Note: Descriptions are shown in the official language in which they were submitted.
~(~4924~
Background of the Invention
This invention relates to nibs for writing implements and
more particularly, it concerns a writing nib structure and method of
manufacture.
Commonly used felt tip pens and marking implements employ
a nib by which ink or other marking fluid contained in a reservoir
within the implement is fed by capillary action along the length of
the nib to its projecting tip in contact with a writing surface.
The popularity of such implements both as writing pens and as mark-
ers is perhaps attributable in substantial measure to such desirab-
le characteristics as adaptability to a wide variety of writing sur-
faces, smoothness with which the pen tip or nib glides on a writing
surface and continuity of ink or marking fluid flow through the nib
onto a writing surface. A principal shortcoming of such felt tip
pens and marking implements, however, is the deterioration with use
of the writing nib tip to a degree that a clear line of uniform thi-
ckness becomes difficult to write, often before the supply of ink in
the pen or implement is exhausted. As a result of this shortcoming,
many materials and pen nib constructions have been developed out of
efforts to achieve or retain the aforementioned desirable character-
istics while at the same time strengthen or rigidify the pen nib to
increase its useful life. Although much progress has been made in
the development of stronger more rigid materials for writing pen
nibs, the use of stronger nib materials involves a compromise betw-
een durability and writing smoothness. In other words, writing smo-
othness is increased with nib material softness whereas nib life is
increased with harder and more rigid materials which have a tendency
to scratch many writing surfaces.
An effective approach to the achievement of both strength
and writing smoothness in a pen nib is exemplified by the disclosures
of such U.S. patents as No. 3,094,736 issued June 25, 1963 to R. H.
Bunzl et al, No. 3,167,803 issued February 2, 1965 to Shigeki Shima-
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1049~41
mura, No. 3,213,025 issued August 31, 1965 to C. Schreur and No.3,464,775 issued September 2, 1969 to K. F. Beal. The pen nib stru-
ctures shown in these patents are generally characteri~ed as having
a relatively soft wicking core enclosed in a reinforcing sheath of
relatively strong solid material. The nibs are usually formed by
providing an elongated strand of the sheathed core element which is
cut to the length of the individual nib and machined or otherwise
treated on one end of the nib to leave the soft core projecting sli-
ghtly from the corresponding end of the sheath as a writing tip.
Although the combination of nib strength and writing smo-
othness achievable by the aforementioned sheathed or reinforced nibs
is highly desirable, the manufacturing costs associated with their
manufacture in quantity are high principally because of the require-
ment for forming a writing tip on each individual nib. While such
costs may fall within tolerable limits where the writing tip end of
each nib is a surface of revolution, such as conical or hemispheri-
cal, they are increased to unjustified levels for non-circular nibs
of the type used, for example, in wide-line writers or marking impl-
ement nibs.
Summary of the Present Invention
In accordance with the present invention, a writing nib
having improved writing and strength properties is provided by form-
ing a laminated strip in which a continuous layer of wicking mater-
- ial is sandwiched between layers of relatively rigid, high strength
material, shaping the edges of the laminated strip such that the
wicking material projects beyond the layers of the relatively rigid
material on at least one edge and severing the strip transversely at
longitudinal increments corresponding to the desired width of the
writing nib to be formed, thereby to provide a writing nib having an
elongated body of generally rectangular cross-sectional configurat-
ion in which the thickness or dimension transverse to the width of
the body is the same as the laminated sheet from which the nibs are
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severed. It is preferred that both eages of the laminated strip be
machined or otherwise formed so that the nib cut transversely there-
from is double ended; that is, formed so that the central layer of
wicking material projects at both ends of the nib as a writing tip.
As a consequence of this, the resulting nib may be assembled in a
writing or marking implement without first requiring lengthwise ori-
entation of the nib to leave only the writing tip of the nib project-
ing from the implement. Additionally, it is preferred that the sev-
erance of individual nibs from the laminated strip be at an angle
with respect to the length of the strip and correspondingly with re-
spect to the formed side edges thereof so that the writing tip in the
nib ultimately incorporated in a pen or marking implement will be
disposed at a comfortable or normal writing angle.
The laminated strip may be formed in different ways dep-
ending on the particular wicking material to be employed in the nib.
For example, if the wicking material is formed of porous thermoplas-
tic material, the relatively rigid reinforcing outer layers of the
strip may be formed by heating the outer layers of a preformed ther-
moplastic porous strip to solidify the outer surface portions there-
of by heat fusion. Alternatively, the relatively rigid outer layersof the strip may be formed by coating a strip of porous wicking mat-
erial with an appropriate material capable of providing the desired
reinforcing characteristics upon solidifying or setting. A preferr-
ed method of coating a strip in this manner is the passage of the
preformed porous wicking strip through an extrusion die by which the
outer layers are deposited on opposite surfaces of the wicking mater-
ial.
Although any desired writing tip configuration may be pro-
vided on the nibs formed in accordance with the present invention by
appropriate selection of the means employed in the shaping of the
strip edges, the nib is preferably provided with a wide-line writing
tip which is essentially continuous or linear in the direction of its
1~49241
width and rounded or semi-cylindrical in a plane transverse to its
width. A writing tip configuration of this type is easily formed by
continuously machining the edges of the strip from which the nibs
are cut and is also desirable during writing use to allow a normal
rocking of the nib without change in the line or mark effected.
Among the objects of the present invention are: the pro-
vision of an unique writing nib for pens or marking implements as
well as a novel process by which the nib ma~ be manufactured; the
provision of such an improved nib having a desirable combination of
structural rigidity and writing smoothness; the provision of such a
writing nib having an unique writing tip; the provision of such a
writing nib for pens or marking implements by which its assembly in
such a writing implement is facilitated as a result of longitudinal
symmetry; and the provision of an unique method for making writing
nibs of the aforementioned type by which any of numerous types of
writing nib materials may be used.
Other objects and further scope of applicability of the
present invention will be apparent from the detailed description
taken in conjunction with the accompanying drawings in which like
reference numerals designate like parts.
Brief Description of the Drawings
Fig. 1 is a side elevation showing the writing nib of the
present invention;
Fig. 2 is an elevation at right angles to that of Fig. l;
Fig. 3 is a fragmentary cross-section depicting one meth-
od of providing a laminated strip used in the formation of the nib
shown in Fig. 2;
Fig. 4 is a similar cross-section view illustrating an
alternative manner of forming the laminated strip shown in Fig. 3;
Fig. 5 is a cross-section similar to Figs. 3 and 4 but
illustrating still a further alternate embodiment of a method for
forming the laminated strip from which the pen nibs of the present
1~49~
invention are formed;
Fig. 6 is a schematic plan view illustrating the success-
ive forming operations employed in the production of pen nibs in ac-
cordance with the present invention; and
Fig. 7 is a cross-section on line 7-7 of Fig. 6.
Detailed Description of the Preferred Embodiments
In Figs. 1 and 2 of the drawings, the improved writing
nib of the present invention is generally designated by the refere-
nce numeral lO and is established by an elongated body 12 of gener-
ally rectangular cross-sectional configuration having a width W and
thickness T. A writing tip 14 is formed at one end of the body 12
and preferably disposed at an angle A with respect to a line perpe-
ndicular to the longitudinal dimension of the body. A writing flu-
id receiving end 16 is located at the opposite end of the body from
the writing tip 14 but is identical in all structural respects to
the writing tip 14. When assembled in a pen or marking implement
18, the writing end of which is partially outlined by phantom lines
in Figs. 1 and 2, the writing tip 14 will project from the writing
end of the pen 18 whereas the ink receiving end 16 of the tip 10 will
be in contact with a supply of ink or marking fluid contained by a
reservoir (not shown) within the body of the pen or marking impleme-
nt~18.
The configuration of the writing tip 14 is preferably li-
near in the direction established by the angle A and semi-circular
in a plane normal to that linear dimension, thereby to establish a
semi-cylindrical writing tip configuration. Such a configuration,
when disposed at the angle A to the writing surface on which the pen
18 is used, will facilitate complete linear engagement of the tip 14
with the writing surface in normal writing practice. Although any
desired angle may be selected, it is preferred that the angle A be
on the order of 30. Also because of the semi-cylindrical configu-
ration of the tip 14, rocking movement of the pen transverse to the
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length of the writing tip will not effect the writing characterist-
ics of the nib 10.
~ s shown most clearly in Fig. 2, the structure of the nib
lO is further characterized as having a central layer 20 of relativ-
ely soft wicking material sandwiched between a pair of relatively
rigid reinforcing layers 22 and 24. Although the manner in which
this laminated construction of the nib 10 is effected will be descr-
ibed in more detail below, it will be appreciated that because the
writing tip 14 constitutes a projection of the wicking material lay-
er beyond the corresponding ends of the reinforcing outer layers 22and 24, the smooth writing characteristics of a relatively soft wic-
king material obtain from the construction of the nib 10. Moreover,
superior writing nib strength is achieved as a result of the reinfo-
rcement provided by the outer relatively rigid and strong layers 22
and 24.
The operation of the nib 10 during use of the pen or mar
king implement 18 is conventional to the extent that ink or marking
fluid supplied to the end 16 of the nib will pass by capillary act-
ion along the layer 20 to the writing tip 14. It is to be noted
that from the standpoint of functioning as a writing nib in this ma-
nner, any configuration of the end 16 which will enable the passage
of ink or marking fluid to the layer 20 is acceptable to effective
operation of the nib 10. A significant assembly advantage is obta-
ined, however, where the end 16 is identical in configuration to the
writing tip 14. Specifically, the longitudinal symmetry or reversi-
bility of the nib 10 permits its assembly with the pen or marking
implement 18 irrespective of longitudinal orientation.
An exemplary embodiment of a preferred method for the
manufacture of the pen nib 10 may be understood by reference to Figs
3, 6 and 7 of the drawings. In this embodiment, it is presumed that
the layer of wicking material 20 is any of many well-known porous
thermoplastic materials conventionally employed in writing pen nibs.
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1~149241
Hence, a strip S of the porous thermoplastic material is fed between
a pair of heated rollers 26 and 28 to fuse the porous material on op-
posite sides and thus form the laminate or sandwich structure in
which the wicking material 20 is sandwiched between the relatively
rigid surface layers 22 and 24. After the laminate thus formed has
cooled, the strip is passed between a pair of edge forming tools 30
and 32. The tools 30 and 32 may be selected from a variety of mach-
ining or abrading tools such as milling cutters as shown in Fig. 6
or coarse abrasive tools. As shown in Fig. 6, the tools 30 and 32
are of a shape to machine the semi-cylindrical configuration of the
nib ends 14 and 16 as described above. The construction of the nib
is completed by a knife 34 to sever the strip S at predetermined se-
verance lines 36 extending transversely of the strip. Although the
knife 34 is depicted schematically in Fig. 6 as a simple blade, it
will be appreciated that high speed operation is achievable using a
rotary-type cutter synchronized with longitudinal travel of the strip
S. Also it will be understood that the angle at which the strip S
is severed to form the nibs lO will determine the writing angle A of
the tip 10 described above with respect to Figs. 1 and 2.
It is contemplated that heating devices other than the
rollers 26 may be employed to form the relatively rigid layers 22
and 24 on the thermoplastic porous strip S. For example, in Fig. 4
of the drawings, the strip is passed through a heated stationary die
34. It is also contemplated that the combination of a heated roller
and stationary die (not shown) might be employed.
A preferred method for achieving the sandwiched strip
structure, particularly where a wicking material other than porous
thermoplastic is desired, is depicted in Fig. 5 of the drawings. In
this instance, the strip S is passed through an extrusion die 36 by
which a plastic material P is extruded onto opposite sides of the
strip to form the layers of rigid material 22 and 24. Co-extrusion
of materials in this manner is well-known to the plastics art. Sub-
1049;~41
sequent treatment of the strip after the layers 22 and 24 are formedwill proceed as described above with respect to Figs. 3~ 6 and 7 of
the drawings.
Thus it will be appreciated that by this invention there
is provided an improved pen nib and method for its manufacture by
which the above mentioned objectives are completely fulfilled. It
is also contemplated that various modifications and/or changes may
be made in the disclosed embodiments without departure from the in-
ventive concepts manifested by those embodiments. For example, the
use of the method to manufacture wide-line writing nibs is preferr-
ed because of the facility for continuously forming the edges of the
strip which is cut transversely to form the nibs. It is contemplat-
ed, however, that pen nibs having other types of tips might be made
using the process by substituting for the tools 30 and 32 shown in
Figs. 5 and 6 intermittently actuated forming tools operated in syn-
chronism with the cut-off knife 34. Thus, while the process of the
invention is particularly applicable to the formation of the nib
structure illustrated in Figs. 1 and 2 of the drawings, it will be
appreciated that other tip formations may be provided using the pro-
cess. In light of the prospective possible modifications and/or cha-
nges which might be made in the embodiments disclosed herein, it is
expressly intended that the foregoing description is illustrative
only, not limiting, and that the true spirit and scope of the pres-
ent invention be determined by reference to the appended claims.
