LINERLESS CLOSURES
United States Patent 3844439
A linerless closure cap comprising a top having integrally formed on the underside thereof inner and outer laterally deflectable sealing fins adapted to engage the generally rounded but inherently non-uniform mouth of a glass container adjacent the inner and outer peripheral portions thereof and to conform thereto and a compression ring stiffer and shorter than the sealing fins located therebetween and adapted to be compressed against the top of the container mouth when the closure cap is secured to the container.
US Patent References:
Method and apparatus for making container caps
Shank - September 1935 - 2013320
Sealing members or elements
Guinet - October 1956 - 2768762
Combination closure cap and stopper
Miller - January 1963 - 3074579
Closure cap
Acton - November 1965 - 3215297
SEAL FOR RESEALABLE BUCKET CLOSURE
Yates - October 1970 - 3532244
Method and apparatus for making container caps
Shank - September 1935 - 2013320
Sealing members or elements
Guinet - October 1956 - 2768762
Combination closure cap and stopper
Miller - January 1963 - 3074579
Closure cap
Acton - November 1965 - 3215297
SEAL FOR RESEALABLE BUCKET CLOSURE
Yates - October 1970 - 3532244
Inventors:
Demers, Jacques (Waterloo, Quebec, CA)
Chartier, Robert (Waterloo, Quebec, CA)
Chartier, Robert (Waterloo, Quebec, CA)
Application Number:
05/276238
Publication Date:
10/29/1974
Filing Date:
07/28/1972
View Patent Images:
Export Citation:
Assignee:
Consumers Glass Company Limited (Rexdale, Ontario, CA)
Primary Class:
International Classes:
B65D41/04; B65D53/00
Field of Search:
215/DIG.1,40,41,43,344
Primary Examiner:
Norton, Donald F.
Claims:
I claim
1. In combination, a glass container whose mouth configuration has a generally rounded upper edge or crown which in vertical section curves downwardly in opposite direction from a generally central crest portion, but which varies in vertical cross-section, crown surface contour around the mouth and eccentricity, and a linerless clsoure cap suitable for sealing the mouth of said container, said closure cap comprising a skirt and top, said skirt having means for securing said cap to the neck of said container, said top having on the underside thereof an integral outer annular resilient readily deflectable sealing fin disposed to cooperate with the downwardly curving portion of the container mouth crown outwardly of the central crest portion, said outer fin having an inner surface sloping outwardly of the fin axis from adjacent to said top to the free edge thereof for displacing said outer fin outwardly on contacting the downwardly and outwardly curving crown portion, an integral inner annular resilient readily deflectable sealing fin disposed to cooperate with the downwardly curving portion of the container mouth crown inwardly of the central crest portion, said inner fin having an outer surface sloping inwardly ofthe fin axis from adjacent to said top to the free edge thereof for displacing said inner fin inwardly on contacting the downwardly and inwardly curving crown portion, and an annular resilient compression ring stiffer and of lesser depth than said outer and inner fins and resistant to lateral deflection, located between said fins, said compression ring terminating in a "V" apex and adapted to contact the central crest portion of the rounded crown when the closure is applied to the mouth of the container, whereby upon contact of the compression ring with the crown surface, a line contact is first provided between the compression ring and the high spot on the crown crest and a wiping contact is provided between said fins and crown on opposite sides of said crown crest as said fins are deflected by said downwardly curving crown portions, and as the closure is advanced to a sealing configuration, said compression ring is compressed into flats at the high spots of the crown crest until at least a line contact is established with the low spots of the crown crest to define two isolated chambers one between the compression ring, the crown surface, and the inner fin, and the other between the compression ring, the crown surface and the outer fin, and said fins are deflected to first exhasut therebeneath air compressed in said isolated chambers and to thereafter establish a sealing contact of appreciable width with the downwardly curving crown portions on either side of the crown crest around said container mouth.
2. The combination as claimed in claim 1 in which the inner surface of the inner fin and the outer surface of the outer fin of said linerless closure cap are substantially vertical.
3. The combination as claimed in claim 2 wherein the angle between said inner surface sloping outwardly and said outer substantially vertical outer surface of said outer fin of said linerless closure cap and the angle between said outer surface sloping inwardly and said inner substantially vertical inner surface of said inner fin of said linerless closure cap are each about 30°.
4. The combination as claimed in claim 3 in which the "V" apex of said compression ring defines an angle of about 60°.
1. In combination, a glass container whose mouth configuration has a generally rounded upper edge or crown which in vertical section curves downwardly in opposite direction from a generally central crest portion, but which varies in vertical cross-section, crown surface contour around the mouth and eccentricity, and a linerless clsoure cap suitable for sealing the mouth of said container, said closure cap comprising a skirt and top, said skirt having means for securing said cap to the neck of said container, said top having on the underside thereof an integral outer annular resilient readily deflectable sealing fin disposed to cooperate with the downwardly curving portion of the container mouth crown outwardly of the central crest portion, said outer fin having an inner surface sloping outwardly of the fin axis from adjacent to said top to the free edge thereof for displacing said outer fin outwardly on contacting the downwardly and outwardly curving crown portion, an integral inner annular resilient readily deflectable sealing fin disposed to cooperate with the downwardly curving portion of the container mouth crown inwardly of the central crest portion, said inner fin having an outer surface sloping inwardly ofthe fin axis from adjacent to said top to the free edge thereof for displacing said inner fin inwardly on contacting the downwardly and inwardly curving crown portion, and an annular resilient compression ring stiffer and of lesser depth than said outer and inner fins and resistant to lateral deflection, located between said fins, said compression ring terminating in a "V" apex and adapted to contact the central crest portion of the rounded crown when the closure is applied to the mouth of the container, whereby upon contact of the compression ring with the crown surface, a line contact is first provided between the compression ring and the high spot on the crown crest and a wiping contact is provided between said fins and crown on opposite sides of said crown crest as said fins are deflected by said downwardly curving crown portions, and as the closure is advanced to a sealing configuration, said compression ring is compressed into flats at the high spots of the crown crest until at least a line contact is established with the low spots of the crown crest to define two isolated chambers one between the compression ring, the crown surface, and the inner fin, and the other between the compression ring, the crown surface and the outer fin, and said fins are deflected to first exhasut therebeneath air compressed in said isolated chambers and to thereafter establish a sealing contact of appreciable width with the downwardly curving crown portions on either side of the crown crest around said container mouth.
2. The combination as claimed in claim 1 in which the inner surface of the inner fin and the outer surface of the outer fin of said linerless closure cap are substantially vertical.
3. The combination as claimed in claim 2 wherein the angle between said inner surface sloping outwardly and said outer substantially vertical outer surface of said outer fin of said linerless closure cap and the angle between said outer surface sloping inwardly and said inner substantially vertical inner surface of said inner fin of said linerless closure cap are each about 30°.
4. The combination as claimed in claim 3 in which the "V" apex of said compression ring defines an angle of about 60°.
Description:
FIELD OF THE INVENTION
This invention relates to improvements in the means utilized to seal a container. In particular, this invention relates to improvements in linerless closure caps for sealing a glass container which presents special problems for sealing due to the fact that the rounded mouth of the container cannot be moulded precisely symmetrical but inherently has some eccentricities or non-uniformity or irregularities relative to the axis and also some non-uniformity or irregularity in the glass surface itself.
BACKGROUND OF THE INVENTION
Linerless caps have been proposed but most of these are for plastic containers wherein an axially symmetrical and accurately flat mouth surface can be obtained and various forms of sealing fins and rings formed on the underside of the cap have been proposed to effect a seal with such containers. However, in the moulding of glass the mouth of the container is required to be rounded and the moulding cannot be carried out with exact precision so that the mouth of the container may be somewhat out of round or lacking in precise axial symmetry and the mouth surface itself may have a considerable unevenness both in cross-section and around the mouth. These non-uniformities or irregularities make it extremely difficult to obtain a proper seal with a linerless cap and such caps proposed to date have not given the degree of seal desired.
SUMMARY OF THE INVENTION
It is therefore the object of this invention to provide an inexpensive one-piece linerless cap moulded from polypropylene or other similar suitable material, which will give an excellent seal when used with a glass container.
According to the invention, the cap is provided on the underside thereof with a sealing ring arrangement comprising inner and outer resiliently deflectable sealing fins for engaging with and conforming to the inner and outer peripheral portions of the rounded mouth of the container respectively and at least one, (preferably one), central compression ring adapted to be compressed against the upper or crown surface of the rounded container mouth, the resilient deflectable fins being longer than the central compression ring and projecting downwardly there beyond.
Further, according to the preferred embodiment of the invention the relatively longer inner and outer deflectable fins have respectively deflecting faces sloping inwardly and outwardly with respect to the container axis and the relatively shorter central compression ring is relatively stiffer than said fins and is of triangular cross section and presents a central apex for initially substantially line contact with the uppermost surface of the rounded container mouth as the closure is applied to the container.
DETAILED DESCRIPTION OF THE DRAWINGS
The invention shall now be described and illustrated with reference to the accompanying drawings wherein:
FIG. 1 is a cross-sectional view of a linerless closure cap illustrating one embodiment of the invention.
FIG. 2 is an enlarged broken away view of the top left portion of the cross-sectional area of FIG. 1.
FIG. 3 is a cross-sectional view of the linerless closure cap as secured to the top of a glass container.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, a closure cap 1 comprises a top 2 and skirt 3, having means 4 to secure the closure cap to the neck of the container 100. In the embodiment illustrated the securing means 4 comprises a male thread formed on the internal surface of the skirt to mate with the helical recesses 5 of the container although it will be appreciated other suitable fastening means may be employed.
As shown in FIG. 3 which is an enlargement of the neck 101 of the container 100, the upper surface 102 defining the mouth of the container is generally rounded but is not uniformly so because of the difficuties of moulding the glass.
Not only is the upper surface 102 not uniformly rounded but the neck 101 itself may not be precisely centered on the axis of the container so that the inner peripheral portion 103 and the outer peripheral portion 104 of the container mouth may be at varying distances from the container axis around the container mouth.
In addition to the lack of uniformity in the curvature of the container mouth in vertical cross section, there will also be a corresponding lack of uniformity in the surface 102 along a circular path centered on the container axis and traced on the surface 102.
This lack of uniformity or irregularity in the container mouth portion renders the usual form of linerless caps or closures ineffective for the purpose of sealing the container. The present invention, however, has been found to provide a cap giving a highly effective seal when used with containers whose mouth configurations vary over the entire gambit of acceptable container mouldings. That is the particular sealing configuration provided on the inside of the cap or closure is capable of accommodating all such variations in vertical cross section, crown or surface contour and axial eccentricity.
As shown particularly in FIGS. 2 and 3, the sealing arrangement comprises an outer annular sealing ring or fin 6, an inner annular sealing ring or fin 7 and an intermediate or central compression seal preferably in the form of a single ring 8 which is substantially shorter and stiffer than the sealing fins 6 and 7, the arrangement being such that a line joining the apexes 6a, 8a and 7a of the rings 6, 8 and 7 describe a surface generally corresponding to the rounded upper end surface 102 of the container mouth.
The outer sealing fin 6 is formed with an inner outwardly sloping surface 9 and an outer preferably substantially vertical surface 10. The angle defined by the intersection of the surfaces 9 and 10 is preferably of the order of about30° so that this outer fin 6 is relatively slender and therefore quite readily deflected when its sloping surface 9 contacts the upper surface 102 of the container mouth.
Similarly the inner fin 7 has its outer surface 11 with respect to the axis of the container sloped corresponding to the surface 9 of the outer fin 6. The inner surface 12 of fin 7 is also preferably vertical and again the intersection of the surfaces 11 and 12 preferably forms an angle of about 30° to provide a slender readily deflectable sealing member for displacement over the surface 102 of the container when the sloping surface 11 contacts the container mouth.
The intermediate ring 8 is V-shaped and preferably defines in cross section an equilateral triangle with the side walls 13 being inclined to each other at approximately 60° so that the apex 8a is blunter than the apexes 6a and 7a and is centered between the sides 13 so that as the apex 7a contacts the container surface 102, the compression ring 8 will be compressed rather than deflected. When the closure or cap formed according to the invention is applied to the container, the apexes 6a and 7a of the sealing fins 6 and 7 will first contact the container surface 102 and depending upon the eccentricity of the container neck, the fins 6 and 7 on further advancement of the closure towards the closed position will be deflected towards or over the outer and inner peripheral portions 104 and 103 respectively of the container mouth. As shown in FIG. 3 the eccentricity of the container mouth is such that the inner fin 7 has been displaced as guided by the sloping or cam surface 11 to substantially cover the inner peripheral mouth portion 103. It will be understood that the fin 7 will have sufficient resiliency so that while it is deflectable under the camming effect of the inter-engagement of the surface 11 with the surface portion 103, it will nevertheless have sufficient resistance to displacement that it will press against the surface 103 as it tends to recover towards its normal unrestained portion shown in FIG. 2.
In the illustration in FIG. 3 it will be seen that the outer fin 6 has contacted the upper surface 102 of the neck inwardly of the outer peripheral surface portion 104 and as the closure is advanced, the outer fin 6 will be deflected more along the top of the surface 102 rather than down over the edge or outer peripheral portion 104 of this surface. Nevertheless, the inherent resiliency of the fin 6 will be such as to cause it to tightly conform to the surface 102 as it wipes over the surface during displacement.
It will be understood that the deflection of the fins 6 and 7 will continue until the compression ring 8 contacts the upper surface 102 of the container mouth and because the apex8a of the compression ring 8 is centrally located, further advancement of the closure will cause compression of the compression ring. The first contact of the compression ring with the surface 102 will provide a line contact with the high spots on the surface and as the container is advanced, the apex8a will be deformed into a flap at the high points of the surface 102 until a line contact is established with the low points of the surface, the ring having sufficient compressibility and sufficient resiliency that for all normal mouth variations a complete seal can be obtained on the surface 102 completely around the mouth, it being understood that some portions of the compression ring 8 will be compressed more than other portions. It will also be understood that when the compression ring 8 has been substantially fully compressed it forms a stop limiting further cap closing movement.
The seal obtained with the sealing arrangement of the present invention has been found very effective and it appears that, during the compression of the compression ring 8 as the cap is closed tight down against the top of the container, air is compressed in the chambers 14 defined between the compression ring 8 and the fins 6 and 7 and the mouth surface 102. This air acting under pressure against the sloping deflecting surfaces 9 and 11 has the tendency to deflect the fins and exhaust therebeneath. Air attempting to move back into the chambers 14 on the other hand, will press against the outer generally vertical surfaces 10 and 12 and act to force the fins into tighter sealing engagement with the surface 102, rather than enter the chambers. Thus, any tendency of the cap to contract or any slight unloosening of the cap does not immediately break the seal across the top of the container but rather appears to increase the intimate fin to container surface contact and the closure seal remains effective indefinitely, regardless of the irregularities or non-uniformities of the container mouth.
While the preferred embodiment of the invention has been particularly described, it will be understood that variations in detail as apparent to those skilled in the art may be made without departing from the spirit of the invention or scope of the appended claims.
This invention relates to improvements in the means utilized to seal a container. In particular, this invention relates to improvements in linerless closure caps for sealing a glass container which presents special problems for sealing due to the fact that the rounded mouth of the container cannot be moulded precisely symmetrical but inherently has some eccentricities or non-uniformity or irregularities relative to the axis and also some non-uniformity or irregularity in the glass surface itself.
BACKGROUND OF THE INVENTION
Linerless caps have been proposed but most of these are for plastic containers wherein an axially symmetrical and accurately flat mouth surface can be obtained and various forms of sealing fins and rings formed on the underside of the cap have been proposed to effect a seal with such containers. However, in the moulding of glass the mouth of the container is required to be rounded and the moulding cannot be carried out with exact precision so that the mouth of the container may be somewhat out of round or lacking in precise axial symmetry and the mouth surface itself may have a considerable unevenness both in cross-section and around the mouth. These non-uniformities or irregularities make it extremely difficult to obtain a proper seal with a linerless cap and such caps proposed to date have not given the degree of seal desired.
SUMMARY OF THE INVENTION
It is therefore the object of this invention to provide an inexpensive one-piece linerless cap moulded from polypropylene or other similar suitable material, which will give an excellent seal when used with a glass container.
According to the invention, the cap is provided on the underside thereof with a sealing ring arrangement comprising inner and outer resiliently deflectable sealing fins for engaging with and conforming to the inner and outer peripheral portions of the rounded mouth of the container respectively and at least one, (preferably one), central compression ring adapted to be compressed against the upper or crown surface of the rounded container mouth, the resilient deflectable fins being longer than the central compression ring and projecting downwardly there beyond.
Further, according to the preferred embodiment of the invention the relatively longer inner and outer deflectable fins have respectively deflecting faces sloping inwardly and outwardly with respect to the container axis and the relatively shorter central compression ring is relatively stiffer than said fins and is of triangular cross section and presents a central apex for initially substantially line contact with the uppermost surface of the rounded container mouth as the closure is applied to the container.
DETAILED DESCRIPTION OF THE DRAWINGS
The invention shall now be described and illustrated with reference to the accompanying drawings wherein:
FIG. 1 is a cross-sectional view of a linerless closure cap illustrating one embodiment of the invention.
FIG. 2 is an enlarged broken away view of the top left portion of the cross-sectional area of FIG. 1.
FIG. 3 is a cross-sectional view of the linerless closure cap as secured to the top of a glass container.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, a closure cap 1 comprises a top 2 and skirt 3, having means 4 to secure the closure cap to the neck of the container 100. In the embodiment illustrated the securing means 4 comprises a male thread formed on the internal surface of the skirt to mate with the helical recesses 5 of the container although it will be appreciated other suitable fastening means may be employed.
As shown in FIG. 3 which is an enlargement of the neck 101 of the container 100, the upper surface 102 defining the mouth of the container is generally rounded but is not uniformly so because of the difficuties of moulding the glass.
Not only is the upper surface 102 not uniformly rounded but the neck 101 itself may not be precisely centered on the axis of the container so that the inner peripheral portion 103 and the outer peripheral portion 104 of the container mouth may be at varying distances from the container axis around the container mouth.
In addition to the lack of uniformity in the curvature of the container mouth in vertical cross section, there will also be a corresponding lack of uniformity in the surface 102 along a circular path centered on the container axis and traced on the surface 102.
This lack of uniformity or irregularity in the container mouth portion renders the usual form of linerless caps or closures ineffective for the purpose of sealing the container. The present invention, however, has been found to provide a cap giving a highly effective seal when used with containers whose mouth configurations vary over the entire gambit of acceptable container mouldings. That is the particular sealing configuration provided on the inside of the cap or closure is capable of accommodating all such variations in vertical cross section, crown or surface contour and axial eccentricity.
As shown particularly in FIGS. 2 and 3, the sealing arrangement comprises an outer annular sealing ring or fin 6, an inner annular sealing ring or fin 7 and an intermediate or central compression seal preferably in the form of a single ring 8 which is substantially shorter and stiffer than the sealing fins 6 and 7, the arrangement being such that a line joining the apexes 6a, 8a and 7a of the rings 6, 8 and 7 describe a surface generally corresponding to the rounded upper end surface 102 of the container mouth.
The outer sealing fin 6 is formed with an inner outwardly sloping surface 9 and an outer preferably substantially vertical surface 10. The angle defined by the intersection of the surfaces 9 and 10 is preferably of the order of about30° so that this outer fin 6 is relatively slender and therefore quite readily deflected when its sloping surface 9 contacts the upper surface 102 of the container mouth.
Similarly the inner fin 7 has its outer surface 11 with respect to the axis of the container sloped corresponding to the surface 9 of the outer fin 6. The inner surface 12 of fin 7 is also preferably vertical and again the intersection of the surfaces 11 and 12 preferably forms an angle of about 30° to provide a slender readily deflectable sealing member for displacement over the surface 102 of the container when the sloping surface 11 contacts the container mouth.
The intermediate ring 8 is V-shaped and preferably defines in cross section an equilateral triangle with the side walls 13 being inclined to each other at approximately 60° so that the apex 8a is blunter than the apexes 6a and 7a and is centered between the sides 13 so that as the apex 7a contacts the container surface 102, the compression ring 8 will be compressed rather than deflected. When the closure or cap formed according to the invention is applied to the container, the apexes 6a and 7a of the sealing fins 6 and 7 will first contact the container surface 102 and depending upon the eccentricity of the container neck, the fins 6 and 7 on further advancement of the closure towards the closed position will be deflected towards or over the outer and inner peripheral portions 104 and 103 respectively of the container mouth. As shown in FIG. 3 the eccentricity of the container mouth is such that the inner fin 7 has been displaced as guided by the sloping or cam surface 11 to substantially cover the inner peripheral mouth portion 103. It will be understood that the fin 7 will have sufficient resiliency so that while it is deflectable under the camming effect of the inter-engagement of the surface 11 with the surface portion 103, it will nevertheless have sufficient resistance to displacement that it will press against the surface 103 as it tends to recover towards its normal unrestained portion shown in FIG. 2.
In the illustration in FIG. 3 it will be seen that the outer fin 6 has contacted the upper surface 102 of the neck inwardly of the outer peripheral surface portion 104 and as the closure is advanced, the outer fin 6 will be deflected more along the top of the surface 102 rather than down over the edge or outer peripheral portion 104 of this surface. Nevertheless, the inherent resiliency of the fin 6 will be such as to cause it to tightly conform to the surface 102 as it wipes over the surface during displacement.
It will be understood that the deflection of the fins 6 and 7 will continue until the compression ring 8 contacts the upper surface 102 of the container mouth and because the apex8a of the compression ring 8 is centrally located, further advancement of the closure will cause compression of the compression ring. The first contact of the compression ring with the surface 102 will provide a line contact with the high spots on the surface and as the container is advanced, the apex8a will be deformed into a flap at the high points of the surface 102 until a line contact is established with the low points of the surface, the ring having sufficient compressibility and sufficient resiliency that for all normal mouth variations a complete seal can be obtained on the surface 102 completely around the mouth, it being understood that some portions of the compression ring 8 will be compressed more than other portions. It will also be understood that when the compression ring 8 has been substantially fully compressed it forms a stop limiting further cap closing movement.
The seal obtained with the sealing arrangement of the present invention has been found very effective and it appears that, during the compression of the compression ring 8 as the cap is closed tight down against the top of the container, air is compressed in the chambers 14 defined between the compression ring 8 and the fins 6 and 7 and the mouth surface 102. This air acting under pressure against the sloping deflecting surfaces 9 and 11 has the tendency to deflect the fins and exhaust therebeneath. Air attempting to move back into the chambers 14 on the other hand, will press against the outer generally vertical surfaces 10 and 12 and act to force the fins into tighter sealing engagement with the surface 102, rather than enter the chambers. Thus, any tendency of the cap to contract or any slight unloosening of the cap does not immediately break the seal across the top of the container but rather appears to increase the intimate fin to container surface contact and the closure seal remains effective indefinitely, regardless of the irregularities or non-uniformities of the container mouth.
While the preferred embodiment of the invention has been particularly described, it will be understood that variations in detail as apparent to those skilled in the art may be made without departing from the spirit of the invention or scope of the appended claims.