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| Anatomy
of a Fountain Pen III: Sheaffer’s Snorkel |
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| (This
article first appeared on Richard's
site.) |
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| The Struggle
to Survive: In 1952, Sheaffer introduced the
most complicated fountain pen ever designed. This pen,
the famous Snorkel, was designed to compete with the burgeoning
popularity of ballpoint pens by virtue of its simple,
convenient filling system that eliminated the mess commonly
associated witih fountain pens. To fill the Snorkel, the
user extends a small tube that is normally hidden within
the feed; only the Snorkel tube is immersed in the ink,
and there is no need to wipe off excess ink after filling.
For about a decade, the Snorkel did compete successfully,
with a range of models culminating in 1959’s PFM,
the Pen For Men. This article illustrates
a pen similar to a Sentinel, with Sheaffer’s conical
Triumph nib; the company also produced Snorkels with the
traditional open nib. The illustrations depict the pen
with its proportions altered for artistic purposes. |
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| “Monkey
Motion”: To make the Snorkel’s filling
system simple for the user meant that the pen would have
to be complicated internally. The first figure shows the
pen with various parts cut away to reveal the inner workings.
You can see immediately that there are a large number
of parts: |
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| The Snorkel uses
the Touchdown filling system that Sheaffer introduced
in 1948, but in the Snorkel it is necessary to move the
entire filling system within the pen. This movement is
accomplished by redesigning the section that it becomes
only a small bit of hard rubber that secures the sac and
the Snorkel tube. The sac protector is a tight slip fit
over the section, so that the assembly becomes a moderately
strong “cartridge” that can slide back and forth
in grooves on the inside of the gripping section, which
has replaced the original section to provide a finger
hold. |
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| The Snorkel tube
is fitted through a small hole in the hard rubber section;
it passes through the point holder gasket and extends
to the end of a hole that has been drilled through the
feed to accommodate it. The Snorkel tube contains a secondary
feed, in the form of a slender strip of hard rubber with
an ink channel. There are small slots near the end of
the tube; these slots allow ink to “leak” from
the inside of the tube to the outside. Once outside the
Snorkel tube, the ink finds that there is also a slit
cut in the main feed, and capillary action draws the ink
through that slit to fill the comb fins and deliver the
ink to the nib in the same way as with an ordinary feed
and nib. |
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| The back end
of the coupling ring screws into the gripping section
to secure the point holder gasket in place. The feed slips
into the coupling ring, and the nib screws onto the front
end of the coupling ring to secure the feed in place. |
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| The sac protector
is threaded for part of its length. At the front end of
the threaded portion is a ring into which one end of the
spring fits; the other end of the spring presses against
a ledge on the interior of the barrel.The Touchdown tube
is threaded to match the sac protector; and the blind
cap, unlike the blind cap in the ordinary Touchdown system,
is not threaded. |
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| The interior
of the pen is sealed airtight by the point holder gasket,
the O-ring, the threaded joint between the barrel and
the gripping section, and a gasket that seals the screw
securing the Touchdown tube to the blind cap. Air can
enter only through a dimpled groove in the Touchdown tube
near the blind cap and through a hole in the Touchdown
tube near the tube’s threaded portion. The dimpled
groove is open at the beginning of the Touchdown tube’s
travel as it is extended from the pen, and the hole is
open when it passes the O-ring as the Touchdown tube reaches
its full extension. If any of the four sealing points
leaks, the pen will not fill properly. |
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| How It
Works: As you can see, the spring tries to force
the sac protector (and the rest of the “cartridge”)
forward, extending the Snorkel tube. The blind cap and
Touchdown tube prevent this. The following figure shows
step 1 of the filling process. The user unscrews the blind
cap, releasing the “cartridge” so that the spring
can slide it forward. |
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| Next, the user
extends the Touchdown tube. A partial vacuum builds up,
but the sac protector keeps the sac from distending. As
the Touchdown tube reaches the end of its outward travel,
air enters the barrel through the hole near the threaded
end of the tube. |
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| The user immerses
the tip of the Snorkel tube in the ink and then presses
quickly down on the blind cap. This restores the Touchdown
tube to its rest position, compressing air as the tube
travels. The compressed air squeezes the sac. The following
illustration shows the pen at the instant just before
the pressure is released by the dimpled groove when the
Touchdown tube reaches the end of its travel; note the
squeezed sac. |
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| When the Touchdown
tube reaches the end of its travel, pressure is released.
As the sac resumes its normal shape, external air pressure
forces ink into the sac. |
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| Last, the user
screws down the blind cap again. The threads on the Touchdown
tube engage the threads on the sac protector, drawing
the “cartridge” backward against the spring.
The Snorkel tube disappears into the section, and the
user returns to writing. |
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| Is It
Working Right? To test a Snorkel, fill it with
water. Aim the filled pen in some harmless direction.
Extend the Touchdown tube and then depress it quickly.
If all the seals are working right, the pen will shoot
a stream of water that can travel about six feet (2 m). |
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