Note: Descriptions are shown in the official language in which they were submitted.
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NECK FINISH FOR CONTAINERS OF RIGID MATERIALS
BACKGROUND OF THE INVENTION
1. Field of the Invention. This lnvention relates
to the neck finish (i.e., cross-sectional shape) of
containers formed of relatively rigid materials such as
polyvinyl chloride. Such neck finishes are formed to
cooperate with standard push-on caps which were initially
designed for use with less rigid materials such as
polyolefins.
1~0 2. ~rior Art. Caps used with the neck finish of
this invention such as those shown in U.S. Patent Nos.
4,676,389 and 4,484,687 as well as many variations
thereof. Such caps have a top disk from wh~ch depends
a 6ubstantially cylindrical outer skirt having at least
i5 one locking bead on the inside surface thereof. The neck
to which the present invention relates i5 formed on the
exteriorwith locking beadswhich matewith lockingbeads
on the cap. Many of these caps have tamper-evident
features whereby the portion of the ~kirt carrying the
lower locking bead is torn away, leaving a reclosure cap
which may be pried off the neck and used to reseal the
remaining contents of the container. Some of the caps
used with the neck finish have an inner skirt or plug
which fits the inside of the neck.
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Prior art containers for the most part have been
made from relatively flexible materials such as
polyolefins. Their lips having relatively sharp inner
and outer peripheral corners. The outer corner engages
the interior of the outer skirt of the cap promoting
distortion of the skirt outwardly particularly when the
cap is being used as a reclosure cap. The pliable
polyolefin containers do not deform to the extent that
the distortion of the closure becomes excessive.
The present invention overcomes some of the problems
which occur when the less rigid polyolefin conta$ners
are replaced with more rigid containers.
SUMMARY OF THE INVENTION
~ eretofore containers have been made of a relatively
flexible polyolefin material wherein the lip deforms if
an oversized plug seal is inserted into the orifice of
the neck. The outer skirt of the cap fits over the upper
locking bead of the neck and is disposed in a generally
vertical position.
However, material~ which are substantially more
rigid than polyolefin6, such as polyvinyl chloride create
certain difficulties. ~he oversize plug of the closure
is cut or ~haved by the sharp inner edge of the lip since
the lip does not deform as much as if a less rigid
material is used. The undercut of the lip, which is
conventionally formed in less rigid containers and
deforms when the plug is inserted, may not be formed with
less resilient materials, which are typically
manufactured with in~ected or pressed (ram-down)
finishes.
35A ~econd problem with rigid container necks arises
when such necks become exce sively oval shaped rather
than round, In such cases, the locking bead on the
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exterior of the neck is forced outwardly in the areas
of greatest radius, and this causes the outer cap skirt
to be slanted outwardly-downwardly, even to 6uch an
extent that the locking beads of the cap and neck do not
inter-engage.
In accordance with the present invention, a cut-out
i8 formed at the corner of the intersection of the lip
of the neck and the locking bead. In such event the
locking bead engages the inside of the neck spaced
downwardly from the lip and hence the distortion o~ the
outer skirt from vertical is considerably minimized.
In another feature of the invention, the lead-in
or inner corner where the lip intersects the orifice of
the neck is formed with a chamfer or radius. This
facilitates insertion of the plug of the cap.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated
in and form a part of this specification, illustrate
embodiments of the invention and, together with the
description, serve to explain the principles of the
invention:
FIGURE 1 is a fragmentary sectional view through
a cap and container neck formed in accordance with this
invention.
FIGURE 2 is a top plan view of the neck 6tructure.
FIGURE 3 i5 a view similar to FIG. 1 showing a neck
which i6 distorted by ovality and illu6trates the
relatively 6~all distortion of the outer 6kirt.
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FIGURE 4 i6 a ~ectional view of the neck used in
FIGS. 1 and 3.
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FIGURE 5 is a view similar to FIG. 4 of a modified
neck finish.
FIGUR~ 6 is a view similar to FIG. 4 of another neck
finish.
PIGURES 7 and 8 are fragmentary vertical sectional
views through prior art neck finishes.
FIGURE 9 is a 6chematic ~iew which should be
compared with FIG. 3 to illustrate an advantage of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the
preferred embodiments of the invention, examples of which
are illustrated in the accompanying drawings. While the
invention will be described in con~unction with the
preferred embodiments, it will be under6tood that they
are not intended to limit the invention to those
embodiments. On the contrary, the invention is intended
to cover alternatives, modi~ication6 and equivalents,
which may be included within the 6pirit and scope of the
invention as defined by the appended claims.
Directing attention first to the structure of
Figures 1-3, neck 11 has an inside orifice or throat 12
and an upper lip 13. In accordance with the present
invention, a lead-in chamfer or radius 14 i5 formed at
what would otherwise be the intersection of throat 12
and lip 13.
on the exterior of neck 11 6paced down from the lip
13 i8 a locking bead 16 having a top surface 17 and a
bottom shoulder 18. As will be understood with reference
to U.S. Patent Nos. 4,676,389 and 4,484,687, below the
top locking bead 16 there i8 generally a second lockinq
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bead which is engaged by the cap until such time as the
lower portion of the cap skirt is torn away. Thereupon
the upper portion of the cap becomes a reclosure cap,
as is well understood in the art~ The cap 21 illustrated
herein is essentially a reclosure cap, it being
understood that the lower portion of the outer skirt
which contains the lower locking bead has been torn away.
Cap 21 is formed with a top disX 22 from which
lo depends an inner skirt or plug 23. In accordance with
the present in~ention, the outer bottom edge 24 is
slanted downwardly inwardly. When the cap 21 is applied
to the neck 11, the lead-in 14 in cooperation with the
slanted edge 24 ensures that the inner 6kirt 23 fits
inside the throat 12 even though the neck 11 may have
been distorted from a circular shape (i.e., is 6ub~ect
to "ovality").
Also depending from top disk 22 is cylindrical outer
skirt 26 which has an upper locking bead 27 spaced
downwardly from the disk 22. Bead 27 has a downward
inward slanted surface 28 and a downward outward slanted
surface 29 which facilitates initial capping of the cap
onto the neck and also facilitates removal of the
reclosure cap 21. As shown in Figure 1 there i6 a bottom
edge 31 to the cap 21, it being understood that the
portion of the cap initially below edge 31 has been torn
away.
The outer corner o~ bead 16 engages outer sklrt 26
at a contact point 33. The position o* contact point
33 is well below lip 13 because of the cut-out 32 formed
above bead 16.
Thus directing attention to Figure 4 which iB a neck
fin~sh substantially similar to that shown in Figures
1 and 3, the cut-out 32 occurs in that the lip 13 has
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an outside edge materially smaller than the diameter of
the outside edge of the bead 16.
Figure 5 ~hows a modification of the structure of
Figure 4 in that the cut-out notch 37 instead of having
an upper vertical edge has a stretch slanted inwardly-
downwardly.
Directing attention to Figure 6~ the upper outex
edge of the neck below lip 13b is formed with a
cylindrical vertical stretch 41 which terminates in a
flange 42 having substantially horizontal top andbottom
surfaces 43,44.
15Advantages of the present invention will be shown
by comparison with examples of the prior art illustrated
in Figures 7, 8 and 9. Figure 7 illustrates a common
type of neck finish used in blow-molded polyolefin
container 45. Thus lip 46 has an inner ed~e 47 and below
20edge 47 i8 an undercut 48 which makes the lip 46 guite
flexible. Formation of the undercut 48 is relatively
easy for blow-molded bottle6 but is difficult or
impossible when the bottle finish is formed by in~ection
or a ram-down pressed operation. The neck finish of
25Figure 7 has an outside cylindrical portion 49, the
corner 51 being rounded and the lower end of the
cylindrical portion 49 terminating in a relatively
horizontal inward directed shoulder 52. The caps shown
in Figures 1 and 3 are designed for closing neck finishes
30such as ~hown in Figure 7.
Figure 8 shows another prior art neck structure 55
of a relatively rigid material which is formed by
injection or ram-down operation. Thus there is a solid
35flange 56 which has an inside surfAce 57 functioning as
the throat of the neck and a horizontal broad top lip
58. Outer cylindrical surface 59 terminates on itslower
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end in a horizontal inwardly directed 6houlder 61 which
in turn is connected to the lower neck 62. Structures
such as shown in Figure 8 have certain problems. First,
excessive mass results in extended proce6s times,
S material waste and difficult dimensional control.
Second, the absence of a lead-in chamfer results in
difficult plug insertion and capping. Third, extension
of the top 6urface outward to the outside diameter leads
to exaggerated distortion of the closure from bottle
ovality resulting from process or use.
In accordance with the present invention, the cut-
out ~ection 32 not only saves mass but has the important
additional function of accommodating bottle distortions.
Directing attention to Figure 9, it will be seen that
with a neck shape having a solid flange 56 6uch as that
shown in Figure 8, the point of contact 33 causes the
outer skirt to slant downward outward 60 that the bead
27 does not even engage the flange 56. Although Figure
9 is somewhat distorted for the purpose of illustration,
by comparison wlth Figure 3 it will be seen that even
though the distortion of the bead 16 i8 a~ great as the
flange 56, the outer skirt 26 of Figure 3 is much more
nearly vertical and there is an inter-engaging of the
bead 16 with the bead 27 which maintains the reclosure
cap 21 on the neck ll against unintentional removal.
Therefore the cut-out 32 results in less cap distortion
because contact point 33 is lower. The cut-out allows
the closure to remain securely fastened to the neck
through a wide range o~ finieh ovalities. It will be
understood that such ovality may result from process,
shock "impacts," or compression during consumer use.
It i6 impor~ant that the lip 13 be suffic$ently wide
80 that if, instead of an inner skirt or plug 23, a seal
is effected by induction heating oftransfer foils, there
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is sufficient annular area of lip 13 to ensure consistent
6ealinq with the foil.
The foregoing descriptions of specific embodiments
of thepresent invention havebeenpresented forpurposes
of illustration and descr$ption. They are not intended
to be exhaustive or to limit the invention to the precise
forms disclosed, and obviously many modifications and
variations are possible in light of the above teaching~
The embodiments were chosen and described in order to
best explain the principles of the invention and its
practical application, to thereby enable others skilled
in the art to best utilize the invention and various
embodiments with various modifications as are suited to
the particular use contemplated. It is intended that
the scope of the invention be defined by the Claims
appended hereto and their equivalenta.
