Note: Descriptions are shown in the official language in which they were submitted.
120108~
CONTAINER CLOSURE AND ASSEMBLY
This invention relates to removable closures for containers
and partlcularly to special closure structures and the assembly
thereof with certain containers.
In its preferred embodiment the invention will be described
in association with a container assembly of the type disclosed in
.S. Letters Patent No. 4,269,722 issued May 26, 1981 to Joshi
et al. As will appear the container may be the same as disclosed
in Joshi et al.except for the neck arrangements.
The invention contemplates as a ma~or object a nvvel con-
tainer closure structure integrally formed of a suitable stiff
synthetic plastic such as polypropylene having its top wall in-
dented to provide an internal pro~ection that is adapted to close
the open end of the container neck when installed. Further to this
ob~ect the pro~ection is surrounded at its base by an annular flat
surface adapted to seat tightly in full surface direct engagement
all around the upper edge of the opening in the container neck.
A further ob~ect of the invention i8 to provide a noveI con-
tainer assembly consisting of a container and the foregoing closure
wherein the closure is secured upon the container as by a speclally
located threaded connection that pu116 the flat sealing surface of
the closure tight upon the edee of the container neck~
It is a further ob~ect of the invention to provlde a novel
generally cylindrical container closure havlng an indented top wall
providing an internal cylindrical neck-closing pro;ection surrounded
by an annular planar surface adapted to seat tightly upon the edge
o~ the container neck and thereby coact with a correspondingly
located external thread formed on the container neck ~ust below the
edge of the dispensing opening.
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Further novel features and other ob~ects of this lnvention
will become apparent from the following detailed description~ dis-
cussion and the appended claims taken in con~unction with the
accompanying drawings.
BRIEF DESCRIPTION OF DRAWING~
Fig. 1 is a side view showing a container closure cap according
to a preferred embodiment of the invention,
Fi~. 2 is a plan view lookin~ up into the interior of the
closure of Fig. l;
Fig. 3 is a section on line 3-3 of Fig. 2;
Fig. 4 is an enlarged partial section showing coaction of the
closure of Fig. 1 with the container nec~; and
Fig. 5 is an illustrative side view showing a filled and
closed container in its normal disposition after packaging for
shipment .
PREFERRED EMBODIMENTS
The invention provides a novel closure cap 11 for the container
12. The cap 11 may be integrally formed of polypropylene while the
container may be integrally formed of polyvinylchloride. The con-
tainer 12 may be blow molded from a suitable synthetic plastic and
is preferably transparent so that the color of its contents may
show.
The container 12 is of known shape and dimensions and, except
for the location of the external threads on the container neck, may
be essentially the same as used prior to the invention and shown in
the Joshi et al. patent.
The container 12 comprises a body 13 havin~ a rounded edge
through-opening that defines a handle 14 at one side of the top, and
a reduced diameter cylindrical neck 15 that terminates in an open
mouth surrounded by an annular axially facing flat smooth end sur-
face 16 lying in a plane perpendicular to the axis A of the con-
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1201087
talner neck. The inner surface 17 o~ the neck 15 is smooth andcylindrical~ and it intersects the end surface 16 in a circular
line indicated at 18.
A substantially helical external thread 19 consisting of a single
revolution with a slight overlap is integrally formed on the neck
15 adjacent the edge thereof ~ust downwardly o~ the mouth. A flat
shoulder 21 lying in a plane parallel to surface 16 is provided at
the ~uncture between the neck 15 and the body 13, and an external
shallow finishing groove 22 is formed in the neck 15 JUst above
the shoulder 21. This finishing groove is adapted to coact with a
trimming apparatus (not shown) which cuts the end surface 16 and
which has lying opposite it an internal continuous rib 23 which
maintains wall thickness of the neck and gives it rigidity.
The cap 11 is symmetrical about an axis B and comprises a top
wall 24 and a depending generally cylindrical side wall 25. The
top wall is indented to form a central depressed relatively shallow
recess 26 that exhibits an annular side wall 27 and a bottom wall
28. As shown, the walls 27 and 28 are of uniform thickness and
substantially maintain the thickness of cap side wall 25.
The outer peripheral surface 29 of the recess side wall is
smooth and preferably either cylindrical or with a slight downwardly
converging conical taper. Thus there is provided within the cap a
substantially cylindrical projection 30 which, as will appear, is
adapted to fit snugly within the neck opening of the container 12.
The end portion 31 of the cap side wall 25 is, where it joins
the cap top wall, of about the same thickness as walls 27 and 28
and uniformly surrounds the recess side wall and defines with the
cap top wall and the recess side wall 27 an annular recess 32 which
surrounds the projection and as will appear receives the end 30 of
the contalner neck 15 when the cap is on the container.
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The bottom of the recess 32 iB a smooth flat annular surface
33 that is planar, smooth and accurately disposed at right angles
to the central axis B of the cap. The surface 33 extends around
the base of the proaection 30 and perpendicularly intersects the
surface 29.
A generally helical thread 34 is integrally formed inside the
cap side wall 25 and extends from the recess 32 to the neck portion
Or the cap. The thread 34 matches the container neck thread 19
and preferably extends for more than two revolutions as shown.
The outer surface 35 of the cap recess 26 is curved, and the
inner surface 36 thereof is correspondingly curved intersecting
the periphery 29 of the recess side wall in a circle as indlcated
at 37. This provides a bowed, inverted dome central region for
the cap top wall, whlch strengthens that wall against lateral
collapse when the cap is screwed onto the container neck as will
appear. The recess 32 thus surrounds the domed internal pro~ection
30 ln the cap.
The skirt portion of the cap side wall may, as indicated at 38,
be thinner than the other portions of the cap because it is not
sub~ected to appreciable stress when the cap is installed, thus
permitting a savings in material. If desired, llght, stiffening
ribs 43 may be provided to make the skirt somewhat more rigid. The
outer side of the closure may be fluted as shown at 41 similarly to
the closure cap ln Joshi et al.
In a cap having a diameter of about 1 3/4 inches and a side
wall length of about 1 1/16 inches3 the depth of recess 32 may be
about 1/4 inch.
The ^ontainer 12 is normally used to package a relatively
heavy detergent powder such as that disclosed in said Joshi et al.
patent, and the cap 12 is employed as a measuring device since only
small quantities of this detergent are required for normal washing
machine loads.
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lZ01087
For example the c~p here defined has a volume of 1/~ cup, so
that two fillinæs will supply the normal 1/4 cup of this detergent
usually used.
As the cap is placed over the container neck ~t is turned
about its axis and engagement of the threads pulls the cap axially
until the pro~ection 30 enters the open neck mouth and the surface
16 is in tight full surface engagement all around with the surface
33. The inherent flexibility of the plastic materials involved
compensates for slight tolerances in molding whereby the projectio~
30 fits snugly and tightly with the neck surface 17 to provide a
longitudinal seal 17, 29 that is substantially continuous with the
axial seal 16, 33.
In addition the pro~ection 30 helps maintain the cylindrical
shape of the container neck while the cap is being turned on the
neck thread, and the assembly is increasingly tight.
By locating the screw thread connection near the outer end of
the container neck and also where the cap wall thickness is greatest,
a more efficient coupling of the cap with the container is secured.
By indenting the top wall of the closure the available internal
volume of the closure for accurate dosage measurement may be accur-
ately controlled, whlle preserving the height appearance of the cap
relatlve to the container.
Thus in summary the advantages of the closure and assemb]y
disclosed over that disclosed in said Joshi et al.patent are:
(1) An unlined cap is provided which exhibits a better seal
with the container neck. In addition to the mechanical advantages,
elimination of a liner reduces manufacturing time and other costs.
(2) The new structure provides a stronger closure of better
external appearance and better holding of the closure on the con-
tainer neck in the assembly.
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(3) Cap damage during transit is practically eliminated. As shown
in Figure 5 these detergent containers are shipped disposed upside down
in cartons. Previously, when a carton was slammed down onto a rigid surface
such as that at 42 in Figure 5, the impact could result in considerable
breakage of prior designed caps. However, where in accordance with the
invention, the end edge of the container neck is in solid abutment with
the bottom wall of the cap as shown in Figure 4, a considerable reduction
in cap damage has been observed under comparable circumstances.
(4) The new construction is so proportioned that it requires consider-
ably less plastic material, thereby effecting an appreciable saving.
~ 5) By indenting the top wall of the cap, accurate control of the
volumetric capacity thereof is attained while preserving the external appear-
ance of the cap design. For example in the case of a known detergent, the
volumetric capacity of the cap is 1/8 cup, and accuracy is important to
avoid wasting expensive detergent.
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