U.S. patent application number 09/837623 was filed with the patent office on 2002-01-03 for plastic pin.
Invention is credited to Jager, Arnold.
Application Number | 20020002082 09/837623 |
Document ID | / |
Family ID | 7638998 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020002082 |
Kind Code |
A1 |
Jager, Arnold |
January 3, 2002 |
Plastic pin
Abstract
A plastic pin having a porous and/or cellular core that is
surrounded by a resilient shell is provided. The base of the pin is
made of a different material than is the shell. The base is
centrally provided with a plug that projects into the core. To
improve the connection between the shell and the base, the outer
side of the plug is provided with projections that form a positive
connection with the core.
Inventors: |
Jager, Arnold; (Burgdorf,
DE) |
Correspondence
Address: |
ROBERT W. BECKER & ASSOCIATES
Suite B
11896 N. Highway 14
Tijeras
NM
87059
US
|
Family ID: |
7638998 |
Appl. No.: |
09/837623 |
Filed: |
April 17, 2001 |
Current U.S.
Class: |
473/124 |
Current CPC
Class: |
A63D 9/00 20130101 |
Class at
Publication: |
473/124 |
International
Class: |
A63D 009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 17, 2000 |
DE |
DE 100 18 917.2 |
Claims
What I claim is:
1. A plastic pin, comprising: a resilient shell that surrounds a
core of porous and/or cellular material; a base that adjoins said
shell and provides a support surface for the pin, wherein said base
is made of a material that differs from the material of said shell,
and wherein said base is provided with a central bore; and a plug
that extends into said shell from a rim region of said central
bore, wherein an outer side of said plug is provided with at least
one projection to provide a positive connection with said core.
2. A pin according to claim 1, wherein said at least one projection
has a saw toothed cross-sectional configuration, wherein a portion
of said projection that faces said base extends further from said
plug than does a portion of said projection that faces from away
said base.
3. A pin according to claim 1, wherein a plurality of annular
projections are distributed over a length of said plug.
4. A pin according to claim 1, wherein venting bores are disposed
in said base.
5. A pin according to claim 1, wherein said plug has an at least
partially conical configuration, with a larger diameter portion of
said plug being disposed at a free end of said plug and forming
said at least one projection thereof.
6. A pin according to claim 1, wherein said base is provided with a
circumferential flange for centering said shell on said base.
7. A pin according to claim 1, wherein said base is provided with a
projecting rim that engages an associated rim of said shell in a
hook-like or tongue and groove manner.
8. A pin according to claim 1, wherein said plug is monolithically
formed with said base and extends essentially perpendicular to said
base.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a plastic pin, i.e. one of
polymeric material, for games, and has a porous and/or cellular
core that is surrounded by a tough or resilient shell. The pin has
a base that forms a support surface and that is made of a different
material than is the shell. The base has a central bore and a plug
or socket that proceeds from the rim of the bore and extends into
the core of the pin.
[0002] Within the context of the present application, plastic pins
for bowling lanes include so-called bowling pins and nine pins.
[0003] It is desirable to use different materials for the base of
the pin on the one hand, and for the shell thereof on the other
hand; for example, polyamides and polypropylenes are suitable for
optimally satisfying the specific requirements of different
portions of the pin. However, during manufacture of the pins
different materials do not always provide the desired intimate
bonding.
[0004] It is an object of the present invention to provide a good
and improved connection between the base of the pin on the one hand
and that portion of the pin shell disposed thereabove on the other
hand.
BRIEF DESCRIPTION OF THE DRAWING
[0005] This object, and other objects and advantages of the present
invention, will appear more clearly from the following
specification in conjunction with the accompanying schematic
drawing, in which:
[0006] FIG. 1 is a plan view of one exemplary embodiment of an
inventive pin;
[0007] FIG. 2 is a partially cross-sectioned view of the lower
portion of the pin of FIG. 1; and
[0008] FIG. 3 is a cross-sectional view of a modification of the
pin of FIG. 2, whereby the right and left portions of FIG. 3 show
different embodiments.
SUMMARY OF THE INVENTION
[0009] The pin of the present invention is characterized primarily
in that the plug that extends into the interior of the pin is
positively connected with the core of the pin by one or more
projections. For this purpose, the pin is expediently provided with
circumferential ribs, which in turn preferably have a saw tooth
shaped cross-sectional configuration.
[0010] The plug of the base of the pin, and hence the base itself,
are thus anchored to the core, whereby this anchoring can be the
sole securing means of the base, or an additional anchoring means
can also be provided.
[0011] The aforementioned anchoring can be very easily realized
pursuant to the present invention. In particular, if the plug that
extends into the interior of the pin is provided with the
aforementioned projections, and if the material that forms the
cellular and/or porous plastic core is introduced into the hollow
interior of the pin from below through the plug during manufacture
of the pin, the material of the core advances downwardly during
introduction thereof to the inner side of the base, whereby such
material surrounds the plug on all sides and thereby completes the
positive connection. In order in this connection not to disrupt the
flow of material, it is advantageous to provide the base with one
or more fine venting bores.
[0012] Further specific features of the present invention will be
described in detail subsequently.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Referring now to the drawing in detail, the pin of FIG. 1 is
provided in the customary manner in the base region with a base 1,
thereabove a barrel or bulging portion 2, which merges into a
reduced-diameter neck 3, and finally a head 4 that has a smaller
outer diameter than does the barrel 2. The components 2, 3 and 4
form the shell 5 of the pin. The pin is additionally provided with
a core 6 that is preferably adhered or secured to the outside. The
core 6 comprises a cellular and/or porous polymeric material and,
after completion of the outer casing (the base 1 and the shell 5),
is formed by introducing an expanding material into the interior of
this casing through the central bore 7 in the base 1.
[0014] Whereas the shell 5 is comprised of a polymeric material
based on polypropylenes, the base 1 is made of a generally harder
polymeric material based on polyamide. Although these materials are
suitable, they do not always form an adequately strong bond with
one another.
[0015] From the rim of the bore 7 in the base 1, a socket or plug 8
extends perpendicularly upwardly, i.e. into the interior of the
pin, for example having a length of about 40-80 mm. The important
feature is that the outer surface of the plug 8, which is
monolithically formed with the base 1, is provided with a plurality
of annular projections 9 that are distributed over the height of
the plug 8. The annular projections 9 preferably have a saw toothed
cross-sectional configuration, and in particular such that the
larger diameter portion of the projections 9 face the base 1, thus
creating corresponding undercuts.
[0016] When the material that forms the core 6 is introduced it
passes not only into the barrel 2, the neck 3 and the head 4, but
also in the direction of the arrows 10 into the region of the base
1, whereby the trapped air can escape via small bores 11 in the
base 1. The plug 8 is thereby surrounded. The strengthening and
reinforcing material of the core forms a positive connection
between the core 6 and the plug 8 and hence the base 1. This means
that the base 1 is securely connected to the shell 5.
[0017] In order to preclude a lateral shifting, the base 1 can be
laterally provided with a rim or flange 12 (shown by dashed lines)
that centers the components 1 and 5 relative to one another.
[0018] If desired, an adhesive can be effective in the region of
the separating faces between the shell 5 and the base 1. However,
the connection of these components is often adequately ensured by
the aforementioned positive connection.
[0019] In the embodiment illustrated in FIG. 3, where the core 6 is
not shown, the base 1 is provided with an upwardly widening plug 8,
in other words, a plug that has an essentially conical exterior
surface (the diameter D is greater than the diameter d). This plug
8 also results in a positive connection, i.e. forms a back taper or
undercut for the material of the core.
[0020] In addition, a hook connection can also be provided between
the shell 5 and an upwardly extending rim 13 of the base 1. For
this purpose, the shell 5 can engage in an inwardly disposed
circumferential groove 14 of the rim 13 (as shown in the left half
of FIG. 3), or the shell 5 can engage in an outwardly disposed
circumferential groove 15 of the rim 13 (as shown in the right half
of FIG. 3).
[0021] It should be noted that in place of the annular,
circumferential projections 9, it would also be possible to use
knobs or studs, in other words, projections that extend over only a
portion of the periphery of the shell. However, the expedient
feature in each case is that adequately large undercuts be
provided. A saw tooth configuration is therefore very suitable. In
addition, in place of the hook connection it would also be possible
to use a differently configured tongue and groove connection.
[0022] The specification incorporates by reference the disclosure
of German priority document 100 18 917.2 of Apr. 17 2000.
[0023] The present invention is, of course, in no way restricted to
the specific disclosure of the specification and drawing, but also
encompasses any modifications within the scope of the appended
claims.
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