US3502417A

US3502417A - Arrangement for improving the writing properties of fiber-point pens and the like

Info

Publication number: US3502417A
Application number: US680420A
Authority: US
Inventors: Heinrich Hartmann
Original assignee: Geha Werke GmbH
Current assignee: Geha Werke GmbH
Priority date: 1966-11-07
Filing date: 1967-11-03
Publication date: 1970-03-24
Anticipated expiration: 1987-03-24
Also published as: SE326385B; BE706008A; DK126849B; NO124358B; DE1511346B1; GB1153019A; CH468884A; DE1511348A1; NL6715039A; CS151463B2

Description

March 24, 1970 H. HARTMANN 3,502,417

ARRANGEMENT FOR IMPROVING THE WRITING PROPERTIES OF FIBER-POINT PENS AND THE LIKE Filed Nov. 5. 1967 3 Sheets-Sheet 1 March 24, 1970 H. HARTMANN 3,502,417

ARRANGEMENT FOR IMPROVING THE WRITING PROPERTIES OF FIBERPOINT PENS AND THE LIKE Filed Nov. 5, 1967 3 Sheets-Sheet 2 /NVN r0? Heinrich A AWm/w H. HARTMANN March 24, 1970 ARRANGEMENT FOR IMPROVING THE WRITING PROPERTIES OF FIBER-POINT PENS AND THE LIKE 3 Sheets-Sheet 5 Filed Nov. 5. 1967 It'll Illlll'f llllllllll l United States Patent Office 3,502,417 Patented Mar. 24, 1970 ABSTRACT OF THE DISCLOSURE The invention provides an improved fiber-point pen and the like with which a point former containing a cavity is associated. The cavity comprises two different coaxial coned sections of which the inner apical section serves to reshape the writing point of the writing utensil when the same is not in use and when its protective cap is screwed on or oil.

BACKGROUND OF THE INVENTION This invention relates to a writing utensil comprising a fiber bundle composed of individual synthetic fibers.

Well known fiber-point pens contain a pin-shaped rigid writing element consisting of a bundle of ultrafine fibers of nylon or the like embedded in plastics. That is, the synthetic fibers are axially interconnected within a holding means by a plastic bond. The synthetic fibers in the writing point are shortened on the outer periphery relative to the fibers lying on the bundle axis. This bundle forms a conical writing point for conveying the ink by capillary action from a supply inside the pen through the writing point to the paper. Cavities which are located in the writing points to produce the capillary action cause the points to wear away. These writing points are compressible and thus lose their original generally conical shape after a relatively short period of use. Flats form on the writing point and cause the ink trace on the paper to be irregular. The compression and deformation of the writing point constrict the cavities in its interior and thereby impede the regular How of the ink. These and many other obvious disadvantages clearly restrict the usefulness of such pens.

SUMMARY OF THE INVENTION It is a primary object of this invention to overcome the disadvantages attendant the fiber pens of the prior art by providing a means in combination therewith which can be used to reshape a deformed writing point comprised of a fiber bundle to its original form for further use.

Another object of this invention is to reshape the writing point consisting of a bundle of fibers by using a means to uniformly maintain the axial pressure on the fiber bundle during nonuse.

It is a still further object of the instant invention to provide a point forming means attached to the interior of the protective cap of fiber point writing pen. This point forming means maintains an axial pressure uniformly on the fiber bundle during nonuse so that any deformity in the writing point will be eliminated through reshaping.

It is still a further object of this invention to provide a protective cap which is provided internally with a point forming member axially having a cone-shaped cavity directed towards the fiber bundle of the writing point. The cone-shaped cavity includes a bigger side of which faces the writing point and has a shape corresponding to the shape of the undeformed writing point. The writing point is inserted into the cavity where it may be reformed under axial pressure.

Further embodiments of this invention provide for the protective cap to be attached to the writing utensil itself.

The location of this protective cap is such that the writing point is under axial pressure when the writing pen is not in use. One specific embodiment includes a mounting for the protective cap having the cone-shaped cavity axially movable through the use of a spring means. The point forming member disposed in the interior of the protective cap is elastically supported against the inner side of the head of the protective cap.

A further embodiment provides for at least one window-like opening in the protective cap to observe the region of the point forming member disposed in the interior of the protective cap. Here the point forming member is constructed of a clear transparent plastic material to provide means for observing the writing point in contact with the said point forming member.

BRIEF DESCRIPTION OF THE DRAWINGS Several embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are two part sectional side views of point formers that constitute separate self-contained elements, each point former being shown facing the writing element of a writing utensil that is to be reshaped;

FIGS. 3 to 5 are similar views showing point formers built into protective caps of writing utensils, each cap being shown facing the writing point of the writing utensil to which the cap belongs;

FIG. 6 is an axial section of a different embodiment of a cap containing a point former;

FIG. 7 is a part sectional side view of a point former adapted to be screwed into the rear end of a barrel;

FIG. 8 is an axial section of a writing utensil adapted for the reception of a replaceable ink storage cartridge insertable into the barrel with a tight friction fit; and

FIG. 9 is an axial section of a writing utensil in which a replaceable ink storage cartridge is positively located, the writing utensil having its protective cap fitted with a point former.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a point former which has a body 1 of circular cross section made of plastics, metal or some other suitable hard material. At one end this body 1 is provided with a central coned recess or cavity comprising two different coaxial coned sections, i.e., an inner apical section 2 and an outer section 3. The inner apical section 2 of the cavity has a cone surface which roughly corresponds to the original cone shape of the writing point 8 of a writing utensil, or it may have a slightly more acute cone angle than that of a writing point that has not yet been worn and deformed. The outer coned section 3 of the cavity opens outwardly and has substantially the shape of a truncated cone having the same cone angle as the taper end 5 of the barrel 4 of the writing utensil. A shoulder 6 is formed between the two

coned sections

2 and 3 of the cavity.

In FIGS. 1 and 2 the cylindrical body 1 of the point former is extended to form a shaft 7 which is provided with longitudinal fiutings or has a surface roughened in some other way to facilitate holding the point former for use. The writing utensil which is to be reshaped in the illustrated embodiments is a fiber point pen of conventional kind comprising a barrel 4 with a conically tapering end 5. The writing point 8 of a pin-shaped writing element projects from an axial bore in the tapering end 5 of the barrel. The writing element may in the known manner consist of a bundle of very fine filaments, such as nylon, embedded in a synthetic plastics matrix and thus forming a solid unit. The portion of the writing element which lies in the outlet bore at the tapering end 5 of the barrel 4 is embraced by a sleeve 9 of metal or plastics from which about 3 mm. of the writing point 8 freely project.

When the writing point 8 is deformed or so worn that it has lost its original shape, and thus, when used for writing. produces uneven lines which can no longer be controlled to be fine or thicker according to the angle at which the pen is held, then the end of the writing utensil with the writing point 8 is pressed firmly into the cavity in the point former. The deformed point 8 of the writing element is thus pressed into close contact with the wall of the inner section 2 of the cavity, whereas the taper end 5 of the barrel 4 fits into the outer section 3 of the cavity. The pressure of the writing point 8 against the internal wall of the inner section 2 of the cavity reshapes the deformed writing point 8 which thus reassumes the shape which it possessed when it was new. The shaping effect of the point former can be improved by repeatedly rotating the inserted writing point 8 several times in the cavity. The rotary movements smooth the freshly formed surface and press projecting nylon fibers back into the embedding matrix of the writing point 8.

1n FIG. 2 the surface of the inner section 2 is formed with undulations extending in the direction of the cone axis and the crests of the undulations which project into the interior of the coned section 2 are provided with a thin layer of emery 10. When the writing utensil is rotated inside the cavity of the point former or conversely when the latter is rotated on the writing point 8 of the writing utensil, the layer of emery has the effect of rubbing projecting ends of nylon filaments and small particles of material off the coned surface of the writing point 8 and of thereby smoothing down the surface to reshape the original shape of the writing point 8. The cylindrical body 1 of the point former is provided with several, for

instance four, axial slit-shaped openings 11 placed in I quadrature and extending to the edge of the cavity. Particles of material that have been abraded by the layer of emery are discharged through these slit-shaped openings 11.

Instead of being provided with a layer of emery 10 the crests of the undulations in the inner section 2 of the cavity may be shaped to form small cutting edges which act on the coned surface of the writing point 8 in the same way as the layer of emery 10. A layer of emery 10 may also be applied to the internal concd surface of the section 2 when the same is smooth.

In the embodiment illustrated in FIG. 3, the point former is resiliently mounted on a precompressed coil spring 17 inside a protective cap 12 of the writing utensil. The cylindrical body 1 containing the

coned sections

2 and 3 of the cavity is rearwardly formed with a squaresectioned tang 13 which is slidably received into a corresponding square-scctioned blind hole 14 in a rear cover member 15 of the protective cap 12 which simultaneously and in conventional manner serves for securing a clip 16 when screwed into the rear end of the protective cap 12. The precompressed coil spring 17 bears with one end against the inside surface of a ring 18 which carries the threads for securing the cover member 15 of the protective cap 12 and with the other end against an external collar 19 on the cylindrical point former body 1. This coil spring 17 urges the point former forwards into contact with a sleeve 20 firmly secured inside the protective cap 12. When the protective cap 12 is pushed over the writing end of the writing utensil the writing point 8 is received into the inner coned section 2 of the point former, whereas the taper end 5 of the barrel 4 is received resiliently into the outer section 3 of the cavity. The point former exerts a continuous reshaping effect whilst the utensil is not in use, as long as the protective cap remains in position on the writing end of the barrel 4. The reshaping effect which in this instance may also be assisted by the provision of a layer of emry 10 or by cutting elements, as in the embodiment described by reference to FIG. 2, is further improved if the prodtl tective cap 12 when being placed on, or removed from, the end of the barrel 4 is slightly rotated as is usually done. not only in the case of protective screw caps, but also when threadless protective caps retained merely by friction are used.

The arrangement of the point former shown in FIG. 4 differs from that in FIG. 3 merely in that the precompressed coil spring 17 has been omitted and that the point former is rigidly mounted inside the protective cap 12, i.e., that it is neither rotatable nor axially yieldable.

In the embodiment according to FIG. 5 the point former body 1 is rotatably located in a central bore 21 in the rear cover member 15 of the protective cap 12, but it cannot axially yield. Its rear extension projects from the outside of the cover member 15 and forms a twirling knob 22. By twirling this knob when the protective cap 12 is in position, the writing point 8 of the writing utensile can be reshaped to the desired original cone form and at the same time its surface smoothed.

In FIG. 6 the body 1 of the point former, which may be either rigidly fitted or yieldingly located into the protective cap 12, consists of a clear transparent plastics material. Openings resembling windows 23 are cut into the wall of the protective cap 12 on diametrically opposite sides in the region where the point former is fitted. These windows 23 permit. the reshaping process to be observed for the purpose of checking that the writing point 8 is being properly shaped as desired.

The location of the point former inside the protective cup 12 of the writing utensil is particularly convenient because the point 8 remains in the reshaping cavity of the point former for longer periods and is therefore more effectively reshaped, and because the point former, being permanently fitted into the protective cap 12, cannot be lost.

In the embodiment illustrated in FIG. 7, the body 1 of the point former is provided with an external screw thread 24 and removably screwed into a female thread cut into the rear end 4a of the barrel 4. A knurled knob 25 of a diameter larger than that of the body 1 of the point former is located on the outside and forms an attractive rear termination of the barrel 4 of the writing utensil. In all the described embodiments the point former also has the effect of helping to prevent the ink in the writing point 8 from drying out.

In FIGS. 8 and 9 the writing utensil comprises a barrel in the form of a hollow plastics or metal shaft which is closed at one end and slightly tapered at the other, and an ink-containing cartridge replaceably inserted into the barrel 30. The cartridge has a rigid or semirigid body made of plastics enclosing a supply of ink in an absorbent wad. The latter communicates with a pin-like writing element resembling a wick which may consist of a bundle of ultrafine filaments, such as nylon filaments, embedded in a plastics matrix and forming an integral element in the manner that is conventional in fiber point writing utensils. The forward coned end of the pin-shaped writing element, which projects about 3 mm. from a central bore in the tapering forward portion 41 of the barrel 40, constitutes the writing point 8 of the pen. The portion of the Writing element which passes through the bore is enclosed in a metal or plastic sleeve 9. At the junction between the cylindrical portion and the tapering forward portion 41 of the cartridge 40 there is a coller 31 which should bear on the front edge of the barrel 30 when the cartridge has been correctly inserted, whereas a shoulder 32 formed at the junction between the cylindrical part of the cartridge 4t] and a reduced end portion 40a bears against a corresponding shoulder inside the barrel 30 (cf. FIG. 8).

The external diameter of the ink cartridge 40 fits into the interior of the barrel 30 in such a way that some force is needed to insert it into the barrel 30, so that the ensuing friction will prevent the cartridge from rotating or from axially moving inside the barrel 30. A point former as hereinabove described may then be pressed over the writing point 8 and simultaneously rotated to restore the deformed and worn writing point 8 to its original coned shape without causing the cartridge 40 to participate in the rotary motion.

In FIG. 9 the external diameter of the cylindrical shell of the ink cartridge 40 is a few millimeters less than the internal diameter of the barrel 30 so that a slight annular clearance x remains between these two members. The ink cartridge 40 is frictionally held in place by an internal bulge 33 in the rear end of the barrel 30 which prevents the cartridge 40 from accidentally being dislodged towards the forward end of the barrel 30 and from slipping out of the barrel 30 when the pen is being used. In order positively to prevent the ink cartridge 40 from rotating inside the barrel 30 the reduced rear end of the cartridge 40 is formed as a hexagon 40b and fits into a correspondingly shaped recess in the closed rear end of the barrel 30. The described positive engagement of the cartridge 40 by the barrel 30 prevents the cartridge from being rotated when the writing point 8 is being reshaped by twirling a point former applied to the writing point 8.

In the embodiment according to FIG. 9 the point former body 1 is shown nonrotatably and unmovably built into a protective cap 12 mounted on the barrel with the point former containing the writing point 8. As already described, the point former consists of plastics, metal or some alternative suitable hard materials and comprises a cylindrical body with a central cavity formed by two differently coned

sections

2 and 3. The cone surface of the inner section 2 corresponds to the cone shape of the writing point 8 of the writing utensil when it is new, the object being to restore the worn and deformed writing point 8 to this original shape. The exposed edge of the sleeve 9 which embraces the writing point 8 extends into the corner formed at the junction between the inner coned section 2 and the outer coned section 3 of the cavity when the point former is applied to the writing point 8 for reshaping the same, i.e., when the protective cap 12 is applied to or screwed onto the barrel 30 of the pen.

The point former 1 is fixed in the protective cap 12 with a press fit or by attaching it to the rivet or screw required for securing a clip 16 to the cap 12, or in some other suitable way in such a manner that when the cap 12 is pushed on the end of the barrel or pulled off the barrel and simultaneously rotated for screwing it on or unscrewing it from a threaded barrel, the point former cannot rotate inside the cap 12. The point former may otherwise be contrived as already described.

The invention may be embodied in other ways and comprise other forms of construction than those that have been particularly described with reference to the accompanying drawings. More particularly, besides the abovedescribed embodiments shown in FIGS. 8 and 9 other possibilities are available for locating the replaceable ink cartridge inside the barrel by friction and/ or by interengaging parts in such a way that when the point former is rotated for shaping the writing point the cartridge will not participate in such rotation. The writing point and the corresponding point former may also have a blunt truncated cone shape, the point being formed to receive a small terminal fiat instead of a point and the edge of the flat being used for writing.

What is claimed is:

1. A fiber-point writing utensil comprising:

(a) means holding a bundle of axially interconnected, individual synthetic fibers to form a conical writing point,

(b) a point forming member having a cone-shaped cavity with a larger forming surface to face the writing point,

(c) the larger forming surface has a shape corresponding to the shape of the undeformed writing point,

(d) the point forming member is mounted in a protective cap,

(e) the protective cap fits over the writing point and axial pressure may be exerted on the writing point when the larger forming surface is juxtaposed the writing point to reshape the writing point after it has been deformed during use.

2. A fiber-point writing utensil as defined in claim 1 wherein the protective cap is attachable over the writing point and fiber holding means when the writing utensil is not in use and the bundle of fibers extend into a writing liquid storage cartridge for conveying writing liquid therefrom,

the bundle of fibers includes a plastic bond material to secure the fibers together and capillary channels located between the individual fibers and plastic bond material,

the synthetic fibers on the outer periphery are shortened relative to the fibers on the bundle axis.

3. A fiber-point writing utensil as defined in claim 1 wherein the point forming member is axially movable within the protective cap and a compression spring located between the point forming member and the inside of the protective cap to exert an axial pressure between the point forming member and the writing point.

4. A fiber-point writing utensil as defined in claim 3 wherein the protective cap is attachable over the writing point and fiber holding means when the writing utensil is not in use and the bundle of fibers extends into a writing liquid storage cartridge for conveying writing liquid therefrom,

5. A fiber-point writing utensil as defined in claim 1 wherein.

the point forming member is composed of a clear, transparent plastic material and the protective cap includes a window means to observe the contact between the point forming member and the writing point.

6. A fiber-point writing utensil as defined in claim 5 wherein the protective cap is attachable over the writing point and fiber holding means when the writing utensil is not in use and the bundle of fibers extend into a writing liquid storage cartridge for conveying writing liquid therefrom,

References Cited UNITED STATES PATENTS 631,000 8/1899 Symonds 401-269 X 2,065,800 12/1936 Freeman 401-50 2,642,039 6/1953 Filak 401-51 2,782,438 2/1957 Wittnebert et al 40l269 3,094,736 6/1963 Bunzl et a1 401-198 3,274,975 9/1966 Dehlsen 401- X (Other references on following page) 7 8 3355,239 11/1967 Albrecht 401-198 422,577 4/1967 Switzerland. 3,365,744 1/1968 Rigondaud 401198 LAWRENCE CHARLES, Primary Examiner FOREIGN PATENTS 307,198 3/1929 GreatBritain. 5 374,350 4/1923 Germany. 401-195 US. C1.X.R.