US2303374A - Fountain pen - Google Patents

Description

1942- V L. MARTIN 2,303,374

FOUNTAIN PE Filed Nov. 3,.1941

I ymv MART/N.

Patented Dec. 1, 1942 1 UNITED STATES PATENT. OFFICE ropm'smrnu Lynn P. Martin; Fort Madison, Iowa, assignor to W. A. Sheaffer Pen Company, Fort Iowa, a corporation of Delaware Application November s, 1941, serial No. 417,667 reclaims. (cl. 120-40) This invention relates to a fountain pen and chambers, the amount of storage space being sufhas special reference to the feeding mechanism flcient to accommodateconsiderably more than a of a fountain pen for directing writing fluid from normal expectant change temperature and the reservoir thereof to the pen nib. pressure conditions.

More particularly, this invention relates to a 5 One of the objects of this invention is to profountain pen including a feed bar having a shank 'vide 'afountain pen having a feeding mechanism portion adapted to be mounted within the bore capable of diverting the excess amount of fluid at the end of the barrel of the fountain pen and not necessary for normal writing to storage a nib supporting portion extendingbeyond th chambers to eliminate flooding or leaking of the end of the barrel, the nib supporting portion be-- o o a p ing of substantially greater diameter than the Another object of s invention i8 60 Provide diameter of the shank portion. Means are proa fountain pen having ,a feeding mechanism vided in the feed bar for supplying writing fluid which is simple and eflicient in operation, is comfrom the'reservoir to the pen nib. paratively j inexpensive to manufacture, and is In the normal operation of a fountain pen, durable. i writing fluid is directed from a reservoir within Other objects and advantages of this invention the barrel thereof to the nib and therefrom onto will hereinafter be more particularly pointed out a writing surface, air being directed into the resand for a more complete understanding of the ervoir to take the place of the writing fluid with characteristic features of this invention, referdrawn therefrom. The air in the fluid reservoir ence may now be had to the following description of the barrel is effected by temperature and presand the accompanying drawin in which latter: sure changes, and the greater the amount of air Figure 1 is a front elevational view. greatly enin the reservoir and the lesser amount of writing larged, of a feed bar embodying the features of fluid therein, the more diflicult it is to control a thisinvention;

normal supply of writing fluid tothe writing sur- Fig. 2 is a sectional I view taken on the line face. 2-2-0! Fig. i; 1

Heat from the hand when the fountain pen is Fig. 3 is a central vertical sectional view taken held in writing position tends to expand the air on the line 3-3 of Fig. 1, a pen nib and pen behind the writing fluid. Of recent years, it has section being fragmentariiy shown in dotted been the tendency of fountain pen manufacturers lines; and

to increase the fluid capacity of a fountain pen. Fig. 4 is a sectional view taken on the line l-l A larger capacity pen, of course, has a larger of Fig.3. amount of air to expand under comparable con- Referring now more particularly to the draw-- ditions. The larger fluid chamber, holding a ing, the.feed barincorporating the features of comparatively greater amount of air when parthe present invention comprises a shank portion tially filled, tends to supply a greater amount of II adapted to be mounted within the bore at the wr ting fluid to the writing surface than is 118 end of the barrel of a fountain pen and a nib essary for ordinary' writing, causing what is supporting portion ll adap ed to extend beyond called a flooding of the pen. if the f edi the end of the barrel. The feed bar is for the mechanism is not capable of diverting a com- 40 purpose of directing writing fluid from the resparatively greater excess of fluid from the writerv'oir within the barrel of the fountain pen to aing p i pen nib i2 shown in dotted lines in Fig. 3 of the The expansion of air behind the writing fluid drawing. The pen nib ii in the present instance within the reservoir may, for example, accomhas a tubular shank portion I! which embraces pany a change of temperature conditions, such inc. fixed relation a plug it. The plug ll has a as is attained in holding h pen in writing pohead portion and a reduced threaded shank porsition after the fountain pen has been maintion II, the shank portion threadedly engaging tained at a substantially lower temperature. Exthe internally threaded portion of the bore at pansion also accompanies a change of atmosthe end of the pen'section or barrel l5.

' ided with an internal duct pheric pressure, as when a fountain pen is car- The feed bar is prov V I ried by a passenger in an airplane. Th pres- H which extends longitudinally thereof from the ent invention contemplates the elimination of reser o end to a point intermediate t en of flooding or leaking of the fountain pen by being the feed bar. A vent opening It extends transcapable of diverting fluid in excess of that which Versely 0f the f bar and P ly Out de for normal writing into storage the end of the ba.. ga g ll, the ventcpening is necessary from the nib supporting surface of the feed bar fiansversely through and below the internal duct it plurality of comb cuts 2| extend transversely on the periphery of the feed bar and communicate with the fissure I. In the instance of the structure shown in the drawing, the comb cuts extend entirely about the circumference of the feed bar, although, it is to be understood, that it may be desirable in instances of use for the comb cuts to extend but partially about the circumference of the feed bar on each side of the fissure l9. The comb cuts are preferably of greater widththan the width of the fissure and extend over a major portion of the length of the. feed bar including the shank'portion II and the nib supporting portion ll. Thus the comb cuts extend outwardly from. a point within the bore at the end of the barrel. I

A plurality of cuts It extend longitudinally over a portion or the-periphery of the feed bar for connecting a substantial number ofthe comb cuts and particularly those comb cuts disposed within the bore at the end of the barrel. The

longitudinal cuts preferably connect all ofthe comb cuts within the bore of the end of the barrel and extend outside the end of the barrel to the atmosphere. In the drawing, three such longitudinal cuts have been shown, the longitudinal cuts. being greater in width than the width of the co'mb cuts and being of lesserdepth than the depth of the comb cuts.

, The nib supporting portion of'the feed bar is for substantially greater diameter than the di-' ameter of the shank portion and'preferably' converges'in a direction outwardly from the barrel end of the fountain pen. The depth of the'comb cuts in both the shank and nib supporting portions of the feed bar terminate at substantially equal distances from the axis of the feed bar so that the actual capacity of the comb cuts of the nib supporting portion is substantially greater than the comb cuts of the shank portion. The enlarged head or nib supporting portion of the feed bar has the advantage, of'course, of having a' much greater capacity than were the shank and nib s ppor nsportions'or the same'or substantially the same external diameter and of the same length.

In the normal writing action of thefountain pen employing a feed bar now in popular use.

when diverting excess fluid not necessary for normal writing operation, the fluid is conducted from the reservoir through an internal duct to the fissure on the nib supporting periphery near the writing point end, theexceas fluid being directed into comb cuts at the writingpointend first and then progressively upwardly in the direction of the comb. cutinearest the reservoir end of the feed bar. It has been found that the height to which fluid could be raised and released to comb cuts in this manner is materially limited and the capacity of the comb cuts within such height is insuificient-for such abnormal conditions as should be accommodated. g

. The present invention determines that the height to which fluid may be maintained in the fissure and comb cuts of a feed bar when'in writ- 19 on the feed being connected with the fluid reservoir and communicating with comb cuts within the end of the bore of the barrel as well as with the comb cuts of substantially greater area on the nib supporting portion outside the end of the barrel 1 The comb cuts nearest the reservoir are filled by writing fluid as the fluid is drawn by capillary attraction along the fissure I! in the direction of the writing point and at the same time the comb cuts nearest the writing point end of the feed bar fill in a direction upwardlytherefrom. In writing position, therefore, the comb cuts flll progressively inwardly from the ends thereof.

It has been found difilcult to conduct writing fluid into and out of comb cuts on the periphery of the feed bar within the bore of the end of the barrel. Such difliculty has been overcome in the provision of the three longitudinally extending cuts 2| which are preferably spaced equi-distantly a from each other and connect the comb cuts inside the bore of the barrel, the, longitudinal cuts extending outside the bore of the barrel for communication with the atmosphere. By reason of the longitudinally extending cuts being made slightly less in depth than the comb cuts and slightly greater in width, the film strength of the fluid is weakened so that they are emptied by the cohesion of the fluid in them with the fluid in the long connecting fissure II on the top of the feed prior to the emptying of the comb cuts.

The longitudinal cuts, by reason of their dimensions, are'the last to fill with excess fluid, so that all of the .air previously contained in the comb cuts within the bore of the end of the barrel that the ion:

and the provision of transversely ,extending comb cuts within the bore of the end of the barrel increases the capacity of the feed bar for diverting excess writing fluid from the nib. However, to further increase this capacity, the 'depth of the comb cuts is increased without weakening the structure of the feed bar. The central drilling I1 is provided with the fissure l9 passing from the periphery of the feed bar through and below the central drilling or so-called internal duct H. The .weakest fluid film is thus formed between the fissure and the central drilling or internal dust I1 somewhere between the lower end of the drilling and the reservoir end thereof, and in order to make all the fluid contract back into the fluid chamber, it has been.found desirabie to have this weakest fiuid film formed near the front end of the center drilling.

The vent opening I8 is provided near the forward end of the internal duct H to connect the internal duct with the atmosphere and to locate the point of weakest film formation thereat.

Thus, contraction from the front or writing point end is accomplished in a desirable manner and fluid which is in the comb cuts and longitudinal cuts within the bore of the end of the barrel is drawn by capillary attraction out of the upper or back end of the fissure I9 where the fluid him is stronger than the film in the air vent, the air vent making the fissure purposely weak at the forward end of the internal duct ll. Fluid will be contracted back through the fissure at a point nearest the reservoir since the fluid film at that point will not break before the fllm at the air vent and the latter film will not break until the comb cuts adjacent the writing point have emptied. Thus it is assured that an expansion chamber free of fluid is formed capable of diverting excess fluid to its full capacity, should expansion occur after contraction.

In normal writing, when the expansion chain bers-that is, the transverse comb cuts andthe longitudinal cuts-are full, the comb cuts closest to the reservoir empty flrst. When the expansion chambers are empty, fluid leaves the flssure I! at the writing point end and lipid taking the place of that leaving the fissure at the writing pointend is directed from the reservoir in the bottom of the fissure l9 below the internal duct H in an unbroken condition and builds up in a direction irom the writing point end toward the reservoir to control the air vent 18.

When contraction takes place due to cooling" of the air in the reservoir or to a change in atmospheric pres are full and the pen is carried with the point directed upwardly, the comb cuts immediately adjacent the writing 'point end of the feed bar are relieved of fluid first and thereafter the comb cuts are relieved progressively toward the reservoir'. Of course, if the expansion chambers are empty, such contraction will merely result in the intake of air. When a change-in temperature or atmospheric pressure is had, resulting in expan: sion, if the expansion chambers are empty and the fountain pen is held in a normal writing position, the comb cuts are filled with writing fluid in excess of that needed for normal writing through the fissures above the central drilling to comb cuts nearest the reservoir and at the same time through fissure I8 below the internal duct ll to the comb cuts farthest from athe reservoir. This has been found to be normal, although this condition varies with a variance in the length of the feed bar and the rate of expansion.

While but a single embodiment of this inven-.

tion is herein shown and described, it is to be understoodthat various modifications thereof may be apparent to those skilled in the art without departing from the spirit and scope of this invention, and, therefore, the same is only to be limited by the scopeof the prior art and the appended claims.

I claim:

l. A feed bar having a shank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, and means for supplying writing fluid from saidreservoir if) said pen nib.

2. A feed bar having a shank portion adapted to be mounted within the bore at the end ofthe barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib supporting portion converging in a direction outwardly from the barrel end and being of substantially greater diameter than the diamsure, if the expansion chambers 80 eter of said shank portion, and means for supplying writing fluid from said reservoir to said pen nib.

3. A feed bar having a shank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel,

greater diameter than the diameter of said shank portion, means for supplying writing fluid from said reservoir to said pen nib, and comb cuts extending transversely over at least a portion of the periphery of both said shank and nib supporting. portions of said feed bar.

'5. A feed bar having a shank portion adapted to be mounted within the bore at theend of the barrel of a fountainpen and a nib supporting portion extending beyond said end oilthe barrel, said nib supporting portion converging in a direction outwardly from the barrel end and being of substantially greater diameter than the diameter of. said shank portion, means for supplying writing fluid from said reservoir to said pen riib, and comb cuts extending transversely over at least a portion of the periphery of both shank and nib supportingportions of said feed bar.

'6. A feed bar having ashank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel,

said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, means for supplying writing fluid from said reservoir to said-pen nib, comb cuts extending transversely over at least a portion of the periphery of both shank and nib supporting portions of said feed banand longitudinally extending ducts disposed peripherally of said feed bar intersecting comb cuts end of the barrel.

7. A feed bar having a shank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, means for supplying writing fluid from said reservoir to said pen nib, comb cuts extending transversely over at least a portion of the periphery of both shank and nib supporting portions of said feed bar, and longitudinally extending ducts disposed peripherally of said feed bar intersecting comb cuts of both said shank and nib supporting portions.

8. A feed bar having a shank portion adapted to be mounted within the boreof the barrel of a fountain pen and a nib supporting portion extending beyond the end of said barrel, said nib supporting portion converging in a direction outwardly from the barrel end and being of substantially greater diameter than the diameter of said shank portion, a peripherally disposed longitudinally extending fissure on said shank and nib supporting portions for supplying writing within the bore at the fluidfrom said reservoir to said pen nib, comb,

cuts communicating with said fissure extending transversely over at least a portion of the periphery of both shank and nib supporting por- -tions of said feed bar, and longitudinally extending ducts disposed peripherally of said feed bar intersecting comb cuts of both said shank and nib supporting portions.

9. A feed bar having a shank portion adapted to be mounted within the bore at the end of the barrel 'of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib-supporting portion being of substantially greater diameter than the diameter of said shank portion, an internal duct extending longitudinally of said feed bar from one end thereof in .com-' munication with a writing fluid reservoir in said barrel to a point intermediate the ends thereof, and a longitudinally extending fissure of capillary dimensions in said feed bar extending from the reservoir end thereof to a point adjacent the other end thereof for supplying writing fluid to said nib, said fissure extending from the surface of said nib supporting portion transversely through and below said internal duct.

'10. A feed bar having a shank portion adapted Tm be mounted within the bore at the end of the barrel of a fountain pen and a'nib supporting barrel to a point intermediate the ends thereof, a vent opening extending transversely of said a feed bar outside the end of said barrel and communicating with said internal duct, and a longitudinally extending fissure of capillary dimensions in said feed bar extending from the reservoir end thereof to a point adjacent the other end thereof for supplying writing fluid to said nib, said fissure extending from the surface of said nib supporting portion transversely through and below said internal duct. I

13. A feed bar having a shank portion adapted to bemounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel,

I said nib supporting portion being of substantially portion extending beyond said end of the barrel,

' said nib supporting portion converging ln'a direction outwardly from the barrel end and being of substantially greater diameter than the diameter of said shank portion, an internal duct extending longitudinally of said feed bar from one end thereof in communication with a writing fluid reservoir in said barrel tov a point intermediate the ends thereof, and a longitudinally extending fissure of capillary dimensions in said feed bar extending from the reservoir end thereof to a point adjacent the other end thereof for supplying writing fluid to said nib, said fissure extending from the surface of said nib supportingportion transversely through and below said internal duct.

11. A feed bar having a' shank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, an internal duct extending longitudinally greater diameter than the diameter of said shank portion, an internal duct extending longitudinally of said feed bar from one end thereof in communication with a writing fluid reservoir in said barrel, a vent opening extending transversely of said feed bar and communicating with said ina t'ernal duct, and a longitudinally extending fissure of capillary dimensions in said feed bar extending from the reservoir end thereof to a point adjacent the other end thereof, for supplying writing fluid to said nib, said vent opening being greater in diameter than the width of said fissure and said -fissure extending from the surface of said nib supporting portion transversely through and below said internal duct.

14, A feed bar having a shank portion adapted to be mounted within the bore at the end of the barrel of a fountain pen and a nib supporting portion extending beyond said end of the barrel, said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, an internal duct extending longitudinally of said feed bar from one end thereof in communication with a wiring fluid reservoir in said barrel, a longitudinally extending fissure of capillary dimensions in said feed bar extending from the reservoir'end thereofto/ alpoint adjacent the other end thereof for supplying writing fluid to said nib, said fissure extending from the surface 'of said nib supporting portion transversely through and below said internal duct, and comb V cuts extending transversely of said feed bar and being in communication with said fissure, said of said feed bar from one end thereof in communication with a writing fluid reservoir in said barrel .to a point intermediate the ends thereof, a vent opening extending transversely of said feed bar and communicating with said internal greater diameter than the diameter of said shank portion, an'internal ductextending longitudinallyof said feed bar from one end thereof in communication with a writing fluid reservoir in said comb-cuts being of greater width than the width of said fissure. I

15. A feed bar havinga shank portion adapted to be mounted. within the bore at the end of the barrel of a fountain penand a nib supporting portion extending bey ond said end of the barrel, said nib supporting portion being of substantially greater diameter than the diameter of said shank portion, an internal duct extending longitudinally of said feed bar from one end thereof in communication with a writing fluid reservoir in said barrel, a longitudinally extending fissure of capillary dimensions in said feed bar extending from with'said fissure.

the reservoir end thereof to a point adjacent the other end thereof for supplying writing fluid to said nib, said fissure extendingfrom the surface .of said nib supporting poi-tion transversely through and below said internal duct, and comb cuts extending transversely over at least a portion of said shank and nib supporting portions of said feed bar and being in communication LYNN P. MARTIN.

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