Transitional Cap Style

October 22, 2018

This is in follow up to the Spring 2018 Pennant article by Glen Bowen regarding taper caps, which also discussed friction fit caps in general. This post is pretty esoteric, and not of general interest.

We usually think of the straight cap, taper cap, and cone cap as illustrated on page 31 of the Pennant.

However, I have two pens with a different cap style. At first glance, the caps appear to be cone caps, but on further inspection, they are not. The barrels are uniform in diameter.

On the Eagle pen, the section more closely resembles that of the earlier straight caps, with knurled rope like bands at the base. however, the section is consistently conical. The Onoto has a long tapered section that screws into the barrel.

The caps fit on to the barrel, rather than the section, like a cone cap. However, the barrels and inside of the caps are uniform in diameter, and the caps slide down until in inner step limits the depth of the cap placement. Both pens are also uniform in diameter on the other end, and the caps also slide on a bit until hitting the positive stop inside the cap.

These appear to be another solution to the step off at the section, which was thought to cause hand cramping. Rather than tapering the section to the barrel, and tapering both the barrel and inner portion of the cap, they both rely on a system more consistent with the straight cap and taper cap. The difference is that the straight cap now fits on the barrel and not the section, and the "stop" is inside the cap rather than at the base of the section.

The Eagle pen is likely c1900. Early Onoto plunger pens use a typical straight cap design, It is not clear to me when to date this Onoto. (OK - I was too stupid at the time of the original post to just READ the engraving stating 1928! - Thanks to Praxim for reminding me to look somewhere obvious).

Edited October 22, 2018 by Greenie

October 22, 2018

The Onoto looks to be a Streamline. The fact it says "The Pen" also indicates 1922 or later (their patent had expired so it no longer said Personal Self-Filling Pen). There is little clear information on when they stopped producing early models so I would say basically 1922-1930, more likely earlier in that range. If that gold band is believed to be original, and hallmarked in any way, I can date it more closely.

October 22, 2018

OK. I was missing a few brain cells during the original post. Praxim reminded me of the obvious. Post corrected without deleting my temporary insanity.