US2645205A - Fountain pen - Google Patents

Description

July 14, 1953 R. w. RANDOLPH FOUNTAIN PEN Filed March 18, 1948 ww uw @w @w @w IN V EN TOR.

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Patented July 14, 1953 FOUNTAIN PEN Robert W. Randolph, Milton, Wis., assigner to The Parker Pen Company, Janesville, Wis., a. corporation of Wisconsin Application March 18, 1948, Serial No. 15,580

Claims. (Cl. 1Z0- 50) This invention relates to fountain pens and has to do particularly with fountain pens of the type having ink overflow control means for preventing flooding or leaking at the writing end.

An object of the present invention is to provide an improved fountain pen of the foregoing character.

Another object is to provide a fountain pen of the foregoing character which has a relatively small number of parts and which is very simple and inexpensive to manufacture and assemble.

A further object is to provide a fountain pen of the foregoing character wherein there are relatively few critical dimensions or adjustments and the several members forming the fountain pen may be manufactured by 'relatively simple and inexpensive operations and may be assembled by relatively unskilled labor.

A still further object is to provide a fountain pen of the foregoing character wherein the adjustment of the parts is not extremely critical and the pen will function satisfactorily even without exact adjustment and alignment of the parts.

Another object is to provide a fountain pen of the type adapted to be filled by manual compression of a portion of the ink reservoir and having an air breather tube extending within the reservoir, which pen is of such construction that the collapsible portion of the reservoir is readily accessible and at the same time may be manipulated to fill the pen without interference with the action of the breather tube.

Still a further object is to provide a fountain pen of the type having ink overflow control means and so constructed that there is a minimum area of ink surface exposed to the atmosphere, thereby minimizing the amount of evaporation of ink from the pen.

Other objects of the invention will appear from the following description taken in connection with the appended drawings wherein:

Figure l is a side elevational view of a fountain pen constructed in accordance with my invention, with certain of the parts sectioned to show the interior;

Fig. 2 is an enlarged fragmentary longitudinal sectional view through the forward portion of the pen shown in Fig. 1;

Fig. 3 is a top plan view of a feed bar forming a portion of the structure shown in Fig. 1 together with a portion of the nib associated therewith;

Fig. 4 is a transverse sectional view taken along line 4-4 of Fig. 2;

v teristics as herein described.

Fig. 5 is a transverse sectional view taken along line 5-5 of Fig. 2; and

Fig. 6 is a transverse sectional view taken along line 6 6 of Fig. 2.

Referring now particularly to Fig. 1, the pen includes a casing or housing formed by a barrel Il! and a forwardly extending shell I I, which together surround and substantially enclose the internal members of the pen. A tubular body I2 which preferably takes the form of a nipple is provided for connecting the barrel and shell, as well as many of the other members forming the pen, and for retaining them in proper assembled relationship. The body member I2 is provided with a forward bore I3 and a rearward bore I4 and is formed with a plurality oil dilferent external diameters providing in effect a plurality of longitudinally adjacent sections of different diameters adapted to receive and support various pen members as hereinafter described.

At its rearward end portion the body member I2 is formed with a section I5 over which is telescoped the forward open end 0f a flexible and resilient sac It, which together with the bore I, defines an ink reservoir Il. The forward end portion of the sac It preferably is so formed that in its normal condition it is of slightly lesser diameter than the section I5 and thus when the sac is assembled on the latter it tightly grasps the same to retain the sac hereon. However, if desired the sac may be secured on the section I5 by a suitable adhesive such as a known cement. Retention ofthe sac on the section i5 preferably is rendered more positive by providing a series of circumferential external grooves I8 into which the sac material enters.

The sac I6 is formed of a suitable material of sufficient resilience to remain in expanded condition except when forcibly compressed and which is resistant to inks ofr the types commonly used, that is, both acid and alkaline inks and which material will not deterioratey or lose its resilience over a long period of use. Preferably the sac is formed from a material which is transparent or sufficiently translucent to permit the user to observe the level of lthe ink therein as hereinafter explained. While any one of a number of elastic materials may be used, excellent results have.

been obtained by forming the sac from a, synthetic resin such as a copolymerized chlorideacetate resin commercially from Carbide and Carbon Chemicals Corp. of New York, N. Y., under the trade -name of Vinylite V, which material has been found to have the desirable charac- The sac I6 is from the pen, a guard I9 is provided. The guard is formed as an elongate, thin-walled, tubular member open at both ends and is telescoped over the sac and the rearward end of the body member I2. The forward end of the guard is secured to an intermediate section 2U of the body member I2, which is of slightly larger diameter than the end section I5. While the guard may be secured in any suitable manner it preferably is threaded onto the section for convenience in assembly, although it may if desired be secured in other ways as by spinning the material of the guard into a groove (not shown) formed in the section 'I'he guard I9 extends rearwardly a sufficient length to permit it to be grasped readily by the user but terminates short of the rear end of the sac I6 to such a point as to permit a sufficient length of the sac I6 to project beyond the rear ond of the guard I 9 to allow the sac to be grasped between the fingers of the user and compressed. The guard I9 is preferably formed of thin-walled, light, but rigid material, which is of sufcient strength and rigidity to prevent the same from being bent in use but sufficiently thin and light weight so as not to consume substantial space within the pen barrel I0 or add materially to the weight of the pen.

The sac IG, or at least the portion which projects beyond the guard I9, may be formed with longitudinally extending, inwardly directed, spaced ribs Ia which render it more rigid.

The barrel I0 is formed with an open forward end and is adapted to be telescoped over the sac I 6 and the guard I9 and a portion of the body I2 to thereby enclose the sac I6 and guard I9. The barrel is connected to the body I2 for ready detachment in order to permit convenient removal thereof to permit access to the sac for the filling operation. The barrel therefore is connected to a section 2| of the body member I2 of maximum diameter and preferably is retained thereon by screw threads. The barrel is adapted to be screwed onto the body I2 with its forward limit of movement determined by abutment against a rearwardly facing shoulder 22 provided by a clutch ring 23 threaded onto a section 24 of the body I2 of lesser diameter than the section 2|. The clutch ring also may serve to retain a slip cap 25 in a manner generally similar to that disclosed and claimed in U. S. patent to Marlin S. Baker No. 2,278,907 granted April '7, 1942.

The barrel is provided with a vent opening 26 preferably located at its rear end for the purpose of equalizing the pressure between the interior and exterior of the barrel to thus prevent compression of the air within the barrel and consequent possible forcible expulsion of ink from the reservoir I1 when the barrel I0 is assembled over the sac I6 and guard I9.

The hollow shell II is secured on the body member I2 preferably by screwing it on the section 24. The shell II thus surrounds and substantially encloses the forward end of the body member I2. The shell is formed with a hollow interior providing a chamber 21 and with an opening 2a in its forward end through Whih a nib 29 and feed bar 30 are adapted to project as hereinafter described. The shell is screwed down against the clutch ring 23 and thus its position on the body member I2 may be predetermined by suitably positioning the ring on the body I2. If desired, the shell may be secured in position by a suitable thermoplastic cement to prevent the user from disarranging the shell but which will permit removal for repair purposes.

The feed bar 30 is formed with a shank portion 32 adapted to be slip-fitted into the forward bore I3 of the body member I2, and a body portion 33 adapted to project from the end of the body member I2. The shank 32 fits snugly in the bore I3 but the latter is relieved sufciently as at 34 so that the rear end or shank 35 of the nib 29 may be inserted in the forward open end of the section 36 of the body member I2. The nib 29 is formed in an arcuate body portion 3l extending forwardly along the feed bar and resting upon the upper surface thereof, and is provided with a tapered writing portion 38 formed with a slit 39 providing two writing nibs 40 and terminating rearwardly in a pierce 4I. The nib 29 and the projecting portion 33 of the feed bar are substantially enclosed and housed by the shell I I except for the extreme writing tip of the nib which projects through the upper portion of the end opening 28 in the shell II.

The feed bar is provided with means for feeding ink from the reservoir I'I to the nib slit 39, which means includes upwardly open feed slots 6.2 extending from the rear end of the feed bar 39 forwardly to adjacent the nib slit 39. Preferably, two slots 42 are provided, for reasons which will hereinafter appear and the two slots are disposed in spaced parallel arrangement. The tapered portion 38 of the nib closely overlies the top surface of the feed bar 30 at its forward end and a small arcuate space 43 of capillary height thereby is provided into which ink is drawn when the pen is in use. This space 43 thus insures that a body of ink is available adjacent the nib slit so that the latter remains filled so long as any ink is in the pen and the pen therefore is always in condition for instant writing.

In order to further insure against the nib slit drying out, an arcuate ink storage space 44 of capillary dimension is provided above the nib into which ink is drawn by capillary action to provide a body of ink which maintains the nib wetted on its upper surface substantially to the writing tip. The feed bar also is provided with means for admitting air to the reservoir to replace ink which is withdrawn in writing and thereby permit further ink to be withdrawn from the reservoir. The feed bar also is provided with means for receiving and storing ink which may flow from the reservoir in excess of that required for writing purposes in order to prevent flooding and leaking at the point.

A longitudinally spaced series of transversely extending ink storage spaces 45 of capillary width are provided in the upper portion of the projecting portion 33 of the feed bar which spaces 45 preferably are formed by slotting the feed bar, the slots being separated by narrow ns 65. The slots 45 are intersected by and communicate with the ink feed slots d2 and thereby are adapted to draw thereinto by capillary action ink which may tend to overflow from the ink feed slots 42 whenever conditions of excess ink flow occur in the pen. In order to insure that the column of ink extending from the reservoir to the nib slit remain unbroken so that ink will be fed to the nib slit at all times, each of the slots 42 is provided in its forward portions with a deepened portion 42h which extends through and belowvthe trans verse slots 45.

The storage slits 45 are Vented to the exterior of the pen by air vent slots 4l extending longitudinally along the sides of the feed bar and intersecting all of the transverse storage slots 45. The vent slots 41 extend through the opening 28 in the shell ll and thus provide communication between each of the storage slots 45 and the atmosphere.

The rearmost storage slots 45' communicate with the reservoir I1 by an air duct 4B which preferably is formed as a slot in the upper surface of the feed bar shank 32 between the feed slots 42 and which opens at its rearward end into the reservoir l1 and at its forward end intersects the rearmost fins 46 and the corresponding slots 45.

As previously stated, the reservoir is filled by compressing the flexible sac I5 to draw ink into the reservoir. Preferably the pen has means for permitting a multiple stroke filling operation which provides for drawing into the reservoir a substantially greater quantity of ink than is drawn in by single compression and release of the sac IB. For this purpose a breather-tube 49 is provided which at its forward end is inserted in a counterbore 50 communicating with a bore 5i which is connected bya transverse duct 52 with the air duct 48. The breather tube 45 extends a substantial distance throughout the reservoir Il and terminates short of the rear end `of the sac I6. Preferably the breather tube terminates at such distance beyond the rear end of the guard I9 that the breather tube is not collapsed or bent during the compression of the sac and thus there is no interference with the passage of airthrough the breather tube during the filling operation.

In order to fill the pen, the barrel l is removed and the writing end of the pen inserted in a supply of ink to immerse the nib slit and preferably the forward ends of the feed slots 42. The sac l5 is repeatedly compressed and released to draw ink into the reservoir. Upon each compression of the sac a quantity of air is forced out through the breather tube 49, the longitudinal passage 5I and transverse passage 52, the air passage 48, the rearmost storage slots 45 and the vent slots 4T. Upon release of the pressure on the sac the latter returns to its normal expanded condition and the vacuum thus created draws ink into the reservoir Il through the feed slots 42, It will 'be understood that, similarly to other multiplestroke bulb filler pens, some ink may be forced out of the pen along with the air when the sac I5 is compressed but that upon the release of the sac more ink will be drawn into the pen than was expelled with the air and thus upon vrepeated compression and release of the sac thevquantity of ink in the pen will increase until the level of ink in the pen (when the pen is held vertically with the writing end downwardly) reaches a height substantially at the level of the rear end of the breather tube. Owing to the transparent or translucent nature of the sac I5 the operator can readily determine by inspection when the ink has reached its maximum level and is thus informed that the filling operation has been completed. As will be understood, the operator may also determine the ex# tent of filling of the pen by the feel of the sac as the pen becomes lled, although generally it will be found easier to determine the completion of the filling' operation by a visual inspection of the ink level.

,-When the pen is flledya column of ink will stand in the feed slots 42 leading from the reser- -voir to the space 43 below the forward'portion of the nib. Ink also may stand in the capillary storage cells 45 and, if desired, this ink may be cleared from the cells during thelling operation by removing the end of the pen' from'the supply of ink prior to the release of manual pressure on the sac at the end of the last stroke and thereafter releasing the pressure, which'operation will cause the ink from the cells 45 to be drawn into the reservoir Il leavingthe cells, or at least cer tain of the cells, empty and in condition to receive any ink which may overflow from the feed slots 42. Ordinarily the rearmost cells 45 will remain filled with ink, which provides a liquid seal serv- `opening air communication between the atmosphere and the air duct 48, thus permitting air to pass along the duct 48 and into the reservoir Il, whereupon ink will flow from the reservoir and along the feed slots 42 to the nib split 39.

Whenever conditions were present which would otherwise tend to cause flooding or leakage of the pen (as forexample, an increase in temperature of the contents of the reservoir or a sudden decrease it atmospheric pressure), ink will overflow from the feed slots 42 into the air duct 48 and seal the air inlet passage, thereby preventing any further air from enteringy the reservoir.,V In addition, the excess ink which overflows the feed slots 42 will be drawn by capillary action into the capillary storage cells 45 and will be held there by capillary action and, therefore, will not leak from the writing end of the pen. Upon withdrawal of ink from the nib slit, as by writing, ink will be drawn first from the capillary cells 45 and thus clear the cells.

In order to insure the 'best operation of the overflow control means, preferably the capillary `cells 45 are arranged so that the forwardmost cells are of the greatest width `and of the least capillarity and the rearward cells are of the least width and the greatest capillarity, thus insuring that inkwill be drawn into the feed slots 42 rst from the forwardmost cells and the cells will progressively empty from the forward end of the series toward the rearward end. For convenience in manufacture the cells are not all formed of different widths but are arranged in a series ywherein the cells 45a (Fig' 3) all have the same capillarity, cells 45h have the same capillarity but greater than that of the cells` 45a and the cells 45o have the greatest capillarity of any of the series.`

The air inlet slots 41 are formed of relatively greater width than the capillary cells 45 and are of such width as not to retain ink by capillary action under ordinary conditions. Under ordinary Iconditions of operation, the edge effect at the :points of intersection between the cells 45 .and the air vent slots 41 is sufliciently effective .to prevent ink` from being drawn into the latter.

It will be understood that the kdimensions of the several parts 0f the pen may be -varied widely.' However, the overall dimensions of the Apen preferably are comparable to those of conventional fountain pens. It is important, however, that the relation between the several prtions of the capillary system and the air vent system be maintained in order to provide the most desirable operation. The dimensions of ink feed slots 42 and the capillary cells 45 are such as to insure that ink is retained therein by capillary action under the vconditions above described. In one practical embodiment of a fountain pen embodying the invention excellent results were obtained by forming the ink feed slots with a width of around 0.008". These slots in their rearward portions were formed with a depth of at least 0.023 and in their forward portion a depth suffi cient to pass well ,below the capillary cells 45. The nib slit was formed with a width around 0.001 to 0.0015 and the arcuate capillary space below the forward end of the nib was greater than the width of the nib slit but less than the width of the feed slots 42. The capillary cells 45a were formed with a width of 0.014", the slots 45h with a width of 0.012 and the capillary slots 45e with a width of 0.010. The side slots 4l were formed with a height of around 0.031" and an approximately equal depth. The air passage 48 was approximately 0.060 in width and 0.008" in depth at the sides adjacent the slots 42 and approximately 0.012" at the center.

From the foregoing it will be seen that the present invention provides a fountain pen having ink overflow control means, `which pen is simple and inexpensive to manufacture and rugged in construction. The pen is formed 4of a relatively small number of parts which may be easily formed by quantity production methods and may be readily assembled by relatively unskilled labor. The construction of the pen is such that there are relatively few critical dimensions and the parts do not require any extremely critical adjustment. In fact the pen will operate satisfactorily even though the parts may become somewhat disarranged after assembly. It is important, of course, that the positioning of the nib relative to the feed bar be preserved with suflicient accuracy to insure that ink would be fed to the nib slit but it is to be noted that even some disarrangement will not prevent this operation.

The ink feed slots provide a direct connection between the ink reservoir and the space under the nib slit and since they are formed in a single unitary member, namely, the feed bar there is little possibility of interruption to the feed of ink from the reservoir to the nib slit. Moreover, since a plurality of slots are provided, the clogging of one slot would not prevent feed lof ink to the nib slit. Moreover, since a plurality of capillary cells at the rearward end of lthe series are interposed in the air inlet passage, the clogging of one of the 'cells would not prevent the admission of air to the reservoir upon the exhaustion of ink from other of these cells. On the other hand, the control of ink flow from the reservoir to the nib slit is positively controlled and promptly upon existence of excess ink flow conditions the admission of air into the reservoir is halted by the filling `of the rearmost cells.

The nib and feed bar are substantially surrounded and enclosed by the shell, thereby preventing soiling of `the fingers of the user. Moreover, the capillary ink feed slots as well as the storage or overflow spaces are substantially enclosed by the nib so that a minimum ink surface 8 is exposed to the air. It will be noted that the side slots communicate with the exterior of the pen only at their forward ends.

The filling mechanism is simple but positive and is not readily subject to disarrangement or malfunctioning but will operate for a long period of use without adjustment or repair. Both the lling arrangement and the ink flow control means are of such form and construction that they do not occupy a substantial portion of the space within the pen barrel and shell and thus a relatively large capacity reservoir may be provided in a pen of any predetermined overall dimensions.

I claim:

l. A fountain pen comprising a hollow body member having an ink reservoir space therein and an open forward end, a feed bar mounted in the open forward end of said body member and projecting therefrom, and a slitted writing nib overlying the projecting portion of said feed bar, said feed bar being formed with a capillary ink feed passage extending continuously therealong for connecting the ink reservoir space in ink feeding communication with the nib slit, a longitudinally spaced series of capillary ink storage slots extending transversely of the projecting portion of said feed bar the rearmost of which are narrower and of greater capillarity than the slots forwardly thereof, in communication with said ink feed passag-e and underlying and substantially inclosed by said nib, said feed bar, body and nib defining an air inlet passage extending along said ink feed passage from said reservoir space to the rearmost slots only of said storage slots and terminating rearwardly short of the nib slit, said air passage being in communication throughout its length with said ink feed slot, and an air inlet slot extending along said feed bar, in intersection with said storage slots and communicating with said air inlet passage for air flow therebetween solely through said rearmost storage slots and having its forward end communicating with the atmosphere.

2. A fountain pen comprising a hollow body member having an ink reservoir space therein and an open forward end, a feed bar mounted in the open forward end of said body member and projecting therefrom, and a slitted writing nib overlying the projecting portion of said feed bar, said feed bar being formed with a capillary ink feed passage extending continuously longitudinally thereof and connecting said ink reservoir space in ink feeding communication with the slit of said nib, a longitudinally spaced series of transversely extending capillary ink storage slots intersected by the forward portion of said ink feed passage, the rearmost of which slots are narrower and of greater capillarity than the slots forwardly thereof, an externally disposed first air inlet duct ez'- tending along and communicating throughout its length with the rearward portion of said ink feed passage and intersecting the rearward storage slots only, a longitudinally extending air breather duct extending internally of said feed bar, communicating at one end with said first, external air inlet duct rearwardly of said ink storage slots, said first air inlet duct being inclosed by said body member and nib and having air flow communication with the atmosphere solely through said rearward slots, and an externally disposed air inlet duct extending along said feed bar, intersecting said storage slots, and communicating with the exterior of said shell.

3. A fountain pen comprising a hollow body member having an ink reservoir space therein and an open forward end, a feed bar mounted in the open forward end of said body member and projecting therefrom, a slitted writing nib overlying the projecting portion of said feed bar, a hollow shell mounted on the forward end of said body member and substantially enclosing the projecting portion of said feed bar and said nib except the writing tip thereof, said feed bar being formed with a pair of spaced, capillary ink feed slots extending continuously longitudinally therealong from the rear end of said feed bar to short of the forward end thereof, a longitudinally spaced series of transversely extending capillary ink storage slots intersecting said ink feed slots at their forward portions, said feed bar, body and nib defining a first air inlet duct extending along the rearward portions of said feed slots,V connected at its forward end to the rearmost storage slots only of said series and communicating throughout its length with said feed slots, said feed bar having an internal air breatherpassage extending from the rear end of said feed bar and com,- municating with said first air inlet duct intermediate its ends and rearwardly of said ink storage slots, and a breather tube communicating at its forward end with said internal air breather passage and extending rearwardly in said body member, said feed bar having a second air inlet duct communicating at its forward end with the exterior yof said shell and intersecting said ink storage slots.

4. A feed bar for a fountain pen comprising a body having a capillary ink feed slot in its upper surface extending longitudinally from the rear end of said body continuously to short of the forward end thereof, a series of longitudinally spaced capillary ink storage slots extending transversely through the upper portion of said body and intersecting said feed slot, the rearwardmost slots of said series being of less width and greater capillarity than the remaining slots of the series, a first air inlet slot extending longitudinally along the side of said body from the forward end to short of the rear end thereof and intersecting said storage slots, and a second air inlet slot extending longitudinally along the upper surface of said body in communication throughout its length with said ink feed slot, vsaid second air inlet slot terminating short of the forward end of said series of storage slots and intersecting thel rearward slots only of said series. I

5. A feed bar for a fountain pen and-adapted to be associated with an overlying nib, said feed bar comprising a generally cylindrical body having a pair of capillary ink feed slots in its upper surface extending continuously longitudinally from the rear end of said body to short of the forward end thereof, a series of longitudinally spaced capillary ink storage slots extending transversely through the upper portion of said body and intersecting said feed slots, the rearmost of saidink' ystorage slots being narrower and of greater capillarity than the ink `feed slots forwardly thereof, a first air inlet slot extending longitudinally along the side of said body from the forward end to short the rear end thereof and intersecting said storage slots to provide an air inlet passage when the feed bar isassembled with the nib in a pen, said body having a depressed, generally flat surface extending longitudinally along the upper surface of said body from the` rear end thereof, between said ink feed slots and terminating short of the forward end of said series of storage slots adjacent the rearward slots only of said series to provide a second air inlet passage when the feed bar is assembled with the nib in a pen, an air breather duct extending interiorly of said body from the rear end thereof to short of the forward portion of said second air inlet slot and Aa transverse air duct4 connected to said air f breather duct and opening into said generally flat surface rearwardly of said ink storage slots and solely between said ink feed slots.

ROBERT W. RANDOLPH.

References Cited in the file of this patent UNITED STATES PATENTS Severy Nov. 29, 1949

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