Big Ben

In 1922, the Benzon Trading Company, founded by Niels Benzon, started as the distributor of Wall Eversharp pens in Denmark. By the 1930’s the company had started manufacturing its own line of pens under the “Big Ben” brand name.

In the second half of the 1930’s, the company started producing piston fillers using a telescopic filling mechanism patented by Heinrich Hebborn and Heinrich Schlicksupp in Britain (Patent number 451168, granted in 1936). This pen, made in celluloid with an ink window, is one of these. Although some of the early Big Ben piston mechanisms were made in hard rubber, many, like this one, were made in aluminium.

Although the pen’s model number is not included, the imprint on the cap reads

Big Ben
British Patent
Nr. 451 168

According to João Martins & Michael Miloro, all of the Big Ben pens made around the 1940’s had this imprint, and there were no model line designations. So, it is likely that this pen never had a model number.

Interestingly, this pen does not have a Big Ben nib. It reads

Eversharp
Gold Seal
Made in USA
Flexible

Which may actually be the original nib for this pen, due to the close cooperation between the two brands.

The combination of the lack of model number, the aluminium piston mechanism, and the Eversharp nib mean that this Big Ben was probably made in the early 1940’s.

When I purchased this pen, the old cork in the piston had rotted away. Unfortunately, it was not possible to simply make a new cork gasket, since the original was fixed to the aluminium screw mechanism by simply flanging its end to hold the cork. So, using a lathe, I removed the flanged portion (which was too brittle to re-shape) and then drilled a 2.5 mm hole into the top of the screw. I then threaded this with an M3 tap to accept a plastic flat-head screw. (A metal screw could, over time, cause galvanic corrosion and destroy the piston.) I then made a new cork gasket using the technique described on this page and this page, and “glued” the screw into the aluminium using shellac (instead of something stronger – to facilitate future repairs).

Of course, this means that the pen is no longer “stock” – but it was unusable without some kind of modification. And, if another pen turns up that can be used for parts, it’s just a matter of replacing the piston screw.

Total weight: 18.4  g
Body weight  11.2 g
Total length (not posted): 123.5 mm
Total length(with cap): 131.1 mm
Barrel max diameter: 12.2 mm
Cap max diameter: 13.7 mm

V2019020