The purpose of this Idea is to extend the shelf-life of ordinary ball-point pens. Over the years I've bought many that ended up getting thrown away, because they sat around unused for so long I couldn't get the ink to flow.
I'm aware that there are various tricks, such as heating the tip of the pen (doesn't work very well when the pen is mostly plastic), or soaking it in water or other substances (messy even if it works).
We need something simple and reliable and fairly safe. The Pentrifuge is offered to fill the bill. It contains two slots, one for the pen, and one for a "dummy" pen that is actually just a counterweight to the real pen. The weight of the dummy pen is adjustable (add/remove some weight, maybe plain sand).
Before putting the real pen into the Pentrifuge, you weigh it so that you can adjust the dummy pen's weight correctly. Then both are placed into the unit and the power is turned on.
The holder for the real pen allows the ball-point tip to be exposed. But nothing touches the tip as the Pentrifuge starts to spin up....
Once up to speed, you now manipulate a kind of wedge or "inclined plane" that is built into the side of body of the Pentrifuge. This thing is removable so you can cover it with a piece of paper before reinsering it.
Once reinserted, a screw-adjustment allows you to move the wedge so that the tip of the pen, revolving inside the Pentrifuge, can gently contact the piece of paper, many many times per minute.
At another point in the body of the Pentrifuge is a small window to let you see the surface of the paper.
Friction as the pen touches and moves across the paper will make the ball-point of the pen turn. Normally this process carries some ink from inside the pen, to the surface of the ball, and then onto the writing surface -- but because the pen in this case is old, there is a blockage of some sort (dried ink, likely).
However, the high artificial G-forces being experienced by the pen should cause the blockage to be overcome by the natural tendency for the REST of the liquid in the pen --however viscous!-- to flow down-hill.
Ink-marks should quickly start appearing on the paper being contacted by the pen. You may now shut the Pentrifuge off, wait for it to stop rotating, and then remove your pen and use it normally.
========= Added Oct 30
An additional gadget inside the Pentrifuge should be helpful. This gadget causes the pen-holder to twist (making the pen it carries also twist), during the overall revolution of the pen-holder about the central axis of the Pentrifuge.
One-tenth of a twist per revolution should be fine. It is important that the twisting-rate of the pen be different from the revolution-rate of the pen. The twists need to cause the ball-tip of the pen to be rotated in different directions as it contacts the paper. It is another aspect of how a Pentrifuge can work to break up an ink blockage.-- Vernon, Oct 29 2011 'crit Spinner http://www.marketla...rPageTitle=CRITSPIN [Klaatu, Oct 29 2011] A hematocrit spinner <link> should do the job nicely, although I wouldn't try it.-- Klaatu, Oct 29 2011 [+]
Would there be a system for stopping biros slipping away through wormholes in space ?-- 8th of 7, Oct 29 2011 No - that would be cruelty to biroid life-forms.-- spidermother, Oct 29 2011 [21 Quest], I will have to dispute your MFD. I agree that the link shows a centrifugal device for pens (and I should have indicated in the main text that the dummy pen could be replaced with a second real pen).
Note that his gadget wasn't good enough (quoting): "I was hoping that this device would be able to bring long unused ball point pens back from the dead, but it didn't work."
I'm pretty sure the reason it didn't work was because he left out the critical thing that I DID include in the main text here.
It is very important to rotate the ball-point tip. It is in direct contact with the ink blockage, after all. Friction with the rotating ball can break up the blockage if there is sufficient pressure on the blockage from the other side. In both versions of the Idea, the centrifuge causes appropriate pressure to be applied, but only in my version does the ball-point tip get rotated as well. So his device didn't work, while mine should.
I'm fairly confident it will, because just the other day I met a blocked pen, and used a less-gentle method of applying pressure while rotating the ball, and it worked. That's when I thought of this Idea.
The non-centrifuge method involves holding the pen vertical, but moving it downward at an angle toward the paper, and striking the paper with some force. The angle leads to some ball-rotation, and the impact applies G-forces. It took a lot of impacts, so, obviously, a Pentrifuge as I've described here would be a lot less tiresome.-- Vernon, Oct 30 2011 I'm pretty sure that the best speed for the ball to move is much much slower than the speed required to produce substantial force of the ink against the backside of the ball.
I always assumed that the issue was the migration of a small quantity of air behind the ball forming a dam of dried ink which, baring the introduction of a solvent, simply will not be able too break down and allow the pen to regain function.-- WcW, Oct 30 2011 [WcW], you may have a point about the speed of rotation of the ball. However, in this Idea, this speed changes from zero to maximum and then drops to zero again, as each overall pen-revolution brings the ball-tip into short-term contact with the paper-covered "wedge". That should be good enough.
Another thing that might be worth adding is some twists to the pen-orientation, around the axis of the pen-length. This will cause the ball, when it contacts the paper, to not always rotate in the same direction. It should facilitate breaking-up the blockage.
Such twists would be applied to the pen-holder of the Pentrifuge. They can be applied at a slow rate, say 1/10 twist for each full revolution of the overall pen in the Pentrifuge.
I probably should add that to the main text, just so there is one more reason for [21 Quest] to remove his MFD.-- Vernon, Oct 30 2011 [21 Quest], thank you!-- Vernon, Oct 30 2011 random, halfbakery