US2618239A - Writing instrument - Google Patents

Description

NOV. 18; 1952' D .TEFFT WRITING INSTRUMENT Filed July 27, 1945 INVENToR. fz/Uv/l f/ff A TTORNEYS.

N QQ uw Nw fw VL Patented Nov. 18, 1952 UNITED STATES WRITING INSTRUMENT Ivan D. Telit, Janesville, Wis., assignor to The Parker Pen Company, Janesville, Wis., a corporation of Wisconsin Application July 27, 1945, Serial No. 607,379

(Cl. 12e-42.4)

12 Claims.

This invention relates to Writing instruments and it has to do particularly with devices of that character having a writing point in the form of a ball fed with a rather viscous ink from a cartridge-type reservoir.

In the use of writing devices of this character, the ball point rotates in accomplishing feed of the ink to the writing surface. It is therefore essential that the ball point be truly spherical and that it be retained in a freely and constantly rotatable condition to insure a continuous and uniform feed of ink to the writing surface.

In use, the ball point and the bearing surface supporting and retaining it tend to Wear rapidly and irregularly in such a way as to destroy the sphericity of the ball point and its proper relationship with its feeding and supporting surfaces so that the writing action is impaired. When these conditions of Wear exist replacement of the ball is necessitated for proper and most eflicient writing. The ink cartridge employed is usually f sufficient size to supply enough ink to satisfy Writing needs for several months, and it has been found that the wear of the ball point and related parts is such that replacement is required by the time the cartridge supply has been exhausted. One of the objects of my invention is to provide an improved device of the foregoing character embodying a self-contained cartridge-and-ball point unit that can readily and easily be replaced by the user as a refill unit when the supply of ink is exhausted so that a new writing point is furnished each time a new cartridge is inserted in the device. f

It is also well known that the feed System of devices of this character must be kept free of air pockets or air block conditions for satisfactory writing performance; otherwise the 110W of ink to the ball point will be interrupted with consequent erratic writing action. Air pockets creating an air block might result if the ink car-l tridge were adapted to be replaced by the user separately from the ball point and the means for feeding ink thereto, because the ink feed passage or passages may be partially or fully exhausted of ink at the time replacement of the cartridge is made and, if that be the fact, an air block Would result unless some step were taken by the user to eliminate the same in applying the new cartridge. The point-and-cartridge unit provided by my invention avoids this condition since the unit; may be prepared by the manufacturer and proper steps taken to insure the complete :lling of the unit without voids or air pockets. Thus the user can depend upon instant writing upon the insertion of a new or refill cartridge.

It is also desirable that devices of the foregoing character be constructed simply, but durably, so that the number of parts involved be minimized. To this ,end my invention provides an improved ink feed control means which eliminates the necessity of using pressure devices and provides a novel cartridge venting means for insuring proper ink feed.

Accordingly, the main object 0f my invention is to provide a ball point Writing device having the foregoing advantageous features.

Another object is to provide such a device which is durable, may be cheaply manufactured, is neat and attractive in appearance and which insures a constant and uniform feed of ink to the Writing surface at all times.

More specific objects are to provide a ball point writing instrument of the foregoing character wherein the ball point constitutes a part of the cartridge unit; to provide an improved cartridge member; to provide improved means for controlling the feed of ink from the cartridge to the ball point; to provide a point-andcartridge unit which may be applied to and removed from its casing merely by a push and pull movement, respectively, and without the aid of devices for securing it directly to the casing; to provide ink feed means, eliminating the necessity of employing a pressure device; and to provide an improved cartridge unit vented to atmosphere in such a way as to eliminate leakage of the ink to the exterior of the device.

Other objects and advantages will become apparent as this description progresses and by reference to the drawing, wherein- Figure 1 is an enlarged longitudinal sectional view of a Writing instrument embodying my invention;

Fig. 2 is a side elevational view of the ink cartridge unit forming a part of the structure shown in Fig. 1;

Fig. 3 is a section taken substantially on line 3-3 of Fig. 1;

Fig. 4 is a section taken substantially on line 4-4 of Fig. 1; and

Fig. 5 is a fragmentary longitudinal sectional view of the rear end of a modified form of device embodying my invention.

'I'he writing instrument illustrated in Figs. l to 4 of the drawing comprises a barrel I0 having a tapered forward end wall II provided With a reduced axial bore Ila connecting with a rearwardly disposed cartridge chamber Illa, the rear end of which is closed by a removable cap I2. A self-contained point-and-cartridge unit I3 is mounted and retained within the barrel I li. The barrel I Il is preferably made of a plastic material, but if desired it may be made of metal or any other suitable material.

The unit I3 comprises an elongated ballsupporting member or writing tip I4 carrying a ball point I5 at its forward end and connected to an ink cartridge I6 at its rear end. The specific form of the means for supporting the ball point I5 is not shown since it does not form a part of the present invention. However, it Will be understood that the ball point I5 takes the form of a substantially true sphere of relatively small diameter seated in a suitable socket at the forward end of the ball-supporting member I4. The

ball point I5, as is customary, is supported Vby bearing means for free rotation wherrit is engaged with the writing surface; and while it projects from its socket sufliciently to contact the writing instrument when the device is held in normal writing position, Without interference by the tip of the supporting member I4, it is sufficiently enclosed in its socket to prevent it from being dislodged. Also, the ball point I5 is so retained that leakage of ink around it is prevented when the instrument is not in use, but when it is engaged with the writing surface and moved therealong it rotates causingV a relatively thin lm of ink to be deposited on such surface.

The ink employed in a writing instrument of this character is preferably of a thick viscous nature. The ball-supporting member I is provided with a small axial capillary passage I'I which leads from the cartridge I6 to the ball point I5 for supplying ink to the latter. Preferably, the ball support is detachably connected at its rear end to the cartridge I6 by -a screw-threaded connection Ia which permits of ready assembling of these parts in the manufacture thereof; but if desired these parts may be detachably or permanently connected in any other suitable manner. The body or casing portion of the cartridge I5 is adapted to fit snugly within the cartridge chamber IUa in condition to be readily inserted and removed without excessive friction merely by sliding it in and out. The body of the cartridge I6 may be of cylindrical shape, as shown, or any other suitable shape, dependent upon the shape of the cartridge chamber Ia or otherwise. The rear end of the cartridge is knurled at Ib to facilitate insertion and removal.

The rear end of the cartridge I6 is vented to atmosphere for preventing the formation of a partial vacuum therein and to thereby insure a constant and uniform feed of ink to the ball point I5. To this end a transverse partition I8 is fixed within the rear part of the casing I6 at apoint.

slightly spaced from its rear end, thereby providing an air space I9. The partition member preferably takes the form of a iine screen or perforated disk havingperforations sufficiently small to prevent the viscous ink from passing therethrough but readilypermitting the passage of air. The air space I9 is connected to atmosphere by way of a small tube 20 extending through and carried by the forward end of the cartridge I6 Y and the partition member I8. The front end of the cartridge I6 terminates short of the tapered endl I of the barrel, thereby providing a chamber space Illb forwardly of the cartridge I 5. The forward end of the vent tube projects into the chamber space Ib and its rear end extends into the air space I9, this latter end being slightly tapered to provide a restricted entrance preventing the passage of ink into the tube 20 in the event that some should leak into the space I9, while readily permitting the passage of air into and through such tube. The wall of the barrel I0 defining the chamber space Ib is provided with a vent opening 2| connecting the cartridge space I9 to atmosphere by way of the vent tube 2U, chamber space I 0b and the vent opening 2 I If desired, the vent tube 20 and barrel vent 2I may be eliminated and the chamber I9 vented directly through the rear end of the cartridge and the rear end of the barrel pressure cap, as illustrated in Fig. 5. In this form a barrel 22 encloses a cartridge unit 23 which is provided with a perforated partition 24 providing a rear space 25. The rear end of the cartridge 23 is provided "with a very small vent opening 26 disposed in alignment with a small vent Opening 21 in the rear end closure cap 28. These vent openings 26 and 21 are of such size that the viscous ink, if it should nd its way into the chamber 25, will not pass therethrough but air will readily be admitted.

The point-and-cartridge unit I3 may readily be applied to and removed from the barrel merely by a push and pull movement in which endwise pressure is applied thereto, this being facilitated by making the cartridge I6 (Fig. l) or 23 (Fig. 5) of su'icient length to project slightly beyond the rear end of the barrel where its knurled portion I5b may readily be grasped. The ball-supporting member I4, ball point I5 and cartridge I6, being a self-contained unit may be applied and removed without detachment of any of the parts thereof. No fastening devices are required to secure the unit to the barrel and no mechanical pressure means is necessary for accomplishing feed of ink from the cartridge to the ball point.

Proper positioning of the ball point I5 relatively to the forward end of the barrel IIB is provided by an annular stop member 29 which is xedly secured to the support member It intermediate its ends and is adapted for engagement with a shoulder I Ib; The point I5 projects slightly from the tapered end I I of the barrel so that the writing instrument may be held at the proper writing angle as permitted by the taper of the end II and the extent of projection of the ball point I5. The point-and-cartridge unit I3 is rmly, but releasably and yieldably, retained in the barrel with the stop member 29 engaged with the shoulder I Ib by a, spring 30 preferably carried by the rear end cap I2 so that when this cap is applied the unit I3 will be yieldably urged for ward and secured in the position described.

The cartridge I6 may be lled by the manufacturer in any suitable manner so as to prevent the formation ofl voids or air pockets therein. The ball support I4, together with the ball I5,

may be assembled withv the cartridge I6 by the manufacturer, appropriate steps being taken to completely ll the ink feed passage I1 all the way from the cartridge to the ball point so that the entire unit is free from air pockets or voids or any air block condition and the unit is ready for instant Writing when assembled in the barrel I0 by the user.' In use, continuous and uniform feed of ink is insured by venting the rear end of the cartridge IB to atmosphere as above 66 explained. vWhenever the cartridge unit is ex- Y hausted ofA ink the end cap is removed and the entire unit I3 is removed and a new unit substituted merely by pulling outwardly on the used unit and pushing inwardly on the new refill unit.V

It will be seen from the foregoing that my invention provides an improved cartridge construction which is of simple form, may be manufactured at minimum cost, and provides maximum efficiency in Writing performance. With this ar- Writing point with each cartridge refill, a new point, thereby avoiding or minimizing the detrimental effects caused or tending to be caused by wear of the ball point surface in the writing operation.

I claim:

1. A ball-point writing instrument comprising a forward casing section open at both ends and having a straight, smooth-walled bore extending from end to end with a forward reduced portion providing a rearwardly facingabutment, a selfcontained rigid writing unit removably disposed in said forward casing section all portions of which unit are permanently secured together and including a reservoir section, means venting the rear end of said reservoir section to the interior of said casing forwardly of said reservoir section, a feed section of reduced diameter forwardly thereof and a ball writing point at the forward end of said feed section in axial alignment with said reservoir and feed sections, said unit having a forwardly facing abutment engaging said rearwardly facing abutment for seating said unit in fully operative position in said forward housing section with said feed section snugly fitted in said reduced bore portion and at least said ball writing point projecting from the forward end. thereof, said unit being formed with smooth exterior walls dimensioned for insertion of said unit through the rear end of said forward housing section and into fully seated position therein solely by a sliding movement, a rear housing section detachably carried on and closing the rear end of said forward housing section, and resilient means between said rear housing sectionv and the rear end of said unit for resiliently maintaining the latter in fully seated position.

2. A ball-point fountain pen comprising an open-ended barrel having a cartridge-receiving chamber therein, an ink cartridge mounted in the rear end of said chamber with a chamber space thereahead, means carried by said cartridge for venting its rear end into said chamber space, means for venting said chamber space to atmosphere, a ball point supporting member connected at its inner end to the forward end of said cartridge and projecting through the forward end of said barrel, a ball point member carried by the projecting end of said supporting member with a portion thereof exposed for Writing purposes, and means for closing the rear end of said barrel to conceal and confine the parts contained therein.

3. A ball-point fountain pen comprising a barrel having a cartridge-receiving chamber therein, an ink cartridge mounted in the rear end of said chamber providing an air space thereahead, means for venting said air space to atmosphere, a tubular member extending from the rear inner portion of said cartridge into said air space, a point supporting unit carried by said cartridge and projecting through the forward end of said barrel, a ball point member carried by the projecting end of said supporting member, and means for feeding ink through said supporting member to said ball point.

4. An ink cartridge adapted for use with a ballpoint type of fountain pen which comprises a body or casing portion adapted to serve as an ink reservoir and a forward portion adapted to be connected to inl: feed means, a transverse, finely perforated ink-excluding partition member disposed within and spaced slightly from the rear end of said cartridge and providing an air space behind the ink therein, and means for venting said air space to atmosphere.

5. An ink cartridge adapted for use with a ball-point type of pen which comprises a body or casing member adapted to contain ink, a transverse member disposed within said casing near its rear end forming an air space therein behind the ink, said member being provided with openings of such size that ink of a viscous and pasty form will not pass therethrough while air will readily flow therethrough, and means for venting said air space.

6. An ink cartridge of the character described comprising a casing or body portion, a transverse, perforated partition member in the rear end of said body portion forming an ink reservoir forwardly thereof and an air space rearwardly thereof, the perforations of said member being of a size to readily pass air but not a pasty, viscous ink, and means for venting said air space including an open-ended tubular member extending from said air space forwardly beyond the front end of said body portion.

7. An ink cartridge of the character described comprising a casing or body portion, a transverse, perforated partition member in the rear end of said body portion forming an ink reservoir forwardly thereof and an air space rearwardly thereof, the perforations of said member being of a size to readily pass air but not a pasty, viscous ink, and means for venting said air space including an open-ended tube extending through said body portion with one end supported by said partition member and opening into said air space and its other end supported by and extending beyond the forward end of said body portion.

8. An ink cartridge of the character described comprising a casing or body portion, a transverse, perforated partition member in the rear end of said body portion forming an ink reservoir forwardly thereof and an air space rearwardly thereof, the perforations of said member being of a size to readily pass air but not a pasty, viscous ink, and means for venting said air space including an open-ended tube extending through said body portion with one end supported by said partition member and opening into said air space and its other end supported by and extending beyond the forward end of said body portion, the end of said tubular member connecting with said air space being restricted to fully pass air but prevent the passage of ink that might accidentally reach said air space.

9. An ink cartridge adapted for use with a ballpoint type of fountain pen which comprises a body portion adapted to serve as an ink reservoir, a transverse, finely perforated partition member disposed in the rear end of said cartridge and providing an air space behind the ink therein, the perforations of said partition member being of a size to freely pass air but not a pasty, viscous ink, and a vent opening in the rear end of said cartridge connecting said space to atmosphere, said vent being of a size freely to pass air but not a pasty and viscous ink.

10. A ball-point type pen comprising a barrel, a cartridge unit mounted in said barrel and including an ink reservoir portion, perforated partition means in the rear end of said portion forming a rear air space and a forward ink space, the perforations of said member being of a size freely to pass air but not a pasty and viscous ink, a cap closing the rear end of said barrel and enclosing and confining said unit, the rear end of said reservoir portion having a vent opening, and said cap having a vent opening raligned with said first opening, both said openings being of suchsize as freely tot pass air; but not a:V pasty remaining the same, comprising a relatively rigidi cartridge member, a point supporting member permanently connected to the cartridge member and in alignment therewith for sliding movement. as a unit into and out of a seated position in a barrel, a ball constitutingA a writing point: carried by saidv supporting member with said ball. partly-exposedfor engagement with a wrtingsurface, afeed passage Vconnecting said cartridge member'with saidrballv member, freely perforated means dividing saidl cartridge into a forward ink chamber and a` rearward air'c'hamber, and. means forventing saidair chamber to atmosphere.

12. Av ball-point writing instrument comprising a4 forward casing section open at bothV ends and having a straight, smooth-walledl bore extending from end to end with a forward, reducedportion providinga rearwardly facing abutment, a writing unit', removably disposed insaid' forward casing section and including. a reservoir section, a feed section forwardly thereof Vand a ball writing point at the forward end of said feed sectionY in axial alignment with said reservoir and feed. sections, means for venting the rear end of said reservoir section to the interior of said' forward casing section forwardly of said reservoir section, said unit having a. forwardly facing abutment engaging said rearwardly facing abutment for seating said unit in fully operative position in said forward housing section with at least said ball Writing point projecting from the forward end thereof, said unit, being formed with smooth exterior walls dimensioned for insertion of said unit through the rear end of said forward housing section and into fully seated position therein solelyl by a sliding movement, and means for closing: tha rearf end. oft-` said, forward casing;l secr` tion` and; for-retaining said unit in seatingA rela-v tion withsardi abutmentinoluding a rear hous-` ing section detachably carried on said forward casing section.

' IVAN D. TEFFT.

REFERENCES. GI'EED Ther following references are of record in thel filev of' this patent:

STATES PATENTS Number Namev Date 538,492 Askew Apr. 30, 1895 554,189 Kochendarfer Feb. 4, 1896 600,299 Werner Mar. 8, 1898. 748,383.2 Langill, Dec. 29, 1903; 987,169 Reimann Mar, 21, 1911A 1,179,086 Ioster- Apr. 11, 1916 1,373,146 Parkinson; Mar. 2,9, 1921 1,808,377. Reichenbach June 2,4 1931 1,935,000v Vessey. Nov. 14, 193,3 1,980,625 Laforest Nov. 13, 1934 2,106,046. Barlow Jan. 18, 1938 2,107,424- Platt Feb'. 8, 1938, 2,128,456' Dusenbury, Sr.n Aug. 30, 1938 2,229,749 Little Jan. 28,y 1941- 2,390,636 Biro Dec. 11, 1945 2,397,229' Biro Mar. 26, 1946 2,400,679 Biro. May 21, 1946V 2,416,896 Biro Mar. 4, 1947 2,428,960l Cloutier Oct. 14, 1947 2,438,786 Moore Mar. 30, 1948 2,495,013 Martin Jan. 17', 1,950

FOREIGN PATENTS Number Coun-tryt Date.

491,059 Germany 1930 491,841 Germany Feb. 14,` 1930 364,359- Ital-y Oct. 31, 1938

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