US2620773A

US2620773A - Writing instrument

Info

Publication number: US2620773A
Application number: US687577A
Authority: US
Inventors: Ivan D Tefft
Original assignee: Parker Pen Co
Current assignee: Parker Pen Co
Priority date: 1946-08-01
Filing date: 1946-08-01
Publication date: 1952-12-09
Anticipated expiration: 1969-12-09

Description

l. D. TEFFT WRITING INSTRUMENT Filed Aug. 1, 1946 INVENTOR.

[van 0 7fft 4 T TORNEYS Dec, 9, 1952 Patented Dec. 9, 1952 UNITED STATES ATENT OFFICE WRITING INSTRUMENT Application August 1, 1946, Serial No. 687,577

3 Claims. i

This invention relates to ball-point writing instruments and has to do particularly with an cartridge for that type of pen, and to a care tridge mounting, means.

Inlwriting instruments of the type using a ballpointwriting element, itis customary to employ a. relatively thick; viscous ink and such writing instruments, therefore, do not lend themselves readily to filling by the customer in a manner similar to thatemployed in filling fountain pens using relatively thin, watery inks. Accordingly, it, is desirable in this type of writing instrument to employ an ink-containing cartridge serving as an ink reservoir. It may be desirable in certain cases, in order to insure proper feeding of the thick viscous ink, to provide a cartridge arrangement wherein the ink is placed under pres sure continuously tending to urge the ink from the cartridge toward the writing element. Where the. ink cartridge is adapted to be removed from the writing instrument so that it can be replaced, when empty, by a full cartridge, this presents the problem of preventing soiling of the hands and clothes of the user by the ink during the operation of replacing the cartridge. The difiiculty of preventing leakage of ink from the cartridge during replacement is increased where the ink is under pressure.

An object of the present invention is to provide a ball-point writing instrument having a removable ink cartridge and means for automatically opening the cartridge and placing it in ink feeding relation with a writing element upon insertion. of the cartridge in the writing instrument.

Another object of the invention is to provide a ball-point writing instrument having a removable ink cartridge wherein the ink is continuously maintained under pressure tending to urge it from the cartridge, and means for puncturing the cartridge and simultaneously connecting the cartridge with an ink feed leading to the writing element.

A further object of theinventicn is to provide a readily replaceable ink refill cartridge for a ball-point writing instrument which is simple and inexpensive to manufacture, which can be stocked and dispensed conveniently by retainers without any danger of leakage and which can be inserted in and removed from the writing instrument readily by the user without soiling the hands or clothes of theuser.

Still another objectv of the invention is to provideiarpoint-and-feed unit for a ball-point writ-,-. ing instrument, whichunitincludes a ball-pointwriting element and a feed. leading theretoand-is adapted, when an ink cartridge is inserted in the instrument, to puncture the cartridge, to place the cartridge in ink feeding relation, withv the writing element and to support the cartridge in the instrument.

Still another object of the invention is the provision of a ball-point writing instrument hav ing a replaceable ink reflllcartridgewhich,,when inserted in the writing instrument, and, moved into its seat therein, is automatically brought into ink feeding relation with an ink feed, channel leading to the writing element and is; sealed to prevent leakage of ink from between the cartridge and the feed channel, definin means.

Other objects and advantagesof. theinvention will appear from the following description taken in connection with the appended, drawings where.-v

Figure l is a longitudinal, sectional View through a writing instrument constructed in. accordance with the present invention, theinstrument being shown in writing condition;

Fig. 2 is a. longitudinal, sectional view through. the ink cartridge forming, a, part of the instrument showninFig. 1; I V

Fig. 3 is a fragmentary, longitudinal, sectional view through the frontendportion ofv thewriting instrument shown in Fig. 1, with the inkcartridgeremoved;

Fig 4 isa transverse, sectionalview, taken line 4-41 of Fig. 1; and.

Fig. 5.is a transverse,,se.ctiona1 view taken along line 5;--5. of,Eig. 3.

Referring now particularly to Fig. 1 of. the drawings there, is illustrated a ball-point, writinginstrument constructed in accordance, with a. preferred embodiment of the invention, which. instrument includes a barrel or housing iformed-v of any suitable, rigid material such as metal or a plastic. The barrel l preferably isformed with a rear section 2 and a forward section 3, con nected together as by screw threads 5. An end; cap 5 of any suitable, form may-beprovidedfor enclosing the writing end of theinstrument whenthe latter is not used in writing, which cap. is adapted to be carried on the rear endv of, the instrument, as shown in Fig. 1, when the instrument is used in. writing.

The barrel sections 2 and 3 together define a. chamber 6 adapted to receive and house an ink cartridge 20. At the forward end ofthe barrel, a bore Or passage 1 of, smaller diameter is proalong ll ll l9;

preferably is formed of a suitable metal, is firmly secured in the forward end of the barrel I, as by screw threads II, with its forward end projecting slightly from the forward end of the barrel I. The forward end 2 of the point-andfeed unit In preferably is tapered and is formed with suitable means, such as a socket (not shown) adapted to receive and seat a ball writing element l3. Inasmuch as the details of the socket and the manner of seating the writing element I3 form no part of the present invention, this portion of the point-and-feed unit I8 is not shown in detail, it being understood that any suitable seating arrangement for the ball-point 3 may be employed which properly holds and seats the ball-point |3 for free rotation while suitably permitting feed of ink to the ball-point l3 when the instrument is used in writing. In order to provide for feeding ink to the writing element l3, an ink feed passage or channel M of relatively small diameter extends into feeding relation with the ball-point l3 at the forward end of the unit Ill. The channel I4 extends longitudinally throughout the length of the unit l and is open at the rear end thereof so that the channel may be placed in ink feeding relation with an ink cartridge as hereinafter described in detail.

The point-and-feed unit It! is formed intermediate its ends, and preferably toward its rearward end, with a portion l9 provided with external threads I5 and comprising a connector element onto which the ink cartridge 20 is adapted to be screwed. The extreme rearward end portion of the point-and-feed unit ID has a piercing point or element 6 adapted to puncture the end of the ink cartridge and place the interior thereof in ink feeding relation with the ink feed channel I which extends from the writing element |3.

The point-and-feed unit In is provided adjacent the forward end of the threads IS, with an abutment I! which preferably takes the form of an annular ring pressed onto or otherwise fixedly secured to the body of the point-and-feed unit l0. Rearwardly of and abutting the ring I! is a sealing element l8 which preferably is formed as a washer of suitable soft sealing material such as soft rubber, the purpose of which will appear hereinafter.

In accordance with the present invention the removable and replaceable ink cartridge or unit 20 is adapted to be stocked and dispensed by dealers as a unit and can readily be removed from the instrument by the user when the ink is exhausted and replaced by a new and similar unit having a full charge of ink. The unit is fully sealed against leakage of ink therefrom to permit storage in handling and insertion in the writing instrument without soiling the hands or clothes of the user. Moreover. the ink cartridge is adapted to be formed of relatively inexpensive materials so that it can be replaced at a small fraction of the cost of the entire writing instrument.

To the foregoing ends the ink refill cartridge 20 includes a rigid casing or container 2| formed of a material which can be easily and inexpensively formed as by moulding or drawing. Preferably the casing 2| is formed from a suitably rigid plastic, although if desired a metal may be used. The casing 2| preferably is of elongated tubular form and is closed at its rear end and open at its forward end.

The cartridge 20 further includes means for confining the ink and for continuously exerting on the ink a pressure tending to urge the ink from .4 the reservoir and to cause it to flow through the feed channel to the writing element. In the preferred embodiment of the invention a flexible collapsible sac 22 is disposed within the casing 2| and has its forward open and secured to a nipple 23 preferably formed integrally with an end plug 24 firmly secured in the forward end of the casing 2| as by an adhesive. The end plug 24 is formed with a discharge outlet 26 closed by an initially imperforate, puncturable closure element such as a relatively thin sealing plug 21 securely seated in and closing the discharge outlet 26. The open end of the sac 2| is suitably attached to the nipple 23 to prevent leakage of ink between the sac 2| and the nipple 23. This may be accomplished by adhesively securing the sac to the nipple as by a cement. However, if desired, a clamping ring 25 may be provided in lieu of, or in addition to, the adhesive for clamping the forward end of the sac 22 about the nipple 23.

The cartridge 20 is adapted to be assembled with the point-and-feed unit l3 in such manner that the sealing plug 21 is punctured and the interior of the casing is placed in ink feeding relation with the ink feed channel I4. To this end the end plug 24 is provided with screw threads 28 adapted to engage cooperating threaded means whereby the cartridge 20 may be securely secured in the barrel. In the preferred embodiment, the forward portion of the discharge outlet 26 is threaded as at 28 and adapted to be screwed onto the threads l5 formed on the rearward end of the point-and-feed unit Ill.

The casing 2|, the end plug 24, the clamping ring 25, and the sealing plug 21 all preferably are inexpensively formed of suitable plastic material or materials. However, if desired any or all of these members may be formed of metal. These members all are formed of a material or materials which provide sufficient rigidity for mechanical strength and, in the case of the end plug 24, a material which may be machined to provide the screw threads 28 which receive the end of the point-and-feed unit l3. The sealing plug 21 is formed of a material which has sufficient strength to retain the ink in the cartridge 20 when the plug is unpunctured, but which can be readily punctured by the piercing point l6 of the point-and-feed unit I0. The sealing plug 21 may be formed with screw threads adapted to fit the threads 28 of the end plug 24 or it may be formed of a material which will adapt itself to the shape of the threads 28 when the sealing plug 21 is inserted in the threaded end of the discharge outlet 26. All portions of both the cartridge and the point-and-feed unit which are contacted by the ink are formed of materials which are not readily deteriorated by inks of the types customarily used in a ball-point writing instrument. Among the materials suitable for forming the sealing plug are Lucite (methyl methacrylate resin) and polystyrene; either of these materials also may be used to form the end plug 24 and the casing 2|.

The flexible sac 22 preferably is normally collapsed and is adapted to be distended by forcing ink thereinto under pressure, which causes the sac to assume generally the shape of the casing 2|. The sac 22 is formed preferably of a resilient material so that the sac will tend always to return to its normal, collapsed condition. Thus, the sac after being filled and distended by the ink is adapted to apply a slight force continuously on the ink tending to urge the ink out of the sac: 2 2? through. then discharge: out-let:v 26: In order tcpermit thesaczzitocollapsedn ithiscman-s ner: andi conformito :the: body: of the ink therein, the casing 21: is provided with a: vent-z. 29: which ventsathe-interior of the casingrtmthe chamber 6 inthe barrel; and t-he barrel. lsinxturn. is :formed with alvent 38 extending from the chamber E to the exterior of 'theabarrel', which ventsthe inter rion of the barrel to the atmosphere;-

After the cartridge '2 0: has beemassembledi ex.- cept for=the=sealing plug 21). the sac 22 is distend'edand the ink is introduced into-thesac 22; The sac 2 2 is 7 held distended by creating a suifi cient vacuum around the-sac in any suitablemanner; Preferably, theacartridgeis assembled'with asuitable device (not-shown) for creating-within the space between the see 22 and thecasing 21- a suificient vacuum to dist-end the'sac 22 substantially; tothe-form which it assumes" when filled with ink; An ink suitable for use with a ball-point writing element, ,asior example a pasty, viscous ink, is" then introduced into the sac through. the opening 261.111; the end. plug 24 to completely fill the sac 22 and theportion of the.

opening 26 uptoatleast the rearward end of the screw threads 28. With the interior of the casing 21* still maintained under subatmospheric pressure,- the sealing plug 21 i is inserted" in the end-plug 2iand firmly-seated therein againstthe body of-ink to sealthe ink within-the sac-22' and theop'ening'2-6; The cartridge-Wis then removed from the vacuum-creatingdeviceand is ready for use.

The cartridge-2 B -isassembled-with the remainder-of the'writing instrument, the forward end of the cartridge-being inserted through the open rearendofthefront section 3-, the rearsection 2 having been previously removed to permit access to the interior ofthe front section 3. The end plug zfl i'sinserted-overthe rear end of the-pointandi-feed unit I 0- and screwed thereon until the forward end of the cartridge-Wis seatedfirmly against, and in sealing relation with, the sealing element I8. When cartridge 2!! is screwed onto the point-and-feed unit I! and advances therealong, the piercing point 16 of the latter punctures the sealing plug 21 and places the feed channel l4 in communication with the interior of the sac 22. The ink in the latter thus is forced from the interior of the sac 22 and into the feed channel I4 and thence into feeding relation with the ball point I3. The rear section 2 is then assembled with the front section and the instrument is ready for use. When the ink in the cartridge 20 has become exhausted, the latter may be readily removed and replaced by merely removing the rear section 2 from the front section 3 and unscrewing the cartridge 20 from the point-and-feed unit I 0, after which a fully charged cartridge 20 may be assembled with the instrument in the manner above described.

The several parts are so dimensioned that the threads 15 sufficiently engage the threads 28 prior to the time the piercing point I6 punctures the sealing plug 21 so that ink will not leak into the chamber it. Moreover, when the cartridge is screwed against the seal I8 a further sealing is provided which insures against any leakage into the interior of the barrel. The length of the point-and-feed unit is, of course, such that when the cartridge is fully seated against the sealing ring 18, the rear open end of the feed channel I4 is disposed rearwardly of the sealing plug 21 and fully exposed to permit ink to be forced therein from the interior of the sac 22. Since the sealing 6 plug 2.1iclosely;engageszthezpiercingspoint1|6. dining the puncturing of? the: plug: .2 T. itprovides a seal to i prevent? ink: from soiling.- the threads l5.

and: 28. Also-.- the sealing: plug: 21; serves during removaliofi'thescartridgefilltas -a'wiper for'remov ingtink from the piercing point. I57 sopthat' there isilittleipossibilityrof inkzbeing leftrthereon when thecartridgeiswremoved:

From the foregoing it will be seen thatthe present? invention provides a. ball-point writing instrument-which canbe manufactured inexpen-e sively' by; a relativelyv small. number of simple .operations: andiatt. arminimumi cost for materials. The replaceahleacartridge.canJce formed fromrelatively; inexpensive materials-and can. be dis carded; when, removed from: the barrel after con-- sumption: of the ink: therein, it? is: not necessary-,- however; ,todiscard the point and-feedunitpwhen the ink: cartridge 1 is: replaced: Thepoint-and; feed :unit, ,onxtheother hand, .may be removed and replaced. readily if: for'any. reason;v this is: desired; 1 01?example;.the pointt-and-feed unit could: be replaced after 'alongperiod ofmsezthe ball seat should become suihciently worn to impair the good writing; characteristics of. the instrument.

In connection with the removability of the pointand-feed unit; it should be noted that this unit iSTthI'BadBd1Y 'SECUIBd in. thebarrel section willciently firm, toprevent accidental loosening; and. displacement of' the: unit. The: point-and -feed unit. must be held: against the; unscrewing: tend-.- ency which: may be developed-when the cartridge is screwed onto. or: off therearward; end of the point-and-feed unit.

Th -insertion and removal of the ink refill cartridg requires no special skill and can.be accomplishedby any. user. No adjustments are required inasmuch as all the parts except the cartridge are fixably retained in their proper positions. The cartridge seats positively at the end of: the screw inser'tionmovement thereof so that the user can determine readily when the cartridge is fully seated: and. properly positioned for use.

The ink refill cartridge is completely and effectively sealed prior to insertion in the writing instrument and can be stocked and handled without danger of leakage of the ink therefrom. Moreover, the seal is not punctured until after the threads on the cartridge have engaged sufficiently with the threads on the point-'and-feed unit so that there is no leakage within the barrel during insertion of the cartridge. Moreover, when the cartridge is fully seated additional sealing means are provided for insuring against leakage of ink into the interior of the barrel.

The screw action employed in assembling the cartridge with the point and feed unit causes the piercing point to cut its way through the sealing plug readily; moreover, the screw action provides a mechanical advantage so that only a very light force is required to screw the cartridge home and puncture the seal. Thus, not only can the assembly operation be performed with a minimum of force but no appreciable strain is placed on the parts by this operation.

I claim:

1. A cartridge for a ball-point writing instrument comprising a rigid casing open at one end, a rigid axially bored end plug secured in and closing the open end of said casing and having a nipple at its inner end, the bore of said plug providing a discharge outlet leading from said casing for receiving therein a threaded end of an ink-feed-and-piercing member and being formed with internal threads of substantial length longitudinally of the casing for positively but detachably securing said cartridge to the feed member, a resilient flexible sac secured on said nipple for confining ink therein, a vent in said casing on the opposite side of said sac from said nipple, and an imperforate punct'urable closure element threaded in said outlet adjacent the inner ends of said threads for sealingly closing said outlet.

2. A self-contained point-feed-and-piercing unit for a ball-point writing instrument of the type including a barrel formed with a cartridgereceiving chamber and an ink-cartridge having a puncturable seal, said unit being adapted to be removably secured in the barrel and to project forwardly therefrom and rearwardly into the chamber, said unit comprising an elongate member having an ink channel extending from end to end throughout said member and ope'n'only at said ends, external threads intermediate the ends of said member for positively but removably securing it in the barrel, a generally tubular piercing element at the rear end of and integral with said member for puncturing the seal and entering the cartridge, external threads of substantial length intermediate said first threads and said element for positively but detach'ably securing the rear end of said unit within the cartridge, an external flange rigid with said member adjacent the forward end of said second threads and having a sealing rear surface of re-' silient material, and a ball-writing point carried in the forward end of said member.

3. In a writing instrument of the type having a casing formed with a vented chamber and an open forward end, the combination with a selfcontained unit including a ball writing point, a tubular member having an ink channel extending from' end to end therethrough and opening solely at its ends, and having external threads intermediate its ends for positively but removably securing it in said barrel with its forward end projecting through the open forward end of the barrel and carrying said ball and its rear end projecting into the chamber and terminating in a fixed tubular piercing element integral with the member, said member also having external threads of substantial length intermediate said first threads and said piercing element and a rigid external flange having a sealing rear surface of resilient material adjacent the forward end of the second said threads, of an ink cartridge including a rigid casing having an internally threaded outlet opening of substantial length longitudinally of the casing for threadedly receiving the second said threads on said member and positively but detachably connecting the cartridge thereto with said piercing element entering in said casing, and an initially imperforate sealing element disposed in said outlet opening adjacent the inner end of the threads therein and puncturable by said piercing element.

IVAN D. TEFFI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 448,939 Cronkhite Mar. 24, 1891 1,065,872 Johnson June 24, 1913 1,472,576 Averill Oct. 30, 1923 1,724,107 Pollock Aug. 13, 1929 1,986,372 Sherman Jan. 11, 1935 2,107,424 Platt Feb. 8, 1938 2,368,425 Reynolds Jan. 30, 1945 2,397,229 Biro Mar. 26, 1946 2,413,904 Biro Jan. 7, 1947 2,425,198 Moore Aug. 5, 1947 2,427,068 Randolph Sept. 9, 1947 2,438,786 Moore Mar. 30, 1948 2,444,003 Chesler June 22, 1948 2,444,004 Chesler June 22, 1948 2,506,035 Parker May 2, 1950