US3468613A

US3468613A - Liquid marker and replaceable ink cartridge therefor

Info

Publication number: US3468613A
Application number: US603650A
Authority: US
Inventors: Frederick W Strickler
Original assignee: Eberhard Faber Inc
Current assignee: Eberhard Faber Inc
Priority date: 1966-12-21
Filing date: 1966-12-21
Publication date: 1969-09-23
Anticipated expiration: 1986-09-23

Description

Sept. 23, 1969 P. w. STRICKLER LIQUID MARKER AND REPLACEABLE INK CARTRIDGE THEREFOR Filed Dec. 21, 1966 o {O \A 2 m A p 1 o 2 4 2 3 ITIYENTOR. FKEDERKLK W S RlCKLER ATTCIRNEY United States Patent US. or. 401-199 1 Claim ABSTRACT OF THE DISCLOSURE A liquid marker having in combination a permanent outer casing assembly and a replaceable inner ink cartridge assembly. The outer assembly consists of a tubular barrel having a closed end, a screw-threaded sleeve fixed within its closed end, and a closure cap having a closed end and a cap insert in its closed end. The replaceable ink cartridge assembly has as its principal element an elongated tubular barrel open at both ends and having an internal taper at decreasing diameter toward its externally tapered forward end. A writing nib adapter is fixed in the forward end of the barrel. The cartridge barrel is substantially filled by an ink absorbent reservoir whose forward movement within the cartridge is limited by an internal abutment. A writing nib extends through the nib adapter into contact with the reservoir. The rear end of the cartridge through which the absorbent reservoir is inserted is sealed by a threaded end plug which engages the threads of the barrel insert in the closed end of the outer barrel to old the barrel assembly and the cartridge assembly releasably engaged with each other.

SUMMARY OF THE INVENTION The primary structure comprising the invention resides in the threaded barrel insert in the end of the permanent outer barrel in combination with the threaded end plug of the replaceable ink cartridge by which the outer barrel and the ink cartridge are releasably held together to form the marker. Contributing structures reside in the inner taper of the ink cartridge and the absorbent reservoir stops at its forward end.

It has been conventional, for many years, to provide replacement ink cartridges for fountain pens using liquid ink as the writing fluid. In all cases, these prior pens have had permanent writing nibs at one end and were refilled by inserting a vial of liquid ink behind the nib by entry into the pen barrel at some point behind the nib. These prior structures and practices do not lend themselves for application to liquid marking devices, wherein a marking liquid is wholly absorbed in an absorbent reservoir within the pen barrel and is fed by capillary action through a porous writing nib. In these latter implements, this is not feasible because the nib, the absorbent reservoir, and its ink content must be supplied as a self-contained unit. A unit, as described, cannot be assembled with an outer casing in the manner of the earlier refillable fountain pens. The novel structures of this application adapt liquid markers to renewal and refilling practices.

Liquid marker refill cartridges are presently available on the market but all of them to date have been in the form of very slender cylinders having only a limited ink capacity. The screw-threaded cartridge closure plug extension of reduced diameter herein requires no reduction in the diameter of the cartridge and, therefore, preserves the full ink capacity of the cartridge while also providing positive means for connecting the cartridge and the barrel of the marker.

It is the purpose of the invention to provide a liquid marker which has a permanent outer barrel open at one end and a threaded insert in the opopsite end thereof, and a replaceable ink cartridge within the barrel which has therein an absorbent ink reservoir and, extending from one end of the cartridge, a writing nib having its inner end in contact with the absorbent ink reservoir, and in which the opopsi'te end of the cartridge is closed by a screw-threaded plug, whereby the threads of the plug are adapted to engage the threads of the insert and thereby hold the assemblies together as a writing unit.

BRIEF DESCRIPTION OF THE DRAWING The foregoing structures, the purpose of the invention, and its advantages will be more fully understood by reference to the drawing, which illustrates a presently preferred embodiment, when viewed in light of the detailed description to follow. In the drawing, like reference numerals indicate like parts, and;

FIG. 1 is a cross-sectional view along the axis of the marker;

FIG. 2 is a foreshortened external view of the marker with its closure cap removed;

FIG. 3 is an external view of the replaceable ink cartridge;

FIG. 4 is a cross-sectional view along the axis of the permanent outer barrel assembly;

FIG. 5 is a transverse sectional view on line 5-5 of FIG. 1; and

FIG. 6 is a transverse cross-sectional view on line 6-6 of FIG. 1.

DETAILED DESCRIPTION The marker herein consists essentially of a permanent outer barrel assembly 10, more particularly shown in FIG. 4, as consisting of an outer barrel 12, a cap 14, a barrel insert 16 and a cap insert 18. The barrel 12 and the cap 14 are preferably formed of metal and may be suitably ornamented, if desired. Both the barrel 12 and the cap 14 are in the form of a tubular shell closed at one end. The closed ends of these shells are preferably somewhat tapered and the open ends are so related in diameter as to permit the cap to telescope over the open end of the barrel with a sufficiently snug fit to keep the two shells assembled when the cap is so telescoped over the open end of the barrel. The tapered closed end of the barrel 12 receives the internally threaded barrel insert 16 with a press fit so that the barrel insert 16 is held firmly within the closed end of the barrel.

The cap insert 18 within the closed end of the cap shell has formed thereon an annular shoulder 20 which fits snugly against the inner wall surface of the cap 14 and holds it in place within the cap.

The permanent barrel assembly 10 receives therein a replaceable ink cartridge assembly 22. This assembly is preferably composed of molded plastic material such as polypropylene. The replaceable ink cartridge includes a cartridge barrel 24 which is in the form of an elongated cylinder adapted to fit snugly into the outer barrel 12 and the cap 14. The cartridge barrel 24 has one end closed by an end plug 26 while the externally tapered opposite end of the barrel is adapted to receive a nib adapter 28. In its preferred form, the cartridge barrel 24 is internally tapered from a larger diameter at the end closed by the end plug 26 to a smaller diameter at its opposite end thereby providing a slight annular space 30 between the outer surface of an absorbent reservoir 32 and the inner wall of the cartridge barrel.

The absorbent reservoir 32 is composed of a pourous felt-like material which is highly absorbent of liquid ink or other marking liquid. The absorbent reservoir 32 is inserted into the cartridge barrel 24 through the open rear end thereof prior to the insertion of the end plug 26. The end plug has an annular shoulder 34 adapted to abut the open end of the cartridge barrel 24. A sleeve 36 extends inwardly of the shoulder 34 into tight contact with the inner wall face of the cartridge barrel. After the absorbent reservoir 32 has been inserted into the cartridge barrel, and has been saturated with ink or other writing fluid, the end plug 26 is applied to the open end of the cartridge barrel and sealed thereagainst, if necessary. Such sealing can be done in any suitable way such as by the use of an adhesive or by spin welding, for example.

The end plug 26 is externally screw-threaded to engage internal screws of the barrel insert 16. Thus, in assembling the replaceable ink cartridge 24 with the permanent outer barrel assembly 10, the ink cartridge is inserted into the outer barrel 12 until the screw threads of the barrel insert 16 and those of the end plug 26 come into engagement with each other. The replaceable ink cartridge assembly and the permanent outer barrel assembly are then relatively rotated in a direction to more fully engage the threads of the end plug and the barrel insert until the open end of the outer barrel 12 abuts an annular shoulder 38 on the cartridge barrel.

The external surface at the forward end of the cartridge barrel 24 is inwardly tapered to correspond to the taper of the cap insert 18, so that an ink-tight seal is produced, and to provide a comfortable fit in the finger of the user. The nib adapter 28 has extending therefrom one end of an axial writing nib 40, the inner end of which is embedded in, or at least lies in substantial contact with, the end of the absorbent reservoir 32. The outer end of the writing nib 40 extends beyond the nib adapter 28 where it is exposed for contact with the paper or other material which is to be marked. The writing nib 40 is a slender, porous body which is preferably quite rigid and resistant to the abrasion encountered while using the liquid marker. Such materials as sintered plastic or metal, or linear fiber, have been suggested.

The nib adapter 28 is simply a sleeve-like element which firmly holds the writing nib 40 within its axial bore and has a body portion which is press-fitted into the end of the cartridge barrel in order to make the assembly liquid tight.

Contact with the absorbent reservoir 32 prevents the nib 40 from moving inwardly under writing pressure. The absorbent reservoir 32 is held against longitudinal movement within the replaceable ink cartridge assembly by means of a plurality of internal ribs 42 which limit the movement of the absorbent reservoir 32 in the forward direction and by the end plug 26 which limits the longitudinal movement of the absorbent reservoir 32 in the opposite direction.

When the replaceable ink cartridge assembly 22 is handled, shipped and stocked, as a marker refill unit, its nib end will be suitably enclosed as, for example, in a cap similar to the cap 18 to avoid evaporation of the marking fluid. Such cap or enclosure is removed and discarded when the replaceable ink cartridge assembly is placed into the permanent barrel assembly for use therein.

The fit between the outer barrel 12 and the cartridge barrel 24 may be enhanced by providing the cartridge barrel with a plurality of external ribs 44, as seen in FIG. 6. Such external ribs improve the contact between the outer barrel 12 and the cartridge barrel 24 and insure that inadvertent separation of the two is avoided.

From the foregoing, it can be seen that a very simple, yet reliable replaceable ink cartridge assembly has been provided for marking implements of the type described. When the marking fluid of the device is exhausted, to remove the cap 14, it is merely necessary to turn the cartridge barrel 24 in respect to the outer barrel 12 until the screw threads of the end plug 26 are disengaged from the barrel insert 16. The replaceable ink cartridge assembly may then be withdrawn from the outer barrel 12 and a replacement can be substituted by reversing the process. The use of a replaceable ink cartridge assembly, long common in conventional liquid ink fountain pens, makes possible, in a liquid marker type of instrument, the construction and design of a permanent outer barrel assembly which does not seriously sulfer from cost limitations since the permanent barrel assembly 10 can now be reused indefinitely and can, therefore, be designed to meet the most fastidious tastes. The replaceable ink cartridge assembly can be very inexpensively manufactured so that no substantial loss is felt when it is discarded upon displacement.

The liquid marker has been specifically illustrated and described in a single embodiment for the purpose of disclosing a presently preferred form of the invention. It is evident that the invention is useful not only in pocket type markers, but equally in other types, as, for example, in desk-set markers and the like. Moreover, the shape of the marker may be selected from a wide variety of shapes that may suggest themselves. It is intended that the particular illustrative embodiment shall not be limiting on the claims beyond the clear meaning of the language therein employed.

I claim:

1. In a liquid marker having a replaceable ink cartridge in combination, an outer barrel open at one end thereof and having an internally threaded insert in the opposite end thereof, an ink cartridge within said barrel, said cartridge having a major and a minor external diameter forming an external annular shoulder at the junction of said diameters, an absorbent ink reservoir within said cartridge, a writing nib in contact with said absorbent ink reservoir and extending from one end of said cartridge, an end plug having a diameter that is less than said minor diameter of said cartridge closing the opposite end of said cartridge, external screw threads formed in said end plug, said threads of said plug being adapted to engage said threads of said insert and draw the open end of said outer barrel into tight engagement with said annular shoulder.

References Cited UNITED STATES PATENTS 1,449,234 3/1923 Laffin 401-133 2,061,059 11/1936 Carlson 40l-134 2,381,898 -8/1945 Gergely 401134 3,048,879 8/1962 Rosenthal 401-199 3,355,239 11/1967 Albrecht 401-198 FOREIGN PATENTS 1,008,626 2/1952 France.

LAWRENCE CHARLES, Primary Examiner