US2971495A - Writing instrument - Google Patents

Description

Feb. 14,y 1961 w. p. GREEN WRITING INSTRUMENT Filed Dec. 5, 1958 o, of

Il |IIl .HHHlHNi EN INVENTOR. WILSON D, GREEN ATTY.

,ink supply remains in the cartridge.

nited States WRITING INSTRUMENT -Wilson P. Green, Janesville, Wis., assignor to The Parker VPeni (1ompany, Janesville, Wis., a corporation of Wisconsm Filed Dec. 5, 1958, Ser. No. 778,486

1 Claim. y(Cl. 1Z0-42.16)

The invention relates to ball point writing instruments and in particular to ball point cartridges for use therein. The invention relates to such cartridges having, in

addition to a main reservoir` of ink, an auxiliary reservoir of ink which may be utilized when the cartridge stops writing due to exhaustion or near exhaustion of the ink supply in the main reservoir.

In most prior art ball point cartridges there is but one reservoir of ink, and when the writer has written out thesupply in the reservoir, the exhausted cartridge must be withdrawn and a new cartridge must be placed in the instrument to replace the exhausted cartridge. Many times a writer nds that, when his cartridge has stopped writing, there is no new cartridge readily available. This is quite common because the expected time of writeeout or exhaustion is not easily estimated.

This invention provides a conveniently and reliably usable `auxiliary supply of ink, which is extremely useful to tide the writer over until anew cartridge can be purchased or located and used to replace the exhausted `much longer the supply will last. Further, one must disassernble the writing instrument casing to enable viewing of the transparent cartridge in order to make such an estimate.

Another of the prior art attempts to solve the problem was to provide a plurality of ball point cartridges in a writing instrument, so that when one was exhausted, another was used. Such arrangements, however, require movement and re-arrangement of the cartridges whenever one of the cartridges stops writing, thus requiring addi tional moving parts. Such arrangements also require a plurality of balls and ball housings (separate ones for each cartridge), and in this respect are wasteful and uneconomical.

Applicant has provided an improved convenient means for temporarily extending the writing life of a ball point cartridge when it stops writing, by simply and conveniently bringing into operation an auxiliary reservoir ink supply.

It is an object of this invention to provide, in a ball point cartridge, in addition to the main reservoir, an auxiliary reservoir having an open front end and a sealed rear end which is openable to vent the rear end, making the auxiliary reservoir operative for writing.

A further object is to provide, in a ball point cartridge, a rear-vented main annular reservoir surrounding a rearsealed auxiliary reservoir of much smaller capacity than the main reservoir, and means for frangibly opening the arent `rear end of the auxiliary reservoir to vent it toatmosphere, making it operative for writing.

It is another object of this invention to provide such a ball point cartridge having an auxiliary reservoir fixed in the main reservoir, `and having no moving parts other than the writing ball.

Still another object is to provide, in a. ball point cartridge, an auxiliary reservoir that is sealed at o ne end,

and at the other end is open and continuously in communication with the feed passage to the writing point.

It is a still further object to provide, in a tball `point. cartridge, a rear-sealed auxiliary reservoir tube extending rearwardly of the main reservoir and being frangible at or near the rearward termination of the main reservoir `for venting the auxiliary reservoir. v

Objects and `advantages other than those set forth above will become apparent from a consideration of the following description and the accompanying drawings, wherein:

Fig. l is a side elevational View, partly in section, ofA

a ball point cartridge embodying the invention;

Fig. 2 is a `front elevational view, partly insection, of said cartridge;

Fig. 3 is a plan view ofthe forward end of theauxiliary reservoir tube; and

Fig. 4 is a perspective View of said forwardend of said tube.

Referring to the drawings, there is shown a ball point cartridge havingan enlarged rear section 5 providing the main reservoir, and a front section or feed section 6 of reduced size extending forwardly from the rear Section5. A ballpoint unit 7 is mounted in the feed section 6. The ball point unit '.7 has a reduced rear end 7a extending into the feed section 6, and hasa tip 7b at its forward end holding a ball 8 in the ball point unit. rI`he ball 8 is, as is well understood, freely rotatable in its mounting,

`and is in communication with the ink through the bore in the portion 7u, which is a feed passage for feeding ink from the ink reservoirs to the writing ball.

A rear plug 9 is mounted in the rearward end of the rear section 5, forming the rearward termination of the cartridge proper and the main reservoir. A bore 9a through the plug 9 receives a tube 12 therethrough. The tube 12 extends rearwardly of the plug and also extends through the main reservoir section 5 and into the `feed section 6, and terminates up against the inner end of the portion 7a of the ball point unit. The tube .l2 is open at its front end, and is sealed at its rearward end as shown at 12a. The tube 12 is scored at 12b to provide a plane of weakness so as to be frangible, so that the tube may be broken off at the scoring 12b to vent the rear of the auxiliary reservoir ink supply 13 to atmosphere.

The tube 12 is smaller in outside diameter than the diameter of the bore 9a, so that the main reservoir is vented to atmosphere. If desired, there may be disposed, atop the rear of the main ink supply 1G, a grease follower such as the viscous pulpy mass 11, The main reservoir is annular in shape, being the annular space between the wall of section 5 and the wall of the tube 12, and thus the grease follower 1i is also annular in shape. If the main reservoir spacing, between tube i2 and section 5, is of larger than capillary dimension with respect to the ink 1h therein, it will of course, as is. well known, be highly advantageous to utilize the viscous pulpy follower 11.

The tube 12, at the front end thereof, is flattened and has a cut out 12d in the attened portion, forming a pair of spreading ear portions 12C. The ears 12C abut walls of feed section 6 and abut the end of the portion 7a of the ball point unit, thereby spacingly positioning the g with the feed passage to the ball S.

The auxiliary ink supply 13 is preferably much smaller than the main ink supply 10. Preferably the auxiliary reservoir l2 contains enough ink 13 for about one hour of continuous writing. whereas the main reservoir contains enough ink for about thirty to forty hours of continuous writing. In terms of the average use, this means a main supply of 'about thirty to forty weeks duration and an auxiliary supply of about one Weeks duration.

The auxiliary reservoir tube 12 is shown as being of capillary size with respect to the ink of the ink supply 13, and thus no greasefollower is required atop the column of ink 13, although such a follower may be used if desired. and would advantageously be used if the tube 12 was of greater than capillary size.

The operation of the device is as follows.

When the ink in the main reservoir has been exhausted or nearly exhausted. the writer-user will notice, when trying to write with the ball point, that writing becomes extremely diicult or stops entirely, and little or no ink will be applied to the paper.

The ink supply 13, however, in the auxiliary reservoir tube 12, will not have been used, because the auxiliary reservoir tube is sealed at its rear end. That is. the rolling o-f the ball 8 could not displace and pull ink from tube l2 because to do so it would have had-to pull against a sealed or vacuum condition.

The reservoir supply of ink 13 can be easily made operative and utilized. however, merelv by breaking otf l tube 12 at the plane of weakness provided by the scoring Y 12b. This, of course, opens and vents the rear of the auxiliary reservoir tube to atmosphere, and thus permits ink to feed to the ball 8 as the ball is rotated in writing. The writer-user, when the cartridge refuses to write -upon exhaustion of the main ink supply, thus merely breaks off and throws away the portion of tube 12 rearwardly of the scoring 12b, and the auxiliary reservoir supply of ink is immediately brought into operative availability, enabling the writer-user to continue writing. The user-writer is also reminded, by this occurrence, to obtain a new cartridge in the near future, but in the meanwhile he may continue writing without having to take time out to try to locate or purchase a new cartridge. This is an important advantage, especially in circumstances where new cartridges are not readily available, such as when one is riding a train, bus or airplane, or when one is writing in bed.

The ball point cartridge has no moving parts other than the writing ball, the auxiliary reservoir tube 12 being fixed within the main reservoir. The tube 12 need not be displaced or repositioned to be made operative.

The open front end of the auxiliary reservoir tube 12 is xed and spaced from the surrounding structure, and thus is always in communication with the feed passage to the writing ball. f

The auxiliary reservoir tube 12 extends a short distance rearwardly beyond the rearrnost portion of the cartridge proper, and thus is conveniently grasped for breaking the tube at the scoring 12b to easily and effectively open the sealed rear end of the auxiliary reservoir tube, thereby venting the auxiliary supply of ink to atmosphere to bring it into operative availability.

I claim:

A ball point cartridge comprising a main reservoir section, a reduced feed section extending forwardly from said main reservoir section, a ball point unit carried by said feed section and having a freely rotatable writing ball mounted therein in ink feeding communication with said main reservoir and feed sections, an auxiliary reservoir tube xed in and extending through said main reservoir section into said feed section and extending rearwardly of said main reservoir section, said auxiliaryf` reservoir tube being closed at its rear end, the forward end of said auxiliary tube being attened and cut out to form a pair of spreading ear portions'for spacing the forward open end of said auxiliary tube from the inner end of said ball point unit and from the walls of said feed section and for permitting ink to feed from said main reservoir section to said feed section through said cut -out between said ear portions, and said auxiliary reservoir tube being scored immediately adjacent the rear end of said main reservoir section providing a plane of weakness thereat for frangibly opening the rear end of said auxiliary reservoir tube, said writing ball being the only moving part of said cartridge.

References Cited in the tile of this patent UNlTED STATES PATENTS 2,521,285 Dearman Sept. 5, 1950 2,829,623 Barnes Apr. 8, 1958 FOREIGN PATENTS 990,028 France May 30, 1951 60,745 France July 13, 1954 (lst addition to No. 1,022,845)

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