Flanked by the 146 on the left and the 149 on the right:
The Boheme's barrel is nearly the same size as a 149:
Nib sizes, the 146 and the Boheme share the same nib but for the monotone plating scheme on the Boheme.
Now we come to the disassembly. The current Bohemes are retractible pens. The procedure to use the pen is as follows:
- Thread the cap to the barrel end.
- continue to twist, the nib unit will extend out of the barrel.
The barrel end threads are single lead and I am very particular that the clip should should line up with the nib when posted. Now the retractible mechanism in turn is threaded into the barrel. Sometimes the mechanism may go out of alignment with the consequence that the clip will no longer line up with the nib when posted. Also sometimes the clip might become sprung(by clipping into a thick leather case) requiring retightening.
My Boheme suffered from both the issues and I decided to do something about it. Peering into the cap, I observed that a slotted screw held everything together. But the problem was a pin that extended from the centre of the slotted screw. So a special screw driver had to be constructed.
This pin shows MB's attention to details and making their pen as idiot proof as possible. Retractible pens suffer from a typical danger, what if the user tries to inadvertently extend the nib, even when the pen is capped? The nib will be destroyed. but not on the Boheme . As the nib is extended, a shoulder on the feed buts against the pin in the cap's centre, thus stopping the nib from touching the cap's roof. Very clever!
Top to bottom: Snowflake holder cum cap nut, cap jewel sleeve, clip, cap, slotted screw with "safety" pin.
The slotted screw with pin:
The shoulder on the feed which buts with the pin if the nib is extended while the pen is still capped:
The clip is allowed to be rotated in steps. The top of the cap has teeth which engage with two tabs on the clip ring inner diameter, the clip will lift out straight and can be repositioned. The following photos show the idea:
Just before repositioning:
The snowcap carrier cum nut also has two vertical slots, this permits only an axial movement for the nut as the slotted screw is tightened:
These two tabs on the cap ID prevent radial movement:
The cap jewel sleeve, again not free to rotate, the teeth on the cap top engage with these slots as you can see:
Once the clip is separated from cap, it can be bent w.r.t to the clip ring to restore the clip tension. Now post the cap sans the clip to the barrel end, extend the nib. Now you can position the clip back in the orientation that pleases you, the following pic shows it positioned:
Due to the teeth it will not move once positioned, again extremely clever engineering. Now place the jewel cover over the clip as shown below:
Slide the snow cap carrier cum nut into the cap, hold the assembly pushed with thumb, invert the cap with the cap mouth facing up, drop the slotted screw inside and use the special screwdriver to gently tighten the screw. You are done.
Now we come to the screwdriver, after destroying one stock screwdriver while attempting to saw a slot through the hardened bit, I decided to use this card frame to make the tool. The electronics engineers among us will recognise this frame instantly. Removed from one of the old ISA cards.
A sketch for the tool drawn with the Boheme, a very juicy writer with some springiness:
I hope you guys enjoyed this thread and found it of some use.