U.S. patent application number 12/455139 was filed with the patent office on 2010-01-07 for screw cap.
Invention is credited to Udo Schutz.
Application Number | 20100000998 12/455139 |
Document ID | / |
Family ID | 40786157 |
Filed Date | 2010-01-07 |
United States Patent
Application |
20100000998 |
Kind Code |
A1 |
Schutz; Udo |
January 7, 2010 |
Screw cap
Abstract
A screw cap of plastic material has a cap disk and an outer cap
rim located adjacent at a right angle to a circumference of the cap
disk. The cap rim has an internal thread for closing a filling
and/or removal socket of a container for transporting and storing
liquid, and a central bung socket arranged retracted in the cap
disk, wherein the bung socket has an internal thread for screwing
in a bung plug. The bung plug has a cylindrical threaded sleeve
with an external thread for screwing in a threaded bore of the bung
plug of the cap, and a sealing end provided with a conical multiple
seal of sealing rings which, when the bung plug is screwed in, are
pressed against a conical inner sealing surface of a sealing
projection located adjacent the threaded bore of the bung socket of
the screw cap.
Inventors: |
Schutz; Udo;
(Selters/Westerwald, DE) |
Correspondence
Address: |
Friedrich Kueffner
Suite 910, 317 Madison Avenue
New York
NY
10017
US
|
Family ID: |
40786157 |
Appl. No.: |
12/455139 |
Filed: |
May 28, 2009 |
Current U.S.
Class: |
220/288 |
Current CPC
Class: |
B65D 39/082
20130101 |
Class at
Publication: |
220/288 |
International
Class: |
B65D 41/04 20060101
B65D041/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 4, 2008 |
DE |
10 2008 031 736.5 |
Claims
1. A screw cap of plastic material comprising a cap disk and an
outer cap rim located adjacent at a right angle to a circumference
of the cap disk, wherein the cap rim has an internal thread for
closing a filling and/or removal socket of a container for
transporting and storing liquid, and a central bung socket arranged
retracted in the cap disk, wherein the bung socket has an internal
thread for screwing in a bung plug, the bung plug having a
cylindrical threaded sleeve with an external thread for screwing in
a threaded bore of the bung plug of the cap, and a sealing end
provided with a conical multiple seal comprised of sealing rings
which, when the bung plug is screwed in, are pressed against a
conical inner sealing surface of a sealing projection located
adjacent the threaded bore of the bung socket of the screw cap.
2. The screw cap according to claim 1, comprising four sealing
rings integrally formed at the sealing end of the threaded sleeve
of the bung plug, wherein the sealing rings are spaced apart by
grooves and are arranged concentrically relative to a longitudinal
axis of the plug, wherein the diameters of the sealing rings become
smaller in a screwing-in direction of the bung plug corresponding
to the conical inner sealing surface of the sealing projection of
the bung plug of the screw cap.
3. The screw cap according to claim 2, wherein the sealing rings
have rounded-off sealing rims.
4. The screw cap according to claim 1, comprising a bung plug with
an integrated aerating device.
5. The screw cap according to claim 1, comprising a bung plug
having an integrated aerating and ventilating device.
6. The screw cap according to claim 1, wherein the cap and the bung
plug are injection-molded parts of plastic material.
7. A screw cap of plastic material comprising a cap disk and an
outer cap rim located adjacent at a right angle to a circumference
of the cap disk, wherein the cap rim has an internal thread for
closing a filling and/or removal socket of a container for
transporting and storing liquid, and a central bung socket arranged
retracted in the cap disk, wherein the bung socket has an internal
thread for screwing in a bung plug, the bung plug having a
cylindrical threaded sleeve with an external thread for screwing in
a threaded bore of the bung plug of the cap, and a sealing end
which comprises a single-piece sealing rings having a rounded-off
sealing rim which is pressed against a conical inner sealing
surface of a sealing projection located adjacent the threaded bore
of the bung socket of the screw cap.
8. A screw cap of plastic material comprising a cap disk and an
outer cap rim located adjacent at a right angle to a circumference
of the cap disk, wherein the cap rim has an internal thread for
closing a filling and/or removal socket of a container for
transporting and storing liquid, and a central bung socket arranged
retracted in the cap disk, wherein the bung socket has an internal
thread for screwing in a bung plug, the bung plug having a
cylindrical threaded sleeve with an external thread for screwing in
a threaded bore of the bung plug of the cap, and a sealing end
which is comprised of a conical sealing rim which, when the bung
plug is screwed in, is pressed against a conical inner sealing
surface of a sealing projection located adjacent the threaded bore
of the bung socket of the screw cap.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a screw cap of plastic
material with a cap disk and an outer cap rim located adjacent at a
right angle to the circumference of the cap disk, wherein the cap
rim has an internal thread for closing a filling and/or removal
socket of a container for transporting and storing liquids, and
with a central bung socket arranged retracted in the cap disk,
wherein the bung socket has an internal thread for screwing in a
bung plug.
[0003] 2. Description of the Related Art
[0004] The screw cap known from EP 0 650 446 B1 of the
above-described type for closing the filling socket of a bung drum
or the internal plastic container of a pallet container with an
outer casing of grate rods or sheet metal have the disadvantage
that the sealing ring for sealing the bung plug in the bung socket
of the screw cap over time does not ensure the tightness of the
bung plug closure due to aging phenomena of the material of which
the sealing ring is manufactured, particularly in containers for
transporting and storing chemical liquids, so that the sealing ring
must be replaced regularly.
SUMMARY OF THE INVENTION
[0005] It is the object of the present invention to improve the
screw cap of the above-described type with respect to an improved
tightness of the bung plug closure, a less expensive manufacture,
and lowering of the operating costs of the liquid containers
equipped with the screw cap which are used as reusable
containers.
[0006] In accordance with the present invention, a screw cap with a
bung socket which is equipped with a bung socket closure has the
following advantages.
[0007] By providing the plastic bung plug for closing the bung
socket of the screw cap with a conical multiple seal in the form of
spaced-apart sealing rings integrally injection molded with the
bung socket, wherein the multiple seal is pressed against a conical
inner sealing surface of the bung socket when the bung plug is
screwed in, an optimum tightness of the bung socket closure is
facilitated. In containers with internal pressure, the tightness of
the bung plug closure for the bung socket of the screw cap is
further improved by additionally increasing the contact pressure of
the sealing rings of the conical multiple seal of the plug relative
to the conical inner sealing surface of the bung socket caused by
screwing in the bung socket as a result of the internal pressure of
the container acting on the inner wall of the sealing end of the
threaded sleeve of the bung plug provided with the multiple seal.
By omitting a sealing ring, which would have to be regularly
replaced, the manufacturing costs compared to known screw caps with
bung sockets which is closed by means of a bung plug with sealing
ring, as well as the maintenance costs for liquid containers which
are equipped with a screw cap with the novel bung plug for the bung
socket of the cap and which are used as multiple-use containers can
be significantly lowered.
[0008] The various features of novelty which characterize the
invention are pointed out with particularity in the claims annexed
to and forming a part of the disclosure. For a better understanding
of the invention, its operating advantages, specific objects
attained by its use, reference should be had to the drawing and
descriptive matter in which there are illustrated and described
preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the Drawing:
[0009] FIG. 1 is a longitudinal sectional view of a screw cap with
a central bung socket which is closed by a bung plug;
[0010] FIG. 2 is a detailed view, on a larger scale, of the screw
cap of FIG. 1, and
[0011] FIGS. 3 and 4 are detailed views, also on a larger scale, of
two further embodiments of the screw cap.
DETAILED DESCRIPTION OF THE INVENTION
[0012] As shown in the drawing, the screw cap 1 manufactured as an
integrally molded piece of plastic material includes a flat cap
disk 2, an outer cap rim 3 adjacent at a right angle to the
circumference of the cap disk 2, wherein the cap rim 3 has an
internal thread 4 for closing a filling and/or removal socket of a
container for transporting and storing liquids, as well as an
internal rim 5. The internal rim 5 is arranged concentrically to
the outer cap rim 3 and forms together with the latter a sealing
bed 6 for placing therein a sealing ring for sealing the screw cap
1 on the upper rim of the filling and/or removal socket of the
liquid container and serves for stiffening and for a better seat of
the screw cap on the container socket.
[0013] Arranged retracted in the cap disk 2 is a central bung
socket 7 which can be closed by means of a bung plug 8 manufactured
as an integrally injection molded piece of plastic material.
[0014] The bung plug 8 is equipped with a cylindrical threaded
sleeve 9 with an external thread 10 for screwing into the threaded
bore 11 of the bung socket 7 of the screw cap 1. The threaded
sleeve 9 of the bung plug 8 includes a sealing end 12 which is
formed onto a conical multiple seal 13 which is formed by four
sealing rings 14 with a rounded-off sealing rim 14a, wherein the
sealing rings are spaced apart from each other by grooves 15 and
are arranged concentrically relative to the longitudinal axis 16-16
of the plug and whose diameter 17 decreases in the screwing-in
direction a of the bung plug 8.
[0015] When the bung plug 8 is screwed in, the sealing rings 14 of
the conical multiple seal 13 at the sealing end 12 of the bung plug
8 are pressed against a corresponding conical inner sealing surface
18 of a sealing projection 19 adjacent the threaded bore 11 of the
bung socket 7 of the screw cap 1.
[0016] In accordance with another embodiment of the screw cap 1, an
aerating device or a ventilating end aerating device are integrated
into the bung plug 7.
[0017] For filling an individual container through the bung socket
7 of the screw cap 1 screwed onto the filling socket of the
container, the bung plug 8 is screwed out manually by means of a
bung wrench from the bung socket 7 of the screw cap 1 and a pump is
connected to the bung socket. When filling a plurality of
containers through the bung socket 7 of the container filling
socket screwed onto the screw cap 1 in automatic filling
installations, the bung plugs 7 are screwed by means of a machine
out of the screw caps 1.
[0018] The bung plug 8 of another embodiment of the screw cap
illustrated in FIG. 3 has a cylindrical threaded sleeve 9 with an
external thread 10 for screwing into the threaded bore 11 of the
bung socket 7 of the cap 1 and with a sealing end 12 which is
provided with a sealing ring 14 formed integrally with the sealing
end 12. The sealing ring 14 has a rounded-off sealing rim 14a
which, when the bung plug 8 is screwed in, is pressed against a
conical inner sealing surface 18 of a sealing projection 19 located
adjacent the threaded bore 11 of the bung socket 7 of the screw cap
1.
[0019] The bung plug 8 of another embodiment of the screw cap
illustrated in FIG. 4 includes cylindrical threaded sleeve 9 with
an external thread 10 for screwing in the threaded bore of the bung
socket 7 of the cap 1 and with a sealing end 12 which is provided
with a conical sealing rim 20 which, when the bung plug 8 is
screwed in, is pressed against the conical inner sealing surface 18
of a sealing projection 19 located adjacent the threaded bore 11 of
the bung socket 7 of the screw cap 1.
[0020] While specific embodiments of the invention have been shown
and described in detail to illustrate the inventive principles, it
will be understood that the invention may be embodied otherwise
without departing from such principles.
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