a spring on the pump the action is not quite as elegant because the filler doesn’t bounce back on it’s own.  You unscrew the blind cap, then using it as a knob you pump the filler up and down to fill the pen.  Like a Vacumatic, it takes several strokes.  When done, screw the blind cap back on, and wipe the ink off the nib.

It works, but I still think of it as an odd duck.