U.S. patent number 3,708,234 [Application Number 05/118,929] was granted by the patent office on 1973-01-02 for ball holder of ball-point pen.
Invention is credited to Tomomitsu Fukuda.
United States Patent |
3,708,234 |
Fukuda |
January 2, 1973 |
BALL HOLDER OF BALL-POINT PEN
Abstract
A ball holder for a ball point pen is disclosed together with a
die for making it, having a ball holder body with an outer
circumferential tip and with a hollow ink reservoir, a ball socket
integrally formed on the outer tip, a writing ball mounted
rotationally within the socket having a crimped rim for retaining
said ball mounted within it, its upper portion protruding
therethrough, a ball seat in the socket underneath the ball, having
a concave polyhedral surface with ball contacts with intermediate
orifices; the ball mounted within the socket supported by the
contacts; ink collecting, ink holding and ink supplying concavities
between the ball and the ball seat; and a pentagonally shaped
ink-feed port between the ball and the reservoir, ink supplyingly,
free flowingly and contiguously connected with said ball seat.
Inventors: |
Fukuda; Tomomitsu
(Higashikurume-shi, Tokyo, JA) |
Family
ID: |
27284088 |
Appl.
No.: |
05/118,929 |
Filed: |
February 25, 1971 |
Foreign Application Priority Data
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Mar 10, 1970 [JA] |
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45/23060 |
Sep 30, 1970 [JA] |
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45/97123 |
Sep 30, 1970 [JA] |
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45/97124 |
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Current U.S.
Class: |
401/216 |
Current CPC
Class: |
B43K
1/08 (20130101) |
Current International
Class: |
B43K
1/00 (20060101); B43K 1/08 (20060101); B43k
007/10 () |
Field of
Search: |
;401/216,214 |
References Cited
[Referenced By]
U.S. Patent Documents
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3166618 |
January 1965 |
Fehling et al. |
3230935 |
January 1966 |
Fehling et al. |
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Foreign Patent Documents
Primary Examiner: Charles; Lawrence
Claims
What I claim is:
1. A ball holder of a ball point pen comprising:
a hollow elongated ball holder body;
a ball socket on one end portion of the body in the form of an
enlarged-diameter axial recess for the rotatable retention of a
writing ball;
an ink reservoir extending into said body;
a central port leading from the ink reservoir to the ball socket
and having a port opening into the ball socket which is
substantially smaller than the diameter of the ball and ball
socket;
a ball seat at the bottom of the ball socket in the form of a
generally tapering transition portion between the larger diameter
of the ball socket and the smaller diameter of the port opening,
said transition portion including a plurality of petal-like,
angularly adjacent, substantially flat contact surfaces which are
oriented to form tangent planes to the writing ball, so as to
present one distinct ball contact point on each contact surface,
the tapering transition portion outside the port opening thus
forming a peripheral succession of shallow ink channels around the
ball, while presenting no ridges or other convex surface portions
to the ball.
2. A ball holder as defined in claim 1, wherein:
the opening of the central port has a regular polygonal outline so
as to form substantially straight edges with the flat contact
surfaces of the ball seat.
3. A ball holder as defined in claim 2, wherein:
the central port has a regular polygonal cross section and includes
in each corner of the polygon a longitudinal ink groove, the
polygonal outline of the port opening including corresponding
narrow lobes at its corners which are located between the flat
contact surfaces of the ball seat.
4. A ball holder as defined in claim 2, wherein:
the petal-like contact surfaces of the ball seat adjoin one another
in the vicinity of the port opening, a regular cone forming
intermediate surface portions in the area where the contact
surfaces are angularly spaced from one another's.
5. A ball holder as defined in claim 2, wherein:
the petal-like contact surfaces of the ball seat adjoin one another
over the entire transition portion of the ball seat in the manner
of a regular polyhedron.
6. A ball holder as defined in claim 1, wherein:
the ball seat has five angularly adjoining contact surfaces so as
to form a ring of ink channels around the writing ball whose
smallest cross section is defined by a pentagon and an inscribed
circle touching the latter at the contact points for the writing
ball.
7. A ball holder as defined in claim 6, wherein:
the port opening has the outline of a regular pentagon which is
concentric and parallel-sided but smaller than the pentagon
defining the smallest cross section of the ink channels.
8. A ball holder as defined in claim 6, wherein:
the port opening has the outline of a regular pentagon which
coincides with the pentagon defining the smallest cross section of
the ink channels, the contact points for the writing ball thus
being located at the edge of the port opening.
9. A ball holder as defined in claim 1, wherein:
the ball socket, ball seat, and central port are adjoining surface
portions of an injection-molded, integral ball holder body of
synthetic plastic material.
Description
FIELD OF THE INVENTION
This invention relates generally to ball-point pens and more
particularly to a new advanced ball holder of a ball-point pen.
DESCRIPTION OF PRIOR ART
In known ball-point pens, the ball holder in each case has a
concave spherical surface constituting a socket which holds and
supports the writing ball, and ink is supplied to the ball through
an ink-feed channel of star-shaped or serrated-periphery cross
section. An ink-feed system of this character, however, is
disadvantageous in that the ink-feed channel of star-shaped cross
section is subject to clogging, which gives rise to a directivity
in the ink outflow, that is, the ink outflow is not uniform for all
directions of writing, whereby irregularities occurs in writing.
Particularly in a ball-point pen wherein a water-soluble ink is
used, the ink does not adhere uniformly to the ball because of the
lack of stickiness of the ink, whereby skipping or thinning of
written lines occurs, and writing becomes difficult. Furthermore,
when foreign matter infiltrates into the ball holding socket, the
ink flowpath becomes clogged, and the flow of ink is
obstructed.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above
described difficulties encountered in the prior ball-point pens by
providing a ball holder in a ball-point pen of novel design.
According to the present invention, briefly summarized, there is
provided a ball holder of a ball-point pen comprising a ball holder
body with a hollow interior for containing ink and an outer tip, a
ball socket formed at the tip and having a crimped rim to retain a
ball within the socket, and a ball seat disposed within the body
inward of and communicatively with the ball socket, and
characterized in that the ball seat has a concave polyhedral
surface for seating the ball whereby the ball is supported with
point contacts, in that an ink-feed port communicates with the
hollow interior of the body directly to the ball seat thereby to
permit unobstructed flow of ink to the ball seat, and in that
ink-collecting concavities are formed between the ball and recesses
in the ball seat and function to collect ink and supply the same
uniformly and in ample quantity to the entire surface of the
ball.
The nature, principle, and utility of the invention will be more
clearly apparent from the following detailed description with
respect to preferred embodiments thereof when read in conjunction
with the accompanying drawing, in which like parts and designated
by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawing:
FIG. 1 is an enlarged fragmentary view, in longitudinal section,
(-- showing the essential parts of a specific example of a ball
holder in a ball-point pen according to the invention;--)
FIG. 2 is an enlarged perspective view, with a partial cut away,
showing the ball holder without the ball;
FIGS. 3 and 4 are respectively an enlarged side view and an
enlarged end view of the forward end of a core pin for forming the
ball holder shown in FIG. 1,
FIGS. 5, 6, 7, and 8 are views similar to FIGS. 1, 2, 3, and 4
respectively and show another embodiment of the ball holder and
tools according to the invention; and
FIGS. 9 and 10 are end views similar to FIGS. 4 and 8 respectively
and illustrate other embodiments of forming tools for forming
ink-feed ports.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is shown a ball holder 1 made of a
synthetic resin and adapted to hold a ball 5 in a ball-point pen.
The ball holder 1 at its forward extremity or outer tip has a ball
clasping socket 4 with a bowl-shape interior constituting a ball
seat 3 and having a concave polyhedral surface as shown in FIG. 2.
The bottom of the ball seat 3 communicates contiguously with the
forward end of an ink-feed port 2 communicating at its rear end
with the hollow interior 12 of the ball holder 1, which interior
constitutes an ink reservoir.
The various internal parts of the ball holder 1 described above are
formed by a die-pressing process with a forming tool having a shape
mating with that as indicated in FIG. 2 and shown in FIG. 3 for use
as a die. This forming tool 7 has a tip 8 for forming the ink-feed
port 2 of the ball holder, an inclined shoulder having a polyhedral
surface 9 of a petal-like pattern shown as a pentagon base with
five petals for forming the ball seat 3 of the ball holder, and a
cylindrical part 10 for forming the ball clasping socket 4. Between
the petal-like parts of the polyhedral surface 9, there are
alternately disposed parts of a convex, conical or spherical
surface 11, whereby concavities 6 become ink-collecting. Ink
holding and ink supplying cavities are formed in the internal seat
surface of the ball socket 4.
The ball 5 is assembled in place by fitting it through the open end
of the socket 4 and onto the ball seat 3 and crimping the rim of
the socket 4 at its extremity so that it clasps the ball 5 and
prevents it from dropping out.
In another embodiment of the invention illustrated in FIGS. 4, 5,
and 6, the ball holder 21, of a structure similar to that of the
ball holder 1 in the preceding example, has an ink-feed port 22
communicating with and interposed between the hollow interior 32 of
the ball holder and a ball seat 23 contignously formed with the
interior of a ball socket 24.
The various internal parts of this ball holder 21 are formed by
die-pressing with a forming tool 27 of a shape mating wit that
indicated in FIG. 5 and shown in FIG. 6. This core pin 27 has a tip
28 for forming the ink-feed port 22 of the ball holder 21, an
inclined shoulder having a polyhedral surface 29 shown as a
petal-like pattern with five petals and a pentagon base for forming
the ball seat 23, and a cylindrical part 30 for forming the ball
socket 24. The intersectional boundaries between adjacent planar
surfaces of the polehedral ball seat 23 and the boundary between
the ball seat 23 and the socket 24 are recessed and form
ink-collecting, ink holding and ink supplying concavities 26.
In still an other improvement of the invention indicated in FIGS. 9
and 10, the forming tools, shown in FIGS. 3 and 4 and FIGS. 7 and 8
respectively are provided with bead-like ridges 33 and 34 at the
corners of the forming tool tips. These bead-like ridges 33 and 34
form corresponding narrow grooves at the corners of the ink-feed
ports 2 and 22 FIGS. 1 and 5 respectively. These narrow grooves
function to impart capillary action whereby ink is always fed at a
constant rate to the ball.
By the above described construction of the ball holder according to
this invention, the ball 5 or 25 respectively is supported with
point contact by the planar surface of the polyhedral surface of
the ball seat 3 or 23 respectively whereby the rotation of the ball
is very smooth. Furthermore, since ink-collecting ink holding and
ink supplying concavities 6 or 26 respectively are formed between
the ball holder 1 and the ball 5, the ink adheres uniformly and in
ample quantity to the ball surface, whereby a uniform ink-flow
without skipping or irregularities is attained. Still another
advantage afforded by this invention is that since an ink-feed
channel of narrow star-shaped cross section is avoided,
malfunctioning of the pen due to causes such as ink clogging and
infiltration of foreign matter is completely eliminated.
A further advantage is afforded by the narrow grooves formed at the
corners of the ink-feed port 2 or 22 respectively by the bead-like
ridges 33 or 34 respectively of the forming tool, whereby the ink,
after passing from the hollow interior 12 or 32 respectively of the
ball holder 1 to the ink-feed port 2 or 22 respectively, is drawn
through the narrow grooves by capillary action and enters the
ink-collecting ink holding and ink supplying concavities 6 or 26
respectively. Accordingly, a constant quantity of ink is always
stored in these ink-collecting concavities, while excessive feeding
of ink is avoided, and dripping of ink and blotching are
prevented.
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