CA1037907A

CA1037907A - Tamper-proof bottle cap and container

Info

Publication number: CA1037907A
Application number: CA242,312A
Authority: CA
Inventors: Ben A. Cochrane
Original assignee: Individual
Current assignee: Individual
Priority date: 1975-02-13
Filing date: 1975-12-22
Publication date: 1978-09-05
Also published as: FR2300716B1; US3927784A; GB1525533A; JPS51106583A; DE2605090A1; FR2300716A1

Abstract

ABSTRACT OF THE DISCLOSURE
TAMPER-PROOF BOTTLE CAP AND CONTAINER

An improved bottle cap and container are disclosed.
The cap is composed of a top disk, a thin-walled outer skirt and a thin-walled inner skirt both attached to the disk.
The outer skirt is weakened along two circumferential score lines to form a weakened cylindrical band around the outer skirt. A tab is attached to the cylindrical band and extends outwardly to provide a means whereby a person may grasp the tab between the fingers and tear the band from the cap. The outer skirt also has two circumferential beads attached to the inside of the skirt with one bead being disposed above the band and one below the band. These beads fit in groove in the container neck. Prior to tearing the band from the skirt, the cap is tamper-proof. When the band is removed the portion above the band functions as a reclosure cap.

Description

This invention relates to a new improved bottle cap. More parcicularly, this invention relates to an improved recloseable plastic bottle capO ?
BACKGROUND GF THE INVENTION
Plastic caps for narrow necked plastic bottles are typically of ;
the type desclosed in ~nited States Patent No. 3,338,4460 The caps have a depending thin-walled skirt weakened approximately midway of its length with a circumferential score line so that the portion of the skirt below the ~i score line may be torn off. The cap has two beads which extend circumfer-entially around the inside of the cap. These beads fit into grooves in the bottle neck and prevent the cap from being removed from the containerO ~hen both beads are in place the cap cannot be removed thereby preventing any tampering with the bottle contentsO The lower bead is torn away when the lower skirt is removed. This then allows the cap to be easily pried over ~
the upper bead to allow access to the contenks. The upper bead rem~ins with ~;
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the cap thereby allowing the cap to be used repeatedly for reclosure until the contents of the bottle are exhausted.
There are several problems with the plastic caps of the prior art. A major problem is the splitting of the lower portion of the cap when it is forced onto bottle neck. The score line for the tear-away lower section extends diagonally through the lower portion of the cap skirt and ter~inates ; a~ its rim. This ~core line weakens the cap rim and when pressure is exerted ..: : ~ :
in an attempt to push the cap onto the bottle, the cap rim often tears along ~-this score line. Bottles with torn rims must be removed from the packaging line, the cap manually removed and the bottle and contents recycled. This ~ ;
tearing problem, referred to as cap splitting, is a substantial burden and significantly increases operating expenses Another problem with the prior art caps is the difficulty by the `~ ~
consumer in tearing the lower skirt from the capO The problem is caused, in ~ ~ -..... . . . . . . . .

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part~ by the manufacturer when it ~st~an~hen~ the score line for the purpose of reducing cap "splitting" as discussed supra. By strengthening the score line, the amount of force or "difficulty" required to tear the lower skirt from the cap is proportionately increasecL.
In addition, the score line as it extends diagonally through the lower skirt of the cap, must penetrate the lower bead which extends circum-ferentially around the inside of the cap. Because the bead increases the thickness of the skirt at this point, the score line does not cut into the ;~
skirt as deeply thereby increasing the difficulty in tearing the lower skirt from the cap.
Another problem existant with the prior art caps is the loose fit of the cap onto the bottle. A t ght fit between the cap and the bottle is essential for a good seal. Although the prior art caps could be made to ;~
fit more tightly on the bottle~ such an improvement would result in a ~ -greater number of cap splitting. Thus an improvement in fit or seal is off-set by an increase in split caps and operating cOsts~
A need thus exists for a tamper-proof cap which can be used repeatedly for reclosure, which can be inserted onto the bottles wi~hout cap splitting, which can be removed from the bottle by the consumer without great difficulty, which has a tight fit or good seal and which is relatively easy to produce and inexpensive to manufacture.
- The invention provides a deformable plastic cap comprising (1) a top disk, (2) a cylindrical thin-walled outer skirt integrally attached t~ and extending substantially perpendicularly from said disk and (3~ a cylindrical inner skirt integrally attached to and substantially perpendicular to said disk positioned inward and enclosed within said outer skirt and sub-stantially co-axial therewith and extending for a shorter distance than said outer skirt; said outer skirt scored and weakened along a circumferential first score line downwardly spaced from said disk, and scored and weakened -. - 2 -.. ... . - - . - - - , -.- . . : . - .

~37907 along a circumferential second score line spaced downwardly from said first score line to form a weakened cylindrical band within said outer skirt~ a tab attached to said cylindrical band and extending from said band and out-wardly from said outer skirt, a weakened area extending between said first ~ ~`
score line and said second score line immediately ad~acent said tab, a narrow radial first bead extending circumferentially around the inside and integrally `
attached to said outer skirt between said first score line and said disk, and a narrow radial second bead extending circumferentially around the ins~de and integrally attached to said outer skirt below said second score line.
10Such an improved plastic cap does not split when inserted onto ~ ~ ,a container and may be removed from the container without diffic~lty. ~he improved plastic cap can be fitted tightly on the container neck to provide improved sealing of the container contentsO ~ ~ `

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I-t is a Eurther and additional object of this invention to

2 provide a container and improved cap combination.

3 Other related and additional objects of this invention

4 ~ill be apparent from the drawing, the follot~ing description ~f the invention and appended claims.
6 In the drawings:
7 ~ Fig. l is a top view of a cap in accordance with this lnvention. I
9 Fig. 2 is a sectional view of a cap taken substantially along line 2-2 of Fig. l.
11 Fig. 3 is a side view of t.he cap showing the skir-t.
12 Fig. 4 is a fragmentary side view of a cap showing 13 the connection of a tear tab to the skirt.
14 Fig. 5 i9 a perspective vibw of the cap.
1~ Fig. ~ is a perspective view of the top portlon o~
16 the oap ~lth the tear band and lower skirt r~movèd.
17 Fig. 7 is a persp~ctive view of the tear band ater 18 it~ remov~l from the cap.
19 Fig. 8 is a perspective view of the lower skirt af~er its removal from its cap.
21 Fig. 9 is a cross-sectional view of the cap on a 22 container neck.

SU~ARY OF THE INVENTION ~
j 24 ~ ~-The aforementioned objects and their attendant ~ `
26 dvantages can be realized by a deformable plastic cap 27 omprising (l) a top disk, (2) a cylindrical thin-walled ; - 28 uter skirt integrally attached to and extending substantially - 29 erpendicularly from said disk and (3) a cylindrical inner -kirt integrally attached to and substantially perpendicular 31 o the disk positioned inward and enclosed within said outer 32 kirt and substantially co-axial therewith and ex-tending for ;:

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1 a shorter distance than the outer skirt. The outer skirt 2 is scored and weakened along a circumferential first score 3 line downwardly spaced from -the disk. The outer disk is 4 also scored and weakened along a circumferential second score line dcwnwardly spaced from the first score line to 'form a weakened cylindrical band within the outer skirt.
7 ~ tear tab is attached to the cylindrical band and extends ~-;
8 outwardly from the outer skirt and downwardly from the ', 9 cylindrical band. An area connecting the first and second ~ ~
10 score lines, adjacent the tear tab, is weakened to allow ~ ;
i11 easy tearing of the,cylindrical band from the cap.
12 In order to hold the cap to the container neck, two narrow :, ~ ~ ~
13 radial beads are pro~ided which e~tend circumferentially , ~ ' 14 around the inside and integrally attached to the outer skirt.
lS ~ne bead is positioned above the c,ylindrical band and 16 ~he bead is po~itioned below the band.
17 Thi9 cap ls not burdened with the splitting problem 18 O~ its prior art caps since there is no score line extending 19 to the bottom of the cap. The cap of this invention `
can be manufactured with a strong lower skirt without 21 ncreasing the difficulty of removing the tear band by the ~ ;
22 consumer. Also, the cap can be inserted onto a container 23 ~ith a tighter fit thereby realizing an improved seal for 24 the container contents. Moreover, since the score line in ' the cap of this invention does not bisect the lower bead, 26 this cap is not burdened by the difficulty in tearing 27 the lower skirt from the cap as experienced with many of 28 the prior art capsO ~
29 ~' ~ , , ~ 37~7 2 ¦ DETAILED DESCRIPTION OF THE INVENTION

3 I When references are made to the accompanying drat~ings 4 ¦the similar characters of reference represent corresponding S ¦parts in each of the several views.
¦ Cap 1 is constructed in accordance with the present `
6 1 invention from a resilient and moderately flexible plastic 7 1 substance so that it will deform slightly to snap on and off 9 ¦of the container. Exemplary plastic materials which may be ~employed include polyethylene, polystyrene, polyvinyl, :
¦chloride, polyacrylates, polyamides, polypropylene, etc.

1~ ¦The preferred plastics are polyethylene and polystyrene.
13 1 Cap 1 is comprised of three difEerent sections, a ¦top disk 2, an outer skirt 4 and an inner skirt 6. The 14 Itop disk 2 is preferably a 1at ciroular plate having a 15 ¦substantially planer exterior surface. This flat exterior ~^
16 ¦surface provides a convenient place for labels or . ~ .
17 ¦instructional material. It should be recognized that the -~
18 ¦disk can hav~ a shape other than circular. For example tha 19 ¦disk can be rectangular, oval, or other. In a preferred ¦embodiment the disk is circular and extends beyond the 21 ¦cylindrical outer skirt to form a circumferential lip 10 ~ ;
laround the cap. This lip thereby provides a convenient 23 ~eans for facilitating the removal of the upper portion Of 1 the cap from the container. Thus, the consumer; after l removing the tear band from the cap, can open the container 26 by applying pressure upwardly on the lip 10 by the thumb 27 lor finger. This action will unseat the upper bead from the 28 ¦upper groove and allow the cap to slide off the container neck.
29 ¦ The outer skirt 4 of Cap 1 is integrally attached ¦to the top disk 2 and extends substantially perpendicularly 31 ¦from the planner surface of the disk. The outer skirt 4 32 ¦is a thin-walled cylindrical shell and is composed of the , . , . ` ! '. ' ` ' . , ` .

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1 thin shell, an upper score line 14, a lower score line 2 16, tear tab 24, an upper circumferential bead 18 and a 3 lower circumferential bead 20. The thickness of the skirt `
4 is not critical to the practice of -this inven-ti.on as long as the cap is sufficiently resi.lient to allow the interna].
6 beads 18 and 20 to expana over -the wide areas of the container ~ -7 neck and snap into the container grooves without tearing of the 8 cap or container. Generally, however, the skirt thickness 9 is governed by economics with the thinnest functional cap being praferred. Usually the thin shell will have a 11 thickness ranging from 0.3 millimeters (mm) to 1.5 mill-12 imeters and more usually from 0.5 mm to 1 mm.
13 The uppe~ score line 14 extends circumferentially 14 around ~he skirt 4 forming a aircular weakened line entir~y enclosing the skixt. 'rhe score line 14 may be ma~e on 16 either the inn~r or oUter surface of the skirt.
17 Th~ Iower score line 16 is the same as ~he upper 18 score line exaept that it is disposed at a lower position 19 around the skirt. Like the upper score line, the lower ~
20 score line may be made on either the inner or outer surface `
21 of the skirt. The portion of the outer skirt between 22 core line 14 and score line 16 is the tear band 22.
23 ~his band is removed when the consumer wishes to open the 24 container and after it ls removed from the cap i-t is discarded. Because it is discarded, it is preferred to make 26 the band as narrow as possible without weakening the band to 27 the point where it could break during removal. Generally, the 28 tear band will range in width from 2 mm to 10 mm.
29 A tear tab 24 is attached to the tear band 22 and provides a means for the tear band to be torn from the cap by the 31 onsumer. The tear tab 24 may be any projecting tab which 32 allows the consumer to easily grasp the tab by the fingers.

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1 In a preferred embodiment, the -tab 24 extends ou-twardly ~rom 2 the tear band 22 and then downwarclly terminating a position 3 below the rim 26 of its outer skirt. By extending the tab 4 below the rim of the skirt, the tab may be used as a guide in automatic capping machines to guide the cap within 6 the machine and onto the container. In order to increase 7 the friction between the-fingers and tear tab, the tab is 8 preferably grooved with serrates 28 or the like.
9 A weakened area extends from the lower score line 16 -to the upper score line 14 substantially adjacent to~ tear 11 tab 24. The weakened area is provided so that the tear band 12 may be a gap in the band such as shown in the drawings 13 or may be a score line extending vertically between the two 14 aircumferen~iàl score lines 16 and 14.
Upper an~ lower internal circumferential bea~s ar~
16 provided ar~und the i~terlor of the outer skirt W~iCh fit 17 into groov~s in the aontainer antl hold the àap 1rmly 18 onto the con~alner neak. ~he uppax bead 18 is disposed 19 above the first score Line between the score llne 14 and ;
the top disk 2. The lower bead 20 is disposed below the 21 second score line between the score line, 16 and the 22 rim 26. The beads 18 and 20 are substantially uniform ;~
23 raised surfaces projecting inwardly from the skirt. In 24 one embodiment, the raised surface has a semi-cïrcular cross-section; in another it may be triangular. In 26 another embodiment, the raised surface may extend substantially 27 horizonally at its upper area and curve downwardly and 28 outwardly to the skirt at its lower area. The type, shape 29 and size of the beads can be the same as the beads discussed in U.S. Pa-tent No.s 3,338,446 and 3,672,528, which patents 31 are herein incorporated by reference.

32 The inner skirt 6 of cap 1 is integrally attached to .
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3~Q37~J7 1 the top disk 2 inward from the outer disk and extends 2 substantially perpendicular to the planner surface of the 3 disk. The inner skirt 6 is disposed inward and enclosed 4 within the chamber of the outer skirt and substantlally co-axial therewith. The inner skirt 6 extends for a distance 6 shorter than the outer s~irt and preferably terminates -before the first score line 14. More preferably the inner 8 skirt 6 termina-tes adjacent to or before the upper bead 9 18. The inner skirt 6 and the outer skirt 4 form an annular chamber in which the container neck is held. The inner skirt 11 is disposed so that it tightly fits into the opening of the 12 container néck, and the outer ski~t is disposed so that it 13 ~ightly its Along the ou-~side o the container n~ck. The 14 annular chamber 34 i~ preferably ~haped at its top with rounded interlor surface 28 to provide a seal with the rounded 16 exterior surface 30 of the container neck lip. The terminus 17 of the inner skirt 6 is preferably slanted inward such 18 as by inwardly curvin~ extexior surface 32. Terminating the 19 inner skirt in this manner allows the inner skirt to guide the top of the container neck into the annular chamber 34.
21 The caps are conveniently prepared by an injection mold 22 technique. Although the injection mold is by far the most 23 convenient, i.t is recognized that other methods for making ¦
24 the cap can be used. ;~
The cap 1 is primarily ~or use with a thin-walled 26 plastic container 36. The container is usually fairly ;~
27 strong and lightweight. Although the walls are reasonably 28 rigid, there is generally suEficient resiliency in the 29 plastic materials so that they will flex slightly u~der pressure.
31 The shape of the lower portion of the container 36 is -32 subject to considerable variation as is well understood in '~' _g_ , .... . ~ , - ,: . : - , ~37~
1 he plastic bottle art. Neck 38 projects upwardly from the 2 ain portion of the container. Neck 38 is an elongated 3 pwardly-inwardly shaped cylindrical thin-walled shell. At 4 he upper end of neck 38 are two peripherally disposed ~
S ircumferential grooves 40 and 42. A cylindrical shell ~;
6 4 extends up from the upper groove 40 and terminates, in perferred embodiment, in a sr,looth rounded container lip : 8 0. The upper groove 40 is disposed so that it encounters 9 ead 18 of cap 1 when the cap is inserted onto the container.
he lower groove 42 is disposed so that it encounters bead 20 li f cap 1 when -the cap is inserted onto the container. The 12 ircumferentiàl groove~ may be of triangular, clrcular, 13 ectangular or other cross~section and are preferably of the 14 ame cross-section as the cap beads. The type, size and hape of the container can be as sho~n and described in 16 .S. Patent N~. 3,338,446.
17 In using the cap and the combination of this invention, 18 Eter the container 36 has been filled with a product, the ;
19 ap 1 is installed. Automatic machinery may be used for his purpose. Outer skirt 4 is slipped on outside neck 21 8 and a downward pressure is applied. The top rim of the - 22 ontainer neck encounters slanted surface 32 which guides the `~ 23 ip 30 between skirts 4 and 6. As the downward pressure ~ ~-- - 24 s continued, ~he beads 18 and 20 slide over the surface of eck 38 and snap into grooves 40 and 42. The flexible nature 26 f the plastic material of which the cap is Eabricated, permits 27 his temporary deformation of the parts. Thus assembled, the `
28 ontainer is sealed since the cylindrical shell 44 is held 29 ightly between skirts 4 and 6 and the rounded lip 30 is ontacted by the rounded interior surface 28 of the cap. It is 31 early impossible to remove the cap 1 while skirt 4 is intact. ;
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1 When the consumer wishes to open the container, he ~rips the tear tab 24 and pulls outwardly tearing tear 3 ~and 22 from the outer skirt 4. The lower portion of the ~uter skirt remains on the container completely severed from cap 1. The portion of the cap above the tear band comprises a re-closure cap for the container 36. Such 7 re-closure cap may be pried off by lifting on lip 10.
8 rhis operation is possible where there is only a single ;;
9 bead 18 in position in groove 40. When skirt 4 is intact ;~
before the tear band is removed, it is almost impossible 11 for a consumer to dislodge both bead 18 and bead 20. The 12 closure portion of cap 1 may be replaced by pushing 13 downwardly on disk 2. The bead 18 then snaps into groove 14 4~ and the cap is again positioned. The c~osure ~ay be performad as may times as desired.
16 ~lthough the foregoing invention has been described 17 in some dètAil, by ~ay of illustration and examplé, for 18 purpose~ o~ alarity and understanding, it is understood ~`
19 that certain changes and modifications may be practiced 20 within the spirit of the invention and such are within the ~ `~
21 scope of the invention as defined by the appended claims.

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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A deformable plastic cap comprising (1) a top disk, (2) a cylindrical thin-walled outer skirt integrally attached to and extending substantially perpendicularly from said disk and (3) a cylindrical inner skirt integrally attached to and substantially perpendicular to said disk positioned inward and enclosed within said outer skirt and substantially co-axial therewith and extending for a shorter distance than said outer skirt; said outer skirt scored and weakened along a circumferential first score line downwardly spaced from said disk, and scored and weakened along a circumferential second score line spaced downwardly from said first score line to form a weakened cylindrical band within said outer skirt, a tab attached to said cylindrical band and extending from said band and outwardly from said outer skirt, a weakened area extending between said first score line and said second score line immediately adjacent said tab, a narrow radial first bead extending circumferentially around the inside and integrally attached to said outer skirt between said first score line and said disk, and a narrow radial second bead extending circumferentially around the inside and integrally attached to said outer skirt below said second score line.

2. The deformable cap defined in Claim 1 wherein said first bead and said second bead have a semi-circular cross-sectional area.

3. The deformable cap defined in Claim 1 wherein said top disk has a flat circular lip extending outwardly beyond said outer skirt.

4. The deformable cap defined in Claim 1 wherein said cap is made of polyethylene or polystyrene.

5. The deformable cap defined in Claim 1 wherein said weakened area is a score line connecting said first score line with said second score line.

6. The deformable cap defined in Claim 1 wherein said first score line and said second score line are made along the outside of said outer skirt.

7. In combination, (1) a container with a cylindrical neck having an opening through said neck to said container, said neck having an circumferential upper groove around the outside of said neck and a circumferential lower groove around said neck spaced downward from said upper groove, and (2) a deformable plastic cap comprising a top disk, a cylindrical thin-walled outer skirt integrally attached and substantially perpendicular to said disk and of a sufficient diameter so as to fit around the exterior of said neck, a cylindrical inner skirt integrally attached and substantially perpendicular to said disk inwardly spaced from said outer skirt and co-axial therewith so as to fit within said opening; said outer skirt scored and weakened along a circumferential first score line downwardly spaced from said disk, and scored and weakened along a circumferential second score line spaced downwardly from said first score line to form a weakened cylindrical band within said outer skirt, a tab attached to said cylindrical band and extending downwardly from said band and outwardly from said outer skirt, a weakened area extending between said first score line and said second score line immediately adjacent said tab, a narrow first bead extending circumferentially around the inside and integrally attached to said outer skirt between said first score line and said disk and spaced so as to fit into said upper groove, and a narrow radial second bead extending circumferentially around the inside and integrally attached to said outer skirt below said second score line and spaced so as to fit into said lower groove.