U.S. patent application number 10/853520 was filed with the patent office on 2005-12-01 for finish for injection blow molded container.
This patent application is currently assigned to CKS Packaging, Inc.. Invention is credited to Harrison, Kevin R., Henson, Jeffrey D., Lloyd, Randall A., Meiring, David P., Roark, Jeffrey P..
Application Number | 20050263476 10/853520 |
Document ID | / |
Family ID | 35424035 |
Filed Date | 2005-12-01 |
United States Patent
Application |
20050263476 |
Kind Code |
A1 |
Harrison, Kevin R. ; et
al. |
December 1, 2005 |
Finish for injection blow molded container
Abstract
An injection molded finish portion of a container preform has an
annular wall with an end sealing surface. A set of ratchet teeth
are located at a lower end of the annular wall on a flange having
upper and lower surfaces including radially inward edges
coterminous with the annular wall. A threaded portion is located
below the sealing surface and above the ratchet teeth that includes
sets of inclined threads extending part way around the annular
wall, the threads having crest portions that terminate at planes
tangent to the annular wall along parting lines on opposite sides
of the finish. Lugs project outward from the annular wall in the
vicinity of the parting lines to ensure correct interaction between
the ratchet teeth and a cooperating flexible closure.
Inventors: |
Harrison, Kevin R.; (New
Madison, OH) ; Roark, Jeffrey P.; (Eaton, OH)
; Henson, Jeffrey D.; (Miamisburg, OH) ; Lloyd,
Randall A.; (Huber Heights, OH) ; Meiring, David
P.; (Troy, OH) |
Correspondence
Address: |
INDIANAPOLIS OFFICE 27879
BRINKS HOFER GILSON & LIONE
ONE INDIANA SQUARE, SUITE 1600
INDIANAPOLIS
IN
46204-2033
US
|
Assignee: |
CKS Packaging, Inc.
|
Family ID: |
35424035 |
Appl. No.: |
10/853520 |
Filed: |
May 25, 2004 |
Current U.S.
Class: |
215/44 ;
215/202 |
Current CPC
Class: |
B29B 2911/14433
20130101; B29C 49/0073 20130101; B29B 2911/14326 20130101; B29B
2911/14333 20130101; B29B 2911/1444 20130101; B29B 2911/14026
20130101; B29B 2911/14473 20130101; B29B 2911/1402 20130101; B29B
2911/14336 20150501; B29B 2911/14033 20130101; B29B 2911/1404
20130101; B29B 2911/1433 20150501; B29B 2911/1442 20130101; B29B
2911/14337 20150501; B29B 2911/14331 20150501; B29B 2911/14446
20130101; B65D 1/023 20130101 |
Class at
Publication: |
215/044 ;
215/202 |
International
Class: |
B65D 055/02; B65B
007/28 |
Claims
1. An injection molded finish portion of a container preform
comprising: an annular wall having an outside surface, an end
sealing surface on an upper end of the annular wall, a set of
ratchet teeth located at a lower end of the annular wall, and a
threaded portion located below the sealing surface and above the
ratchet teeth, the threaded portion including two sets of inclined
threads extending part way around the annular wall, the threads
including crest portions terminating at planes tangent to the
annular wall along parting lines on opposite sides of the
container.
2. The injection molded finish portion of claim 1 further
comprising lugs projecting outward from the annular wall in the
vicinity of the parting lines.
3. The injection molded finish portion of claim 2 wherein the lugs
extend equally on each side from the parting lines.
4. The injection molded finish portion of claim 2 wherein the lugs
are aligned with adjacent ends of the threads.
5. The injection molded finish portion of claim 4 wherein each lug
includes a base portion adjacent to the annular wall defined by a
first vertical cross-sectional geometry and a radially outward
crown portion defined by a second vertical cross-sectional
geometry.
6. The injection molded finish portion of claim 5 wherein the first
vertical cross-sectional geometry includes arcuate surfaces above
and below a midline of the lug, and the second cross-sectional
geometry comprises a wedge extending outward from a middle sector
of the first geometry arcuate surfaces.
7. The injection molded finish portion of claim 4 wherein the lugs
comprise an upper lug and a lower lug straddling each parting line,
the lower lug crown portion extending radially outward further than
the upper lug crown portion.
8. The injection molded finish portion of any of claims 1, 2, 3, 4,
5, 6 or 7 wherein the ratchet teeth are disposed on a flange having
an upper surface and a lower surface, the flange upper and lower
surfaces including radially inward edges meeting with said annular
wall.
9. The injection molded finish portion of claim 8 wherein the
ratchet teeth include a radial surface and an outer surface
inclined with respect to the radial surface, outer ends of
adjoining radial and outer surfaces being joined by a curved
portion and inner ends of adjoining radial and outer surfaces being
joined by a segment parallel to said annular wall.
10. The injection molded finish portion of claim 9 wherein the
outer surface of each ratchet tooth is inclined at about 75.degree.
with respect to the radial surface of the same tooth.
11. The injection molded finish portion of claim 8 wherein the
flange upper and lower surfaces are outwardly tapered so that the
flange is thickest at the radially inward edges of the upper and
lower surfaces.
12. The injection molded finish portion of any of claims 1, 2, 3,
4, 5, 6 or 7 wherein each of the threads is defined by an upper
wall and a lower wall, the upper and lower walls extending radially
outward from said annular wall, a tapered surface extending
downwardly from the upper wall outer extremity, and a curved
surface joining the tapered surface to the lower walls, the curved
surface defining said thread crest portion.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] The present invention is directed generally to neck
structures of containers and preforms that are particularly adapted
to receiving flexible closures that include a tamper indicating
band.
[0003] 2. General Background
[0004] Flexible closures that include a tamper indicating band are
commonly employed on extrusion blow molded plastic jugs typically
used in the dairy industry. Closures of this general type are
disclosed, for example, in U.S. Pat. Nos. 3,980,195; 5,480,045 and
6,003,701. Another similar closure in common use is a Super Quad
ASP-100 available from Blackhawk Molding Co., Inc., of Addison,
Ill. Closures of this general type are typically made of low
density polyethylene and are therefore very flexible and unsuitable
for use to contain carbonated beverages. Such closures generally
include an end panel having an interior surface that can include
various sealing elements. The end panel is surrounded by a skirt
having an interior surface including threads or other container
engaging structures. The tamper indicating band can be connected to
the lower edge of the skirt by a plurality of circumferentially
spaced frangible webs. The tamper indicating band can include a
series of inward projections designed to interact with a related
structure on the container. Closures of this general type are
suitable for use to contain still liquids in addition to dairy
products, such as distilled water, mineral water, filtered water,
and natural spring water. While such products can be marketed in
the extrusion blow molded plastic jugs typically used in the dairy
industry, enhanced market acceptance might be enjoyed by adopting
more stylish containers that can more easily be manufactured using
the injection blow molding procedure on polyethylene terephthalate
and other similarly performing resins.
[0005] Injection blow molding procedures for forming articles such
as containers are well known. The injection blow molding procedure
can be accomplished as a continuous process in a single machine or
can be divided into two distinctly different processes accomplished
in two separate machines that need not be located at the same
facility. In a typical injection blow molding procedure, a preform
is first formed in an injection mold. The injection molded preform
includes a body portion and a finish portion. The finish portion of
the preform includes the geometry that cooperates with the
structure of a pre-selected closure. While the body portion of the
preform is deformed during a subsequent blow molding step of the
procedure, the finish portion of the preform generally remains
unchanged. Thus, the geometry of the finish created by the
injection molding of the preform is generally the same geometry as
exists in the completely formed container. This is quite different
from the finish portion of extrusion blow molded containers, such
as plastic jugs typically used in the dairy industry, wherein the
finish is formed during the blow-molding step of the process.
[0006] The finish portion of extrusion blow molded containers
designed for use with flexible closures that include a tamper
indicating band typically have an end sealing surface defining the
opening into the interior of the container. A closure retaining
structure, typically in the form of a plurality of threads,
projects outward from a cylindrical surface below the end sealing
surface. A tamper evident band retaining bead is situated below the
closure retaining structure. The retaining bead generally has a
minimum diameter that exceeds the outermost projection of the
closure retaining structure. Typically, an essentially radially
extending surface connects the cylindrical surface at the lower end
of the closure retaining structure to the retaining bead minimum
diameter. The retaining bead is typically characterized by a
corrugated surface designed to interact with inward projections on
the tamper indicating band so that any attempt to remove the
closure from the finish will generally result in separation of the
tamper indicating band from the remainder of the closure.
[0007] The finish portion of extrusion blow molded containers
typically has a substantially uniform wall thickness with the
interior of the finish portion reflecting, more or less, the
exterior features. While the wall thickness of the finish portion
can be somewhat thicker than the body portion of the container, it
is generally still quite flexible, which facilitates removal of the
molded article from the mold in which it is formed. By contrast,
the interior of the finish portion of an injection blow molded
container is usually uniformly cylindrical or slightly outwardly
tapered toward the mouth of the container. Further, the finish
portion can be quite rigid so that removal of the molded article
from either the injection mold or the blow mold generally cannot
require any flexing on the part of the molded finish. Any attempt
at a straight reproduction of the exterior finish geometry of a
given extrusion blow molded container into an injection blow molded
container would result in a very heavy, and thus overly expensive,
finish, probably containing flaws due to the general inability of
the injection molded finish to flex as the molded article is
removed from the mold.
[0008] Thus, there remains a need for a low cost injection moldable
finish, which can be incorporated into containers made by an
injection blow molding process, that can accommodate a flexible
closure that includes a tamper indicating band as are commonly
employed on extrusion blow molded plastic jugs typically used in
the dairy industry, such as the Blackhawk closure.
SUMMARY OF THE INVENTION
[0009] Accordingly, an injection molded finish portion of a
container preform of the present invention includes an annular wall
having an outside surface and an end sealing surface on an upper
end of the annular wall. A set of ratchet teeth are located at a
lower end of the annular wall. A threaded portion is located below
the sealing surface and above the ratchet teeth. The threaded
portion includes two sets of inclined threads extending part way
around the annular wall. The threads have crest portions that
terminate at planes tangent to the annular wall along parting lines
on opposite sides of the container preform finish.
[0010] The finish portion can also include lugs projecting outward
from the annular wall in the vicinity of the parting lines. The
lugs can extend equally on each side from the parting lines. The
lugs can be parallel to the sealing surface or aligned with the
adjacent ends of the threads of the threaded portion. Each lug can
include a base portion adjacent to the annular wall, defined by a
first vertical cross-sectional geometry, and a radially outward
crown portion, defined by a second vertical crow-sectional
geometry. The first vertical cross-sectional geometry can include
arcuate surfaces above and below a midline of the lug, while the
second vertical cross-sectional geometry can include a wedge
extending outward from a middle sector of the first geometry.
[0011] The ratchet teeth of the finish portion can be disposed on a
flange having an upper surface and a lower surface. The flange
upper and lower surfaces can include radially inward edges
coterminous with the annular wall of the finish. The flange upper
and lower surfaces can taper outwardly. The ratchet teeth can
include a radial surface and an outer surface inclined with respect
to the radial surface. Outer ends of adjoining radial and outer
surfaces can be joined by a curved portion while the inner ends of
adjoining radial and outer surfaces can be joined by a segment
parallel to the annular wall of the finish portion. The outer
surface of each ratchet tooth is preferably inclined at about
75.degree. with respect to the radial surface of the same
tooth.
[0012] One feature of a finish portion molded in accordance with
the present invention is the termination of the crest portions of
the threads in planes tangent to the parting lines so that the
threads are not deformed by the outwardly moving mold surfaces upon
release of the finish portion from the corresponding mold.
[0013] Another feature of a finish portion molded in accordance
with the present invention is the incorporation of lugs in the
region of the parting lines so that a cooperating closure is
inhibited from flexing enough to permit the closure to be removed
without tearing the tamper indicating band from the skirt of the
closure.
[0014] A further feature of a finish portion molded in accordance
with the present invention is the placement and configuration of
the ratchet teeth so that interaction with the tamper indicating
band in maximized.
[0015] Still further features and advantages of an injection molded
finish portion of a container preform will become apparent to those
skilled in the art from a consideration of the following
description of the preferred embodiments illustrated in the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a sectional view of an injection molded preform
including a finish according to the present invention.
[0017] FIG. 2 is a sectional detail view of a portion of FIG. 1
showing a preferred thread cross-section.
[0018] FIG. 3 is a plan view of the finish of FIG. 1 showing the
threads and lugs of a preferred finish.
[0019] FIG. 4 is a schematic view of an entire thread development
around the finish shown in FIG. 3.
[0020] FIG. 5 is another sectional view of the finish of the
previous Figures taken along line 5-5 of FIG. 3.
[0021] FIG. 6 is a sectional detail of the lugs.
[0022] FIG. 7 is a sectional view taken along lines 7-7 of FIG. 1
showing the ratchet toothed flanges and support ring.
[0023] FIG. 8 is a detail view of two adjacent ratchet teeth.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] FIG. 1 is a vertical sectional view of an injection molded
preform 10 including a finish portion 12 according to the present
invention and a body portion 14. The body portion 14 can have a
wide variety of shapes that generally is a function of the size and
shape of the container that is to be formed from the preform in any
subsequent blow molding operation. The body portion 14 is typically
rotationally symmetric about a vertical axis Y of the preform. The
body portion 14 and finish portion 12 are generally formed in a
single unitary process, which is well known, in an injection mold
that typically includes a core unit, a cavity unit, and a pair of
thread splits. The core unit defines the interior surface 16 of the
preform 10 including the interior surface 18 of the finish portion
12. The cavity unit defines the exterior surface 20 of the body
portion 14. The thread splits define the outside configuration of
the finish portion 12. As suggested by the name, the thread splits
are generally formed in pairs that can reciprocate laterally with
respect to the vertical axis Y. The juncture of the two thread
splits defines parting lines, which are generally vertically
oriented, located on opposite sides of the finish portion 12. The
finish portion 12 includes an annular wall 22 having an outside
surface 24 and an end sealing surface 26 on an upper end of the
annular wall 22. A threaded portion 28 is located below the sealing
surface 26. The finish portion 12 also includes a set of ratchet
teeth that are located on an outward protruding flange 30 located
below the threaded portion 28. A support ring 32 can be located
below the ratchet teeth bearing flange 30.
[0025] A preferred embodiment of the threaded portion 28 can be
seen in FIG. 2 to include threads having an upper wall 52 and a
lower wall 54. The upper and lower walls 52 and 54 extend radially
outward from the annular wall 22. A tapered surface 56 extends
downwardly from the upper wall 52 outer extremity. A curved surface
58 joins the tapered surface 56 to the lower wall 54. The curved
surface 58 defines a thread crest 44. FIG. 3 shows a plan view of
the upper part of the finish portion 12 including the sealing
surface 26, the interior surface 18, and the outside surface 24.
The sectional view shown in FIG. 1 is taken along the diameter line
1-1 of FIG. 3. The orthogonal diameter line 5-5 is located in
alignment with the vertical axis Y and the parting lines 34 created
by the thread splits during the molding process. A set of four
thread segments 36, 38, 40 and 42 are located on each side of the
diameter line 5-5. The four thread segments 36-42 protrude outward
from the outer surface 24 of the annular wall 22 to a radially
outer edge of each thread segment defining the crest 44 of the
threads. The crests 44 of the threads 36-42 terminate at planes W-W
that are tangent to the outer surface 24 of the annular wall 22
along the parting lines 34. The termination of the crests 44 of the
threads 36-42 in planes W-W tangent to the parting lines 34 ensures
that the freshly molded threads are not deformed by the outwardly
moving thread split mold surfaces upon release of the finish
portion 12 from a corresponding thread split mold at the completion
of the injection molding step. Lugs 46 project outward from the
annular wall 22 in the vicinity of the parting lines 34. The lugs
46 can extend equally on each side of the parting lines 34.
[0026] FIG. 4 is a schematic view of an entire thread development
around the finish portion 12 of the preform 10 extending from one
parting line 34 at the left edge of the diagram to the same parting
line 34 at the right edge of the diagram. The four thread segments
36-42 can be seen to form four discontinuous threads A, B, C, and
D, which are composed of two thread segments each. An upper end of
the threads A-D can be uniformly spaced below the sealing surface
26 of the finish portion 12. Each of the threads A-D can include a
lead-in section 48 and a locking section 50. The thread crest 44 in
the locking section 50 can project outward from the annular wall 22
by a greater distance than does the lead-in section 48, as shown in
FIGS. 2 and 3. The difference in vertical cross-section between the
lead-in section 48 and the locking section 50 can be seen in FIG.
2.
[0027] FIG. 5 is another sectional view of the finish 12 taken
through diameter 5-5 of FIG. 3 at right angles to the view shown in
FIG. 1. The sectional view of FIG. 5 is aligned with the parting
lines 34 and passes through lugs 46. A detail view taken from FIG.
5 and shown in FIG. 6 reveals a preferred cross-sectional shape for
the lugs 46 in which each lug 46 can include a base portion 52
adjacent to the annular wall 22 and a radially outward crown
portion 54. The lug base portion 52 can exhibit a first vertical
cross-sectional geometry including arcuate surfaces 60 and 62 above
and below a middle sector 64 of the lug 46. The radially outward
crown portion 54 can be defined by a second vertical
cross-sectional geometry including a wedge 66 extending outward
from the middle sector 68 of the first geometry 56. It is to be
noted that the ratchet toothed flanges 30 do not protrude outward
from the annular wall 22 in the cross-sectional view of FIG. 5. The
incorporation of lugs 46 in the region of the parting lines 34
inhibits a cooperating flexible closure from flexing enough to
allow the closure to be removed without tearing the tamper
indicating band from the skirt of the closure. While the lugs 46
are shown in FIGS. 3-5 to be generally aligned with the ends of the
adjacent threads, the lugs 46 could be situated at other locations
on the annular wall 22 of the finish portion 12 so long as the lugs
46 did not interfere with the application of the selected
closure.
[0028] Returning to FIG. 1, it will be seen that the ratchet
toothed flanges 30 can include upper and lower surfaces 80 and 82
that can include radially inward edges 84 and 86, which can be
coterminous with the outer surface 24 of annular wall 22 of the
finish 12. The flange upper and lower surfaces 80 and 82 can taper
outwardly to ensure quick mold release. FIG. 7 is a sectional view
taken along lines 7-7 of FIG. 1 showing a preferred embodiment of
the ratchet toothed flanges 30 and support ring 32. In this
preferred embodiment, the flanges 30 are confined essentially to
occupy two opposite quadrants 70 and 72 of the finish 12. A lateral
surface 74 of each flange 30 is situated parallel to the planes W-W
that are tangent to the annular wall 22 at the parting lines 34.
Each of the teeth 76 can be related to its nearest neighbors by a
fixed geometric relationship shown in detail in FIG. 8. The ratchet
teeth 76 can include a radial surface 88 and an outer surface 90
that is inclined with respect to the radial surface 88. Outer ends
of adjoining radial and outer surfaces can be joined by a curved
portion 92. The inner ends of adjoining radial and outer surfaces
can be joined by a segment 78 that is arranged to be generally
parallel to the outer surface 24 of annular wall 22. In the
illustrated preferred embodiment, the outer surface 90 of each
ratchet tooth 76 is preferably inclined at about 75.degree. with
respect to the radial surface 88 of the same tooth. The placement
and configuration of the ratchet teeth 76 as previously described
maximizes the interaction of the ratchet teeth 76 with the tamper
indicating band on a flexible closure such as the Blackhawk Super
Quad ASP-100.
[0029] The foregoing detailed description should be regarded as
illustrative rather than limiting, and the following claims,
including all equivalents, are intended to define the spirit and
scope of this invention.
* * * * *