Tuesday, December 1, 2015

The cerruti 1881 automatic

 [First posted on facebook in feb 2015]

Well, I made a number of modified version pens for this particular cerrruti model. It has great potential, that's the bottom reason, and that I like demonstrator doesn't help. Anyway, here goes.

For a start, this is only an automatic fountain pen that requires a special feed. I don't know if this is done before, but I don't think anyone is more insane than me.

So, how does this work? it loads the ink by pulling the string that pulls the plunger up, and that strings sits quietly in that space. adding some aesthetic to it. that is the simple part.

the magic comes in when it is in use. with the special feed, the plunger will automatically move down when in use, as the air will enter from the rear than the front of the pen. thus when the pen is emptied, the plunger is already touching the nipple. it moves down automatically. The next step to reload is to just pull the string again.


Silicon oil is used extensive to ensure that the plunger is able to move freedom and yet do not move too freely. The right amount of silicon oil also ensures that the the plunger do not act as a weight on the ink and forces ink out. The balance of the amount of frictional force is the key. 


So, why doesn't the air comes in from the front? easy, I reversed what Waterman did decades ago; he opened the air inlet, I closed everything. no air can enter into the feed and into the reservoir. The seal is delicate which requires careful studying of the nib. the feed is filled with superglue where the air might move, and the nib is closely sealed with the feed whereby there is no air inlet from the drain to the nib. thus obviously, this nib cannot flex. It is a hard nib anyway. this nib also do not have a breather hole by its own design.

Honestly, I didn't come up with the engineering in totality. It was an idea borrowed from this vacuum pump from daiso which obviously works, and it works when i use it. 




This is a novelty prototype btw...so, while it works, it may not be practical to all situation.





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