|Filling Instructions: Touchdown (Pneumatic)|
Pneumatic-fillers are filled using a procedure similar to that for the plunger-fillers they superficially resemble (one can immediately differentiate the two by examining the plunger: if it is a tube and not a rod, it is pneumatic). The key difference in use is that the nib must be left in the ink for several seconds after depressing the plunger, since these are sac pens and the sac must be given time to expand fully.
The most common pneumatic-fillers are Sheaffers, but the filling system was pioneered by Boston penmaker Chilton. The filler tube on early Chiltons is pulled out between the extended section and the barrel, as shown below, whereas on later Chiltons the filler tube was attached to a knob at the end of the barrel -- the same arrangement later adopted by Sheaffer.
Most Chiltons have a small hole at the end of the barrel or plunger knob, which must be covered by a finger to keep the compressed air from escaping when the plunger is depressed. The hole is then uncovered to allow the sac to reinflate. The simplest pneumatic-fillers are the blow-fillers, in which the barrel is pressurized by blowing through a hole.