US2669223A - Antiflood fountain pen - Google Patents

Description

Feb. 16, 1954 WESSNER 4 2,669,223

' ANTIFLOOD FOUNTAIN PEN Filed Jan. 18, 1951 n. cHeNNEur ims lo 20 30 'nucKNEss OF Amwm Ram-AL Patented Feb. 16, 1954 UNITED STATES PATENT OFFICE ANTIFLOOD FOUNTAIN PEN Benjamin F. Micssner, Morristown, N. J.

Application January .18, 1951, Serial No. 206,677

(Cl. mil-50) 9 Claims. 1

This invention relates to what I consider to be a new type of fountain pen. It is one of the objects of the invention to provide a fountain pen wherein leakage due to internal over external air increase is prevented. A further ob- .ject of my invention is to provide a new and struction that is extremely simple and low in cost of manufacture and yet effective in its operation. These and other objects and advantages will appear from a reading of the following specification wherein,

Figure l is a view on a much enlarged scale of the parts, except the cap which is not shown, in section except the air tube which is shown in elevation;

Figure 2 is a view of the upper end of the interior construction at the line 22;

Figure 3 is a longitudinal view of a modified arrangement of the air tube and associated part;

Figure 4 is a view at the line 44 of Figure 3';

Figure 5 is an end view of Figure 6 at the line 5-5;

Figure 6 is a part elevational and part sectional view on an enlarged scale of the air tube;

Figure l is a view similar to Figure 4 but of a modified construction;

Figure 8 is a curve showing the principles involved in my new construction. j In the various views wherein like numbers refer to corresponding parts, I is the barrel of the pen made of suitable plastic material which is transversely compressible but axially stifi. The barrel 1 is preferably made of transparent material such as Celluloid having a thickness of about .010 to .015 inch. Where a Celluloid is used I prefer to impregnate its inner surface translucent or opaque, may be used or even thin stainless steel.

The barrel 1 is attached to a hood 2 which may be made of suitable material such as hard rubber or the equivalent. The hood 2 has the end which receives the barrel which is made in hollow cylindrical form and the end of the barrel is attached thereto preferably by a forced fitting joint 9 so that the elastic expansion of the barrel I will make a firmly ink tight yet sep arable joint, the surfaces of which are preferably covered with silicone grease or the equivalent to assist in making the joint and in keeping the same tight. Also is shown in the drawing that the joint is made so as to provide a smooth surface l0 between the barrel I and ,the hood 2. The hood 2 tapers to a rounded point at H and has one side ground ofi at an angle of about 30 to the hood axis forming an oval shaped hole. The hood 2 has three bores of different diameters. The inner bore I2 is about inch long and adjacent to this is a somewhat larger bore 13 which is about inch long and the largest bore I4 is about inch long. In the bore I2 is force fitted an ink tight ink tube 3. I- have obtained very satisfactory results for this tube by using a stainless steel hypodermic tubing having an outside diameter of .065 inch and inside diameter of .046 inch. This tube extends from a, point I5 adjacent the nibs I6 of the pen point 4,'to a point on the axis of the barrel l short of the longitudinal volumetric center of the barrel indicated by the broken line II. This inner end of the end tube 3 is flared outwardly into a small cup l9. Inside of the ink tube 3 is an'air tube 5 which is somewhat longer than the ink tube 3 so that it may be projected slightly at both ends from the ink tube, which extends from the end [8 to the end 2| where it is anchored by soldering or spot welding to an oval plate 20, which is positioned in the oval surface formed in the hood 2. This plate 20 encloses the oval hole in the hood 2 and prevents ink from creeping into the open end 2| of the air tube 5. The air tube 5 has an outside diameter of approximately 2 to 4 mils smaller than the inside diameter-of the ink tube 3 so as to form therebetween an annular capillary ink channel 6. I have obtained quite satisfactory results for this air tube, another stainless hypodermic needle like tube having an outside diameter of .042 inch and an inside diameter of .015 inch.

In order to get the capillary attraction I have found that surfaces which are etched, pitted or scored develop great capillary action preferably from other surfaces, and to this end as shown in Figures 5 and 6 one way of securing the desired efiect is by forming on the outside of the air tube a plurality of triangularly shaped grooves 23. Besides serving to increase the capillary action this scoring as illustrated in Figure 5 serves an additional purpose in that it is made so that the edges of the scoring is such that the maximum diameter across two opposite scored parts is slightly in excess of the inside diameter of the end tube 3 so that when the ink tube and air tube are assembled the air tube will be co-axially spaced within the ink tube. As shown in Figure 1 the co-axial arrangement is at least partially provided for by passing a thin stifi pin 24 through the upper end of the air tube 5 and anchoring its ends to the top .01" the cup it. Still another wayof obtainingco-axiality of the two tubes 3 and 5 is that shown in Figure 3, wherein a strong ink resistant but wettable wire 22 is spirally wound in a coarse manner around the tube 5, at least the ends 25 and 'izfi being soldered or welded to the endsoi .a tube $315 if necessary the wire 22 may be fastened to the tube 51) at one or more intermediate points. A still further way of co-axial arrangement as shown in Figure '7 is wherein the pipe 5a cor responding to pipe 5 is extruded so a rib 21 is positioned thereon in a spiral manner as :shown in Figure 7. it is to be meted from Figure "1 that pen 4has a split shank' whichsecurely fits into the bore 13 of medium diameter in the hood '2 while the larger *bore 4'4 provides arrannular "space 1 outside the shank of the pen for cooperation with the space 8 provided by the medium -diameter bore P3,

In Fig '8 I have shown acurve made from measurement data to determine the capillary action that goes I on within the pen constructed to the foregoing, this 'data being obtained "at clean wettable surfaces. of annular channels in the f or rnof tubular boresin a glass tube having an n id 'dia e r ff- 35 in 'By-reference'tothe QlIlV6itfWl11 be observed t at t e h h 1 .1 11mb "of a e i trade f ounta e a afielfs m el "G n k i l r es n ersely with t e di t f he ca ar b0 ??-v li s'cur ha be s d o. ete mine m dal mc ne s 9f the r v s ii/ k ch nn s de cribed 1. 9. 1 a hann d '8 n'i la ion tg he n h-0f h se h e s.- -T e b c a epre e t e adia banne thick.- n n m nd th dina s e r sentth rtical heighttowhichinkwillclimbto the surface of a .vessel or besecur'ely 'heldj;i n the tube wh is r mo edffrom "the essel- These r h i hts-Mathew in hich ca llar 2 611st a ce .s a tiona 121111 11 t e ink column in the ink tube. "With increasedheight f n -c l mn av wilL ull q he-e c ss and cause' d i i o lth ih tb m end oilthe tube .or other channel. until the capillary attraction .balances the, gravitational pull.

However, when ..the.capilla'r rforce the. tube lanc e a nl l P1111 he J col mn will still iiowqntoon be .absorheldby wet.- table. surface or. body contacting theilower ,end of. the tube. .Thus the. ink. so; held in the tube is still. n an r vai bl f -e p ica cn. suc a writing on paper or the like.

The m -i l va e oi bhwrdi aws 9 hi curve will vary somewhat withlthe. nature-"pi the .material. comprising. the .capillary channel walls, I e n th u h he e be a re cr ase or i the like- Such -.a curve then :as .Eig ..8 is .plotted from .measurements of the capillary ."iorce, of annular channels for the material and surfacesto be used! and-this curve. isused. for-,deterrnin ing-the radial thicknesses .oftheasereral; ink channelsbeltween the reservoir and the; peninib-tips .inanerlationto the lengths ofthesenchannels. :Eoneaample ifvall of. the channel-surfaces! have: capile lary forcesv in accordance with: the :curve: ofrFig h 1 it and the ink tube has a length of 2% inches inspection of this curve indicates that the radial thickness of the annular ink channel must be no greater than 8 mils, in order for it to hold this 2% inch high column of ink without over flowing.

Likewise, if as an Figure 1, the length of ink collector spaces 7 and 8 are /2 inch. Their annular thicknesses must not exceed 20 mils, in ord r l1at he@an icen es he an -fi s may atleast balance the gravitational pull on their continued columns of ink. Since the thickness, that is the inside diameter of the air tube is 15 mils, its capillary force even if its bore were wcttable, could sustain an ink column of only about qlinchas shown on the curve of Fig. 8.

From the end it of the ink tube 3 ink, which ihaszfilled .thesmallcup, flows down through the annular channel 6 to its lower end l5. There it contacts the under surface of the plate 20 and flows over its surface to the pen bore and nibs, due both to gravitational and capillary action. It flows therefore into the annular collector space'8'and thence into annular collectorspace 7. Air in these spaces escapes-aroundtheedges of plate 26.

The butt end of :the nib slit in the pen point is preferably no more-than'one'or =two rni1gwide. This-slit tapers to zero =wid-th-at the tip'cnds 9f the contacting nibs. The capillary force inthis slit is therefore very large and increasesat the tip end, so that this; will be -ink-charged-so long as there 'is ink above =it-as described. Thus-far I have considered only the lqlyd rostatic p-ressu-re due to gravity of theink in'a'nnulanchannels fi, "l andj8.

In order thattheir containedink'columns rnay not overflowwhenoverbalanced by -an addition, to their hydrostatic pressures-of the usual hydrodynamic pressures set up by the-usual-axialn otions nvq e ri n and. n hand n 5. 9 9 p ns 1 .65? "ch-3 1N 5 il? g q? s m w less in'radial-thickness than those values ind a d a sufficient 9 ydrq t ti rmessu a1one," by the absc' evalues cf the curve shown im -isur 8 0 i s milar curves or ther ami k-Qh !l6 ?:y r a e ama seleiact of e etyfisthus prq d das az ua a a ns verflqfw hich. he ve ne q'n t large enough to operate satisfactorily ,forrsuch unu ual hyd aq namis lly-s v lq .iq W rd ,presslilifi ldflit Ql1 'th$ hih 9 ,91 f r s m e when. the. me i dress d. hun down into an unyielding s aceas a 'fioorf his ewt penf.nen with in tby su merging" its ters; aainksl ppl an iteen a rnat l .trac ve ysqu beans releasi thebar relfacfewmi es. Sue ansyersepressure redness themlmnet capacity of th..,b rel and forcesairout. ,Release,,of 1t 1is pressure,al* l w the e astic ba rel to s ring ba k I o .c lin d c.a Sha e thusr clu n the. nternalair, press'ureand allowing the now. higher g mastm sph rie s u e oiorcc in u s t-sl h cu h both the airj'.tube 4 and .thelink channel .6; into thepenreserroir. -sincethecrczsssectionalareas of .the bore;.oi air t uber5, ,and oi tha nn ular hann S are.a prosimatelnecual.their in 319 ra esar -a proxim el equal since thes vhave apprcximat lyceq alcross lse ticnalaareas and lengths they will both carry approximately equa QmQUQtSDfvlIIK QQW-Q l d nne e ds-i to the barrel; tiens s fi es to fil e haw-cha t top nd -c -the tube amcrrtb tub le els ade'itneal 10 :9 at wartor r. overth squeezes across the section occupied by these ink tube filled with ink. The annular ink collector spaces 1 and 8 will also be filled with ink.

' The aggregate amount of ink in the annular channel 6 and the annular collector spaces 1 and 8, is sufiicient for a few pages of writing without further replenishment of this supply when this ink has been written out'it is only necessary to tilt the pen to point up or to a horizontal position, whereupon the rapid fiow of ink in the reservoir will lodge another drop or two into the cup l9 and thus replenish the supply. Should an ink droplet become lodged in the air tube 5 it will soon be moved back into the reservoir or to the pen point by movement of air into .or out of the pen. Likewise, a concurrent squeeze of the barrel with the tilting on shaking of the pen will insure quick transfer of the ink from the cup l9 or the open end of the air tube 5 to the pen point.

It may thus be seen that this pen has a small reservoir in the form of the spaces 6, 1, and 8, and a main reservoir in the barrel I, and that these reservoirs are interconnected for ink passage in either direction, when the pen is filled as above stated; in either point-up or point-down position. The non-wettability of the outer surface of ink tube 3 prevents capillary rise of ink along and over the inner end of 3 to the channel 5, when the pen is point down. When the pen is point up, there is a completely effective air space between the ink in the reservoir and the inner ends of tubes 3 and 5.

When the pen is horizontal, even though the ink level may be at or slightly below the axes of tubes 3 and 5, ink inflow to these tubes is prevented by the non-wettability of the ends of these tubes. This non-wettability however does not prevent ink from flowing into the cup l9 as it flows rapidly past it in a penward direction. Once thus caught in this cup the ink drop forms into a bell like mass in good capillary connection with the end of the channel 6. When the ink supply in the barrel l becomes low, mere tilting of the pen may be insufilcient to lodge ink drops in the cup l9. Then a single axial shake of the pen will do so.

If the pen, after writing, is capped and put in the users pocket, point up, ink will remain in channels 6, 1, and 8, and held there by capillary force. Then upon reinversion for writing, it will be instantly available at the pen point nib ends for writing.

The actual ink capacity of this pen filled as explained in a conventional size of 1 3' inch outside diameter by 4% inch long over-all, but exclusive of cap, not shown, is approximately 4 cc. which is from four to six times that of conventional fountain pens of the same size.

It has been noted that the cross-sectional areas of the ink tube bore and the channel 6 are approximately equal. In filling, as well as in expulsion of overfilled ink, both of these passages are flushed by rapidly moving ink streams so that any sedimentary ink deposits on their walls, left from continued, emptiness of disuse, will be wetted and flushed out. This flushing out occurs of course, with each refilling operation so that 6 these passages are maintained inoperable condition with ink in at least the barrel reservoir, these passages are bathed in aqueous vapors so'that sedimentation will not occur. It is evident therefore that this pen construction and operation meets all of the operation conditions desiderataof fountain pens, most of which are not found in such conventional pens. It is further evident from what has been said that this pen is simple, durable, and effective, of low manufacturing cost, and attractive in appearance and that it has an exceptionally largeink capacity, with completely visible operation. Of course many of the details can be varied without de- ..parting from the spirit of my invention and the scope of the appended claims.

Having thus describedmy invention, I claim: 1. A fountain pen having ahoodcarrying. a

pen with ink collector spaces around the shank of the pen, an ink barrel fastened to the hood,

the barrel being of elastic material transversely compressible but axiallystiif, an ink tube securely carried by the hood and extending on the barrel axis, from a point near the pen nibs to a point near the volumetric center of the barrel, a complete air tube located in closely spaced annular relationship within the ink tube, to promote capillary action between the tubes and extending from a point adjacent the open end of the ink tube to a point near the nibs of the pen.

2. A fountain pen as set forth in claim 1 further defined in that the spacing between the inner wall of the ink tube and the outer wall of the air tube is of the order of 2 mils in radial distance as and for the purpose described.

3. A fountain pen as set forth in claim 1 further defined in that the inner end of the ink tube terminates in a cup as and for the purpose described.

4. A fountain pen as set forth in claim 1 further defined in that the spacing between the inner wall of the ink tube and the outer wall of the air tube is of the order of 2 mils in radial distance while the inner end of the ink tube terminates in a cup and means for centralizing the adjacent end of the air tube in the cup.

5. A fountain pen as set forth in claim 1 further defined in that the outer surface of the air tube has means thereon for promoting capillary action, said means comprising an outer scored surface made up of a plurality of projecting scores preferably extending longitudinally of the air tube.

6. A fountain pen as set forth in claim 1 further defined in that means are provided for 00- axially aligning the air tube within the ink tube in said closely spaced, annular relationship, said means comprising, a relatively coarse spirally wound wire around the air tube and having its ends fastened to the ends of the air tube, said wire being preferably ink resistant but wettable.

'7. A fountain pen as set forth in claim 1 further defined in that means are provided for coaxially aligning the air tube within the ink tube in said closely spaced, annular relationship, said means comprising a spirally formed integral rib extending along the length of the air tube.

8. A fountain pen as set forth in claim 1 further defined in that the pen end of the hood terminates in an oval shaped hole and the air tube terminates in an oval shaped plate that covers said oval hole in the hood as and for the purpose described.

9. A fountain pen with a hood having at one end a hollow cylindrically shaped formation while

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