Integral self-closing dispensing closure for a tube

Abstract

 A self-closing membrane closure (19) that is an integral part of the shoulder (15) of a tube container (10) provides for an efficient method for packaging and dispensing paste-like products. The self-closing membrane is formed at the same time as the supporting shoulder by compression molding or a related technique. This negates the need for any assembly and the potential for leakage. In addition to the self-closing membrane closure, there can also be cap fitted over the membrane closure.

Description

[0001] This invention relates to a dispensing tube which has a self-closing membrane at the exit orifice which is an integral part of the shoulder of the tube. More particularly, this invention relates to a dispensing tube where the shoulder and membrane closure are molded in a single operation whereby the membrane closure is an integral part of the shoulder.

[0002] The self-closing dispensing closures that are in use are comprised of a pliable material which has at least one slit. This type of a dispensing closure is very effective for use with various viscous and paste-like materials. Such viscous and paste-like materials include various food products, dentifrices, lotions, shampoos and other personal care products. In order to dispense such products from a container, it is only necessary to apply a force onto the product within the container so that it can be displaced from the container. Since the only mode of displacement from the container is through the slit opening, the product will be delivered through the slit opening. Upon the release of the force on the product in the container the pliable membrane of the slit opening returns to its original position thereby ceasing the dispensing of the product from the container. The product remaining in the container is then retained in a sealed condition. These closures can be effectively used on pliable tubular containers.

[0003] Self-closing dispensing closures of this type are not complicated and provide for a positive dispensing action. Further, such self-closing dispensing closures are usually low in cost in comparison to other types of closures and serve very effectively to preserve the product which remains within the container. The slit opening in the closure will usually be a single slit or a double slit which will usually intersect at the center of each slit. A prime requirement with regard to the material from which the closure is constructed is that the material have a memory with regard to its original orientation. That is, the material must be of a type which will return to its original orientation upon the cessation of a pressure on the product which is being dispensed. It is this memory which will cause the slit opening to close and to thereby cut off the flow of product from the container.

[0004] Self-closing dispensing closures are usually constructed of a number of pieces. In this construction, they effectively dispense the contained product. There is also a good cut-off of the product being dispensed when the pressure on the product in the container is released. However, when an item is made of two or more pieces that must be assembled, there is the added cost of assembly. It is preferred that an item be of one-piece construction. There is also the potential for leakage. It has now been found that a self-closing dispensing closure for a tubular container can be formed as a single item integral with the shoulder for the tubular container. This shoulder is then heat sealed onto the end of a tube to produce the dispensing end of a tubular container.

[0005] Self-closing dispensing closures have been used for the dispensing of paste-like products. In U.S. Patent 2,147,164 there is disclosed such a closure for use in a dispensing collapsible tube container. The slitted membrane closure which is disclosed in this patent consists of a rubber disk which has a single slit therein. This slitted disk is held in place by means of a flange on the upper part of the collapsible dispensing tube. This slitted closure is then further covered by means of a cap which is threadedly engaged to the tube. While this is a useful structure for a tube closure, it is rather complex and requires assembly. The closure membrane is not an integral part of the shoulder of the container.

[0006] U.S. Patent 2,552,715 discloses a pressure operated dispensing nozzle for collapsible tubes. This dispensing nozzle is fitted onto the top of the collapsible tube. It has a slit opening for dispensing a paste-like product. The paste-like product is dispensed via pressure which is applied to the exterior of the collapsible tube. In this patent, the membrane closure is not an integral part of the shoulder of the container.

[0007] U.S. Patent 2,620,949 discloses another type of membrane closure for collapsible tubes. In this closure, there is more than a slit opening. There is as a part of the structure of the cap, two side compartments and the walls of these compartments for sealing off the closure when material is no longer to be dispensed. This cap closure is crimped onto the top of a collapsible tube and functions as its own support.

[0008] U.S. Patent 2,670,884 is directed to a self- sealing membrane closure for a collapsible tube. This is an upwardly extending shaped means. Further, in the area of the slit opening, the closure is of an increased thickness. This increased thickness is to ensure the closure of the slit opening when a force is no longer applied on the tube and it is intended to close dispensing product.

[0009] U.S. Patent 2,679,954 discloses a collapsible container which has as the dispensing portion a membrane disk which has a crossed slit opening. This crossed slit opening is in a membrane disk which is maintained in place on the collapsible tube by means of a threaded cap. The upper portion is open over a significant part of its area to expose the membrane disk. This provides for a positive containment of the disk onto the container.

[0010] U.S. Patent 2,802,607 discloses a domed shaped dispensing cap for collapsible tubes. In this dispensing cap, there is a slit opening on the top of the cap for the dispensing of the contained product and a threaded portion on the base portion of the cap for attaching the cap to a collapsible tube. This threaded cap is constructed of a single material. However, this closure membrane is not an integral part of the shoulder of the container.

[0011] U.S. Patent 2,937,795 discloses a domed shaped dispensing closure for a collapsible tube. In this embodiment, the domed shaped closure has a crossed slit membrane and is attached directly onto the top of the collapsible container. This closure membrane and upper container shoulder portion are not one integral part.

[0012] U.S. patent 3,669,323 discloses a one-way valve insert for collapsible dispensing containers. This is an insert that fits below the slot opening of the closure. This embodiment, like the embodiments of the other patents, is a multi-piece unit which requires assembly.

[0013] The present self-closing dispensing membrane closure is an improvement over the various prior art closures. In the present closure, the closure membrane is an integral part of the shoulder of the container. The closure membrane and shoulder are molded as one piece. This obviates the need for assembly and removes the potential for leakage. This results in a savings in time and money.

BRIEF DESCRIPTION OF THE INVENTION

[0014] This invention is directed to a tubular container which has a membrane closure wherein the shoulder of the tubular container and the membrane closure are an integrally molded piece. The tubular container can be a collapsible container or a non- collapsible container. It can also be a tubular container in which the force on the contained product is supplied by a piston. The membrane closure provides for a positive dispensing of the contained product. Product is dispensed by applying a force onto the product. This can be a squeezing force when it is being dispensed from a tubular container and a force applied by a piston for a pump container. When the force pushing the product from the container is released, the membrane closure closes and cuts off the flow of product. This also protects the product near the opening from drying or becoming encrusted during storage.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] 

Figure 1 is a perspective view of a collapsible container having an integral dispensing closure.

Figure 2 is a side view of the shoulder and dispensing closure.

Figure 3 is a side view of the tube portion of the dispensing container.

Figure 4 is a top view of the dispensing closure showing a single slit.

Figure 5 is a top view of the dispensing closure showing two slits.

Figure 6 is a side view of a preferred embodiment of the dispensing closure with the closure elevated above the threads.

DETAILED DESCRIPTION OF THE INVENTION

[0016] In Figure 1, there is shown tubular container 10 having a tube portion 11 sealed at the bottom at 12. The upper portion of the tubular container consists of shoulder 15 which has shoulder wall 16 and exit nozzle 17. On the exterior of the exit nozzle, there is shown threads 18 for attaching a threaded cap. The top portion 19 will have one or more slit openings.

[0017] In Figure 2 and Figure 3, there is shown the shoulder section 15 and the tube section 11 respectively. The tubular portion 11 has an upper opening 13 defined by rim 14. The shoulder portion 15 has a vertical portion 21 which terminates in rim 20. Rim 20 defines aperture 22. In assembling the shoulder 15 onto the tube 11, the vertical portion 21 extends downward into opening 13 of the tube portion 11. The two portions are then heat sealed. It is also an embodiment where the vertical portion 21 of the shoulder extends down over the wall of tube 11 and is then heat sealed. This can be by any convenient heat sealing technique, including RF sealing and ultrasonic sealing.

[0018] Figure 4 and Figure 5 show configurations for the openings in the membrane closures on the nozzle portion of the shoulder. In Figure 4, there is shown to be one slit opening 23 while in Figure 5 there is shown to be two slit openings, 23 and 24, which slit openings intersect. These two slit openings need not intersect, and further, there may be more than two slit openings.

[0019] Figure 6 sets out an alternate embodiment for the shoulder portion. In this embodiment, the slit region 19 is elevated above threads 18 by sidewall 26. This is in the nature of a hat type of dispensing slit arrangement. As with the prior embodiments in this embodiment, the shoulder is a single molded piece.

[0020] The entire shoulder portion is molded as a single piece, including the membrane 25 on the top portion. This can be conveniently accomplished by compression molding. Since the shoulder portion is constructed as one piece, there is removed the likelihood of leakage at joints. The slits 23 and 24 are cut into the membrane 25 at a convenient time. This can be after the shoulder portion has been molded and prior to bonding to the tubular container portion, after attachment to the tubular container portion, or after the tube has been filled with a paste-like product.

[0021] The tube portion and shoulder portion can be made out of any single or multilayer compatible materials. These include polyolefin, polyester polymers and copolymers, including polyethylene, polypropylene, vinyl acetate, and ethylene-vinyl acetate copolymers, polyethylene terephthalate polymers and polyethylene terephthalate copolymers.

Claims

1. A tubular container for dispensing a paste product comprising a tube portion and a closure portion, said tube portion being sealed at one end with the other end having said closure portion attached thereto, said closure portion comprised of a one-piece flexible polymeric material having a shoulder portion attached to said tube portion by means of a skirt, symmetrical in shape to said tube portion and which contacts a sufficient area of the tube portion to form a seal, said shoulder portion having extending upwardly a nozzle having threads on the exterior thereof, said nozzle terminating in a continuous substantially flat section elevated a distance above the threads on the exterior thereof, said flat section having at least one slit therethrough for dispensing of the paste product contained in the tubular container.

2. A tubular container as in Claim 1 wherein said tube portion is heat sealed at the lower end.

3. A tubular container as in Claim 1 wherein said tube portion is comprised of a material selected from the group consisting of polyolefin and polyester polymers and copolymers.

4. A tubular container as in Claim 1 wherein said continuous flat section has two intersecting slits therethrough.

5. A method of making a tubular container for dispensing paste product comprising forming a tube portion and a flexible shoulder portion, said shoulder portion formed by injecting molding as a single piece the shoulder portion of said container, a nozzle portion extending upwardly from said shoulder portion having external threads on the lower part thereof and a flat section covering the opening of said nozzle portion, said flat portion elevated a distance above said exterior threads, connecting said tube portion to said shoulder portion, and cutting at least one slit in said flat section.

6. A method as in Claim 6 wherein said tube portion is filled with a paste product and the end of said tube opposite said shoulder portion is sealed.

7. A method as in Claim 6 wherein said at least one slit is cut in said flat section after said tue portion is filled with paste product.

8. A method as in Claim 5 wherein there are at least two slits cut in said flat section.

9. A method as in Claim 5 wherein said slits intersect.

10. A method as in Claim 5 wherein the nozzle portion on its exterior surface has threads.

11. A method as in Claim 10 wherein a cap engages said threads and covers said flat section.

Drawing