US3767077A

US3767077A - Pilfer-proof closure cap

Info

Publication number: US3767077A
Application number: US00245844A
Authority: US
Inventors: J Rhoades
Original assignee: Kaiser Aluminum and Chemical Corp
Current assignee: Kaiser Aluminum and Chemical Corp
Priority date: 1972-04-20
Filing date: 1972-04-20
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

This invention relates to a pilfer-proof closure for a bottle top and the like having a threaded neck portion and a locking shoulder. The closure is provided with a sealing and locking ring adapted to be turned under the locking shoulder of the bottle top when the bottle top is sealed and this ring contains a plurality of circumferentially spaced vertical weakening lines or scores. The scores advantageously have tapered or differential depths which provide an improved controlled fracture and outward flaring of the sealing ring segments and overall ring when the pilferproof closure is twisted during opening of the bottle.

Description

United States Patent n 1 Rhoades Oct. 23, 1973 PlLFER-PROOF CLOSURE CAP Primary ExaminerDonald F. Norton [75] inventor: John S. Rhoades, Lafayette, Calif. Atwmey Paul Calrow at [73] Assignee: Kaiser Aluminum & Chemical 57 ABSTRACT Corporauon Oakland This invention relates to a pilfer-proof closure for a [22] Filed: Apr. 20, 1972 bottle top and the like having a threaded neck portion and a locking shoulder. The closure is provided with a [21] Appl' 245844 sealing and locking ring adapted to be turned-under the locking shoulder of the bottle top when the bottle [52] U.S. Cl. 215/42 top is sealed and this ring contains a plurality of cir- [51] Int. Cl B656 41/34 cumferentially spaced vertical weakening lines or [58] Field of Search 215/7, 42 scores. The scores advantageously have tapered or differential depths which provide an improved controlled [56] References Cited fracture and outward flaring of the sealing ring seg- UNITED STATES PATENTS ments and overall ring when the pilfer-proof closure is 3,601,273 3 1971 Kutcher 215 7 twsted dmng Pemng the 14 Claims, 7 Drawing Figures PAIENIEnncI 23 ms FIG.

FIG.2

FIG.4

W IIIIA 30 &

IIIII'IIIIII FIG.7

PILFER-PROOF CLOSURE CAP BACKGROUND OF THE INVENTION' This invention relates to a pilfer-proof closure for bottles, jars and containers having externally screwthreaded necks. More particulary, it relates to an improved pilfer-proof closure cap formed of a thin gauge ductile metal such as aluminum and preferably one from an extra-hard temper aluminum base alloy. The particular pilfer-proof closure cap of this invention also constitutes an improvement over those caps disclosed in U.S. Pat. No. 3,601,273, issued Aug. 24, 1971, and Canadian Pat. No. 479,892, issued Jan 1, 1952, in that the sealing ring of the instant closure cap has unique tapered scores which function, when the cap is twisted and sufficient torque applied to the sealing ring, to effect a controlled fracturing and outward flaring and release of the ring from the bottle to which it is attached without the ring disintegrating in an injurious fashion in the hands of the user. Because of this controlled fracturing, the sealing ring will remain in firm depending contact with the main skirt portion of the closure during the times the pilfer-proof closureis removed from the bottle or container. Thus, the sealing ring part of the closure cap will not be left wholly or partly on the bottle or .left dangling in a dangerous fashion from the main body of the closure cap at only one point as in the case with previously developed pilfer-proof tops of the type shown in various U.S. and foreign patents on the subject, such as U.S. Pat. No. 3,303,955, issued Feb. 14, 1967, Canadian Pat. No. 553,475, issued Feb. 25,- 1958, and British Pat. No. 1,021,712, published Mar. 9, 1966.

In prior art caps represented, for example, by the aforesaid U.S. Pat. No. 3,60l,273,the scores or weakening lines that were impressed in the depending sealing ring were not impressed or located in the ring in any special fashion. It appears instead that during the design of these caps, most attention was directed to and reliance placed upon the structure of the so-called bridges or ties between the closure cap proper and the depending sealing ring for allegedly controlling the fracturing and desirable outward flaring of the sealing ring during opening of the bottle to which the cap is attached. This reliance has not been well placed in that tops made with specially designed bridge or hinge elements have not always effectively controlled the fracture of the sealing ring on a day-to-day basis and under all the usual and expected types of opening conditions and pressures. For example; if an exceptionally hard and powerful twist were given to the cap of U.S. Pat. No. 3,601,273, the sealing ring of the cap could either disintegrate completely or partly in'the hands of the operator, and/or partly break away from the main body of the cap whereby at least part of the ring would still be left on the cap in a distorted condition and with ragged edges protruding. The overall result was that sharp metal edges were presented to the user that could injure the user unless he or she handled the closure cap with care.

The demands of the ecology today require more and more recycling of containers, such as bottles, and, if anything, these demands will increase and not decrease. Consequently, pilfer-proof closures of the type shown in U.S. Pat. No. 3,303,955, where the sealing band attached to the closure skirt of the cap by virtue of bridges, fractures upon opening so that the band stays with the container at all times, are no longer universally acceptable. The reason for this is that in order to recycle bottles to which the bands remain attached, the bands first have to be removed at considerable expense. This means then that as to all bottles that can be legally and practically recycled pilfer-proof closures of the instant type will become more and more in demand and will have to be made as fool-proof and safe as reasonably possible.

SUMMARY OF THE INVENTION Accordingly, it is the primary purpose of this invention to provide a pilfer-proof closure cap which, because of the tapered structure or graduated depth of the scores or weakening lines in the sealing ring thereof, will possess improved controlled fracture and outward flaring characteristics such that the ring will ordinarily correctly release its grip upon the locking shoulder of a bottle or container whenever any torque above the minimum is applied to the cap. In other words, the container cap or closure of the invention is designed to ordinarily open up and release its grip of a bottle top uniformly under all the normal varying conditions of handling and engagement by the user. The scores or weakening lines are designed to produce a substantially fully controlled and uniform opening of the various parts of the sealing ring of the cap and without breaking the bridges linking the ring to the cap proper. Furthermore, because of the manner in which the sealing ring of the cap is controllably fractured, the sealing ring or band will not be left behind on the container after the seal is broken. The cap can also be easily replaced on the bottle on a repetitive basis because the ring segments will have been pushed out far enough to clear the bottle threads and no problem will ordinarily be encountered in replacing and rethreading the cap about the threads of the bottle or container.

BRIEF DESCRIPTION OFTHE DRAWING FIG. 1 is an elevational and partly sectional view of the pilfer-proof closure cap of the instant invention prior to the time that it is applied to a container such as a bottle provided with a threaded neck portion;

FIG. 2 is an elevational view also partially in cross section and illustrates how the pilfer-proof closure cap of the instant invention is disposed on a bottle and how it is pressed into engagement with the threaded portions of the bottle;

FIG. 3 is a perspective view of the closure cap of the instant invention after it has been removed from the bottle and the depending sealing ring controllably fractured in a uniform manner into a plurality of outwardly flared segments;

FIG. 4 is an enlarged fragmentary sectional view taken within the circumscribing line 4 of FIG. 1 and illustrates in more detail the special configuration that is given to the scores or weakening lines of the skirted sealing ring; a

FIG. 5 is a fragmentary sectional view taken generally along the line 5-5 of FIG. 4;

FIG. 6 is a fragmentary sectional view taken generally along the line 6-6 of FIG. 4; and

FIG. 7 is a fragmentary sectional view taken generally along the line 7-7 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With further reference to the drawing, the pilferproof cap 5 shown therein is designed for sealing or \closing a container, such as a bottle 10, in the manner illustrated in FIG. 2. In the bottle of FIG. 2, the top of the bottle neck terminates in an externally screw-fitted portion 12. The bottom of screw-threaded portion 12 terminates in a bulbous portion 14, the bottom edge of which constitutes a shoulder 16 that can be somewhat slanted or inclined, if desired.

The closure cap of the invention is made from a cupshaped shell of thin ductile metal such as aluminum and preferably of an extra-hard temper aluminum base alloy whereby it is provided with a top 18 to which a suitable plastic liner 19 has been applied and a cylindrical skirt 20. Overall skirt 20 is subdivided into a top portion 22 and a bottom portion 24. Bottom portion 24 in effect constitutes an overall sealing and locking ring with the top and

bottom portions

22 and 24 in turn being separated by the annular slot or slit 26 separated into slit segments 27 by a plurality of narrow bridge elements 28.

The bridge elements are all preferably of the same uniform width of several thousandths of an inch in contrast to prior art pilfer-proof closure caps wherein certain of the bridges were wider than others purportedly to effect a controlled and preselected fracturing of the bridges and the selective retention of the sealing ring 24 with the rest of the cap 5 when the cap 5 was removed as a unit from the bottle. The bottom portion 24 or sealing ring is advantageously provided with an annular outwardly bulged stiffener or buffer ring 29 and a plurality of uniformly and circumferentially disposed unique vertical weakening scores 30 impressed in outer wall 34 of ring 24.

In order to obtain a better understanding of the function of ring 24 and scores 30, the manner in which the cap is affixed to and removed from a bottle will now be described.

When the cap 5 is placed upon the bottle or container as indicated in FIG. 2, the skirt portion 20, which as initially formed is generally flat, except for the

knurled portions

36 and 38, is rolled into place against the threaded area 12 of the bottle top by appropriate sealing machinery, so that a part of skirt is formed with threads 12' which match the threads of threaded section 12 of the bottle top 10.

To open a bottle 10 provided with a pilfer-proof closure cap of the instant invention, the closure cap 10 is simplygripped by the operator, particularly in the areas of

knurled portions

36 and 38, and twisted to the off position. The top section 22 of skirt 20 which is now screw-threaded by virtue of the rolled-on bottle matching threads 12' being formed or impressed upon the container top as indicated in FIG. 2 begins to be moved up and against the bottom surface 16 of the screwthreaded section 12 of the bottle. As the cap moves upward or tends to move upward, it entrains the bottom unthreaded portion 24 of the skirt 20 which has been closed about the shoulder 16. This bottom portion, however, tends to remain in engagement with the shoulder 16 and cannot follow the upward ascent of the top portion 22 of skirt 20 unless there is a proper fracture of the ring 24 in the areas of the scores 30.

The slits or scores 30 in the cap of the invention as indicated particularly in FIGS. 4-7, are so impressed or coined on one side of the thin wall of the lower skirt section 24, such as the outside wall 34 and preferably intermediate or offset from the bridge elements 28 whereby they are gradually tapered in depth from the top to the bottom of the sealing ring 24 and with the depth of the score being slightly smaller at the top thereof than at its bottom in a manner analogous to that shown in U.S. Pat. No. 3,195,765, issued July 20, 1965. For example, in the case of where the metal thickness of the cap including its skirt 20 is on the order of between 0.0085 inch to 0.0095 inch in thickness, the depth a of a score 30 at the top thereof as shown in FIG. 6 could be on the order of 0.003 inch deep while the depth of the bottom portion of the score 30 as shown in FIG. 7 could be on the order of 0.005 inch.

If desired, and as particularly indicated in dotted lines in FIG. 4, the score can also be somewhat tapered in the horizontal plane or direction in addition to being tapered or of a graduated depth in the vertical plane or direction. Thus, at the time a twisting pressure is exerted on the sealing ring 24 as the cap is unscrewed to remove the same from its bottle there will be the least amount of metal and least amount 'of resistance offered by the metal in the ring in the lower area b of the bottom of a score channel or the part of the metal sealing ring in direct contact with the shoulder or ring bearing surface 16 on section 14 of the bottle. Put another way, when a twisting pressure is applied to the ring as the cap 5 tries to move up upon being turned, the thinnest parts of themetal ring 24 adjacent the bottoms of the scores 30 will break first and result in a controlled, uniform and substantially simultaneous fracture of all parts of the ring 24 and a uniform outward flaring and formation of the different ring segments 40 constituting the fractured ring. Thus, the ring 24 will not tend to fracture into irregular and jagged sections which can be injurious to the fingers of the user. Instead, the ring 24 though segmented will remain substantially intact and fully attached to the closure cap proper by-way of the bridges 28.

In a further advantageous embodiment of the invention, reference being made particularly to FIGS. 4 and 5, the scores 30 of graduated depths extendfrom bot tom 32 of the cap upwardly to terminate preferably at the point of mergence X of rib 29 with the lower-skirt wall 34 of ring 24 and at a point belowthe top of ring 24. At the most, scores 30 should penetrate only slightly into stiffener or buffer rib 29. This manner of score line termination allows rib 29 to act as a fracture barrier and to resist further undesirable fracture of the sealing ring in the areas of scores 30 above the normal upper terminus of the scores so that the ring 24 will not split in two or more parts i.e., disintegrate in the band of the operator and/or completely or partly break away from the cap proper.

By virtue of the scores 30 being formed or impressed in the skirt wall in the manner aforedescribed, that is, with a tapered depth and with the weakest portion or thinnest portion of the ring being located at the bottom of the scores where the first fracturing is desired, the ring will advantageously controllably fracture in the score area just up to but not substantially beyond stiffener rib 29 and into the slit areas '27. By virtue of the uniform camming action of the shoulder 16 substantially simultaneously on all parts of the ring as the cap 5 ascends upon twist off, the segments 40 of ring 24 will uniformly flare or fan out and slip over and adequately clear the shoulder 16.

The uniform breaking or fracture of ring 24 in the areas of scores 30 results primarily from the tapered or differential depth of the scores. A further assist is given by the stiffener rib 29 when the scores advantageously terminate in the area of the junction of rib 29 and the skirt wall 34 of ring 24. This tapered depth of the scores provides a further manufacturing advantage in that it compensates for many manufacturing tolerances or slight imperfections which may occur during mass production of the pilfer-proof cap of the instant invention.

An advantageous embodiment of the invention has been shown and described. It is obvious that various changes and modifications may be made therein without departing from the invention as defined by the appended claims, wherein:

What is claimed is:

1. A metallic pilfer-proof closure cap for bottles and the like provided with a threaded neck and a lock shoulder, said cap being made of thin ductile metal and having interconnected top and skirt portions, the upper section of the skirt being susceptible to being deformed about the threaded neck of a bottle and the lower section of the skirt comprising a sealing ring that is adapted to be at least partly turned inwardly and into sealing engagement with the locking shoulder of said bottle, said sealing ring being separated from and interconnected to the main part of said skirt by alternate horizontally arranged slits and bridge elements and a plurality of vertically arranged scores forming weakening lines selectively and circumferentially impressed in the sealing ring and generally extending from points located below the top of the ring to the bottom thereof and said scores being of graduated depths whereby an individual score has a greater depth at one end thereof than at another end.

2. A pilfer-proof closure cap as set forth in claim 1 wherein the greater depth of a score occurs at the bottom portion of the sealing ring.

3. A pilfer-proof closure cap as set forth in claim 1 wherein said bridge elements are all of uniform width.

4. A pilfer-proof closure cap as set forth in claim 1 wherein said scores in said sealing ring are offset from the bridge elements.

5. A pilfer-proof closure cap as set forth inv claim 1 wherein the wall thickness of the skirt and sealing ring is on the order of from 0.0085 inch thickness to 0.0095 inch thickness and said scores are impressed in the ring to a depth of about 0.003 inch at the top portion of the score and to a depth of about 0.005 inch at the bottom of the score and skirt ring.

6. A pilfer-proof closure cap as set forth in claim 5 wherein the cap is made from an aluminum alloy that has an extrahard temper.

7. A pilfer-proof cap as set forth in claim 5 wherein the bridge elements are all of uniform width and the scores in the sealing ring are offset from the bridge elements.

8. A metallic pilfer-proof closure cap for bottles and the like provided with a threaded neck and a locking shoulder, said cap being made of thin ductile metal and having interconnected top and skirt portions, the upper section of the skirt being susceptible to being deformed about the threaded neck of a bottle and the lower section of the skirt comprising a sealing ring that is adapted to be at least partly turned inwardly and into sealing engagement with the locking shoulder of said bottle, said sealing ring being separated from and interconnected to the'main part of said skirt by alternate horizontally arranged slits and bridge elements an annular reinforcing rib located in the top of said sealing ring and a plurality of vertically arranged scores forming weakening lines selectively and circumferentially impressed in the sealing ring and generally extending from the bottom areas of said reinforcing rib to the bottom of the sealing ring and said scores being of graduated depths whereby an individual score has a greater depth at one end thereof than at another end.

9. A pilfer-proof closure cap as set forth in claim 8 wherein the greater depth of a score occurs at the bottom portion of the sealing ring.

10. A pilfer-proof closure cap as set forth in claim 8 wherein said bridge elements are all of uniform width.

11. A pilfer-proof closure cap as set forth in claim 8 wherein said scores in said sealing ring are offset from the bridge elements.

12. A pilfer-proof closure cap as set forth in claim 8 wherein the wall thickness of the skirt is on the order of from 0.0085 inch thickness to 0.0095 inch thickness and said scores are impressed in the sealing ring to a depth of about 0.003 inch at the top portion of the score and to a depth of about 0.005 inch at the bottom of the score.

13. A pilfer-proof cap as set forth in claim 12 wherein the bridge elements are all of uniform width and the scores are offset from the bridge elements.

14. A pilfer-proof closure cap as set forth in claim 8 wherein the cap is made from an aluminum alloy that has an extra-hard temper.

i l 4! t 0

Claims

5. A pilfer-proof closure cap as set forth in claim 1 wherein the wall thickness of the skirt and sealing ring is on the order of from 0.0085 inch thickness to 0.0095 inch thickness and said scores are impressed in the ring to a depth of about 0.003 inch at the top portion of the score and to a depth of about 0.005 inch at the bottom of the score and skirt ring.

8. A metallic pilfer-proof closure cap for bottles and the like provided with a threaded neck and a locking shoulder, said cap being made of thin ductile metal and having interconnected top and skirt portions, the upper section of the skirt being susceptible to being deformed about the threaded neck of a bottle and the lower section of the skirt comprising a sealing ring that is adapted to be at least partly turned inwardly and into sealing engagement with the locking shoulder of said bottle, said sealing ring being separated from and interconnected to the main part of said skirt by alternate horizontally arranged slits and bridge elements an annular reinforcing rib located in the top of said sealing ring and a plurality of vertically arranged scores forming weakening lines selectively and circumferentially impressed in the sealing ring and generally extending from the bottom areas of said reinforcing rib to the bottom of the sealing ring and said scores being of graduated depths whereby an individual score has a greater depth at one end thereof than at another end.