COMBINED LIP AND SHOULDER SEAL FOR THREADED CAP
An improved cap is provided for sealing an opening formed in an associated bottle. The cap is preferably internally threaded for receipt over a threaded portion of the bottle. A flap extends from a planar surface of the cap and is directed for receipt in the associated bottle opening. A shoulder also extends outwardly from the planar surface and is spaced inwardly from the flap to engage the seal flap as the cap is threaded onto the bottle. The cap is preferably formed of a rigid plastic such as high density polyethylene (HDPE).
Blow molded containers or bottles are used for a wide variety of fluid products, and find particular use in the dairy industry for milk, juices, flavored waters, etc. The bottle typically includes a raised shoulder or neck surrounding an opening that is used for introducing or filling the fluid into the bottle, and likewise the same opening is oftentimes subsequently used for dispensing the fluid from the bottle. In some instances, the opening may be used for only one of filling or dispensing and, in either situation, a closure cap is typically positioned over the opening once the bottle has been filled.
Oftentimes, the cap is internally threaded and cooperates with external threads on the neck that surround the bottle opening (see, for example, WO2008/091936 developed by the same inventors, the details of which are expressly incorporated herein by reference). It is desirable for the opening to be sealed from the external environment. This can be accomplished in a number of different ways. For example, a foil or gasket seal is commonly placed over the opening and secured to the bottle. Although this arrangement provides an effective seal, and provides a clear indication of whether the seal has been tampered with, the foil seal represents extra material, i.e., the gasket or foil, as well as additional processing which includes associated equipment, material, and additional time in the processing line to secure the gasket/foil seal over the opening for use in conjunction with the cap.
In other instances, the opening is sealed in a different manner. For example, an internal surface of the cap includes a series of closely spaced concentric ribs, i.e., a series of concentric projecting surfaces, placed under axial compression as the ribs are essentially compressed or crushed against an outer radial surface of the neck as a result of imposing a high torque on the cap as the cap is threaded onto the bottle. Because the ribs are compressed, the material used is preferably a softer material that is capable of being compressed, for example a polypropylene is commonly used. This arrangement does not provide a tamper evident feature. Further, if the threads are not well formed, the torque developed between the neck and cap may be insufficient to develop the desired force to compress the ribs and provide an effective seal. Similarly, an imperfect neck finish (e.g., a burr or flash remaining on the neck) will prevent the ribs from being properly compressed. As a result, the cap does not properly seal to the bottle.
An alternative manner of sealing the bottle is to use a flexible flap that extends from the internal surface of the cap and forms an interference seal with a shoulder on the bottle neck. The flap extends downwardly from the inner surface of the cap, and has an outer radial dimension greater than an inner diameter of the bottle opening. The cross-sectional thickness of the flap preferably decreases as the flap extends outwardly from the cap. Moreover, a distal end of the flap is positioned for receipt within the neck that forms the opening of the bottle and advantageously centers or orients the cap in place on the neck. Again, a softer material such as a polypropylene is commonly used for a cap of this type in order to provide sufficient flexibility to the flap as the flap is urged into sealing engagement with the inner wall surface of the shoulder that forms the opening. This seal arrangement also requires a precise fit or else the flap is not properly oriented relative to the neck and there is no other structure in the arrangement that holds or guides the flap into the correct location. Further, this seal arrangement does not provide tamper evidence.
It is still desirable to locate the seal at the edge of the opening, or preferably inside the throat of the opening. However, this is difficult to do with existing cap designs.
SUMMARY OF THE DISCLOSUREAn improved cap is provided that provides an effective seal with the bottle opening, and substantially decreases the cost per cap.
The cap includes a generally planar surface that overlies the bottle opening. A sidewall extends from the planar surface and surrounds the bottle opening. The lip extends from the planar surface and is directed inwardly from the side wall for receipt in the bottle opening. A shoulder extends outwardly from the planar surface and is spaced laterally or radially inwardly from the lip for engaging the seal lip.
Preferably, the lip has a variable thickness along the length thereof.
The cap is preferably formed of a rigid plastic such as HDPE. The shoulder extends outwardly from the generally planar surface a dimension less than the lip extends outwardly from the same surface.
In addition, a stop surface may be provided on the cap to operatively engage a corresponding stop shoulder on the bottle to limit or define a maximum force imposed on the lip and shoulder.
A pour opening may be incorporated into the generally planar member, and a closure lid hinged to the cap.
The pour opening includes a thin-walled tamper-evident member that is integrally molded with the generally planar member.
A primary advantage associated with the present disclosure is the improved sealing associated with the new cap.
Another advantage residing in this disclosure relates to the substantially reduced costs to manufacture.
Still another benefit is associated with the reduced quality required of the neck finish.
Yet another advantage resides in the elimination of components (such as a separate gasket or foil seal) as well as reduced processing time in the manufacture of the bottle.
Yet another advantage is associated with the ability to provide a tamper-evident feature without additional costs.
Still other benefits and advantages of the disclosure will become apparent from reading and understanding the following detailed description.
In the arrangement shown in
This interference fit between the flap of the cap with the interior shoulder of the neck encounters the following problems—it is not always a perfect fit and potential leaking can develop at the cap, there is no tamper evidence, and instead requires the additional expense of an additional foil seal.
An alternative arrangement is shown in
Turning to
The interconnecting region of the flap with the interior surface of the cap is preferably spaced radially inward from the sidewall 194 to accommodate the cross-sectional thickness of the shoulder 120 extending from the bottle. Thus, as illustrated in
The seal assembly of the present disclosure also includes a rigid pinch rib or shoulder 210 that is disposed radially inward of the flap. Particularly, the rib is spaced by radial gap 212 from the flap. The pinch rib extends generally normally outward from the underside or interior surface of the cap planar portion at a substantially reduced height relative to the height of the flap. As shown in
This arrangement allows significant torque to be imposed on the cap to create the seal. The chamfer of the body shoulder serves as a self-centering or lead-in portion for the flap to assure proper location of the cap on the neck opening. Moreover, the pinch rib 210 serves as a stop to limit the torque imposed on the flap.
Moreover, because a sufficient torque on the order of about 20 inch pounds can be imposed on the cap (as compared to a approximately 2-5 inch pounds in the prior art), there is no need for a separate foil seal, no need for a gasket, and if desired, the structure can be made so that the cap is never removed from the bottle. That is, it is contemplated that the opening may be used only for filling the bottle, the cap then positioned in place, and an anti-taper member or ring to 240 (shown in dotted line in
Alternatively, the arrangements of
As generally illustrated in
The price of each cap can be reduced by approximately fifty percent (50%) with the present cap, while still maintaining the ability to effectively seal along the inside of the neck, providing for tamper-evident capability, and providing an effective seal that allows substantial torque to be imposed on the cap to create the seal.
The disclosure has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
Claims
1. A cap for selectively sealing an opening formed in an associated bottle that includes an external thread portion around the opening, the cap comprising:
- a generally planar surface dimensioned to overlie the associated bottle opening;
- a sidewall extending from the planar surface including internal thread portions thereon dimensioned for cooperative threaded engagement with the associated bottle thread portion;
- a lip extending from one of the planar surface and the sidewall and directed inwardly from the sidewall for receipt in the associated bottle opening; and
- a shoulder extending outwardly from the planar surface and spaced inwardly from the lip for engaging the seal lip as the cap is threaded on to the associated bottle.
2. The cap of claim 1 wherein the lip has a variable thickness along a length thereof.
3. The cap of claim 2 wherein the lip has a thicker cross-sectional dimension adjacent an interconnecting region with one of the planar surface and the sidewall.
4. The cap of claim 1 wherein the lip has a thicker cross-sectional dimension adjacent an interconnecting region with one of the generally planar surface and the sidewall.
5. The cap of claim 1 wherein the cap is formed of a rigid plastic such as HDPE.
6. The cap of claim 1 wherein the lip extends from the generally planar surface and is spaced radially inward from the sidewall.
7. The cap of claim 6 wherein the shoulder is spaced radially inward of the lip.
8. The cap of claim 7 wherein the shoulder extends outwardly from the generally planar surface a dimension less than the lip extends outwardly from the generally planar surface.
9. The cap of claim 1 wherein the shoulder extends outwardly from the generally planar surface a dimension less than the lip extends outwardly from the generally planar surface.
10. The cap of claim 1 wherein the shoulder is spaced radially inward of the lip.
11. The cap of claim 1 further comprising a stop surface on the cap that is located to operatively engage a corresponding stop shoulder on the associated bottle to limit forces imposed on the lip and shoulder.
12. A molded plastic cap for a fluid bottle having an opening, the molded plastic cap comprising:
- a generally planar member dimensioned for covering receipt over the bottle opening;
- a sidewall extending outwardly in a first direction from adjacent a perimeter of the generally planar member and surrounding the opening;
- a contoured lip extending a first dimension from an interior surface of the generally planar member and inwardly from adjacent a perimeter thereof; and
- a shoulder extending a second dimension from the interior surface of the generally planar member and spaced further inwardly from the perimeter than the lip for sealingly engaging the lip to the associated bottle.
13. The cap of claim 12 wherein the lip has a reduced thickness at a distal end relative to a proximal end.
14. The cap of claim 12 wherein the cap is formed of a rigid HDPE material.
15. The cap of claim 12 wherein the lip first dimension is greater than the shoulder second dimension.
16. The cap of claim 12 wherein the sidewall includes a thread portion along an inner surface thereof for cooperative threaded engagement with an external thread portion around the opening of the associated bottle.
17. The cap of claim 12 further comprising a stop surface for limiting advancement of the cap onto the bottle over the opening.
18. The cap of claim 12 further comprising a pour opening in the generally planar member and a closure lid hinged thereto.
19. The cap of claim 18 wherein the pour opening includes a thin walled tamper evident member integrally molded with the generally planar member.
Type: Application
Filed: Jan 6, 2011
Publication Date: Nov 1, 2012
Inventors: Daniel P. Soehnlen (Canton, OH), Gregory M. Soehnlen (North Canton, OH)
Application Number: 13/520,638
International Classification: B65D 55/16 (20060101); B65D 41/04 (20060101);