Gasket for press-on twist-off closure

Information

  • Patent Grant
  • 6786348
  • Patent Number
    6,786,348
  • Date Filed
    Thursday, May 24, 2001
    23 years ago
  • Date Issued
    Tuesday, September 7, 2004
    19 years ago
Abstract
A press-on, twist-off container assembly of the type that is used, for example, and baby food containers includes a container that has, as conventional, a finish portion with at least one external threadand a closure that is mounted on the container. The closure is of the press-on, twist-off type and includes a panel portion and a skirt portion that together define a generally cylindrical interior recess. As is conventional, a deformable gasket is mounted within the interior recess that has a thread engaging portion that is deformed so as to at least partially conform to the external threads of said finish portion of said container. The thread engaging portion advantageously has a plurality of inwardly extending raised flutes that are circumferentially spaced irregularly about the thread engaging portion. At least some of the flutes are in contact with at least one of the external threads at respective points of contact, and each external thread has a total distance spanned by such points of contact. As a result of the irregular spacing of the flutes, the container assembly will have an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads that is less than it would be were the flutes spaced regularly. Accordingly, the amount of torque that is necessary to remove the closure is comparatively reduced.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




This invention relates to a closure of the type which may be applied to a helically threaded finish of a glass or rigid plastic container by a press-on action, but which may be normally removed from the finish of the container only by a twisting action. More particularly, this invention relates to a press-on, twist-off closure that is constructed and arranged to optimize torque that is required to remove the closure.




2. Description of the Related Technology




Closure caps of the press-on turn-off variety for glass or hard plastic containers are known and are in wide commercial use. Such closure caps provide a hermetic seal with the container for packing and holding hot-fill or cool food or beverage products such as baby food. Typically, such closure caps have a metallic body including a top panel and a depending skirt portion, both of which are lined with a deformable gasket material. This construction permits the closure caps to be pressed vertically downwardly onto the mouths of glass containers that are provided with circumferential bands of thread formations. The gaskets are formed of suitable plastomeric compounds such as plastisols, which are capable of taking cold flow sets under compression and thereby form thread formations which compliment or mate with those on the neck of the containers. The closure cap may then be removed by a consumer by twisting it like an ordinary twist off closure to unscrew it from the container.




Conventional closure caps of the press-on turn-off variety tend in many cases to be difficult to open for some consumers because of the amount of torque that is required to remove the closure cap from the container. In an attempt to address this issue, certain closure caps that are in commercial use are provided with equally spaced flutes of raised gasket material on the inside of the depending skirt portion of the closure, which is intended to reduce the amount of contact surface between the gasket and the container threads. In actual practice, however, such closures do not always provide the desired removal torque. The inventors have determined that this is due in part to the fact that the equal and symmetrical spacing of the flutes provides too much contact with the embedded glass container threads.




A need exists for an improved closure cap of the press-on turn-off variety that is configurable so as to permit a significant reduction in the amount of torque that is required to remove the closure cap from a container, without compromising the quality of the hermetic seal that is formed with the container during packaging.




SUMMARY OF THE INVENTION




Accordingly, it is an object of the invention to provide an improved closure cap of the press-on turn-off variety that is configurable so as to permit a significant reduction in the amount of torque that is required to remove the closure cap from a container, without compromising the quality of the hermetic seal that is formed with the container during packaging.




In order to achieve the above and other objects of the invention, a press-on, twist-off closure for a container of the type that has at least one external thread on a finish portion thereof includes, according to a first aspect of the invention, a panel portion; a skirt portion depending downwardly from the panel portion, the skirt portion and the panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within the interior recess, the deformable gasket having a thread engaging portion that is mounted to an inner surface of the skirt portion, and wherein the thread engaging portion comprises a plurality of raised flutes that are integral with the deformable gasket and wherein the raised flutes are arranged in a plurality of separate groups about an inner circumference of the thread engaging portion, each of the separate groups containing at least two flutes, and wherein a circumferential distance between any two adjacent groups is greater than a circumferential distance between any two adjacent flutes within a group, so that when mounted on a container the total span of contact of the flutes across individual external threads of the container will be less than if the flutes were evenly spaced, whereby the torque needed to remove the closure from the container will be less than if the flutes were evenly spaced.




According to a second aspect of the invention, a press-on, twist-off container assembly includes a container having a finish portion with at least one external thread defined thereon; and a press-on, twist-off type closure including a panel portion; a skirt portion depending downwardly from the panel portion, the skirt portion and the panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within the interior recess, the deformable gasket having a thread engaging portion that is deformed so as to at least partially conform to the external threads of the finish portion of the container, the thread engaging portion having a plurality of inwardly extending raised flutes, and wherein at least some of the flutes are in contact with at least one of the external threads at respective points of contact, each external thread having a total distance spanned by such points of contact, and wherein an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads is less than an internal circumference of the thread engaging portion.




According to a third aspect of the invention, a press-on, twist-off container assembly includes a container having a finish portion with at least one external thread defined thereon; and a press-on, twist-off type closure including a panel portion; a skirt portion depending downwardly from the panel portion, the skirt portion and the panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within the interior recess, the deformable gasket having a thread engaging portion that is deformed so as to at least partially conform to the external threads of the finish portion of the container, the thread engaging portion having a plurality of inwardly extending raised areas, and wherein at least some of the raised areas are in contact with at least one of the external threads at respective lengths of contact, each external thread having a total distance spanned by a sum of such lengths of contact and distances spanned by adjacent raised areas on the thread, and wherein an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads is less than an internal circumference of the thread engaging portion.




According to a fourth aspect of the invention, a press-on, twist-off container assembly includes a container having a finish portion with at least one external thread defined thereon; and a press-on, twist-off type closure including a panel portion; a skirt portion depending downwardly from the panel portion, the skirt portion and the panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within the interior recess, the deformable gasket having a thread engaging portion that is deformed so as to at least partially conform to the external threads of the finish portion of the container, the thread engaging portion having a plurality of inwardly extending raised flutes, the flutes being circumferentially spaced irregularly about the thread engaging portion, and wherein at least some of the flutes are in contact with at least one of the external threads at respective points of contact, each external thread having a total distance spanned by such points of contact, whereby the irregular spacing of the flutes will cause the container assembly to have an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads that is less than it would be were the flutes spaced regularly, whereby the amount of torque that is necessary to remove the closure is comparatively reduced.




According to a fifth aspect of the invention, a method of making a press-on, twist-off container assembly includes steps of (a) providing a container having a finish portion with at least one external thread defined thereon; (b) providing a press-on, twist-off type closure including a panel portion and a skirt portion that together define a generally cylindrical interior recess and a deformable gasket mounted within the interior recess that has a thread engaging portion having a plurality of inwardly extending raised flutes; and (c) pressing the closure onto the container so that at least some of the flutes are in contact with at least one of the external threads at respective points of contact, each external thread having a total distance spanned by such points of contact, and wherein an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads is less than an internal circumference of the thread engaging portion.




A method of making a press-on, twist-off container assembly according to a sixth aspect of the invention includes steps of (a) providing a container having a finish portion with at least one external thread defined thereon; (b) providing a press-on, twist-off type closure that includes a panel portion and a skirt portion that together define a generally cylindrical interior recess and a deformable gasket mounted within the interior recess that has a thread engaging portion having a plurality of inwardly extending raised areas; and (c) pressing the closure onto the container so that at least some of the raised areas are in contact with at least one of the external threads at respective lengths of contact, each external thread having a total distance spanned by a sum of such lengths of contact and distances spanned by adjacent raised areas on the thread, and wherein an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads is less than an internal circumference of the thread engaging portion.




A method of making a press-on, twist-off container assembly according to a seventh aspect of the invention includes steps of (a) providing a container having a finish portion with at least one external thread defined thereon; (b) providing a press-on, twist-off type closure that includes a panel portion and a skirt portion that together define a generally cylindrical interior recess and a deformable gasket mounted within the interior recess that has a plurality of inwardly extending raised flutes, the flutes being circumferentially spaced irregularly about the thread engaging portion; and (c) pressing the closure onto the container so that at least some of the flutes are in contact with at least one of the external threads at respective points of contact, each external thread having a total distance spanned by such points of contact, whereby the irregular spacing of the flutes will cause the container assembly to have an aggregate distance spanned that is a sum of the total distance spanned for all of the external threads that is less than it would be were the flutes spaced regularly, whereby the amount of torque that is necessary to remove the closure is comparatively reduced.




These and various other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a fragmentary perspective view of a container assembly that is constructed according to a first embodiment of the invention;





FIG. 2

is a fragmentary cross-sectional view depicting one area of the container assembly that is shown in

FIG. 1

;





FIG. 3

is a fragmentary perspective view of a container assembly that is constructed according to a second embodiment of the invention; and





FIG. 4

is a diagrammatical view depicting advantageous operation of the container assembly that is depicted in FIG.


1


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)




Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to

FIG. 1

, a container assembly


10


that is constructed according to a first embodiment of the invention includes a container


12


that is conventional in construction and that includes a finish portion


14


having at least one external thread


6


integrally molded into an external surface thereof. The finish portion


14


defines an opening


18


that provides access to the container


12


.




Container assembly


10


further includes a closure


20


that has an upper panel


22


and, as is best shown in

FIG. 2

, a skirt portion


24


that depends downwardly from the upper panel


22


and together with the upper panel


22


defines a generally cylindrical internal recess


26


that is sized and shaped to receive the threaded finish portion


14


of the container


12


. As may be seen in

FIGS. 1 and 3

, a deformable gasket


28


, which is preferably fabricated from a material such as plastisol, is mounted within the recess


26


and includes a thread engaging portion


30


that is attached to an internal surface of the skirt portion


24


.




In the first embodiment of the invention that is depicted in

FIG. 1

, the thread engaging portion


30


has integrally molded therein a plurality of inwardly extending raised flutes


32


, which are arranged in groups


34


. In the illustrated embodiment, each group


34


contains three flutes


32


that are arranged in six groups


34


that are evenly spaced about the inner circumference of the thread engaging portion


30


. As may be seen in FIG.


1


and in

FIG. 4

, the circumferential distance between the adjacent groups


34


of flutes


32


is greater than the circumferential distance between any of the flutes


32


within any of the groups


34


. Looking briefly to

FIG. 4

, which is a diagrammatical depiction wherein circumferential distance about the inner surface of the thread engaging portion


30


is represented as a horizontal linear distance, it will be seen that the various flutes


32


make contact with the different threads


16


on the finish portion


14


of the container


12


at a number of different contact points


50


. Each external thread has a total distance that is spanned by these points of contact within the thread


16


. According to one advantageous aspect of the invention, it has been found that removal torque is reduced to an optimal level when the aggregate distance spanned that is a sum of the total distance spanned for all of the external threads


16


is less than the internal circumference of the thread engaging portion


30


.




This aspect of the invention will become more apparent as a result of the description of one prototype that is described below.




A prototype of the container assembly


10


was fabricated with a container


12


that had a nominal industry sizing of 51 mm. Accordingly, the inner circumference of the thread engaging portion


30


of the closure


20


was about 160 mm. As may be seen in the diagrammatical depiction provided in

FIG. 4

, the prototype was provided with a thread engaging portion


30


that included six groups


34


of flutes


32


, which are respectively numbered as groups 1-6. The container


12


at a finish portion


14


that had


10


different threads


16


defined thereon. As may be seen in

FIG. 4

, a first thread contacted all three flutes


32


and the first group


34


, and was measured to span a distance


52


of 16 mm along the surface of the first thread


16


. A second thread contacted only the second two flutes


32


of the second group and was measured to span a distance


54


of 9 mm. A third thread contacted the second two flutes


32


in the second group, spanning a distance


56


that was measured at 9 mm. A fourth thread contacted all three flutes in the third group, spanning a distance


58


of 16 mm. A fifth thread contacted the last flute of the third group and the first flute of the fourth group, and spanned a distance


60


that was measured at 14 mm. A sixth thread contacted all three flutes within the fourth group, spanning a distance


62


of 16 mm. A seventh thread contacted only the second two flutes within the fifth group, spanning a distance


64


of 9 mm. An eighth thread contacted the last two flutes in the fifth group, spanning a distance


66


that was also 9 mm. A ninth thread contacted all three flutes in the sixth group, spanning a distance


68


of 16 mm. A tenth thread contacted the last flute in the sixth group and the first flute in the first group, spanning a distant


70


of 14 mm.




For this prototype, the aggregate distance spanned that is a sum of the total distance spanned for all of the external threads


16


was equal to about 128 mm, or an average of 12.8 mm per thread. In contrast, it has been determined that a closure of identical construction but with the flutes


32


evenly spaced about the inner periphery of the thread engaging portion would create a total distance spanned about 175 mm, which is an average of 17.5 mm per thread. Accordingly, spacing the flute members


32


in groups according to the invention permits a significant reduction in the total distance spanned, which has been found to correlate with a significant reduction in the door that is necessary for a consumer to open the container assembly


10


.




A container assembly


40


that is constructed according to a second, alternative embodiment of the invention is depicted in FIG.


3


. Container assembly


40


is identical in all respects to the container assembly


10


described above except that it includes a closure


42


having a gasket


44


that includes a plurality of integrally molded raised areas


46


. The raised areas


46


may correspond in position to the groups


34


of flutes


32


in the previously described embodiment, and are constructed and arranged to contact at least one of the external threads


16


of the finish portion


14


of the container


12


at respective lengths of contact. Each external thread will thus have a total distance spanned by a sum of such lengths of contact as well as distances spanned by adjacent raised areas on the thread. This may be thought of as conceptually corresponding to the total distance spanned in the previously described embodiment. Preferably, in this embodiment, the aggregate distance spanned that is a sum of the total distance spanned for all of the external threads is less than an internal circumference of said thread engaging portion.




In a method according to the invention, a closure such as the closure


20


or the closure


42


described above will be pressed onto a container


12


in the conventional manner after the container


12


has been filled with product in a packaging facility.




It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.



Claims
  • 1. A press-on, twist-off closure for a container of the type that has at least one external thread on a finish portion thereof, comprising:a panel portion; a skirt portion depending downwardly from said panel portion, said skirt portion and said panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within said interior recess, said deformable gasket having a thread engaging portion that is mounted to an inner surface of said skirt portion, and wherein said thread engaging portion comprises a plurality of raised flutes that are integral with said deformable gasket and wherein said raised flutes are arranged in a plurality of separate groups about an inner circumference of said thread engaging portion, each of said separate groups containing at least two flutes, and wherein a circumferential distance between any two adjacent groups is greater than a circumferential distance between any two adjacent flutes within a group, so that when mounted on a container the total span of contact of said flutes across individual external threads of the container will be less than if said flutes were evenly spaced, whereby the torque needed to remove the closure from the container will be less than if said flutes were evenly spaced.
  • 2. A closure according to claim 1, wherein said panel portion and said skirt portion are metal.
  • 3. A press-on, twist-off container assembly, comprising:a container having a finish portion with at least one external thread defined thereon; and a press-on, twist-off type closure including a panel portion; a skirt portion depending downwardly from said panel portion, said skirt portion and said panel portion together defining a generally cylindrical interior recess; and a deformable gasket mounted within said interior recess, said deformable gasket having a thread engaging portion that is deformed so as to at least partially conform to said external threads of said finish portion of said container, said thread engaging portion having a plurality of inwardly extending raised flutes, said flutes being circumferentially spaced irregularly about said thread engaging portion, and wherein at least some of said flutes are in contact with at least one of said external threads at respective points of contact, each external thread having a total distance spanned by such points of contact, whereby said irregular spacing of said flutes will cause said container assembly to have an aggregate distance spanned that is a sum of said total distance spanned for all of said external threads that is less than it would be were the flutes spaced regularly, whereby the amount of torque that is necessary to remove the closure is comparatively reduced.
  • 4. A container assembly according to claim 3, wherein said flutes are arranged in a plurality of groups, each of said groups containing more than one flute.
  • 5. A container assembly according to claim 4, wherein a circumferential distance between any two adjacent groups is greater than a circumferential distance between any two adjacent flutes within a group.
  • 6. A container according to claim 4, wherein at least a plurality of said groups contain at least three flutes.
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4552279 Mueller et al. Nov 1985 A
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4603786 Lecinski, Jr. et al. Aug 1986 A
4709825 Mumford Dec 1987 A
4717034 Mumford Jan 1988 A
4863030 Bayer et al. Sep 1989 A
5119962 Vercillo et al. Jun 1992 A
5692628 Montgomery et al. Dec 1997 A
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