Patent Application
20090101645
1. Field of the Invention
This invention relates to tamper resistant containers for holding edible materials such as spices.
2. Description of the Related Art
In recent years there has been an increasing interest in providing food containers with tamper resistant features to ensure that the contents of the container have not been disturbed prior to opening and use by a consumer. Tear strips that must be removed in order to access the contents of the container are one well known approach to providing tamper resistance. However, conventional tear strips have often required the container top to be made from two or more separate pieces that must then be assembled. Even where container tops that include a tear strip have been formed in one piece, two or more separate mechanical operations have been required to attach the top to the container and create the tear strip. Assembling the tops to these conventional containers (such as pepper containers) has thus required multiple steps in the manufacturing process.
Another problem with conventional tear strips is that they can be difficult to remove from the container. Similarly, the tear strips sometimes do not tear off completely leaving a portion of the strip on the container thereby making it difficult to open the container doors to access the container contents.
In some conventional containers (both metal and plastic), the container top and container body are snapped or pressed together. As a result, these containers sometimes suffer from another problem because the seal between the top and the container is not perfect. The imperfect seal can allow the container contents to escape between the lid and container during use or transport. The phenomenon where the container contents escape between the lid and the container body is also known as sifting. Sifting has been observed, for example, in some conventional pepper containers when pepper escapes between the container lid and container body due to an imperfect seal between the lid and container. The seal in such conventional containers allows for easy removal of the lid and thus also does not provide a tamper evidence benefit.
Another feature of some conventional containers, particularly containers for spices such as pepper, is to have multiple doors on the container top to permit a consumer to access the container contents in different ways. For example, some pepper containers have three doors: one allowing access to the container contents with a spoon, a smaller door allowing significant quantities to be poured out of a single mid sized opening, and a third door allowing the spices to exit more slowly through a series of small holes.
Accordingly, it is an aspect of one example of the invention to provide an integral one piece container top having a tamper resistant strip that can be assembled in a minimum number of operations without requiring a separate mechanical operation to attach the tear strip to the container.
Another aspect of one example of the invention is to provide a sift-proof seal between a container top and the container body that can be easily formed.
Still another aspect of one example of the invention is to provide an improved method of attaching doors to a container top to create a hinged connection between the door and container top.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.
In an exemplary embodiment of the invention, a plastic lid having an integral tear strip and doors has been made to attach to a plastic can. As shown in
The tear strip portion 3 is connected to the lid base 2 and the cover portion 4 of the lid 1 by a series of spaced apart bridges 8. See
In addition, the bridges 8 of the tear strip portion 3 serve another important function in the formation of the one piece integral lid 1. The lid 1 is formed in a single mold, for example, by injection molding. Specifically, the lid base 2 and the cover portion 4 can be molded flat with the tear strip portion 3 creating the bridge between the two halves of the part, allowing the plastic material to flow and fill out the lid 1 with a single injection location on the main body. Thus, formation of the lid 1, plastic flows through mold channels defining the bridges from one section of the mold to the next. The dimensions of the bridges 8 have been developed so that the channels in the mold which form the bridges 8 are wide enough to permit plastic to flow between the mold sections. Accordingly, such a lid 1 can be formed by a single molding step that would previously require a much more complicated mold and molding process to produce. The bridges 8 perform still another function related to the folding of the one piece lid 1 onto the filled can 20. Specifically, the bridges 8 are of appropriate size, shape, and spacing to permit the one piece lid 1 to be folded so that the cover portion 4 can be attached to the lid base 2 to form doors such as 5, 6, and 7.
While the number of bridges 8 shown in
Preferably, the entire lid 1 is made of plastic. One example of a material used for the lid is polypropylene. Other resins and resin blends may be used. However, polypropylene provides better functionality of the hinges (discussed below) and is better for welding (also discussed below).
A cross section of an exemplary embodiment of the lid 1 is shown in
The beading and scan welding each provide a sift-proof seal that prevents the container contents from escaping between the joint formed by the lid 1 and the can 20. The use of scan welding also provides additional tamper evidence by providing a permanent weld between the lid 1 and can 20. In other words, after scan welding the lid 1 typically cannot be removed from the can 20 without creating obvious damage to the container.
More specifically, the upper portion of the can body 11 may be provided with an outer circumferential bead 12 and outer circumferential groove 13 as shown in
The scan welding is a continuous process in which the can 20 with the lid 1 thereon can move along an assembly line and wipe the horn which produces the ultrasonic vibration. In comparison, in a sonic welding process such as spot welding, the package needs to stop for the horn to come in contact with the part to be welded. Thus, the scan welding allows for faster line speeds and less equipment, resulting in higher productivity and lower cost.
Another aspect of an exemplary embodiment relates to the structure utilized to create the hinges that attach the doors 5, 6, 7 to the lid base 2. As can be seen in
Although the description above contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
This application claims the benefit of priority under 35 U.S.C. § 119 from U.S. Ser. No. 60/981,069, filed Oct. 18, 2007, the entire contents is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60981069 | Oct 2007 | US |
