US3232279A

US3232279A - Writing instrument

Info

Publication number: US3232279A
Application number: US161155A
Authority: US
Inventors: Francis J Meinhardt
Original assignee: Parker Pen Co
Current assignee: Parker Pen Co
Priority date: 1961-12-21
Filing date: 1961-12-21
Publication date: 1966-02-01
Anticipated expiration: 1983-02-01
Also published as: DK108064C; GB964464A; DE1411961A1

Description

Feb. 1, 1966 Y F. J. MEINHARDT WRITING INSTRUMENT Filed Dec. 2l, 1961 Qwsww MN MM N MY, 8% im United States Patent O 3,232,279 Y WRHRNG INSTRUMENT Francis l. Meinhardt, Edgerton, Wis., assigner to The Parker len Company, Janesville, Wis., a corporation of Wisconsin Filed iDec. 21, 19M, Ser. No. 161,155 4 Ciaims. (Cl. 12d-42.4)

The present invention relates in general to writing instruments of the ball pen type, and it more particularly relates to a new and improved writing instrument in which the ink reservoir is removably attached to a relatively permanent writing tip, so that when the reservoir has been exhausted of ink a new reservoir may be substituted therefor, thus enabling the use of the same writing tip with a new supply of ink.

For the most part, ball point pens of the type now being marketed utilize a ball pen cartridge which includes a reservoir portion permanently connected to a ball and socket writing tip. Since the writing tip thus constitutes a permanent part of the reservoir and is not adapted to be removed therefrom, when the ink initially supplied with such a unit becomes exhausted, the entire cartridge must be discarded and replaced with a new cartridge containing a full supply of ink. Consequently, the writing tip is usable Afor only one charge of ink, and even though it may be in relatively good working order when that charge of ink is exhausted, it must, nevertheless, be replaced.

inasmuch as the writing tip of such a cartridge need only function satisfactorily for a time suicient to write out the supply of ink contained in the associated reservoir, the manufacturing cost of such a writing tip is ordinarily kept at a minimum, and particularly in the less expensive units, the dimensions of various parts of the socket are not as precisely controlled as they might be if the writing tip were to be used for longer periods of time. Accordingly, such pens leave something to be desired in regard to their writing characteristics.

Therefore, it would be desirable to provide a ball pen cartridge wherein the writing tip would be removable from the reservoir, so that the ink reservoir portion could be replaced when necessary, but the same writing tip could b-e used over and over again with successive charges of ink. By producing such a cartridge, the increased cost of producing a better tip would be justified since it could be sold at a price commensurate with its manufacturing cost.

Therefore, an object of the present invention is to provide a new and improved ball point writing instrument.

Another object of the present invention is to provide a new and improved replaceable ink reservoir for a ball point writing instrument.

A further object of the present invention is to provide new and improved means for capping the feed end of a replaceable ball point pen ink cartridge.

Briefly, the above and further objects are realized in accordance with the present invention by supporting the writing tip portion of the pen within a removable barrel tip in which it is ixedly connected. The ball point writing tip is spring biased by spring means also mounted Within the barrel tip so that the writing ball is normally shrouded within the barrel tip. The barrel portion of the pen includes operable means for moving the writing tip against the biasing force of the spring to a writing position wherein the tip extends outwardly of the barrel tip. The barrel further includes locking means for holding the writing tip in the extended position during writing. However, upon removal of the barrel tip from the barrel, such locking means is rendered ineffective to maintain the writing tip extended, and the tip automatically moves to a shrouded position under the biasing force of the return spring.

3,232,279 Patented Feb. l, 1966 ICC Another important feature of this invention is the provision of capping means for the feed end of a replaceable inl: reservoir, which seals the ink within the reservoir during shipping and storage and which, when removed, partially draws ink from the reservoir to reduce, if not entirely eliminate, the amount of air trapped in the connection between the reservoir and the tip.

The above and further objects and a better understanding of the present invention will be had by reference to the following detailed description taken in connection with the accompanying drawings in which:

FIG. l is a longitudinal, sectional View of a ball point writing instrument embodying the present invention;

FIG. 2 is an enlarged, sectional view of the `forward end of the writing instrument of FIG. l showing the writing tip in a shrouded position; and

FIG. 3 is an enlarged, longitudinal, sectional view of the forward portion of a cartridge used in the instrument of FIG. 1 and having a protective cover over its forward end.

Rererring now to the drawings, and particularly to FIG. l thereof, there is shown a writing instrument 10 of the ball point type comprising as its principal components a barrel 12 having a forward portion 12a, threadedly attached thereto, a writing cartridge 13 and a combination pocket clip and actuator i7. The actuator 17 is slidably movable along the longitudinal axis of the barrel 1b to project the writing tip 14, including a rotatably mounted writing ball 1S from the forward end of the barrel 12. Suitable mechanism, more fully described hereinafter, is mounted within the barrel 12 in association with the cartridge 13 and the clip 17 to hold the writing tip 14 in the extended writing position and to release the Writing tip to permit withdrawal thereof upon successive actuations of the clip 17. The latter position in which the writing tip is shrouded within the forward end 12a of the barrel protects the user from inadvertent Contact with the ball lo' which might result in smearing ink on him.

The mechanism which is connected between the clip 17 and the cartridge 13 is essentially the same as the operating mechanism employed in the Jotter ball point pen manufactured and sold by the assignee of this application. This mechanism is fully described in co-pending application Serial No. 400,933, led by Nolan Kent Rhoades on December 29, 1953, now Patent 3,205,863. The operating mechanism may, however, be any other type of mechanism wherein actuation of the clip i7 towards the forward end of the instrument results in extension of the writing tip, but the mechanism described in the aboveidentified co-pending application is believed to be preferable.

The operating mechanism for projecting and retraeting the writing tip i4 may thus comprise a plunger bushing 20, to which the clip 17 is suitably attached by means of a screw 21 having a threaded end portion 21a -received in the rearward end of a plunger 23. The screw 21 holds the rearward end 23a of the plunger 23 within a counterbore 25 in the forward end of the plunger bushing 20, thereby to connect the clip 17, the bushing 20 and the plunger Z3 together `in a unitary assembly. A suitable tassie 27 is cemented into rearward end of the barrel 12 after the operating mechanism has been inserted therein, thereby to maintain the pen in an assembled condition. A ratchet frame 3U is secured in the barrel 12 by a suitably threaded connection thereof and is provided with a rearwardly directed counterbore 32 in which the forward end of a coil spring 33 is located. The coil spring 33 surrounds the plunger 23 and acts upon the forward shoulder of the bushing 20 thereby to bias the clip 17 and the associated assembly rearwardly. The plunger Z3 is provided at its forward end with a plurality of cam-operating surfaces 35 which coaet with a ratchet plug 37 xedly mounted at the rear end of the cartridge 13 so that forward actuation of the clip 17, which moves the cam 35 forwardly, not only pushes the cartridge 13 in a forward direction to extend the writing tip 14 from the forward end of the barrel, but, in addition, exerts a counterclockwise torque on the cartridge as viewed from the rear along vthe axis of the pen. The ratchet 37 comprises a plurality of forwardly extending slots 37a land 37b, two of each such slots being provided, It will be noted that each slot 37a is substantially longer than each slot 37b and therefore continues to a point substantially forward of the bottom of the slot 37b. The ratchet frame 30 is provided with a pair of longitudinally extending ribs 40, having a sumciently narrow width as to be receivable within the

slots

37a and 37b of the ratchet. When the ribs 40 are aligned with the longer slots 37a, a coil spring 41 at the front of the pen which exerts a constant rearward force on the cartridge, moves the cartridge rearwardly a suicient distance to withdraw the writing tip 14 within the forward barrel end 12a. On the other hand, when the slots 37b are aligned with the ribs 40, the bottoms of the slots 37b constitute stops which, by engaging the forward ends of the ribs 40, retain the writing tip 14 in an extended position wherein the ball 15 protrudes from the barrel. The counterclockwise torque exerted by the interengaging cam surfaces on the ratchet 37 and the cam 35 is not effective to rotate the cartridge until it has been moved sufficiently far forward to clear the ribs 40 at which time the cartridge rotates in a counterclockwise direction a sufiicient distance, so that when the clip 17 is released to enable the coil spring 33 to move the cam 35 out of engagement with the ratchet 37, the ratchet 37, under the influence of the coil spring 41, is pressed rearwardly. The cam surfaces at the end of the plug 37 engaging the tapered forward surface on the ribs 40, cause the cartridge to continue rotating in the same counterclockwise direction until the ribs 40 are aligned with the

slots

37a or 37b, respectively, and the cartridge 13 is held in a fixed angular position. It will thus be seen that upon successive actuations of the clip 17, the cartridge not only moves between extended and retracted positions, but additionally is rotated through 180 degrees, thereby to equalize the wear exerted on the socket during writing.

In order to replace the reservoir 13, it must be removed from the barrel 12 and this is readily accomplished by unscrewing the barrel tip 12a from the main barrel portion 12 and simply withdrawing the tip 12a together with the reservoir which is attached to it. While replacing the cartridge the forward end of the pen must be handled more than usual and, consequently, there is a greater opportunity for ink to be smeared on the person making the change. In order to prevent this form occuring, there is provided, in accordance with the present invention, means for insuring that the writing tip 14 and particularly the writing ball 1S is shrouded within the barrel tip 12a during the reservoir changing operation. To this end the coil spring 41 surrounds the writing tip 14 and engages at its rear end a forwardly facing shoulder 44 on a generally tubular member 46 which is permanently attached to the writing tip 14. A washer 47 is received in a counterbore at the rear end of the barrel tip 12a and is staked in place whereby it provides a stop against which a flange 49 on the tube 46 abuts when the tip 14 is in the shrouded position, It may thus be seen that the writing tip portion of the cartridge is permanently mounted within the barrel tip 12a and is resiliently biased by the spring 41 into a shrouded position. Accordingly, w-hen the barrel tip 12a is removed from the counterbore of portion 12, the cartridge 13 is freed from the projectretract mechanism at the rear af the barrel 12 and thus moves rearwardly under the influence of the spring 41 until the flange 49 engages the stop washer 47. At this time the tip 14 is shrouded and the possibility of spurious smearing of the ink on the user is automatically avoided.

Another important advantage of this feature of thef instrument is that the tip cannot be used for writing with' the reservoir removed. Consequently, the feed passage cannot be written out by removing the reservoir therefrom. This might be done if the tip were not shrouded in the tip 12a.

Once the cartridge 13, together with the associated writing tip 14 and the barrel tip 12a have been removed from the barrel, the reservoir portion of the cartridge may be withdrawn from the forward portion by merely pulling the two parts apart. Thereafter, a new cartridge, which is filled with ink, may be attached to the writing tip by merely pushing the writing tip and the new reservoir portion together.

In order to permit this ready replacement of the rest ervoir portion of the ball point writing instrument 10, the writing tip 14 includes a ball and socket assembly which is connected by a suitable feed conduit (not shown) which extends rearwardly through a tubular conduit 52. The conduit 52, as shown, extends along the axis of a tubular member 46 which is press-fitted onto the tip 14. The reservoir comprises an enlarged tubular rearward porion 54 having at the forward end thereof a feed tube 55 having a rearwardly disposed external flange over which the forward end 54a of the met-allie body portion of the reservoir 54 is tightly fitted to fixedly attach the feed tube 55 to the main body of the cartridge. A suitable resilient' ring 58 having a cross-like central feed hole may be usetf to provide a seal to assist in preventing the leakage of ink from the cartridge between the body portion 54a and the tube 55 and plug 59 is press-fitted in the cartridge behind the ring 58 to maintain the ring 58 in a compressed condition whereby it provides the necessary tight fluid seal.

The forward part of the feed tube 55 tightly receives the tip feed conduit 52 and is provided at its forward end with a pair of spaced-apart

internal flanges

60 and 61 which prevent spurious removal of the reservoir from the writing tip but do not grip the feed conduit 52 so tightly as to prevent separation of the reservoir from the tip for normal replacement of the reservoir.

As described above, it is important that the conduit 52 ybe filled with ink when a new reservoir cartridge is attached thereto, and it is desirable that the -feed tube 55 also be lled with ink when the conduit 52 is initially pushed therein. In order to insure that the tube 55 of a replacement cartridge is filled with ink at the time it is attached to the point assembly, there is provided in accordance with the present invention a novel closure or cover 70, shown in FIG. 3, Afor covering the end of the feed tube 55 of a replacement cartridge. Prior to use of a replacement cartridge the cover 70 seals the end of the feed tube 55 from the atmosphere to prevent the leakage of ink therefrom.

The cover 70 is generally cup-like in configuration having an imporforate bottom Wall 72 and a generally tubular side wall 74 which extends a sufficient distance from the bottom 72 to provide a portion which may be readily grasped by the fingers to pull it from the feed tube 55 which it frictionally engages. The tubular side wall 74 has a lower portion 74a having an internal cross-sectional conguration which is circular to provide a cylindrical portion which conforms to the cylindrical external surface of the fed tube 55 and which tightly grips the feed tube 55 to removably secure the cap 70 to the cartridge and to provide a hermetically tight seal which prevents the leakage of ink `from the cartridge. Outwardly of `the lower side wall portion 74a the cover 74'- has a portion 74b having a non-cylindrical internal con-- figuration differing from the external configuration of theV tube 55 to provide a longitudinal air space 75 extending. throughout the full length of the cover portion 74b. Preferably, the cover portion 74b tightly -grips the feed tube 55 to provide additional friction to hold the cover 70 on the cartridge during shipping, and to this end it may have a generally cylindrical internal configuration with one or more longitudinally extending iiats (not shown) which tightly engage the feed tube 55. The open end cap portion 74C is cylindrical, having an internal diameter greatly exceeding the external diameter of the -feed tube 55, and it loosely overlies the forward end of the cartridge portion 54a.

Because the cover 70 sealingly engages the fed tube 55, as the cover 70 is removed from the cartridge a vacuum is created at the end of the feed tube 55 which sucks ink through the feed tube 55 from the reservo-ir. This pulling of the ink from the tube 55 is desirable in order to insure that the feed tube 55 is completely filled with ink when the cover 70 has been removed. However, 4for reasons of cleanliness it is essential that excess ink not be sucked out of the reservoir. Therefore, in accordance with another aspect of this invention, the cover 70 is designed so that a controlled quantity olf ink is pulled through the tube 55 when the cover 7 t) is removed therefrom. Accordingly, the cover 70 is provided with an axial boss 71 which extends inwardly from the bottom wall 72 and is receivable in the end of the feed tube 55. Preferably, the boss 71 is tightly received within the tube 55 but a slight clearance of, for example, the order of one one-thousandth of an inch 4may be tolerated. The length and diameter of the boss 71 are selected relative to the dimensions of this tapered inner end of the feed tube 55 so that with the cartridge completely lled with ink to the boss 71, just enough ink is sucked through the feed tube 55 during removal of the cover 70 to completely ill the end of the tube 55 with ink. rThe length of the lower side wall portion 74a of the cover is also chosen so that when the portion 74a clears the end of the feed tube 55 during removal of the cap, the feed tube 55 is just filled with ink. The suction terminates, of course, at this time because of the air spaces 75 which break the seal between the atmosphere and the vacuum space at the end of the feed tube 55.

As indicated hereinabove, it is desirable that the feed tube 55 be filled with ink up to the boss 7l soy that no air is trapped between the boss 71 and the ink supply. At the present time, ball pen ink reservoirs are centrifuged after filling lto insure that the ink reaches the ball and that substantially all air bubbles are removed from the ink. This centrifuge operation may thus be used to also insure that the feed tube 55 is completely filled with ink up to the boss 71 by placing lthe cover 74 on the feed tube 55 prior to the centrifuging of the cartridge. When back filling is used the cover 7 #i may be connected to the cartridge before the ink filling operation, and when front filling is used, the cover 70 'may be connected to the cartridge after filling.

In accordance with another feature of the present invention the cartridge 13 and particularly the reservoir portion 54 includes at the rear end thereof, a plug of a thick, grease-like substance 65, of the type disclosed in U.S. Patent No. 2,678,634 to Henriksen. The purpose of using this type of cartridge is to prevent the entrapment of air in the feed passage between the main ink supply in the cartridge and the writing tip during replacement of the reservoir. If air were to be so trapped, the trapped body of air would move toward the writing ball l5 until it finally reached the ball, at which time the peu would starve out, i.e., no ink would be fed to the ball. Of course, .this condition would be only temporary if the pen were to be left for a few minutes in an upright, point down, position. However, the average person who uses a ball point pen would not recognize this trouble, nor woud he know how to correct it and, consequently, he would probably lay the pen aside, assuming that it were out of ink or defective. Accordingly, it is extremely important to insure that air is not trapped within the ink 'feeding conduits during replacement of an ink reservoir. The use of the grease-like plu-g or follower 65 in the cartridge 13 serves to eliminate the entrapment of air, inasmuch as the ink feeding conduits cannot be completely written out of ink as 4long as the thick plug 65 is provided. The material of which the plug is composed must be sufficiently thick and viscous that it will not flow during normal writing through the lfeed conduit, but instead becomes physically trapped at the lower end of the feed reservoir at the location of the plug 59. When this occurs, atmospheric pressure can no longer act on the rear end of the ink column and the pen stops writing even through the feed conduit 52 is completely filled with ink. Now, therefore, when a new cartridge is inserted into the writing tip, since the feed tube 55 is partially filled with ink, as supplied to the user by the manufacturer, in accordance with the present invention, no air can be entrapped in the feed conduit or in the passageway between the feed conduit 52 and the main reservoir 54. Accordingly, replacement of the ink supply lis achieved without entrapping any air in the system.

While the present invention has been described in connection with a particular embodiment thereof, it will be understood that those skilled in the art may make many changes and modications without departing from the true spirit and scope of the invention and, therefore, it is intended by the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.

l claim:

1. A ball point Writing instrument comprising a barrel having forward and rear portions removably connected together to permit assembly and disassembly thereof,

means for securing said portions together for facile connection and separation thereof,

an ink reservoir cartridge having a tubular ink supply chamber and an ink feed conduit extending from one end thereof,

said cartridge being disposed in said barrel with said tubular ink supply chamber located entirely within said rear barrel portion and said feed conduit extending toward said forward barrel portion,

a ball point writing unit including a writing ball at the front end and an ink supply tube extending rearwardly therefrom,

said unit being mounted in said forward barrel portion for slidable movement along the longitudinal axis thereof between a first position wherein said ball protrudes from the front end of said forward barrel portion and a second predetermined position wherein said ball is retracted within said forward barrel portion,

means for permanently retaining said unit in said forward barrel portion,

spring means mounted in said forward barrel portion for biasing said unit toward said second predetermined position,

means for detachabiy and sealably interconnecting said ink supply tube and said feed conduit together to permit replacement of said cartridge on said writing unit, and

means disposed in said rear barrel portion for acting on said cartridge to hold said unit in said first position against the force of said spring means,

whereby when said barrel portions are disassembled to replace said cartridge, said spring means forces said writing unit into said second position.

2. A ball point writing instrument comprising a barrel having separable forward and rear portions,

said unit being mounted in said forward portion for slidable movement along the longitudinal axis thereof between a first position wherein said ball protrudes from the front end of said forward barrel portion and a second predetermined position wherein said ball is retracted within said forward barrel portion,

means for permanently retaining said unit in said forward portion,

means connected to said writing unit and extending rearwardly from said forward barrel portion to provide a finger gripping surface for holding said unit relative to said forward barrel portion,

spring means mounted in said forward portion for biasing said unit toward said second predetermined position,

means for detachably and sealably interconnecting said ink supply tube and said feed conduit together to permit separation of said cartridge from said writing unit, and

whereby when said barrel portions are disassembled to replace said cartridge, said spring means forces said writing unit into said second position and said unit may be manually held in said second position during assembly of another reservoir.

3. A ball point pen comprising a writing tip and a replaceable ink reservoir removably secured thereto to permit replacement of said reservoir,

housing means permanently mounting said tip and enclosing said reservoir and preventing spurious disassembly of said reservoir from said writing tip and including means for opening said housing to permit disassembly of said reservoir from said Writing tip, and

means responsive to the opening of said housing for automatically shrouding said tip when said housing is open,

whereby when said pen is in a condition for replacement of said reservoir said writing tip is shrouded to protect the user therefrom when the reservoir is disconnected from said tip.

4. A writing instrument comprising a barrel having an axial bore that opens toward the front and including separable forward and rear portions,

a writing unit including an ink reservoir and a writing tip,

said writing unit being housed within the barrel and movable therein between a forward position in which the writing tip projects from the forward barrel portion and a rearward position in which the writing tip is retracted within the forward barrel portion,

spring means disposed in the forward barrel portion urging the writing tip toward retracted position, and

means disposed in the rear portion of the barrel for moving the writing unit into said forward position against the force of said spring means,

said ink reservoir being non-permanently and removably connected to the writing tip, and

said writing tip being permanently and non-removably connected to the forward barrel portion.

References Cited by the Examiner UNITED STATES PATENTS 2,166,619 7/1939 Becker 206-56 2,594,083 4/1952 Silver 120-42.04 2,620,773 12/1952 Telit 12C-45.4 X 2,809,609 10/1957 Clary et al 12C- 42.03 2,809,748 l0/1957 Barnaby 206-56 2,934,038 4/1960 Meier 1Z0-42.03

FOREIGN PATENTS 203,793 10/1956 Australia.

EUGENE R. CAPOZIO, Primary Examiner. GEORGE NINAS, TEROME SCHNALL, Examiners. E. HOROWITZ, Assistant Examiner.

Claims

3. A BALL POINT PEN COMPRISING A WRITING TIP AND REPLACEABLE INK RESERVOIR REMOVABLY SECURED THERETO TO PERMIT REPLACEMENT OF SAID RESERVOIR, HOUSING MEANS PERMANENTLY MOUNTING SAID TIP AND ENCLOSING SAID RESERVOIR AND PREVENTING SPURIOUS DISASSEMBLY OF SAID RESERVOIR FROM SAID WRITING TIP AND INCLUDING MEANS FOR OPENING SAID HOUSING TO PERMIT DISASSEMBLY OF SAID RESERVOIR FROM SAID WRITING TIP, AND MEANS RESPONSIVE TO THE OPENING OF SAID HOUSING FOR AUTOMATICALLY SHROUDING SAID TIP WHEN SAID HOUSING IS OPEN, WHEREBY WHEN SAID PEN IS IN A CONDITION FOR REPLACEMENT OF SAID RESERVOIR SAID WRITING TIP IS SHROUDED TO PROTECT THE USER THEREFROM WHEN THE RESERVOIR IS DISCONNECTED FROM SAID TIP.