Twist Pen Repair

[orik]

Hello, I hope you can help me with the repair of this pen. This is a twist pen (silver 925) made by an italian brand (I suppose), like columbus or aurora.

 

In a moment of madness I have smashed the pen against the desk and I have broken the twist mechanism. The damage consist in the loss of a plastic button in the part B (the hole you can see). The thing I don't understand is how exactly the twist mechanism works. I searched on internet for spare part but because the pen is old, its mechanism is hard to find.

 

For what I have understood until now, the mechanism works in this way: part A and B are inside part C, the broken plastic button should fit and slide in part D. Part C (and A, are inside part E.

 

Now the problem starts because you can see that inside part E there is, on the botton, a sort of plastic button (F) that I suppose should lock in some way the part C or A.

When you rotate part E I suppose that part C remain firm and only part A turns, pushing up part B and so the refill. But what is the connection between part A and F?

 

I made a copy (G) of the parts A and B with a tube of brass but I have to understand how the mechanism works to keep going.

[kkshadow]

It's my guess FWIW that part F interacts in Part A in such a way as to prevent the pen from turning accidentally. That assumes that the Button F exists so that the pen will only turn when F is pushed. It's hard to tell from the picture exactly how they fit together. It also appears that the top of Part A is damaged.

 

Edited to add: From your construction of the groove in part G-A, a ball in part G-B would not allow turning as the edges of the groove are too steep. The ball would be captured. Assuming that the button would press on part G-B and push it down just enough to escape to the more gentle slope, then the pen would twist. So in this scenario, pushing button F would press slightly down on part B allowing the ball to ride on the gentle slope of the part A cutout, and extend the pen.

Edited March 17, 2013 by kkshadow

[orik]

F is not a pushable button, it is only a circular piece of plastic.

I have uploaded two videos in which I try to explain how the B and A mechanism works. http://www.mediafire.com/?83lvo49v8wsmf2t http://www.mediafire.com/?llx5pjar3rlj9f5

The first is referred to the actual mechanism and you can see that the broken button of B should turns on the edge of A. The second video shows a standard mechanism you can find on internet and that I have obtained from another and inexpensive pen but that doesn't fit my pen. The working principle is the same.

 

So if the button of B slide inside D and if C is fixed because it is screwed than the only mobile part that turns should be A.

 

However I think that only a person with this kind of pen or that has repaired one of them can solve my problem.