US3610766A

US3610766A - Fountain pen

Info

Publication number: US3610766A
Application number: US839227A
Authority: US
Inventors: Heinz Gunther Herrnring
Original assignee: Montblanc Simplo GmbH
Current assignee: Montblanc Simplo GmbH
Priority date: 1968-07-13
Filing date: 1969-07-07
Publication date: 1971-10-05
Anticipated expiration: 1988-10-05

Abstract

A fountain pen and method of making the same in which liquid ink is fed from an ink container through a capillary section of a shape-maintaining writing tip which is characterized primarily in that the writing tip is formed by a thin-walled cap provided with ink from the inside while said cap has an end face in which a plurality of closely adjacent capillary openings or passages are provided.

Description

United States Patent 1,254,701 1/1918 Keplinger Heinz Gunther Herrnring llarnburg-Fuhlsbuttel, Germany 839,227

July 7, 1969 Oct. 5, 1971 Montblanc-Simplo Gmbll Hamburg, Germany July 13, 1968 Germany lnventor App]. No. Filed Patented Assignee Priority FOUNTAIN PEN 8 Claims, 22 Drawing Figs.

US. Cl r 401/256 Int. Cl 543k 1/06 Field of Search ..40 1/ 5 References Cited UNITED STATES PATENTS 1,949,162 2/1934 Kallenbach 2,558,828 7/1951 De Sierra 401/265 2,948,008 8/1960 Leeds et 401/283 X 3,449,054 6/1969 Lundsager..... 401/265 X 3,467,478 9/1969 Webber 401/265 X FORElGN PATENTS 27,343 2/1964 Germany 401/265 121,064 6/ 1927 Switzerland 401/265 Primary Examiner-Lawrence Charles Attorney-Walter Becker ABSTRACT: A fountain pen and method of making the same in which liquid ink is fed from an ink container through a capillary section of a shape-maintaining writing tip which is characterized primarily in that the writing tip is formed by a thin-walled cap provided with ink from the inside while said cap has an end face in which a plurality of closely adjacent capillary openings or passages are provided.

PATENTEU UBT 5 I97! sum or 2 PATENTEU um 51971 Fig. 9a.

SHEET 2 [IF 2 Hg. 10a.

Fig-10 Fl'g. 10c.

Fig. 10d.

Fig. 10 e.

Fig. 101.

Jnven lor- FOUNTAIN PEN The present invention concerns a fountain pen in which liquid ink is conveyed from an ink container or reservoir through a capillary section to a writing tip.

Fountain pens for liquid ink with shape-retaining pen tip are employed in practice for tracing and for preparing technical sketches, even though an impressive writing cannot be produced as is the case, for instance, with ordinary writing pens. These fountain pens also have the drawback that they have a relatively complicated ink-feeding system which in most instances comprises a needle valve and a venting capillary which easily gets clogged up.

It is, therefore an object of the present invention to provide a fountain pen for liquid ink which has a particularly simple ink supply system and enables the user to write with a particular writing strength giving the signature a particular character.

This object and other objects and advantages of the invention will appear more clearly from the following specification, in connection with the accompanying drawing, in which:

FIG. 1 illustrates a cross secton through a writing tip according to the invention on an enlarged scale.

FIGS. 2-4 represent views of writing tips according to FIG. I with end faces of different configuration.

FIGS. la -4a are end faces of the writing tips of the pens illustrated in FIGS. I-4.

FIG. 5 is a cross section through the wall of the metal cap within the range of a capillary on a still larger scale.

FIG. 6 represents a section through a still differently designed capillary in conformity with FIG. 5.

FIG. 7 is an end view of FIG. 6.

FIG. 8 illustrates a detail concerning the design of a capillary according to a special modification.

FIGS. 9a 9b 9c 9d and FIGS. 10a 10b 10c 10d l0e 10f respectively show purely schematic representation of method steps disclosed for the present invention.

The fountain pen according to the present invention is characterized primarily in that the writing tip is fonned by a thin-walled metal cap which is supplied with ink from the inside and that the end face which has a configuration in conformity with the desired writing position and strength of the writing, has a plurality of closely adjacent capillary openings 3 to form a foraminous end wall.

Such capillary openings may be fed with ink from a porous mass which is arranged in the said metal cap and preferably consists of synthetic material, e.g. polyurethane.

Preferably, the capillary openings are so designed that they widen in a direction opposite to the through-flow direction of the ink. In this way, foreign bodies which could enter the metallic cap from the paper surface can be moved into the interior of the metal cap and will then be unable to interfere with the passage of ink in the capillary.

The capillary openings or foramina which may be of a circular cross section or a longitudinal or oval cross section or of a similar design are preferably etched into the metal cap. To this end, an unperforated metal cap may first be coated with a photosensitive cover lacquer which is exposed to light in conformity with the etch pattern and is developed before the metal cap is etched.

Referring now to the drawing in detail, the fountain pen writing tips illustrated in FIGS. 1-4 and la -4a consist of a thin-walled metal cap 1 which adjacent to a substantially cylindrical section has an foraminous end face or wall 2 which is decisive for the ink feed. This end face or wall 2 may be semispherical (FIG. 1), may have the shape of a roof with a gable or the shape of a hip roof, or may have a somewhat inclined writing edges, as shown in FIG. 4. In practice the end face of the respective writing tip provided in conformity with the invention may be selected in conformity with any standard pen tip shapes of customary writing pens.

For purposes of feeding ink, the end faces of the metal caps are foraminous i.e. are provided with a plurality of closely adjacent capillary openings 3 which may likewise be of different shape. In addition to a circular cross-sectional shape, also rectangular longitudinally slotted or oval capillary openings are possible. Furthermore, various capillary shapes may be combined on the same metal cap. Inasmuch as the wall thickness of the metal cap 1 is rather thin and may, for instance, have a magnitude of 0.1 millimeters, also correspondingly shortly dimensioned capillary openings will be possible. The capillary openings 3 are supplied with ink from the ink container or reservoir of the fountain pen, preferably through a porous ink-storing mass 6 which is provided in the interior of the metal cap I. The ink-storing mass consists preferably of an ink-resistant synthetic material of corresponding porosity.

Especially with roof-shaped end faces of the writing tips it is advantageous to provide longitudinal or slotlike capillary openings directed toward the zenith point of the writing tip.

If, in conformity with the preferred embodiment of the invention, the capillary openings 3 are so designed that their cross section widens in a direction opposite to the ink flow therethrough, foreign bodies picked up by the writing tip or particles detached from paper and having entered the capillaries will be transported into the interior so that the capability of the capillaries to give off ink will be retained. This withdrawal of foreign bodies into the interior of the metallic cap is also aided by the thin wall of the metallic cap and the short capillary length inherent thereto. Such capillary is illustrated in FIG. 5. A further possibility of reducing the danger of soiling the metal cap serving as writing tip, consists in surrounding the ink exit opening of the capillary with a flat recess 4 of a larger cross section asshown in FIG. 6. This arrangement also has the advantage that the capillary cannot be clogged up if, for instance, by an undue writing pressure or by other mechanical damage, the edges of the capillary openings 3 are upset toward the center of the capillary.

FIG. 7 illustrates a top view of the exit opening of a capillary according to FIG. 6. In this connection there also exists the possibility to arrange the capillary openings so close to each other that flat broadened portions provided at the exit opening will overlap each other. Those parts of the metal cap or metal cap end face which remained standing will assure that the outer borders proper of the capillaries 3 cannot directly come into contact with the paper on which the writing takes place.

As shown in FIG. 8, the capillaries 3 which widen toward the inside may also be arranged so closely to each other that overlapping areas will be obtained on the inner side. Such overlappings will bring about that the wall thickness of the metal cap is reduced within the area of the writing tip and that on the inner side of the metal cap ink-supplying grooves 5 are formed which are interconnected in a netlike manner.

The metal caps employed according to the invention consist of an ink-resistant metal, for instance, of stainless steel, nickel, brass or the like. The shape of the cap may be produced either by a galvano plastic method or by a deep drawing operation. A forming sintering operation is also possible. Furthermore, there exists the possibility of producing the metal caps by chemically reducing nickel solutions. In this connection, there exists the further possibility of correspondingly hardening such nickel caps by heat treatment. For purposes of increasing the wear resistance, the metal caps produced in the various manner may subsequently be covered by a coat. For instance of chromium.

.The capillaries to be provided on the end face of the metal cap 2 are preferably etched. This may be brought about by covering the nonperforated metal cap first with a photosensi tive cover lacquer 6 which is exposed to light and developed in conformity with the etch sample prior to etching the metal cap. By a corresponding selection of the etching medium it is possible to bring about that the walls of the capillary opening will broaden inwardly in conformity with an angle of about 30 relative to the longitudinal axis of the capillaries as has been shown in FIG. 5. By etching a plurality of times, it is also possible to design the capillaries 3 so that they will be stepped, or in conformity with FIGS. 6 and 7 the capillaries 3 may be provided with a bowl-shaped outer recess. This can be carried out in a particularly simple manner by employing photosensitive position lacquer which is first exposed to light in conformity with the outer minimum opening of the capillaries 3, is then developed and after the etching operation is again in conformity with the greater dimension of the flat recess 4 exposed to light and developed, and is finally again etched.

If in an embodiment of the invention about 2,000 pores with a circular cross section of a -micron diameter were etched on the front side, on the inside the width of the pores would be 30 microns. The distance between the pore centers in individual areas of the tips were selected with 40 and 60 microns, and on the inner side a relief was formed as shown in FIG. 8. The diameter of the pores may be selected in conformity with the purpose of employment in conformity with the ink and the conveying or transfer of ink to the tip. This diameter of the pores should be between 2 and 100 microns, preferably between 5 and 20 microns. If the cross section is not circular, the capillary potential is selected accordingly.

It is, of course, to be understood that the present invention is, by no means, limited to the particular constructions and designs set forth above, but also comprises any modifications within the scope of the appended claims.

What I claim is:

l. A fountain pen writing tip in communication with an ink supply in the form of a thin-walled tube having a cylindrical wall portion and a foraminous end wall extending across the end of the cylindrical wall portion and forming a writing surface extending between the sides of said cylindrical tube, said foraminous wall being perforated throughout substantially its entire area by spaced capillary passages, each of which converges from the internal surface of said wall toward the outer surface, so that said passages constitute the foramina of said foraminous wall and said capillary passages in said wall conduct ink to the outer writing surface at any point of said end wall which may be in engagement with an ink-receiving surface.

2. A fountain pen in combination according to claim I, in which said cap is a metallic cap, and which includes a porous ink-storing mass.

3. A fountain pen in combination according to claim 2, in which said ink storing mass is formed by a synthetic material.

4. A fountain in combination according to claim 1, in which said end face portion is roof shaped.

5. A fountain pen in condition according to claim I, in which the capillary passages are at least in part arranged so close to each other as to overlap each other and to form netlike interconnected ink supply grooves at the overlapping areas. v

6. A fountain pen in combination according to claim 1, in which the outside of said end face portion is at the mouth of said capillary passages provided with flat recesses.

7. A fountain pen in combination according to claim 1, in which said writing pen has a tip and in which said capillary passages are formed by slots converging to the center of the tip of the writing pen.

8. A fountain pen in combination according to claim 1, in which the walls of the capillary passages flare in a direction toward the inner surface of the pen so as to form with the longitudinal axis of the ends of the capillary passages an angle of approximately 30.

Claims

1. A fountain pen writing tip in communication with an ink supply in the form of a thin-walled tube having a cylindrical wall portion and a foraminous end wall extending across the end of the cylindrical wall portion and forming a writing surface extending between the sides of said cylindrical tube, said foraminous wall being perforated throughout substantially its entire area by spaced capillary passages, each of which converges from the internal surface of said wall toward the outer surface, so that said passages constitute the foramina of said foraminous wall and said capillary passages in said wall conduct ink to the outer writing surface at any point of said end wall which may be in engagement with an ink-receiving surface.

2. A fountain pen in combination according to claim 1, in which said cap is a metallic cap, and which includes a porous ink-storing mass.

5. A fountain pen in condition according to claim 1, in which the capillary passages are at least in part arranged so close to each other as to overlap each other and to form netlike interconnected ink supply grooves at the overlapping areas.

8. A fountain pen in combination according to claim 1, in which the walls of the capillary passages flare in a direction toward the inner surface of the pen so as to form with the longitudinal axis of the ends of the capillary passages an angle of approximately 30*.