US3815771A

US3815771A - Linerless closure cap

Info

Publication number: US3815771A
Application number: US00260366A
Authority: US
Inventors: W Marks
Original assignee: Anchor Cap and Closure Corp
Current assignee: Anchor Hocking Packaging Co
Priority date: 1972-06-07
Filing date: 1972-06-07
Publication date: 1974-06-11
Anticipated expiration: 1991-06-11

Abstract

The invention is a closure cap for sealing glass or plastic containers. The one piece closure cap is characterized by having integral sealing means formed as a portion of the inner surface of the cap for providing a seal without the use of a separate liner such as cut liners or flowed-in liners normally used in closure caps. The sealing means provided in the caps of this invention comprises downwardly extending sealing rings or members having tapered sealing surfaces for engaging corner portions of the container finishes and with additional sealing rings positioned to engage other spaced portions of the container finishes.

Description

I 1 LINERLESS CLOSURE CAP [75] Inventor: Walter J. Marks, Mississauga,

Ontario, Canada [73] Assignee: Anchor Cap & Closure Corporation of Canada, Limited, Toronto, Ontario, Canada 22 Filed: June 7, 1972 [21 l I Appl. No.: 260,366

52 11.5. CI ..21s/34 4, 2 5/p (1. 1

[4 June 11, 1974 667,287 9/1964 Italy ..215/D1o.1

Primary Examiner-Donald F. Norton Attorney, Agent, or Firm-Holland, Armstrong, WiIkie & Previto [57] ABSTRACT corner portions of the container finishes and with additional sealing rings positioned to engage other spaced portions; of the container finishes.

7 Claims, l2 Drawing Figures 51 Int. Cl .J B6 5 d 41704' [58] Field of Search 215/40, DIG. I

[56] References Cited UNITED STATES PATENTS 3,074,579 1/1963 Miller 2l5/DIG. 1

3,125,237 3/1964 Kitterman 2I5/DIG. l 3.180.534 4/1965 Duda 215/40 X 3,428,208 2/1969 Kosar 215/40 UX FOREIGN PATENTS OR APPLICATIONS 960,443 6/1964 Great Britain r. 215/40 l LINERLESS CLOSURE CAP.

} BACKGROUND OF THE INVENTION The present inventionrelates to'improved closure caps for sealing containers fonned of glass or plastic or other materials and more particularly to such closure caps where the sealing means is an integral portion of the unitary cap formed with the cap whereby separate flowed-in or pre-cut sealing liners are eliminated.

Linerless'closure caps molded as a single piece and including integral sealing rings have previously been proposed and in some cases produced. These prior closure caps have been satisfactorily employed in certain cases for products presenting no critical sealing problems. Prior linerless cap designs, however, have not heretofore provided caps for forming acceptable high pressure seals or seals which are useful with highly volatile products where evaporation and product loss must be held at an absolute minimum. The closure caps in accordance with the present invention, for example, have been found to provide seals for resisting pressures in excess of 40 pounds and for sealing alcoholic beverages with insignificant product loss through evaporation and leakage. Closure caps in accordance with the present invention have been found useful in a variety of sealing situations which previously required 'and more expensive and the less easily manufactured and handled closure caps having separate sealing liners.

Accordingly, an object of the present invention is to provide an improved linerless closure cap.

Another object of the present invention is to provide a molded linerless closure cap particularly useful for effectively sealing high pressure products.

Another object of the present invention is to provide an improved molded linerless cap for forming an effective seal for highly volatile products including alcoholic beverages and other easily vaporized products.

Another object of the present invention is to provide an improved linerless closure cap for sealing glass and plastic containers.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described or will be indicated in the appended claims, and 'various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the inventionhas been chosen for purposes of'illustration and description and is shown in the accompanying drawings, forming a part of the specification, wherein:

FIG. 1 is a perspective view partially in section illustrating a preferred embodiment of a closure cap in accordance with the present invention.

FIG. 2 is a top plan view of the closure of FIG. 1.

FIG. 3 is an enlarged vertical sectional view of the closure cap of FIG. 1 before application to a container.

FIG. 4 is an enlarged. vertical sectional view of the closure corresponding to FIG. 3 after application to a container.

FIGS. 5 and 6 are enlarged vertical sectional views of alternate embodiments of the closure cap of FIGS. 1 4 according to the invention.

closure cap of FIG. 7.

FIG. 7 is a perspective view partially cut away illus- FIG. 10 is an enlarged sectional view of the closure corresponding to FIG. 7 after'application to a container. Y

FIGS. 11 and 12 are alternate embodiments of the DESCRIPTION OF THE PREFERRED EMBODIMENTS vention includes a cover 2 and a depending skirt 3 ineluding container engaging threads 4. The outer surface of the skirt may include suitable knurls or other gripping elements 5 to facilitate the removal and reapplication of the closure cap 1. The cover 2 and skirt 3 together with the threads 4 and the knurls 5 and a container sealing means which will be further described below, comprise a unitary or one piece molded cap formed on conventional cap molding machinery.

' A preferred embodiment of the container sealing means on the cap 1 comprises a plurality of downwardly directed sealing ribs or rings 6, 7 and 8 as illustrated in detail in FIGS. 3 and 4. The embodimentillustrated in these figures is particularly adapted for application to a glass container 9 having a glass finish 10 of the general shape illustrated in FIG. 4. The sealing rings 6, 7 and 8 are seen to comprise downwardly directed tapered members having a generally triangular crosssection preferably in the form of a right triangle with the radially outward surfaces of the ribs being cylindrical. The radial outermost sealing ring 6 is seen to extend downwardly below the tips of the shorter inner sealing rings 7 and 8. The inner or flared surface 11 of this sealing ring is positioned to engage the outer edge 12 of the glass finish 10 moving diagonally across it and into sealing relationship with it in the manner illus trated in FIG. 4. When downward sealing movement of the closure cap 1 moves the outermost sealing rib 6 into this position,.'it is seen that the rib 6 has been bent or flexed outwardly thereby generating a substantial contact pressure betweenthe sealing ring 6 and the outer edge 12 of the glass finish 10. The glass finish 10 illustrated in FIG. 4 may be a conventional or standardized glass finish and may include a mold line in the form of the small step present at the outer edge 12 of the glass finish 10. g

In addition to the outermost sealing ring 6, the preferred embodiment of FIGS. 3 and 4 includes the additional similarly shaped but smaller sealing rings 7 and 8 positioned radially inwardly of the outermost ring 6 for engagement with spaced portions of the top 13 of the container finish 10 in the manner illustrated in FIG. 4.

FIG. 5-illustrates at 14 an alternate embodiment of the cap including a main outer ring 15 similar to ring 6 as described for FIGS. 3 and 4 and including a single inwardly positioned and smaller sealing ring 16 in place of the two ribs 7 and 8 employed in the embodiment of FIGS. 3 and 4. FIG. 5 also illustrates an alternate embodiment of the glass finish 17 which may be used with the cap of FIG. 5 as well as with the closure caps of FIG. 3 or FIG. 6. This alternate embodiment of the glass finish includes a flat flared or beveled corner 18 at the top outer edge of the glass finish 17. This angular portion 18 of the container finish is generally parallel to the inner or flared surface 19 of the sealing ring 16 or may have a slightly greater angle with the vertical than the surface 19 of the outer sealing ring 16 in its unapplied position. This permits the inner and flared surface 19 of the sealing ring 16 to align itself with the corner 18 of the glass finish 17 when the ring 16 is forced or bent outwardly after sealing to the position illustrated in FIG. 5.

FIG. 6 illustrates at 20 an additional embodiment utilizing a main sealing ring 21 alone. This ring 21 is similar to the main sealing ring 6 already described. The closure cap 20 of FIG. 6 is illustrated in position an another embodiment of the glass finish wherein the outer corner 22 of the glass finish is generally arcuate or rounded, as shown in FIG. 6, a satisfactory radius being of a general length of about one-half the depth of the sealing rib 21.

A preferred plastic for the closure cap described above and illustrated in FIGS. 1 through 6 is a polypropylene which provides a desirable degree of flexibility or softness for the above described sealing operation particularly with respect to the flexed main sealing rings and also with respect to the line sealing effect of the lesser or secondary sealing rings used to provide a seal at the top area of the glass finish.

The improved seal obtained with the closure cap 1 and container 9 as illustrated in FIGS. 1 through 4 has been tested for sealing a fifty percent alcohol solution in a glass container. Table 1 below contrasts the'liquid loss resulting from this test with the liquid loss using a conventional molded threaded closure employing a regular paper pulp and plastic lined cut liner. The results shown for the conventional paper lined closure cap are considered typical, however, the improved and simplified one-piece cap in accordance with the present invention is seen to provide not only satisfactory but significantly improved results with a markedly reduced evaporation loss. The pulp liner closure of Table II is seen to show an average weight loss of 0.3427 grams in a range from about 0.217 to 0.537 grams. The polypropylene closure of Table I is seen to show a markedly reduced average weight loss of 0.0227 grams in a reduced range of from about 0.009 to 0.035 grams. The tests for these tables were run on a group of containers stored for 60 days at a temperature of 105 F. with a liquid solution containing 50 percent alcohol.

TABLE 1 Startling Ilottlc with wulglit 4th day 4th day day 00 day linerless cap (grams) ruudlng loss reading :48

No. 1 75. 2330 75. 2300 .0030 N0. 2 74.1726 74.1718 0008 74.1637 0081) N0. 3 74. 415B 74. 4135 0023 74. 3811 0347 N0. 4 76. 0793 76. 0769 0024 76. 0647 0246 Average .0021 0227 TABLE 11 Starting Bottle with weight 4th day 4th day 60 day 60 day pulp liner (grams) reading loss reading loss N 0. 1 76. 0096 75. 9364 0732 75. 7706 2390 N0. 2 75. 1646 75. 0939 0707 74. 6275 5371 N0. 3 76. 5579 76. 5335 0264 76. 3411 2168 N0. 4 8725 75. 8082 0043 75. 41:47 3778 Average 0586 3427 TABLE I11 Polypropylene Metal CT Linerless Closure Control 95% Alcohol Solution Evaporation loss (7c) .0091 .024l Removal Torque Average (in.-lbs.) 10.0 20.5 Removal Torque Range (in-lbs.) (9-l I) (20-22) 80 Proof Whiskey Evaporation loss (72) .0090 .0 I 53 Removal Torque Average (in.-lbs.) 9.0 12.1 Removal Torque Range (in.-lbs.) (IO-14.5)

FIGS. 7 through 10 illustrate another embodiment of a linerless closure 25 utilizing a corner seal between a flared or sloping sealing surface 26 on the closure cap top 27 and the outer edge of the container 28 finish orring 29. This design is particularly useful in sealing plastic containers. In this embodiment, the one-piece molded closure cap 25 is preferably formed of a relatively hard plastic such as polystyrene which is harder than a typical polyethylene or other plastic container.

The one-piece molded closure cap 25 includes the usual top 27 and skirt 30 having interior container engaging threads 31 and an outer knurled gripping surface 32. Sealing surfaces and rings are provided on the underside of the cap top 27. The principal container sealing surface on the cap top comprises the flared or sloping outer sealing surface 26 positioned in the cap corner between the cap top 27 and the cap skirt 30. A

satisfactory angle for this surface 26 is about 45. The surface 26 is forced into sealing engagement with the outer edge 33 of the plastic container 28. The edge 33 preferably comprises a generally rectangular edge as illustrated at 33 in FIG. 10. A tight seal for containing high pressure and for permitting only minimal product evaporation results providing reduced evaporation of the general order described above in connection with the closure caps of FIGS. 1 through 6.

A preferred embodiment of the closure 25 is illustrated in FIGS. 7 through 10 which includes a second flared sealing surface 34 provided by a flared and radially outward surface 34 on a sealing ring 35. This ring 35 engages the inner edge 36 of the plastic container 28 rim thereby providing an additional seal. A third seal is provided in this preferred embodiment by the pointed lower edge 36 of a small intermediate sealing ring 37 positioned between the above described

surfaces

26 and 34 for engaging the top 38 of the container finish 29.

Where a relatively hard plastic, such as polystyrene, is used for the cap 25 and where a softer plastic, such as polyethylene, is used for the container the principal deformation at the sealing lines of surfaces occurs in the relatively softer plastic of the container 28.

FIG. 11 illustrates at 40 an alternate embodiment of the closure cap in which the central sealing ring is omitted and where the principal seal is provided by surface 41 at the outer edge 33 of the container 28 together with an additional seal being provided by the inclined surface 42 of an inner sealing ring 43.

FIG. 12 illustrates a further embodiment 44 wherein the innermost sealing ring is-omitted and where the plastic container is sealed by an inclined outer sealing surface 45 and a small pointed sealing ring 46 positioned above the top 38 of the container finish 29.

It will be seen that an improved linerless closure has been disclosed which is suitable for generaluse as well as for difficult packaging operations of volatile products. The closure is capable of resisting high pressures and of insuring low evaporation losses even for volatile products. The improved closure design, being formed in one piece in a relatively simple cap forming or molding operation, may be easily manufactured and may be provided at competitive costs.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

7 Having thus described my invention, I claim:

1. In a one-piece molded plastic closure cap having a cover and a depending skirt with container engaging means on the skirt for engaging cap engaging means on the container finish below a cap engaging edge on the outside of the container rim, the improvement comprising a first circular sealing ring of generally triangular cross-section positioned on the underside of the cap cover having a radially inner surface flaring downwardly andoutwardly for sealing engagement with the container rim outer edge corner, and a second sealing ring of lesser diameter and lesser vertical height than said first circular sealing ring and extending downwardly from the cap cover and having a generally triangular cross-section and being positioned so that its lower edge engages an upwardly facing surface of the containerrim radially inwardly of said cap engaging ther comprises a third sealing ring having a lesser diam eter than said second ring and a generally similar triangular cross-section for engaging the container rim radially inwardly of said second ring.

4. In a sealed package an open mouthed rimmed container sealed with a one-piece moldedclos'ure cap having a cover and a depending skirt with container engaging means on the skirt for engaging cap engaging means on the container finish below a cap engaging edge on the outside of the rim, the improvementcomprising a first circular sealing ring of generally triangular crosssection positioned on the underside of the cap cover having a downwardly and outwardly flared sealing surface in sealing engagement with the container rim outer edge, and a second sealing ring of lesser diameter and vertical height than said first circular sealing ring and extending downwardly from the cap cover andhaving a generally triangular cross-section and being positioned with its lower edge engaging .an upwardly facing surface of the container rim radially inwardly of said cap engaging edge of the container rim.

5. The sealed package as claimed inclaim 4 in which said closure cap is polypropylene.

claim 4 which- I said container is plastic and said closure cap is a rela tively harder plastic.

Claims

1. In a one-piece molded plastic closure cap having a cover and a depending skirt with container engaging means on the skirt for engaging cap engaging means on the container finish below a cap engaging edge on the outside of the container rim, the improvement comprising a first circular sealing ring of generally triangular cross-section positioned on the underside of the cap cover having a radially inner surface flaring downwardly and outwardly for sealing engagement with the container rim outer edge corner, and a second sealing ring of lesser diameter and lesser vertical height than said first circular sealing ring and extending downwardly from the cap cover and having a generally triangular cross-section and being positioned so that its lower edGe engages an upwardly facing surface of the container rim radially inwardly of said cap engaging edge of the container rim.

2. The closure cap as claimed in claim 1 in which said closure cap is polypropylene.

3. The closure cap as claimed in claim 1 which further comprises a third sealing ring having a lesser diameter than said second ring and a generally similar triangular cross-section for engaging the container rim radially inwardly of said second ring.

4. In a sealed package an open mouthed rimmed container sealed with a one-piece molded closure cap having a cover and a depending skirt with container engaging means on the skirt for engaging cap engaging means on the container finish below a cap engaging edge on the outside of the rim, the improvement comprising a first circular sealing ring of generally triangular cross-section positioned on the underside of the cap cover having a downwardly and outwardly flared sealing surface in sealing engagement with the container rim outer edge, and a second sealing ring of lesser diameter and vertical height than said first circular sealing ring and extending downwardly from the cap cover and having a generally triangular cross-section and being positioned with its lower edge engaging an upwardly facing surface of the container rim radially inwardly of said cap engaging edge of the container rim.

5. The sealed package as claimed in claim 4 in which said closure cap is polypropylene.

6. The sealed package as claimed in claim 4 which further comprises a third sealing ring having a lesser diameter than said second ring and a generally similar triangular cross-section engaging the container rim radially inwardly of said second ring.

7. The sealed package as claimed in claim 4 in which said container is plastic and said closure cap is a relatively harder plastic.