US2931339A - Writing instrument - Google Patents

Description

plri 5, 1960 A. J. THOMAS WRITING INSTRUMENT Filed Feb. '18, 1955 INVEL/OR.

vm Nn Nm mn nited States Patent "O WRITING INSTRUMENT Arthur Jacob Thomas, Chicago, Ill.

Application February 18, 1955, Serial No. 489,053

4 Claims. (Cl. 12il-46) This invention relates to a writing instrument and more particularly to a self filling fountain pen which draws from an external fluid ink supply to lill its ink reservoir.

In the usual fountain pen of the nib type, a substantial part of the writing portion must be submerged within the body of ink in the filling operation. This requires a degree of exactness upon the user, for if too shallow in submersion, air will be drawn and prevent proper filling; should the pen be submerged beyond the proper point, ink will be applied to the area which usually contacts the ngers in the writing position, making it necessary to clean the affected area. This condition has been aggravated in recent years with the introduction of hooded form of pens in which the uib is substantially covered by the outer shell, except for the writ` ing tip, to give the pen a streamlined appearance, and to control evaporation loss oy reducing the area of exposure to the atmosphere. With a pen of this type, it becomes necessary to wipe the pen each time it is lled.

` One prior art device presently in commercial use utilizes a retractable lling tube situated below and parallel to the nib. ln order to draw an ink supply, the tube must be extended a distance beyond the nib. This includes a screw feed arrangement actuated from the opposite end of the pen, and involves the necessity of having moving parts of precision character integral with the ink reservoir and ink flow controlling elements. Also the user still must exercise reasonable care as it is possible to inadvertently submerge the writing portion.

Although there exist in the prior art some developments 5 of fountain pens which draw their ink supply from the end opposite the writing point, these disclose an opening or duct at this end which is independent of the feed bar element and which terminates directly in the ink reservoir. The outer end of said opening or duct must be sealed from atmosphere by means of a cap or the like after the pen is lled. If through manufacturing variation or through eventual wear there develops a slight imperfection in the seal, ink will be drawn from the reservoir by capillary attraction to the external areas of the pen. A vent opening to permit constant flow of ink when the pen is in use must usually be closed off during the lling operation by a valve or other moving part which requires opening again after the pen has been lled.

Accordingly it is an object of this invention to provide a self filling fountain pen having a filling tube which need not be extended or retracted.

A further object of this invention is to provide a fountain pen having a filling tube in which there is no possibility of any part of the writing portion ever contacting the supply of ink. l

A further object of this invention is to provide a fountain pen of the foregoing character which does not involve the use of moving parts.

A still further object of this invention is to provide a fountain pen of the foregoing character which has a relatively small number of parts and which are simple and inexpensive to manufacture and assemble.

A still further object of this invention is to provide a fountain pen of the foregoing character having a minimurn of critical dimensions and the components coinposing the fountain pen may be manufactured and assembled at lower cost.

Another object of this invention is to provide a fountain pen of the foregoing character which utilizes substantially the same ink feed and overow collector means found to be satisfactory in most present fountain pens.

Another object of the present invention is to provide a fountain pen of the foregoing character which requires a minimum of vigilance on the part of the user during the filling operation.

Still another object of the present invention is to provide a fountain pen of the foregoing character in which the usual evaporation loss through the vent openings is reduced to a minimum.

Still another object of the present invention is to provide a fountain pen of the foregoing character'in which the external appearance is not marred or design limitations required because of the filling tube feature.

Further and additional objects will appear hereafter from the following description, the accompanying drawing and the appended claims.

In accordance with the above ends, one embodiment of this invention consists of a fountain pen which includes an ink feed and overflow collector means, a collapsible ink sac disposed in a removable barrel, a filler vent tube in series connection with the ink feed and collector element vat its for-ward end within the pen and extending rearwardly generally through the longitudinal axis of the pen body to a suitable distance beyond the ink sac. In order to replenish the ink supply, the barrel of the pen body is withdrawn exposing the ller vent tube and the ink sac collapsing means.

To acquire a more complete understanding of the invention herein described, reference is now made to the drawing, wherein:

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

Figure 2 is au enlarged fragmentary longitudinal sectional view through the forward portion of the pen shown in Fig. l;

Figure 3 is a transverse sectional view taken along line 3--3 of Fig. 2;

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

Figure 5 is an enlarged fragmentary top elevation showing a portion of the sac collapsing means and;

Figure 6 is a fragmentary top elevation of the writing point.

Referring particularly to Fig. l, the pen includes a housing or barrel 10 and a forward shell 1l, which together form a substantial part of the outer body of the pen. A center body 12 of hollow tubular form is provided as a means for connecting the b-arrel and shell as well as most of the other members forming the pen. The center body 12 is formed about its bore 13 and has a plurality of different external diameters to provide a number of surfaces to receive and secure the various pen members as herein described.

At the extreme rear portion of center body 12 is formed a section 14 over which is telescoped the forward end of exible and resilient sac 16 which forms a part of the ink reservoir 21. The sac 16 is so constructed so as to grip tightly over section 14 by virtue of its resilient nature, and may be secured more positively by the use of suitable adhesive, or by a series of circumscribed grooves 17. Sac 16 is preferably composed of a suitable plastic material which will remain in an expanded condition except when compressed, and which Y 1 aaai-,ess

will resist physical and chemical deterioration yfrom cornmonly known inks. Sac 16 extends rearwardly to provide a suitable ink reservoir volume 4and is formed to grip' tightly about liller vent tube 18 fat 19 in a manner similar to that described at section 14.

Following generally the contour of sac 16, guard tube Ztl is provided to protect sac 16 when exposed for the filing operation, and provide the hand a rigid surface to grasp. Guard tube 20 is threaded to center body 12 at 22 at its forward end, and at its rear most end is provided with an aperture 23 of suflicient size to permit passage of filler vent tube 18, which in effect serves to support tubey 4 in other fountain pens, past and present, will indicata, the arrangement of its related elements, ducts, passages, and slots may be altered in form or relationship while still performing substantially the same function.

In order to replenish the reservoirs ink supply, the barrel 10 is withdrawn from the pen exposing the filler vent tube 18 and the sac collapsing means. Holding the pen body somewhat vertically with the writing tip upward, the tip 18a of tube 18 isinserted into the body of ink so that it is somewhere below the surface of the ink at any depthlimited by the exposed length of said tube 18.

' The sac V16 is then repeatedly compressed and released.

18 against bending or distortion. To provide suiici'en't Y strength and rigidity, guard may be formed of a suitable metal so it may be made thin and light so as not to consume volume or add unduly to the weight of the pen Openings 24 and 25 in guard 20 are of such form and size to permit compression of the sac 16 by the fingers, such as the thumb and index finger. To provide strength and rigidity to the thinned portion 20a, inwardly projecting ribs 20b are provided. To permit suiiicient room for sacr16 to be displaced laterally upon compression within guard 20, the cross section of sac 16 may be f narrowed laterally as atr16a and 16h in Fig. 5.

The barrel v10 is threaded at its open end to center body 12 at 26 againstthe maximum diameter 12a which may be of suflicient length to prevent the overlapping of cap 27 with barrel 10, thus permitting'convenient withdrawal'of `barrel 10 without the necessity of rst removing cap 27 should the user so desire. YA vent opening 2S is provided in the barrel to equalize air pressure Within said barrel 10 with the outside atmosphere, and prevent compression within barrel 10 when assembled over sac 16, causing a forcible expulsion of; ink from the reservoir 21; Vent 28 is preferably located along the side and toward the rear of barrel 10 so as not to have a direct The forward shell 11 is threaded to center body 12 Yat 29 and thus substantially encloses the forward portion of center body 12 and the feed bar 31. The usual nib 30 which closely overlies the feed bar 31, projects from cells, 32 of capillary width which are separated by fins 33. The cells 32 are ntersected by and communicate with feed slot 34 and are adapted to receive by' capillary action ink which may tend` to over-dow from feed slot 34 whenever conditions cause an excess flow of ink to occur. The projecting portion 35 of feed bar 3,1 is formed to iit snugly in opening 36 to seal the interior of shell 11, including feed bar 31 to the outside atmosphere excepting for theV minute capillary passage provided by feed slot 34 to nib 30 which usually reduces the capillary exposure to the exterior to microscopic dimensions of approximately one thousandth of an inch. VTo achieve a more positive seal, any suitable form of packing vgland or resilient washerY may be provided as at 37. A passage 38 is provided on the top surface of'feed bar 31 to communicate the reservoirV 21 with the feed slot 34 and the rearmost cells 32a. A vent slot 39 extending longitudinally along the bottom of feed barY 31 intersects all of the transverse storable cells 32. A transverse duct 40 connects the vent slot 39 with a bore 41 communicating with 4a counterbore 42 into which the ller vent tube 18 is inserted. The filler vent tube `18 extends rearwardly through the reservoir 21 generally parallel toone foi-m it may take, and not to berconstrued as being Asthe variety ofv forms in which the ink feed and overflow collector means definitive ofthe present invention.

n linear connection between the filling tip 18a and vent 28.

Upon compression of the sac a quantity ofair is displaced from the reservoir and forced out through passage 38,

lradially through the rear cells 32a, through venty slot v 39, the transverse duct 40, the bore 41, `and the tube 18.

Upon release of the sac to its normal expandedV condition, the vacuum thus createddraws ink up through the tube 1S and through the various passages'in-the feed bar Y as is true with other multiple stroke bulbrliller pens, is

Vgreatly reduced until the reservoiry becomes filled.

To insure against any `ink being forced out through the nib 30 by way of the usual relatively large pierce or aperture located atthe rearward end of; thel nib slit 13011,. the nib 30 may be provided with an elongated shield V45 which is fused or suitably attached to the upper surface of the nib, so as to closely overlie the usual pierce 30h and the portion of the nib slit 30a inV directcontactvwith the feed slot 34. Also suicient cells should be intel-7 sected by the passage 38 so as to provide enough flow cap: city through the cells. Should conditions ever cause any ink to be forced through the nib slit 30a during the.

filling operation, itwould be of a minute quantity and,

forced out through the nib is very unlikely, as air andr ink being fluids will tend to follow a path of least resistance. l i t t The means herein described for creating. aY vacuum within the ink reservoir for drawing ink into said reser voir is shown primarily for illustrative purposes, though due to its simplicity is lgiven as a preferred construction. With a quantity of inkrin the reservoir, ink will be drawn from the passage 38 into the feed slotv 34 by capillary action to provide the nib 30 witha constant` supply of Yink for writing. Under ordinary conditions, the. rear cells 32a will remain filled with ink, which will act as a liquid seal by closing olf the air communication between the'reservoir 21 and the atmosphere provided through the filler vent tube 18k, the transverse duct 40, the vent slot 39, the cells 32a, and the passage 38. As a capillary flow of ink takes place fromY the reservoir, as in writing, a, partial vacuum is created behind the bodyl of ink in.

` the reservoir which will resist the continued flow of ink from the reservoir. Ink will then be drawn from the rear cells'32a andas a result eliminate the seal formed by the ink within cells 32a, and thus permit an, air communica;V

tion between the atmosphere and the passage 38,-which will allow air to pass along passager38 and into] the reservoir V21, after which ink will tiow from the reservoirk along feed slot 34 to the niby 30. As with usualy overtiow collector means of present fountainv pens any conditions which cause a flooding of the pen (such as a sudden deL f crease in atmospheric, pressure), will cause the. overflow;

to be drawn by capillary action into, the. cells 32 and held,

It can be seen that the possibility. Yof ink being forced out with the air on each 'compression there by capillary attraction. Ink will then be drawn from the cells 32 upon withdrawal of ink from the nib as would be caused by writing, and thus empty the cells.

The dimensional width of the vent slot 39 is sufficiently greater than that of the cells 32 so as not to draw or retain ink therein by capillary action from the cells. The diametrical size of the transverse duct 40, the bore 41, and the ller vent tube 1.8 are sutiiciently large to permit a free iow of ink during the filling operation, and may be increased respectively in diameter to produce a relative capillarity with each other which would draw any inl; retained within the said passages toward the feed bar; the vacuum created within the pen body by ink leaving the nib as in writing would also tend to draw any ink within the passages into the feed bar.

Since the filler vent tube 18 is usually enclosed by the barrel 10, except during the lling operation, it can be seen that evaporation loss through the tube is reduced to a minimum by the action of barrel serving as a vapor barrier about the tube against the outside atmosphere. In the fountain pen of the usual construction, which draws its ink supply from the forward, writing portion, the relatively large vent opening is exposed directly to the atmosphere when the cap is removed for writing purposes.

While a particular embodiment of the present invention is disclosed herein, it is to be understood that the invention is not to be limited thereto, since many modifications may be made; it is therefore contemplated by the appended claims to cover any such modifications as may fall within the true spirit and scope of this invention.

I claim and desire to secure by Letters Patent:

l. A fountain pen comprising body member having a front and rear end, a bore extending through said body member, an ink reservoir communicating with the rear end of the bore of said body member and terminating in a collapsible sac, feed bar means extending forwardly from said reservoir and including a capillary feed-slot portion communicating with said reservoir through the bore of said body member, a pen nib attached to a forward portion of said feed bar means for receiving ink from said feed-slot portion, and a combination vent-andsupply tube disposed longitudinally of the bore of said body member, extending through said collapsible sac and terminating in an open end beyond the rear end of said sac, a vent-and-supply slot portion on said feed bar means communicating the other end of said tube with said reservoir through the bore of said body member, said ventand-supply slot portion including a duct section extending partially along said ink feed-slot portion and having a lesser capillarity than said ink feed-slot portion, said open end of said tube constantly venting the interior of said reservoir during normal writing conditions and being submersible in a source of supply of ink for filling said reservoir when said fountain pen is disposed rear-enddown.

2. A fountain pen as set forth in claim 1 in which said sac is manually compressible for causing a partial vacuum therein to draw ink into said reservoir, said ventand-supply slot portion including capillary cell portions communicating with said ink feed-slot portion, some of said cell portions communicating with the duct section of said vent-and-supply slot portion through which said tube communicates with said reservoir.

3. A fountain pen as set forth in claim 1 in which said body member includes a hollow removable barrel extending rearwardly about and enclosing said ventand supply slot portion, and vent means extending through a portion of said barrel normally communicating atmospheric pressure to the interior of said barrel, the open end of said tube and said reservoir and sac during normal Writing operations.

4. A fountain pen as set forth in claim 3 in which said sac is manually compressible for causing a partial Vacuum therein to draw ink into said reservoir, said vent-and-supply slot including capillary cell portions communicating with said ink feed-slot portion, some of said cell portions communicating with the duct section of said vent-and-supply slot through which said tube communicates with said reservoir.

References Cited in the file of this patent UNITED STATES PATENTS 294,340 Tyrreu Feb. 26, 1884 1,336,119 Anderson Apr. 6, 1920 1,719,374 Ihara July 2, 1929 1,864,050 Myers .lune 2l, 1932 2,158,615 Wright May 16, 1939 2,514,729 Snodgrass July 11, 1950 2,522,553 Wittnebert Sept. 19, 1950 2,602,423 Smith July 8, 1952 2,645,205 Randolph July 14, 1953 2,708,903 Fehling May 24, 1955 2,717,578 Koreska et al. Sept. 13, 1955 2,724,366 Miessner Nov. 22, 1955 FOREIGN PATENTS 403,127 Italy Apr. 6, 1943 723,484 Great Britain Feb. 9, 1955

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