US2642043A - Fountain pen - Google Patents

Description

June 16, 1953 B. F. M'lEssNER FOUNTAIN PEN Filed July '7, 1950 u, /lf//lf//f/ the pen, because the pen `and extending at the barrel Patented June 16, 1953 UNITED STATES PATENT OFFICE FOUNTAIN PEN Benjamin F. Miessner, Morristown, N. J., assignor to Miessner Inventions Inc., Morristown, N. J.

Application July '7, 1950, Serial No. 172,534

This inventionvis an improvement over myv in- 'vention disclosed in my co-pendingpatent appliw 'pansion of trapped air within the pens ink reservoir.

The construction here employed involves an vair breather tube mounted axially in the pen barrel and having its internal, open end at the volumetric center of the ink reservoir, and having its outer end exposed to free atmosphere 'at the pens writing pon tube is never submerged in ink in any position of is filled only to a point short of the volumetric center, .and the air breather tube allows in and ou flow of air to equalize the internal with any external, atmos- .11 pheric pressure.

In order to remove the ine-qualities of ink'iiow due to varying hydrostaticv ink pressures acting as it does in conventional fountain pens, on the constricted, ink feed channels in'their feed bores, I Vuse a wick type of Yink. feed, which operates oy capillary action rather than by hydrostaticpressure. Such pens are disclosed in my aforementioned co-pending patent application, wherein I have disclosed a breather tube and wick feed arrangement in which the wick is located both on the outside and the inside surfaces of the breather tube, clearance being, provided on the inside to allow air to flow freely and axially through this .breather tube.y The breather tube itself lts ink tight in the hood portion of the pen so. as .to preclude any ink ow directly from the reservoir to the point around the; ink tube.

Inthe presentA case I provide a separate, axial, breathertube inside ofthe wickV covered ink tube, end slightlyv beyond the ink tube. In this case the construction is substantially the sameasv that shown in my co- Ipending patent application, with the exception that a small-bore thin walled, metal or other tube is forced into the wick covered tube here shown.

This internal tube I calledthe air tube while the larger, concentric, wick covered tube I vcall the .ink tube. Both extend outwardly inside the tu- :bular writing point, and are ground ofi, wedgeshaped and parallel to the wedge shape of the pen point and hood.

By this means this air i.

5 Claims. (Cl. 1Z0-50) as Lucite, Celluloid, and similar transparent plastics may be used. This construction provides complete visibility not only of the amount and condition of the ink in the pen reservoir, but also of the condition and operationl of the other parts of the pen. Additionally the transparent cap gives assurance that no ink has collected therein to soil the hands or the clothing of the user when the cap is removed from the hood.

I further make the barrel of my pen with such thin walls, say .010 to .015 thick, that it can be iiattened somewhat by -pressure between the thumb and forenger of a user so as to expel air. In filling the pen, a series of such squeezing pressures and following release with the pen point yend immersed in ink, will pump ink into the reservoir. The ink flow, of course, being produced by atmospheric pressure. To prevent breakage of the barrel by unintentional, too strong a squeezing pressure, a disc of Lucite, Celluloid, etc. somewhat smaller than the bore of the pen barrel,` is mounted at the volumetric center of the barrel and preferably on the projecting end of the air breather tube. This disc may have several holes, parallel tothe pen axis, to facilitate the-rapid movement of ink through the'barrel, as when the vertically positioned pen is turned end for end. This disc allows the Abarrel to be deformed by lateral pressure to a point sufficient vfor expelling air, as in filling the pen, or for expelling through the air tube, and not the pen point, a drop or two of inkv which may have collected, or have been shaken into its inner end, for priming an otherwise dry pen point. At the same time this disc limits such barrel deformations to an amount which will prevent over stresses or fracture. Being quite elastic, the Celluloidor Lucite barrel will return instantly, after vpressure release,l toits cylindrical' shape.

The test tube-shaped Celluloid barrel reservoir fits Vtightly by press and/or twist action, onto the hood section of the pen. This slip joint i'svsufl- -ciently long and tight that it is prefectly ink tight. These joined parts may be greased with non-wettable silicone grease, DC to facilitate slippage and to improve ink tightness. The thin wall of the barrel section is sufficiently elastic, so that itenlarges slightly (by expanding its diameter) as it is forced onto the hood section.

The axial distance from the butt of the pen point to the ink reservoir is made relatively short, by boring out the hood at the barrel end to a relatively large. diameter as shown at 23 leaving a wall thickness at the joint portion 24 with the barrelof only about,.015x to .020. Theinkl-,ube lits tightly by a force fit into a ias" long bore in the hood section. It may be cemented thereinto to assure maintenance of the air breather tube and on the :barrel axis and at its volumetric center.

The pens writing point is preferably of the cylindrical type, with an axially extending slot to provide radial spring action. It is of short length (1/2") and slips into a bore in the hood of a few mils smaller diameter than the normal diameter of the cylindrical top-end portion of the pen point. This hood bore is about 1A long. Outwardly toward the tip end of the hood this bore is increased in diameter by or 10 mils to provide an annular space around the nib end of the pen for the capillary collection of ink. This ink keeps the nibs fully wetted so that the pen,

functions immediately and perfectly. The wick is of tubular form and consists of cotton or flex woven sleeving. It extends, on the outside of the ink tube from the pen end of the reservoir space inside the hood section. There it is cemented to the ink tube and hood section.

The various parts of the structure and manner of assembly will now be described.

Figure 1 is a longitudinal section through the pen with certain of the centrally located parts in elevation;

Figure 2 is a much enlarged sectional View of the pen point end of the structure without the cover cap, certain portions being shown in elevation.

Figure 3 is a View on an enlarged scale show ing how the inner wick end can be attached to the outer wick at its inner end.

In the figures I is the pen barrel made of Celluloid, Lucite or some other satisfactory transparent material. The wall thickness I have found can be .010 to .015". To the barrel I is attached a hood 2, also of similar kind of material, as by a press tight fit I 3 as heretofore described. For protecting the hood and pen point a cap 3 of suitable transparent material is used together with a clip 4 of suitable material. An annular ink space 6 is provided around the outside of the pen point 5 while a similar space 'I is provided around the inside of the pen point 5. To feed ink to the pen point 5 the following assembly is used. To start there is an inner tube 9 preferably of stainless steel which has .065 O. D. by .045 I. D. that I have found satisfactory for an air breather tube which has an air opening I4 to free atmosphere. Around the tube 9 is located a tubular wick II and outside of this is an ink tube 8 preferably of stainless steel .112" O. D. x .104 I. D. which I have also found satisfactory. Outside of the ink tube 8 is a tubular wick I0 which is preferably cemented at I'I to the hood 2. Where the ink tube 3 goes through the base I3 in the hood 2 Athe joint should be ink tight. A lateral holev I2 in the ink tube is provided as well as a hole 2I in the pen point. A slot I5 is located in the butt end of the pen to provide radial spring action to hold the pen in the hood. A circular disc located near the volumetric center of the barrel I, is preferably mounted on the end of the air breather tube 9. This disc I5 with the holes I8 therein is used as a protector for the barrel I and the holes therein speed the movement of ink through the barrel as heretofore explained. Attached to the outside wick I0 is a plurality of ink conductors 22 extending at an angle thereto for preventing ink drops from collecting on the internal end of the air breathing tube 9 when the pen is held in point up or horizontal position. The assembly of the wicks I 0 and II to the outside and inside of the ink tube 8 may be done in more than one way but I prefer the following as shown in Figure 3, which is to fray out at 25 the end of the inner wick Il and bend these ends over the outer end of the ink tube 8 and the outer wick I0 and then tie these bent over ends to the outer wick I0 with a thread wrapping 26, it being assumed that the wicks I0 and II have been installed over and within the tube 8 as described.

Thus, in effect, one wick encircles the ink tube outside and inside, having an axial bore inside the internal wick. Into this axial hole, the air tube B' is pressed, having a short section, (say g protruding from the barrel end of the ink tube. The pen end of the ink tube, Wick tube, inside the ink tube, and around the air tube, and the air tube are then ground or cut off to form a flat slanting or wedge shape surface 20 on one side, parallel to and in the plane of the wedge shaped side of the ground-off hood section and up to near the edges of the point nibs. The wick tube thus extends to the nib section of the writing point, that is, about midway between the nib tips and their lateral hole terminations. The nib tube extends to within 1% of the nib tips. A lateral hole I2 through the ink tube wall directly opposite the lateral hole 2l in the point, but not through the wick II, allows ink to feed laterally through this ink tube hole from the tubular wick to the lateral hole 2i in the pen point, to the annular space 6 around the point and inside the hood. The wick, of course, also extends between the pen nibs and the top end of the air tube, so this feeds ink to the inside surfaces of the pen nibs to within 11-6 to 1/8" of the nib points. These are thus maintained constantly in wetted condition both inside and outside.

This pen has its ink supplied from the reservoir in the barrel I to the point entirely by capillary wick action. Y

In writing position, point down, the ink travels upy the wick Voutside Ythe ink tube to the now top end, aroundrand over this end, and down the internal tubular wick to the pen point. l

The cap 3 of this pen has no customary air vent hole so that when it is removed from the hood 2 end of the pen for use, it reduces the air pressure around the point end of the pen. The higher air pressure in the reservoir end of the pen then forces ink from the wick, or a drop of ink which may have collected in the barrel end of the air breather tube, up into the pen point where it insures a well-wetted point, instantly available forwriting. Furthermore, the air tight cap seals the entire pen against any possible leak when not in use and prevents evaporation from the point end of the wick which would cause it to vdry out and to becomesediment clogged.

From what has been said it will be seen that the general advantages of this pen are l. It is very simple and of extremely low cost.

2. It is very light in weight, weighing from 1/4 to l as much as conventional pens of lightweight construction.

3. It will not leak or ilood in any position, even point down, with temperature increase or atmospheric pressure decrease, with cap on or off.

4. Its reservoir, filled to its volumetric center, holds from 3 to 5 times as much as conventional pens, yet it is of standard size fg" O=. D. x 5" long over al1.

5. The Writing point is easily interchangeable.A merely by pulling it out and pressing in another' with the ngers.

6. rThe transparent cap gives the user assurance that it contains no ink which might so1l the ngers or the clothing of the user when removed.

7. The barrel press-fits onto the hood section f merely by repeatedsqueezing and release of the pen barrel itself.

10. It can be shaken to get a drop or tWo of ink to the point, if dry, or this may be accomplished also by squeezing the barrel.

l1. Removal of the air tight cap will always draw a drop ortWo of ink through the air tube to the point to prime it, if dry, so that the pen is instantly usable. L

12. It is Very attractive looking.y

Having thus described my invention, what I claim is:

1. A fountain pen having an ink reservoir or barrel with a hood securely attached thereto, an air tube of suitable metal extending through the,

hood and into the reservoir to a point nearrits y volumetric center, a tubular wick extending over the air tube for substantially its full length, an ink tube of suitable metal extending over said tubular Wick substantially yfor its full length through the hood and a tubular Wick positioned over said ink tube and intimately joined at the reservoir end to the Wick Within the ink tube, the exterior Wick terminating against an inner part of the vhood and preferably secured thereto, and a pen point carried by the hood concentric with said tubes and Wicks, said ink tube having a lateral hole therein located intermediate the ends of the pen point permitting ink to. pass therethrough, the pen point having a lateral hole therein preferably in alignment with the hole in the ink tube for better transporting the ink from the main part of the Wicks to the pen point.

2. A fountain pen construction as set forth in claim l further defined in that said tubes and wicks terminate on a slanting surface extending from theend of the pen point tc a part of the hood beyond the exits of the tubes and Wicks.

3. A fountain pen With Writing point and ink reservoir having concentric separate, ink andair conductors extending from the reservoir to the- Writing point and separated by a tubular ink feeding Wick providing ink feeding communication between the reservoir and the pen point.

4. A fountain pen asset forth in claim 3 furthei characterized in that the air and ink:` conductors with the interposed Wick terminate shorty of the volumetric center of the inl: reservoir.

5. A fountain pen as set forth in claim l further characterized in that the outer wiel; has a. plurality of ink conductors extending therefrom at points spaced from the inner end for preventing ink getting into the air breather tube when the pin is held in some non-Writing position.

BENJAMIN F. MlESSNER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 364,772 S'chmackelsen June 14, 1887V 703,323 Wall June 24, 1902 715,359 Dickie Dec. 9, 1902 l 737,687 Bolles Sept. 1,1903 888,955 Barrett May 26, 1908 2,332,771 Alstrom, Jr Oct. 26, 1943 2,400,758 Mohns` May 21, 1946 FOREIGN PATENTS Number Country Date 818,824 kFrance June 28, 1937

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