| Design Features: Safety Pens |
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The Problem
Early fountain pens were all too likely to leak in the user’s pocket. The first generation of manufacturers made their pens of hard rubber and fitted them with slip caps in two general types: the straight cap (illustrated below, upper), which slips onto a cylindrical area at either end of the barrel — to cap the pen or to post the cap for writing — and the cone cap, with a bore that is conically tapered instead of cylindrical (below, lower). A cone-cap pen’s barrel tapers at the back end in the same manner as at the front in order to provide a place for posting the cap.
Hard rubber slip caps are not all that reliable. With use, a straight cap wears and becomes loose, and it can slip off when the pen is in a shirt pocket or a purse. A cone cap, on the other hand, is not tight at all unless it’s forced onto the tapered barrel. But if the user forces the cap on too tightly, the cap can split. Carrying the pen nib upward, then, is risky in case the cap lets go. Carrying the pen in some other attitude, such as nib downward, is even more risky; the reservoir can leak into the cap if the pen is jostled. Furthermore, most early pens had vent holes in their caps that could leak directly onto the user’s clothing even while the pen remained capped.
Solving the problem of slip-cap unreliability is the first step to creating a pen that is “safe.” One solution is threaded caps, which began to appear around 1900. One early threaded-cap pen is Moore’s Non-Leakable Safety Pen:
But simply threading the cap is not enough. The presence of vent holes still provides a relatively unimpeded path for ink to leak from the pen’s reservoir onto the user’s clothing. Solutions to this problem became known as “safety” pens because they could be carried safely.
Some Solutions
Morris W. Moore’s Non-Leakable Safety Pen (U. S. Patents Nos 567,151 and 567,152), illustrated above by a compact (45/8" capped) Nº 2 Tourist, was one of the earliest safety pens. Here is another Non-Leakable, a much larger Nº 450:
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Moore’s Non-Leakable Safety Pen Nº 450. Top to bottom: capped,
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This eyedropper-filling pen takes the threaded-cap concept one step further by providing a retractable nib. (Instead of screwing the pen apart to fill it as with an ordinary eyedropper filler, you simply put the ink in through the opening the nib leaves when retracted.) Below is a schematic drawing of Moore’s pen, with the operating parts colored for easy identification. The nib is mounted on a slender shaft (gray) that is also the feed. The shaft runs the length of the pen’s barrel and out through an opening that is lined with cork (magenta) to produce an ink-tight seal. At the end of the shaft is a knob (red); to retract the nib, you pull the knob. To protect the shaft, Moore attached a sleeve (orange) to the end knob; the sleeve rides along the outside of the barrel.
The purpose of a retractable nib is to permit an ink-tight seal of the reservoir. The retracted nib leaves a conical opening that is plugged tightly by a short cylindrical projection on the inside of the cap, providing a seal that does not permit ink to escape to the outside.
Thus, as long as the cap remains secure, there is no risk of leakage with the pen in any attitude. The American Fountain Pen Company, maker of Moore’s pen and renamed in 1917 as the Moore Pen Company, was not slow to point out this advantage in its advertising:
“Every person that has carried a Fountain pen realizes the necessity of carrying it in the pocket POINT UP, as directed, or their clothing will soon be badly soiled with ink; also their hands when using it. NOT SO WITH THESE PENS. Being AIR and INK TIGHT, they can be carried in ANY POSITION IN ANY POCKET when filled with ink, and cannot leak…”
Other safety-pen manufacturers made the same point in different words.
The safety principle addresses leakage in the pocket, but how does Moore’s pen keep itself from leaking when the nib is extended? The exterior of the collar that secures the nib and feed to the shaft is a very close fit in the open end of the barrel, and when the nib is extended the space between these parts is so small that the ink’s own surface tension keeps ink from leaking out.
In Moore’s pen, the nib is held in the extended position only by friction between the shaft and the packing that seals the back end of the barrel. This system works quite well, but a more positive design holds a certain attraction to those who might be unwilling to trust the simple Moore. “More positive” implies ”more complicated,” and Waterman’s Ideal Safety Pen is both.
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Waterman’s Ideal Nº 45, very late production, probably 1930s.
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Introduced in 1907 or 1908, Waterman’s pen uses a long-pitch screw mechanism within the barrel to extend the nib. Here is a schematic drawing of the system, with the operating parts colored for easy identification:
The orange pin secures the green knob to the blue shaft, and a cork packing (magenta) seals the shaft where it passes through the barrel’s end cap (red). The end cap screws tightly against the barrel to provide a seal at that joint. Two grooves run lengthwise along the inside of the barrel (shown along the top and bottom in this drawing). A sliding carrier holds the nib and feed, and a crosswise pin (purple) through the back end of the carrier rides in two long helical slots in the tubular portion of the blue shaft. The pin extends far enough through the shaft to engage the grooves in the barrel. Turning the knob/shaft unit forces the pin to slide along the grooves, and this action extends or retracts the nib.
Unlike Moore’s pen, Waterman’s has a tapered seat at the front of the barrel against which the nib carrier seats to provide a more positive seal against leakage.
The schematic drawing above reflects a pen made by Waterman. Many “copycat” manufacturers used only one helical slot and, correspondingly, only one barrel groove. Some of them even avoided having to make and assemble a crosswise pin by bending the end of the carrier over at a right angle and filing it to a shape that would ride in the helical slot. The single-slot version is less costly to make, but it is also less reliable. Interestingly, it is also the version shown in Francis C. Brown’s original 1898 design (U. S. Patent Nº 612,013).
A Gallery of Waterman-Style Safety Pens
As with any other pen design, manufacturers seem able to produce a virtually infinite variety of styles. Here is a small sampling of the incredible variety of vintage safety pens using the basic design of Waterman’s mechanism.
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Waterman’s Ideal Nº 42, Art Deco gold and sterling overlay. 425/32"
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Waterman’s Ideal Nº 412½VS BABY sterling overlay.
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Fendograf (Italian), green gold-filled overlay. 421/32" capped |
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Regina Nº 410 (German), BCHR. 51/8" capped |
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Siekling floral enameled pen (German), 37/16"
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Popularity is not always linked with superior engineering. The proliferation of Waterman-type safety pens should not be taken to imply that this design was the best possible within the technological limits of the time. Stepping back to the concept of a threaded cap, but forgoing the complexity that a retractable nib adds, we find the Parker Jack-Knife Safety pen, the forebear of one of the most successful pen designs of all time:
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Parker Jack-Knife Safety Nº 23, BHR eyedropper filler,
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Parker’s pen qualified as a safety pen by virtue of its threaded inner cap (U. S. Patent Nº 1,028,382). Note that this patent permits a nonretractable nib but does not specify whether the outer cap is threaded or a slip fit. The patent describes the invention as follows:
“…said inner cap being screwed into the outer tubular sleeve so as to be adjusted tightly and accurately against the mouth of the nozzle after the outer sleeve or main cap has been put in place upon the barrel.”
By adding to the section a flange against which the end of the inner cap could seal, Parker created an ink-tight seal. The two-step process of capping was not as straightforward as it might be, and Parker soon simplified the user’s handling by providing a threaded outer cap into which the inner cap was screwed to a fixed position. Screwing the outer cap down until the inner cap stops against the section seals the pen. (Parker was not the first to adopt this design, however; other makers were already using it.) This simple design is obviously superior to the more complex retractable designs, but retractables continued to sell, in dwindling numbers, for more than 20 years after the appearance of the Jack-Knife Safety. The earliest Jack-Knife Safety pens were eyedropper fillers.
In 1912 or 1913 Parker introduced a completely new pen featuring the button filling system patented in 1905 by Walker & Davison (U. S. Patent Nº 787,152), licensed to Parker and slightly modified for more economical manufacture (illustrated here by a schematic of a 1920s Duofold):
In a button filler, pressing the button attempts to compress the pressure bar’s leaf spring lengthwise. With its other end resting on a ledge in the section, the spring resists, instead bending away from the barrel wall to push the bar itself into the sac to compress it. Releasing the button allows the spring to return to its rest shape, in turn allowing the sac to re-expand and take in ink. At first consideration, a button filler does not seem very “safe”; after all, it has a hole in the back of its barrel through which the button itself must pass. But the blind cap, when screwed in place securely, forms an ink-tight seal against the end of the barrel to render the pen proof against inadvertent leaks. This feature was an essential part of Parker’s “Safety-Sealed” system, which provided the company with advertising copy for the next several years. Ironically, the first button fillers Parker sold had ordinary “unsafe” slip caps:
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Parker Lucky Curve button filler, unknown model, c. 1912 |
The second half of the “Safety-Sealed” system was Parker’s elimination of the then-standard breather hole or holes in the cap. The cap of the pen shown above fits so smoothly and tightly that the user feels the resistance of compressed air when capping the pen too hastily. Only a few years later did the company combine the button mechanism and the Jack-Knife Safety cap. In 1916, the company patented its famous washer clip and soon thereafter began applying it to pens to produce the shape of the pen shown here:
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Parker Jack-Knife Safety Nº 23½, BCHR button filler, c. 1918 |
This shape is more widely recognized in the 1920s descendant of the Jack-Knife Safety, the famous flat-top Duofold:
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Parker “Big Red” Duofold Senior, c. 1924 |
The basic design of the Duofold continued in manufacture, with styling updates, into the 1940s with models such as the Duofold Geometric and the Challenger line, and with a filler change, the Vacumatic and its kin (but not the “51”). All of these pens are safety pens in the sense originally meant by their manufacturers, i.e., that they are safe from inadvertent leakage. (The “51” is not a safety because its clutch cap, although remarkably secure, is not proof against slipping off the pen.)
Safeties Today
The nonretracting pens discussed here are safety pens in the original sense of the term, as indicated above, but they are not safety pens in the sense generally understood by today’s collectors, which arbitrarily limits the term “safety” to mean pens with retractable nibs.
By definition, any cartridge/converter pen is a safety (by the original criteria) so long as the barrel is without holes (in case of cartridge or converter failure) and the cap screws on to seal the nib area. Also, considering that Parker’s button fillers are safeties, the same can be said of modern button fillers from such makers as Krone and Filcao.
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Filcao Silvia LE, “horn” body, ivory resin cap, 2005 |
But the enhanced safety of a retractable nib retains a certain appeal, and today Montblanc’s Bohème (the smaller version) and several Stipula pens, such as the La 91, are true retractable safeties:
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Montblanc Bohème (upper) and Stipula La 91 (lower) |
The Bohème uses a twist-knob mechanism similar in principle to the original Waterman design, as do most of Stipula’s retractables; but the La 91 is a clever capless adaptation of the simple push-pull design of Moore’s Non-Leakable. To extend the nib, you twist the ring encircling the barrel to open a hatch in the pen’s end cap, then slide the ring to move the nib into position.
Last but not least, the retractable Namiki/Pilot Vanishing Point is a safety. (This innovative pen, in production since its 1964 inception as the Pilot Capless, has gone through slight changes, but its ballpoint-style “click-click” design remains its salient feature.)
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Pilot Vanishing Point in Blue Carbonesque |
Safety’s in the Mind of the Beholder
How safe is safe? In strict terms, the retractable modern safeties shown here are not truly “safe.” Their retractable mechanisms keep the nib safe, but the back ends of these pens are not sealed and will leak should a cartridge or converter fail. In practical terms, on the other hand, these pens can be considered as safe as Waterman’s and Moore’s designs, which can leak if their corks dry or wear out.
The information in this article is as accurate as possible, but you should not take it as absolutely authoritative. I am indebted to Daniel Kirchheimer, who contributed much useful information and guidance in the creation of this article.
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