PRESS-ON TWIST LIFT-OFF CONTAINER SEALING MEANS
United States Patent 3741423
A closure cap is described which is pressed without rotation onto a cooperating container to initially seal it. The cap is removed from the container by a twisting and lifting motion and may thereafter be snapped back onto the container to reseal it. The rim of the container has an interrupted circular slot with radially outwardly directed camming ramps between the slot sections. The closure cap has a plastisol lined skirt including anchoring portions which enter into the slot sections after the press-on sealing operation to hold the closure cap in place. The portions of the gasket entering the slots may be preformed on the gasket or they may be formed during sealing as bulges in the gasket material resulting from a deformation of the gasket during sealing. The outwardly directed ramps facilitate cap removal by wiping off the gasket anchoring positions when the cap is twisted on the jar permitting the cap to be lifted off. Where the cap is used for a vacuum seal, an additional vacuum breaking venting groove may be included in the glass finish. The venting groove is filled with the gasket compound during sealing to provide a hermetic seal and when the cap is twisted during removal, the twisting motion carries the gasket material out of the groove permitting air to pass under the cap gasket and into the sealed package.
US Patent References:
Container finish and closure cap construction
Moloney et al. - November 1966 - 3285452
Container closure
Zipper - October 1967 - 3344943
Tamper-proof package
Zipper - March 1968 - 3374913
Container finish and closure cap construction
Moloney et al. - November 1966 - 3285452
Container closure
Zipper - October 1967 - 3344943
Tamper-proof package
Zipper - March 1968 - 3374913
Inventors:
Acton, Daniel D. (Lancaster, OH)
Foss, George J. (Lancaster, OH)
Foss, George J. (Lancaster, OH)
Application Number:
05/193031
Publication Date:
06/26/1973
Filing Date:
10/27/1971
View Patent Images:
Export Citation:
Assignee:
Anchor Hocking Corporation (Lancaster, OH)
Primary Class:
Other Classes:
215/346
International Classes:
B65D41/04; B65D23/00; B65D53/00
Field of Search:
215/40
Primary Examiner:
Hall, George T.
Claims:
Having thus described our invention, we claim
1. A press-on closure cap for sealing a container comprising the combination of a cap shell having a cover and a depending skirt, a gasket on the inside of said depending skirt, and said gasket having a plurality of circumferentially spaced and directed anchoring portions with substantial horizontal sections spaced from the top and bottom of the gasket and projecting radially inwardly of the cap for engaging horizontally positioned slots on the rim of said container and forming removable container engaging projections.
2. The closure cap as claimed in claim 1 in which said gasket extends from an annular zone at the edge of said cover downwardly over the skirt to a line adjacent the skirt edge.
3. The closure cap as claimed in claim 1 in which said gasket comprises plastisol.
4. A press-on twist lift-off closure cap for sealing a container comprising the combination of a cap shell having a cover and a depending skirt, a plastisol gasket covering a major portion of the inside of said skirt, a portion of said gasket spaced from both the gasket top and bottom having a plurality of radially inwardly projecting anchoring portions with substantial horizontal circumferentially directed sections projecting inwardly into horizontally positioned slots adjacent to the rim of said container and forming removable container engaging projections.
5. The closure cap as claimed in claim 4 in which said projecting portions include an inclined cap lifting section.
6. The closure cap as claimed in claim 4 which further comprises an annular top sealing plastisol gasket extending from the top of said gasket on the cap skirt inwardly on the underside of said cover.
7. The cap as claimed in claim 4 which further includes knobs on said gasket for preventing cap nesting.
8. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt, a container, a plurality of horizontal slots on said container forming a circular interruptal groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container.
9. The package as claimed in claim 8 in which said gasket comprises a plastisol gasket.
10. The package as claimed in claim 8 which further comprises an annular top sealing gasket extending from the top of said gasket on the cap skirt over the container rim.
11. The package as claimed in claim 8 in which said container rim is generally circular and includes a non-circular surface below said slots engaging the gasket on the cap skirt.
12. The package as claimed in claim 11 in which said non-circular surface comprises a plurality of adjacent flat sections.
13. The package as claimed in claim 11 in which said non-circular surface includes downwardly and outwardly flared portions for lifting said cap when it is turned.
14. The package as claimed in claim 8 which further comprises knobs on said cap gasket for preventing cap nesting.
15. The package as claimed in claim 8 in which said projecting portions include inclined cap lifting sections.
16. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt and around the underside of the margin of the cap cover, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at ends of said slots for engaging said gasket projections when said cap is turned on said container, and a vent in said container rim position for receiving a portion of said gasket and for being partially opened when said cap is turned on said container.
17. The package as claimed in claim 16 in which said gasket comprises a plastisol gasket.
18. A container finish for receiving and engaging a closure cap having a cover and a depending gasket covered skirt comprising a plurality of horizontal and spaced slots forming an interrupted groove around the outside of the container rim, and said slots having radially outwardly directed gasket wiping ramps at their ends.
19. A container finish for receiving and engaging a closure cap having a cover and a depending gasket covered skirt comprising a smooth rim portion, a plurality of horizontal and spaced slots forming an interrupted groove around the outside of the container rim, said slots having radially outwardly directed ramps at their ends, and a vent in said finish at said rim portion.
20. The container finish as claimed in claim 19 in which said rim portion comprises a generally upwardly facing top sealing surface and a generally cylindrical side sealing surface, said vent being positioned in said top sealing surface, and a second detent in said side sealing surface.
21. The container finish as claimed in claim 19 in which the portions of the groove intermediate said spaced slots have an at least partially upwardly facing cap lifting portion.
22. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container, and a vent in the container rim being filled with a portion of said gasket and positioned for being at least partially opened when said cap is turned on the container.
23. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt and having a portion on the outer portion of the cap cover, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container, and a vent in the container rim filled with a portion of the cover portion of said gasket and positioned for being at least partially opened when said cap is turned on said container.
1. A press-on closure cap for sealing a container comprising the combination of a cap shell having a cover and a depending skirt, a gasket on the inside of said depending skirt, and said gasket having a plurality of circumferentially spaced and directed anchoring portions with substantial horizontal sections spaced from the top and bottom of the gasket and projecting radially inwardly of the cap for engaging horizontally positioned slots on the rim of said container and forming removable container engaging projections.
2. The closure cap as claimed in claim 1 in which said gasket extends from an annular zone at the edge of said cover downwardly over the skirt to a line adjacent the skirt edge.
3. The closure cap as claimed in claim 1 in which said gasket comprises plastisol.
4. A press-on twist lift-off closure cap for sealing a container comprising the combination of a cap shell having a cover and a depending skirt, a plastisol gasket covering a major portion of the inside of said skirt, a portion of said gasket spaced from both the gasket top and bottom having a plurality of radially inwardly projecting anchoring portions with substantial horizontal circumferentially directed sections projecting inwardly into horizontally positioned slots adjacent to the rim of said container and forming removable container engaging projections.
5. The closure cap as claimed in claim 4 in which said projecting portions include an inclined cap lifting section.
6. The closure cap as claimed in claim 4 which further comprises an annular top sealing plastisol gasket extending from the top of said gasket on the cap skirt inwardly on the underside of said cover.
7. The cap as claimed in claim 4 which further includes knobs on said gasket for preventing cap nesting.
8. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt, a container, a plurality of horizontal slots on said container forming a circular interruptal groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container.
9. The package as claimed in claim 8 in which said gasket comprises a plastisol gasket.
10. The package as claimed in claim 8 which further comprises an annular top sealing gasket extending from the top of said gasket on the cap skirt over the container rim.
11. The package as claimed in claim 8 in which said container rim is generally circular and includes a non-circular surface below said slots engaging the gasket on the cap skirt.
12. The package as claimed in claim 11 in which said non-circular surface comprises a plurality of adjacent flat sections.
13. The package as claimed in claim 11 in which said non-circular surface includes downwardly and outwardly flared portions for lifting said cap when it is turned.
14. The package as claimed in claim 8 which further comprises knobs on said cap gasket for preventing cap nesting.
15. The package as claimed in claim 8 in which said projecting portions include inclined cap lifting sections.
16. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt and around the underside of the margin of the cap cover, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at ends of said slots for engaging said gasket projections when said cap is turned on said container, and a vent in said container rim position for receiving a portion of said gasket and for being partially opened when said cap is turned on said container.
17. The package as claimed in claim 16 in which said gasket comprises a plastisol gasket.
18. A container finish for receiving and engaging a closure cap having a cover and a depending gasket covered skirt comprising a plurality of horizontal and spaced slots forming an interrupted groove around the outside of the container rim, and said slots having radially outwardly directed gasket wiping ramps at their ends.
19. A container finish for receiving and engaging a closure cap having a cover and a depending gasket covered skirt comprising a smooth rim portion, a plurality of horizontal and spaced slots forming an interrupted groove around the outside of the container rim, said slots having radially outwardly directed ramps at their ends, and a vent in said finish at said rim portion.
20. The container finish as claimed in claim 19 in which said rim portion comprises a generally upwardly facing top sealing surface and a generally cylindrical side sealing surface, said vent being positioned in said top sealing surface, and a second detent in said side sealing surface.
21. The container finish as claimed in claim 19 in which the portions of the groove intermediate said spaced slots have an at least partially upwardly facing cap lifting portion.
22. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container, and a vent in the container rim being filled with a portion of said gasket and positioned for being at least partially opened when said cap is turned on the container.
23. A sealed package comprising the combination of a closure cap having a cover and a depending skirt, a gasket on the interior surface of the cap skirt and having a portion on the outer portion of the cap cover, a container, a plurality of horizontal slots on said container forming a circular interrupted groove adjacent the container rim, said gasket having horizontal anchoring portions projecting into said slots, radially outwardly directed ramps at the ends of said slots for engaging and wiping off said gasket projections when said cap is turned on said container, and a vent in the container rim filled with a portion of the cover portion of said gasket and positioned for being at least partially opened when said cap is turned on said container.
Description:
BACKGROUND OF THE INVENTION
This invention relates to packages which are sealed with a closure cap, as for example, a package comprising a glass container and a metal closure cap. Such packages are now used in quantities numbering many millions per day for packaging a variety of products and particularly food products under vacuum. The enormous quantities of the packages being used requires them to be easily sealed by the packer and as well as being easily opened and reclosed by the consumer.
A variety of caps and container finishes have been produced for some time using lugs or threads for removably attaching the closure caps to the containers. Many of these caps are applied to the containers by machinery which twists the caps onto container threads and in other cases the caps are applied to special glass finishes which permit the caps to be pressed on and twisted off.
In connection with the caps which are twisted on, the sealing machinery itself and the sealing operations are somewhat more complex than press on operations and have speed limitations. The presently used design of press-on and twist-off caps have been found to have several disadvantages including an unsatisfactory reliability with respect to their hermetic seals and unpredictable removal torques which may be either so low to cause unintentional vacuum release or so high that the caps cannot be easily removed by the consumer. The package of this invention takes advantage of a simplified sealing means which permits it to be applied with a simple press-on operation. In addition, the cap is easily removed by the consumer by a simple twisting and lifting motion which releases the cap from the glass finish while simultaneously breaking the package vacuum.
Accordingly, an object of the present invention is to provide an improved sealed package including a novel closure cap and a cooperating closure cap engaging glass finish.
Another object of the present invention is to provide an improved package comprising a closure cap and a glass container where the closure cap is easily removed and reapplied to the container.
Another object of the present invention is to provide an improved glass container finish for a press-on twist lift-off closure cap.
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 invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing forming a part of the specification, wherein:
FIG. 1 is a perspective view of a sealed package in accordance with the present invention.
FIG. 2 is an exploded perspective view illustrating the closure cap and the improved glass finish in accordance with the present invention.
FIG. 3 is a horizontal sectional view of the container finish taken along line 3--3 on FIG. 2.
FIG. 4 is a vertical sectional view taken along line 4--4 on FIG. 1.
FIG. 5 is a horizontal sectional view of the sealed container of FIG. 4 taken at the glass finish along line 5--5 on FIG. 4.
FIG. 6 is a horizontal sectional view corresponding to FIG. 5 showing the closure cap being twisted during cap removal.
FIG. 7 is a fragmentary perspective view, partially in section, illustrating the vacuum release during cap removal.
FIG. 8 is an enlarged top plan view of a portion of the glass finish showing vacuum releasing venting grooves.
FIG. 9 is a vertical sectional view illustrating the closure cap and the container finish prior to sealing.
FIG. 10 is a development of the container finish.
FIG. 11 is a vertical sectional view of the top glass finish of FIG. 11 illustrating vacuum releasing flats.
FIG. 12 is a horizontal sectional view of the glass finish of FIG. 11 illustrating vacuum releasing flats.
FIG. 13 is a vertical sectional view of the top portion of a sealed package illustrating an additional embodiment of the glass finish.
FIG. 14 is a vertical sectional view of another embodiment of the closure cap illustrating preformed gasket anchoring portions and abuttments for preventing nesting of stacked caps.
FIG. 15 is a vertical sectional view of an additional embodiment showing a preformed cap anchoring portion including an inclined cap lifting ramp.
FIG. 16 is a vertical sectional view of the glass finish illustrating another embodiment of the cap engaging slot.
FIG. 17 is a fragmentary perspective view of the finish of FIG. 16.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of a sealed package 1 is illustrated in FIGS. 1-7 comprising a closure 2 applied to a container 3.
The closure cap 2, as best illustrated in FIGS. 4 and 9 includes an annular container engaging gasket 5 applied over a substantial portion of the cap skirt 6 and extending inwardly over the bottom cap cover 7 beyond the inner edge 8 of the container rim 9. This gasket 5, in its preferred form, is a plastic such as a plastisol which has been either flowed into the cap shell in the form of a ring or inserted as a pre-cured and cut plastic ring and which is thereafter shaped by a molding plunger to the form illustrated in FIG. 9. The gasket 5 is thus seen to have a thicker top and corner sealing portion 10 at the cap cover 7 and a relatively thin downwardly extending portion 11 on the cap skirt for forming a secondary seal and a container engaging means which will now be further described.
When the cap 2 is applied to the container 3 finish 4, in accordance with one embodiment of the invention, a portion of the skirt portion 11 of gasket 5 is caused to bulge inwardly into a number of slots 12 in the glass finish 4 thereby forming lug-like cap anchoring projections 13 to retain the closure cap 2 on the container 3. This means for attaching the cap 2 to the container 3 as well as the cooperating means whereby the cap 2 is removed by a twisting and lifting motion will now be described in connection with a more detailed description of the container 3 glass finish 4.
As seen in the sectional view of FIG. 4, the rim 9 of the container 3 has a curved top sealing portion 14 which terminates at its outer edge in a rounded corner sealing section 15. The above referred to slots 12 are seen to be provided in the outwardly projecting and thickened finish portion 4 of the container 3. These spaced slots 12, which may also be considered as an interrupted groove, are illustrated in greater detail in FIGS. 5, 6 and 10. Each of the slots 12 is seen to have gently sloped edges or ramps 17. These edges or ramps 17 on each of the slots 12 function during cap removal in the manner illustrated in FIGS. 5 and 6 to wipe off and remove the inwardly projecting lug portions or projections 13 on the cap gasket 5 which were described above. Thus, as the cap 2 is rotated on the container 3 from the sealed position of FIG. 5 and through the position of FIG. 6, it is seen that this rotation draws the lug portions 13 of the gasket 5 out of the slots 12 and over the inclined camming or ramp portions 17 simultaneously reducing the radial depth of this portion of gasket 5 and also carrying the lugs 13 out of the slots 12 to a position adjacent the bridge or connecting portions 18 between the slots 12. FIG. 10 illustrates an arrangement of slots 12 which has proven satisfactory. The four slots 12 are seen to each extend for about 60° including ramps 17 of about 15° .
It is seen that this rotation eliminates the holding force on the cap between the cap gasket 5 and the container 3 thereby leaving the vacuum force, if any, as the remaining cap attaching force.
Means are provided which simultaneously break the vacuum force during the above described cap rotation. An air path 19 (FIG. 7) is established under the skirt portion 11 of the gap gasket 5 due to the above rotation and due to the lesser sealing action present between these skirt portions 11 of the cap gasket and the glass finish 4.
An air path is provided over the corner 15 and top sealing portion 14 of the container when the cap is twisted on the container. The breaking of the vacuum may be facilitated by the provision of spaced venting grooves in the glass finish 4 including a groove 20 as shown in FIG. 8 positioned just below the container rim corner 15. Several such grooves 20 may be used. An alternate embodiment may add additional detents 21 on the glass finish 4 top sealing surface 14. During the initial sealing operation, it is seen that plastisol is forced into these detents 20 and 21 by the sealing force so that they are air-tight. When the cap 2 is twisted, these projecting portions of the gasket 5 will seem to be carried clear of the detents leaving an air passage under the gasket 5 and through the detents 20 and 21.
It is therefore seen that the twisting motion of the closure cap 2 releases both the basket lug or projection 13 connection and the vacuum sealing force from the cap 2. The cap 2 may now be easily lifted directly off of the container 3.
FIGS. 11 through 13 illustrate two additional embodiments of the container sealing means having a modified glass finish.
FIG. 11 illustrates a closure cap 2 of the type described above where the annular lower portion 22 of a modified glass finish 23 below interrupted grooves 24 has a series of flats 25 formed at its outer cap gasket 5 engaging surface and extending completely around this portion of the glass finish, as illustrated in FIG. 12. When the closure cap 2 is pressed on to the container 26 during the original sealing operation, the lower portion of the cap gasket 5 will be pressed into sealing engagement around the entire circumference of the container engaging all portions of the flats 25. When the cap 2 is twisted during removal, it is seen that the radially outward portions of the flats 25 will be forced into and will deform the portions of the gasket 5 originally engaging the central portions of the flats 25 thereby creating air passages upwardly past this lower portion of the cap gasket 5. Where the outer surfaces of the flats 25 are in a generally vertical plane and without any taper, it will be seen that the flats 25 will exert no axial forces during cap rotation so that their principal function is to provide the above noted air passages.
FIG. 13 illustrates another embodiment of the container glass finish. This embodiment also includes a continuous series of flats 27 generally similar to those of FIGS. 11 and 12 except that each of the flats 27 is seen to taper inwardly and upwardly. With this embodiment, an initial sealing action would occur of the type already described where the plastisol of the gasket is forced into sealing engagement around the entire circumference of the container finish engaging all portions of the flats 27. When the cap 2 is rotated during removal, these flats 27 will also deform the gasket 5 forming air passages to break the container vacuum. Additionally, however, the tapered positions of the flats 27 will tend to provide a slight lifting action which would tend to lift the cap off of the container 2 after the gasket lugs 13 are wiped off and as the package vacuum is broken.
As already indicated, the means on the closure cap for attaching the cap to the container may be a bulged portion 13 of the cap gasket 5 as formed during sealing or may be a lug-like projection preformed in the cap gasket as the gasket is molded into place on the cap skirt 6 and cover 7.
FIG. 14 illustrates one embodiment of such a preformed lug or attaching projection 30 which is molded by the gasket shaping member during cap manufacture as a suitably shaped molding plunger is forced against the plastisol or other gasket material within the shell of cap 31. The gasket 32 is provided with a number of radially inwardly projections or lugs 30 positioned so that an effective portion of them enters into the slots 12 in the glass finish as the cap 31 is pressed downwardly onto the container finish during sealing. These portions 30 engage the top wall of the spaced slots 12 thereby holding the closure cap 31 in tight sealing engagement with the container 3. When the cap 31 is twisted during removal, these attaching projections or lugs 30 are wiped off in the manner already described and this elimination of the lugs 30 together with the release of the vacuum, in the manner already described, permits the cap 31 to readily be lifted from the container 3. In order that the cap 31 may be pressed onto the glass finish without regard to its particular position on the container finish, a series of preformed lugs 30 are provided which are greater in number than the slots 12 in the glass finish. For example, a suitable number of lugs 30 for a four slot glass finish would be eight lugs on the cap gasket 32. Each of these lugs occupy about 30° of the 360° circumference of the gasket thereby assuring the penetration of a substantial section of lugs 30 into each container finish slot 12.
A cap 31 might be positioned with four lugs 30 fully engaging four slots. If the position of four lugs 30 within the slots 12 is toward one end of the slots 12, portions of four adjacent lugs 30 will engage the opposite ends of the four slots. Thus, there will be adequate holding action between the caps and containers no matter what position the caps may be applied to the containers during sealing which may vary from full engagement of four lugs 30 to substantial engagement of eight lugs 30. Other numbers of slots and lugs may be used in the same manner.
FIG. 15 illustrates an additional embodiment which shows a cap 35 having preformed lugs 36 on the cap gasket 37 with inclined trailing portions 38 which act to lift the cap 35 during cap removal. Each of the lugs 36 includes an inclined surface 39 on portions 38.
A preferred embodiment of the glass finish which may be used with any of the above described caps, but which is of particular value with the cap 35 of FIG. 15, is illustrated in FIGS. 16 and 17. This glass finish 40 differs from the glass finish already described in the connecting portions 41 provided between cap anchoring slots 42. In this embodiment, these connecting portions 41 extend radially outwardly beyond the outer surface of the upper section 43 of the glass finish 40 resulting in the provision of at least partially upwardly facing cap lifting surfaces 44. These surfaces 44 combine with the gasket lugs 13 or 30 or 36 and particularly with the inclined surfaces 39 of the lugs 36 as illustrated in FIG. 15 to cause a simultaneous wiping off and lifting action as the caps are twisted during removal.
FIGS. 14 and 15 also illustrate radially inwardly projecting knobs or abuttments 33 and 45, respectively, which are formed on the cap gaskets during the gasket molding and which function as illustrated in FIG. 14 to prevent objectionable nesting of the closure caps 31 or 35 during cap storage and cap feeding in sealing machines. These knobs 33 and 45 are wiped off or flatened during sealing so that they do not interfere with the sealing operation. Portions of the knobs 33 and 45 which may happen to overlie a slot 12 or 42 in the glass finish during the sealing operation will enter the slot to assist in the cap anchoring function and these portions will be removed in the same manner as the cap anchoring lugs 13, 30 or 36 as the caps are twisted during cap removal.
It will be seen that an improved press-on twist lift-off sealing means has been described comprising a closure cap with a plastic gasket and a cooperating glass finish including an interrupted closure cap engaging groove. The cap is particularly advantageous in high speed package sealing operations since a positive and reliable cap attachment and seal are formed with a simple press-on sealing operation where only a minimal deformation of the plastic gasket is required. Additionally, a press-on and twist lift-off sealing means is provided where predetermined removal torques may be provided which remain stable over extended periods of package storage. The cap is easily reapplied after the initial opening to provide a resealing of the container. Both the closure cap manufacture and the container finish formation may be readily carried out on conventional manufacturing machinery with minor modifications only being required to provide the novel cap and container structures.
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.
This invention relates to packages which are sealed with a closure cap, as for example, a package comprising a glass container and a metal closure cap. Such packages are now used in quantities numbering many millions per day for packaging a variety of products and particularly food products under vacuum. The enormous quantities of the packages being used requires them to be easily sealed by the packer and as well as being easily opened and reclosed by the consumer.
A variety of caps and container finishes have been produced for some time using lugs or threads for removably attaching the closure caps to the containers. Many of these caps are applied to the containers by machinery which twists the caps onto container threads and in other cases the caps are applied to special glass finishes which permit the caps to be pressed on and twisted off.
In connection with the caps which are twisted on, the sealing machinery itself and the sealing operations are somewhat more complex than press on operations and have speed limitations. The presently used design of press-on and twist-off caps have been found to have several disadvantages including an unsatisfactory reliability with respect to their hermetic seals and unpredictable removal torques which may be either so low to cause unintentional vacuum release or so high that the caps cannot be easily removed by the consumer. The package of this invention takes advantage of a simplified sealing means which permits it to be applied with a simple press-on operation. In addition, the cap is easily removed by the consumer by a simple twisting and lifting motion which releases the cap from the glass finish while simultaneously breaking the package vacuum.
Accordingly, an object of the present invention is to provide an improved sealed package including a novel closure cap and a cooperating closure cap engaging glass finish.
Another object of the present invention is to provide an improved package comprising a closure cap and a glass container where the closure cap is easily removed and reapplied to the container.
Another object of the present invention is to provide an improved glass container finish for a press-on twist lift-off closure cap.
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 invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing forming a part of the specification, wherein:
FIG. 1 is a perspective view of a sealed package in accordance with the present invention.
FIG. 2 is an exploded perspective view illustrating the closure cap and the improved glass finish in accordance with the present invention.
FIG. 3 is a horizontal sectional view of the container finish taken along line 3--3 on FIG. 2.
FIG. 4 is a vertical sectional view taken along line 4--4 on FIG. 1.
FIG. 5 is a horizontal sectional view of the sealed container of FIG. 4 taken at the glass finish along line 5--5 on FIG. 4.
FIG. 6 is a horizontal sectional view corresponding to FIG. 5 showing the closure cap being twisted during cap removal.
FIG. 7 is a fragmentary perspective view, partially in section, illustrating the vacuum release during cap removal.
FIG. 8 is an enlarged top plan view of a portion of the glass finish showing vacuum releasing venting grooves.
FIG. 9 is a vertical sectional view illustrating the closure cap and the container finish prior to sealing.
FIG. 10 is a development of the container finish.
FIG. 11 is a vertical sectional view of the top glass finish of FIG. 11 illustrating vacuum releasing flats.
FIG. 12 is a horizontal sectional view of the glass finish of FIG. 11 illustrating vacuum releasing flats.
FIG. 13 is a vertical sectional view of the top portion of a sealed package illustrating an additional embodiment of the glass finish.
FIG. 14 is a vertical sectional view of another embodiment of the closure cap illustrating preformed gasket anchoring portions and abuttments for preventing nesting of stacked caps.
FIG. 15 is a vertical sectional view of an additional embodiment showing a preformed cap anchoring portion including an inclined cap lifting ramp.
FIG. 16 is a vertical sectional view of the glass finish illustrating another embodiment of the cap engaging slot.
FIG. 17 is a fragmentary perspective view of the finish of FIG. 16.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of a sealed package 1 is illustrated in FIGS. 1-7 comprising a closure 2 applied to a container 3.
The closure cap 2, as best illustrated in FIGS. 4 and 9 includes an annular container engaging gasket 5 applied over a substantial portion of the cap skirt 6 and extending inwardly over the bottom cap cover 7 beyond the inner edge 8 of the container rim 9. This gasket 5, in its preferred form, is a plastic such as a plastisol which has been either flowed into the cap shell in the form of a ring or inserted as a pre-cured and cut plastic ring and which is thereafter shaped by a molding plunger to the form illustrated in FIG. 9. The gasket 5 is thus seen to have a thicker top and corner sealing portion 10 at the cap cover 7 and a relatively thin downwardly extending portion 11 on the cap skirt for forming a secondary seal and a container engaging means which will now be further described.
When the cap 2 is applied to the container 3 finish 4, in accordance with one embodiment of the invention, a portion of the skirt portion 11 of gasket 5 is caused to bulge inwardly into a number of slots 12 in the glass finish 4 thereby forming lug-like cap anchoring projections 13 to retain the closure cap 2 on the container 3. This means for attaching the cap 2 to the container 3 as well as the cooperating means whereby the cap 2 is removed by a twisting and lifting motion will now be described in connection with a more detailed description of the container 3 glass finish 4.
As seen in the sectional view of FIG. 4, the rim 9 of the container 3 has a curved top sealing portion 14 which terminates at its outer edge in a rounded corner sealing section 15. The above referred to slots 12 are seen to be provided in the outwardly projecting and thickened finish portion 4 of the container 3. These spaced slots 12, which may also be considered as an interrupted groove, are illustrated in greater detail in FIGS. 5, 6 and 10. Each of the slots 12 is seen to have gently sloped edges or ramps 17. These edges or ramps 17 on each of the slots 12 function during cap removal in the manner illustrated in FIGS. 5 and 6 to wipe off and remove the inwardly projecting lug portions or projections 13 on the cap gasket 5 which were described above. Thus, as the cap 2 is rotated on the container 3 from the sealed position of FIG. 5 and through the position of FIG. 6, it is seen that this rotation draws the lug portions 13 of the gasket 5 out of the slots 12 and over the inclined camming or ramp portions 17 simultaneously reducing the radial depth of this portion of gasket 5 and also carrying the lugs 13 out of the slots 12 to a position adjacent the bridge or connecting portions 18 between the slots 12. FIG. 10 illustrates an arrangement of slots 12 which has proven satisfactory. The four slots 12 are seen to each extend for about 60° including ramps 17 of about 15° .
It is seen that this rotation eliminates the holding force on the cap between the cap gasket 5 and the container 3 thereby leaving the vacuum force, if any, as the remaining cap attaching force.
Means are provided which simultaneously break the vacuum force during the above described cap rotation. An air path 19 (FIG. 7) is established under the skirt portion 11 of the gap gasket 5 due to the above rotation and due to the lesser sealing action present between these skirt portions 11 of the cap gasket and the glass finish 4.
An air path is provided over the corner 15 and top sealing portion 14 of the container when the cap is twisted on the container. The breaking of the vacuum may be facilitated by the provision of spaced venting grooves in the glass finish 4 including a groove 20 as shown in FIG. 8 positioned just below the container rim corner 15. Several such grooves 20 may be used. An alternate embodiment may add additional detents 21 on the glass finish 4 top sealing surface 14. During the initial sealing operation, it is seen that plastisol is forced into these detents 20 and 21 by the sealing force so that they are air-tight. When the cap 2 is twisted, these projecting portions of the gasket 5 will seem to be carried clear of the detents leaving an air passage under the gasket 5 and through the detents 20 and 21.
It is therefore seen that the twisting motion of the closure cap 2 releases both the basket lug or projection 13 connection and the vacuum sealing force from the cap 2. The cap 2 may now be easily lifted directly off of the container 3.
FIGS. 11 through 13 illustrate two additional embodiments of the container sealing means having a modified glass finish.
FIG. 11 illustrates a closure cap 2 of the type described above where the annular lower portion 22 of a modified glass finish 23 below interrupted grooves 24 has a series of flats 25 formed at its outer cap gasket 5 engaging surface and extending completely around this portion of the glass finish, as illustrated in FIG. 12. When the closure cap 2 is pressed on to the container 26 during the original sealing operation, the lower portion of the cap gasket 5 will be pressed into sealing engagement around the entire circumference of the container engaging all portions of the flats 25. When the cap 2 is twisted during removal, it is seen that the radially outward portions of the flats 25 will be forced into and will deform the portions of the gasket 5 originally engaging the central portions of the flats 25 thereby creating air passages upwardly past this lower portion of the cap gasket 5. Where the outer surfaces of the flats 25 are in a generally vertical plane and without any taper, it will be seen that the flats 25 will exert no axial forces during cap rotation so that their principal function is to provide the above noted air passages.
FIG. 13 illustrates another embodiment of the container glass finish. This embodiment also includes a continuous series of flats 27 generally similar to those of FIGS. 11 and 12 except that each of the flats 27 is seen to taper inwardly and upwardly. With this embodiment, an initial sealing action would occur of the type already described where the plastisol of the gasket is forced into sealing engagement around the entire circumference of the container finish engaging all portions of the flats 27. When the cap 2 is rotated during removal, these flats 27 will also deform the gasket 5 forming air passages to break the container vacuum. Additionally, however, the tapered positions of the flats 27 will tend to provide a slight lifting action which would tend to lift the cap off of the container 2 after the gasket lugs 13 are wiped off and as the package vacuum is broken.
As already indicated, the means on the closure cap for attaching the cap to the container may be a bulged portion 13 of the cap gasket 5 as formed during sealing or may be a lug-like projection preformed in the cap gasket as the gasket is molded into place on the cap skirt 6 and cover 7.
FIG. 14 illustrates one embodiment of such a preformed lug or attaching projection 30 which is molded by the gasket shaping member during cap manufacture as a suitably shaped molding plunger is forced against the plastisol or other gasket material within the shell of cap 31. The gasket 32 is provided with a number of radially inwardly projections or lugs 30 positioned so that an effective portion of them enters into the slots 12 in the glass finish as the cap 31 is pressed downwardly onto the container finish during sealing. These portions 30 engage the top wall of the spaced slots 12 thereby holding the closure cap 31 in tight sealing engagement with the container 3. When the cap 31 is twisted during removal, these attaching projections or lugs 30 are wiped off in the manner already described and this elimination of the lugs 30 together with the release of the vacuum, in the manner already described, permits the cap 31 to readily be lifted from the container 3. In order that the cap 31 may be pressed onto the glass finish without regard to its particular position on the container finish, a series of preformed lugs 30 are provided which are greater in number than the slots 12 in the glass finish. For example, a suitable number of lugs 30 for a four slot glass finish would be eight lugs on the cap gasket 32. Each of these lugs occupy about 30° of the 360° circumference of the gasket thereby assuring the penetration of a substantial section of lugs 30 into each container finish slot 12.
A cap 31 might be positioned with four lugs 30 fully engaging four slots. If the position of four lugs 30 within the slots 12 is toward one end of the slots 12, portions of four adjacent lugs 30 will engage the opposite ends of the four slots. Thus, there will be adequate holding action between the caps and containers no matter what position the caps may be applied to the containers during sealing which may vary from full engagement of four lugs 30 to substantial engagement of eight lugs 30. Other numbers of slots and lugs may be used in the same manner.
FIG. 15 illustrates an additional embodiment which shows a cap 35 having preformed lugs 36 on the cap gasket 37 with inclined trailing portions 38 which act to lift the cap 35 during cap removal. Each of the lugs 36 includes an inclined surface 39 on portions 38.
A preferred embodiment of the glass finish which may be used with any of the above described caps, but which is of particular value with the cap 35 of FIG. 15, is illustrated in FIGS. 16 and 17. This glass finish 40 differs from the glass finish already described in the connecting portions 41 provided between cap anchoring slots 42. In this embodiment, these connecting portions 41 extend radially outwardly beyond the outer surface of the upper section 43 of the glass finish 40 resulting in the provision of at least partially upwardly facing cap lifting surfaces 44. These surfaces 44 combine with the gasket lugs 13 or 30 or 36 and particularly with the inclined surfaces 39 of the lugs 36 as illustrated in FIG. 15 to cause a simultaneous wiping off and lifting action as the caps are twisted during removal.
FIGS. 14 and 15 also illustrate radially inwardly projecting knobs or abuttments 33 and 45, respectively, which are formed on the cap gaskets during the gasket molding and which function as illustrated in FIG. 14 to prevent objectionable nesting of the closure caps 31 or 35 during cap storage and cap feeding in sealing machines. These knobs 33 and 45 are wiped off or flatened during sealing so that they do not interfere with the sealing operation. Portions of the knobs 33 and 45 which may happen to overlie a slot 12 or 42 in the glass finish during the sealing operation will enter the slot to assist in the cap anchoring function and these portions will be removed in the same manner as the cap anchoring lugs 13, 30 or 36 as the caps are twisted during cap removal.
It will be seen that an improved press-on twist lift-off sealing means has been described comprising a closure cap with a plastic gasket and a cooperating glass finish including an interrupted closure cap engaging groove. The cap is particularly advantageous in high speed package sealing operations since a positive and reliable cap attachment and seal are formed with a simple press-on sealing operation where only a minimal deformation of the plastic gasket is required. Additionally, a press-on and twist lift-off sealing means is provided where predetermined removal torques may be provided which remain stable over extended periods of package storage. The cap is easily reapplied after the initial opening to provide a resealing of the container. Both the closure cap manufacture and the container finish formation may be readily carried out on conventional manufacturing machinery with minor modifications only being required to provide the novel cap and container structures.
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.