Plug for container
An embodiment of a plug for insertion into an opening of a container has a handle attached to a wall of the plug and at least one line of weakness in the wall. When a force is exerted on the handle to remove the plug from the opening, the wall tends to fail along said at least one line of weakness, thus showing tamper evidence and releasing the plug for removal.
This application claims the benefit of U.S. Provisional Patent Application No. 60/650,793, filed on Feb. 8, 2005.
FIELD OF INVENTIONThe present invention relates to a plug for an opening of a container, and in particular to an end-plug for a shipping tube or the like.
BACKGROUND OF INVENTIONShipping tubes are known for shipping long narrow objects, including rolled up sheets. One form of shipping tube consists of a tube of cardboard or fiberboard that is closed at each end by a plastic plug inserted into the tube. The tube may be cylindrical or some other shape. The plug is typically in the form of a shallow dish, with a wall that fits the inside of the tube and is cylindrical or otherwise corresponds to the shape of the tube, with a lip that abuts the end of the tube, and with a flat bottom. This sort of plug is held in place by friction between the tube and the wall of the plug.
However, the frictional force impedes insertion as well as removal of the plug. In order for the plug not to be too difficult to insert, the frictional force is limited. As a result, the plug may be dislodged by the contents moving around in shipping, and provides no security against unauthorized removal. Other measures are therefore taken to secure the end plugs. For example, a strip of adhesive tape may be placed across the end plug, and stuck down to the material of the tube on both sides, or staples may be driven through the walls of the tube and the end plug. However, these and similar measures are unsightly, and require additional operations to secure the end plug after the plug has been inserted in the tube. In addition, it is not very difficult to cut away the tape, or pry out the staples, remove and replace the end plug, and reseal the tube in a way that is not easy to detect.
SUMMARY OF INVENTIONOne embodiment of the present invention provides a plug for insertion into an opening of a container, comprising at least one line of weakness in a wall of the plug, the plug being so arranged that a force exerted on the plug in a direction to remove the plug from the opening can cause the wall to fail along the at least one line of weakness, and that after failure of the line of weakness at least a part of the plug is removable from said opening.
Another embodiment of the present invention provides a plug for insertion into an opening of a container, having a surface extending in a direction of insertion, ribs projecting from the said surface transverse to the direction of insertion, the ribs being arranged to engage a container opening to present less resistance to insertion of the plug into the container opening than to removal of the plug from the container opening.
The container may be a shipping tube, and the opening may then be an end of the tube.
Another embodiment of the present invention provides a combination of a shipping tube and at least one end plug for an open end of said shipping tube, comprising the plug having a wall extending in a direction of insertion of the plug into the end of the tube, ribs projecting from the said wall of the plug transverse to the direction of insertion, the ribs tending to deflect as the plug is inserted into the tube and act as barbs resisting removal of the plug from the tube, whereby the force required to remove the plug from the opening is substantially greater than the force required to insert the plug in the opening, the plug having a handle, the plug having at least one line of weakness, wherein when a force is applied to the handle to remove the plug from the tube the plug tends to fail at the at least one line of weakness before the ribs release from the tube.
BRIEF DESCRIPTION OF THE DRAWINGSFor the purpose of illustrating the invention, there are shown in the drawings various forms which are presently disclosed; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities particularly shown.
In the drawings, where like elements are identified by like numerals, and initially referring to
Referring now also to FIGS. 2 to 4, each end plug 14 comprises a generally flat floor 16 and a wall 18 upstanding from the periphery of the floor 16. A lip 20 runs round the top of the wall 18. In the embodiment shown in FIGS. 1 to 4, the end plug 14 is generally triangular, to correspond to the triangular profile of the tube 12. If the tube 12 is of a different shape, the end plug 14 may be of a correspondingly different shape. The end plug 14 may be made from any material having suitable strength and rigidity, and which lends itself to providing a line of weakness, and is preferably molded from plastic material. High-density polyethylene, low density polyethylene, or polypropylene are examples of suitable materials. When the end plug 14 is inserted in the tube 12, the wall 18 fits inside the tube, with the lip 20 resting on the end of the tube. The floor 16 spans and closes the tube within the wall 18. The lip 20 is shaped so that its outer edge is substantially flush with the outside of the tube 12 when the end plug 14 is inserted in the tube. The straight sides 22 of the wall 18 are then in contact with the inside of the tube 12, so that the floor 16 supports and stiffens the tube.
At each corner, the wall 18 is rounded off in a curved surface 24 that is spaced inward from the corresponding corner of the tube 12. As may be seen in
When the end plug 14 is inserted in the tube 12, the ribs 26 are deflected by the end of the tube 12, so that they become angled, with their outer edges nearer to the end of the tube than their roots. If the end plug 14 is then forced outward, for example, in an attempt to remove it from the tube, or as a result of the contents of the shipping tube 10 moving within the tube and striking the inside of the floor 16, the ends of the ribs 26 tend to dig into the inside of the tube 12 like barbs, resisting removal. The material, and the dimensions, of the ribs 26 are selected so that the ribs 26 are sufficiently flexible to deflect as the end plug 14 is inserted in the tube 12, but sufficiently rigid to resist outward movement of the end plug. The material of the tube 12 is selected to be sufficiently soft that the ends of the ribs 26 dig into the tube for a more secure grip and, if the end plug 14 is removed by force, the ribs tear the tube and cause visible damage. The end of the tube 12 can thus be closed in a single operation, using only the single piece end plug 14. No additional components, and no additional assembly operations, are used. Separate external fasteners, staples, tape, or the like are needed neither for reliable closure against accidental opening nor as a precaution against tampering.
Because the curved surface 24 is sloped, the ribs 26 are of different widths from root to tip, with the widest rib nearest the floor 16. Consequently, the thicknesses of the ribs 26 may be different to give the ribs the same effect as barbs. Alternatively, the ribs 26 may be constructed to have different effects, to give the end plug 14 as a whole more tolerance for variation in the size and/or material of the tube 12.
The end plug 14 is provided with a handle 28. One end of the handle 28 is connected to the middle of one of the straight sides 22 at the lip 18, and the other end of the handle is connected to the floor 16. The handle is substantially flush with the lip 20 for most of its length, and does not project significantly beyond the plane of the lip 20. Two lines of weakness in the form of scores or grooves 30 are formed in the end plug 14, connecting the ends of the handle on each side of the handle. The spacing between the scores 30 is roughly constant along their length. At one end, the scores 30 extend to the outer edge of the lip 20. For ease of molding and pleasing appearance, the scores 30 are formed in the outer side of the lip 20, the side that is exposed when the end plug 14 is inserted in the tube 12, and in the inner side of the wall 18 and the floor 16, the side that is hidden when the end plug is inserted in the tube. The scores 30 are arranged to weaken the material of the end plug 14 sufficiently that, if an attempt is made to remove the end plug 14 from the tube 12 by pulling on the handle 28, the scores 30 will tear before any other part of the shipping tube 10 fails.
The separation of one or both of the scores 30 allows the corners of the end plug 14 to move together, narrowing the gap left by tearing out the strip 32 of plastic between the scores or allowing the strip to overlap adjoining parts of the end plug. This reduces the engagement of the ribs 26 with the tube 12, facilitating removal of the end plug 14 from the tube. If the ribs 26 remain firmly engaged with the tube 12, then the end plug 14 can be removed by bending outward the parts adjacent to the strip 32. Whatever method of removal is used, the torn score 30 cannot be easily concealed or repaired. If the damaged end plug 14 is replaced, it is evident that it has been removed and replaced.
Thus, opening the shipping tube 10 by removing the end plug 14 from the tube 12 can be made easy for the end user who pulls the handle 28 and tears out the strip 32, while removing the end plug 14 without doing conspicuous damage can be made difficult.
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The features of two or more of the ribs 26A, 26B, 26C, 26D may be combined in a single rib 26.
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Although specific embodiments have been described, various modifications may be made without departing from the scope and spirit of the invention as defined by the appended claims. For example, although the described embodiments have generally triangular tubes 12, and correspondingly triangular end plugs 14, 64, 74, other shapes may be used. A circular tube is possible, but is presently less favored than polygonal shapes for many purposes, because circular tubes are not easy to handle in shipping, as they do not stack well and may roll around. Also, a circular tube allows the end plugs to be rotated, which may allow the end plug to be removed by an unscrewing motion without tearing the tear strip. The shape of the tube 12 is not limited to simple geometrical shapes. For example, a package for merchandise of a specific shape may comprise a short tube with a shape that follows closely the silhouette of the merchandise, and two end caps that follow the shape of the tube. If the merchandise is, for example, a pair of headphones, the shape may be quite complex.
Although molded plastic end plugs 14 and a cardboard or similar tube 12 have been described, other materials may be used. However, for the configuration shown in the embodiments, the ribs are sufficiently flexible to deflect when the plug is inserted in the tube, and sufficiently rigid to resist buckling if the plug is forced outwards. The tube 12 is sufficiently soft that the ribs dig into the material of the tube and visibly damage the tube if the end plug 14 is forced outwards.
The shapes and sizes of the various components may vary depending on the materials used for the shipping tube 10, on the size of the shipping tube, and on the properties of the intended contents. For example, if components are described as straight or parallel, and are made of molded plastic, those components may in practice be tapered by several degrees for easier demolding. For example, where components are described as “triangular” or “polygonal,” geometrical perfection is not required. Those skilled in the art will understand how close an approximation to a triangle is either necessary or reasonable given the intended function of a specific container and the economics of producing what is in most cases a disposable container.
As shown in
Although the end plug 14, 64, 74 has been described as used in combination with a shipping tube 12, the plug may be used with other forms of container, provided that the container has an opening into which the plug 14 can be inserted and can engage securely. For example, as suggested above, the tube 12 could be shorter between the end plugs than across them. For example, an end plug could form one side of a cuboidal box, or could form one end of a barrel, or could form a bung for an outlet in a barrel.
Although specific examples of handles 28, 66 have been described, it will be understood that other forms of handle are possible. The handle may be of any shape that allows the recipient of the container 10 to apply a force to the handle and, by doing so, to cause the material of the end plug 14, 64 to fail at the scores 30, 72. It is preferred for many uses that the handle be of a form that is immediately recognizable to the recipient as a handle to which the recipient is intended to apply force to open the container 10. Labeling, including words or symbols molded into the material of the end plug 14, may be used to assist the user to recognize the handle. It is preferred for many uses that the handle be of such a form that it is easy for the user to apply the necessary force. It is preferred for many uses that the handle be of a form that is not likely to foul or catch on other objects in shipping. The actual preferred shape will depend on the intended use and the intended user, as well as on the relative importance of the various functional aspects.
It will be appreciated by those skilled in the art, that the present invention may be practiced in various alternate forms and configurations. The previously detailed description of the disclosed embodiments is presented for purposes of clarity of understanding only, and no unnecessary limitations should be implied therefrom.
Claims
1. A plug for securely covering an opening of a container, the plug comprising:
- a floor defining a periphery;
- a wall extending from the periphery of the floor, the wall being structured to engage the container;
- at least one line of weakness defined in the wall or the floor of said plug; and
- said plug being structured to be retained over the opening of the container and to fail along the at least one line of weakness upon the application of a force exerted on said plug in a direction to remove said plug from said opening, and after failure of said at least one line of weakness at least a part of said plug is removable from said opening.
2. The plug according to claim 1, further comprising a handle attached to said plug adjacent to the at least one line of weakness; whereby a force exerted on said handle to remove said plug from said opening will cause the plug to fail along said at least one line of weakness.
3. The plug according to claim 2, further comprising two said lines of weakness generally parallel to one another, said handle being attached between said two lines of weakness.
4. The plug according to claim 2, wherein said handle is an elongate handle having a pair of ends, one of said ends being attached to said wall of said plug, and wherein at least one said line of weakness extends from one of said two ends to the other of said two ends.
5. The plug according to claim 1, wherein at least one said line of weakness extends to a free edge of said wall.
6. The plug according to claim 1, wherein said at least one line of weakness encircles said floor.
7. The plug according to claim 1, wherein said at least one line of weakness extends from said floor over said tubular part to a free edge of said wall.
8. The plug according to claim 1, further comprising ribs projecting from the wall of said plug, the ribs being structured to engage the sides of said container opening.
9. The plug according to claim 8, wherein said ribs are substantially transverse to a usual direction of installation of said plug into said container opening.
10. The plug according to claim 9, wherein at least some of said ribs project from a surface of said plug oblique to said direction of installation, said at least some ribs being spaced apart in said direction of installation, said ribs further having free edges defining an imaginary surface that is more nearly parallel to said direction of installation than is said surface of said plug, said imaginary surface and said surface of said plug being furthest apart at the end of said plug that is intended to be installed furthest into said container opening.
11. The plug according to claim 8, wherein said ribs are substantially parallel to a usual direction of installation of said plug into said container opening.
12. The plug according to claim 11, wherein said ribs define a barb structured to engage said container upon installation of said plug over said container opening.
13. The plug according to claim 8, wherein the at least one line of weakness is so positioned that failure of the plug along the at least one line of weakness permits the ribs to disengage from the container.
14. The plug according to claim 8, wherein the ribs are structured to present less resistance to installation of the plug to cover the container opening than to removal of the plug from the container opening.
15. The plug according to claim 13, wherein said ribs are sufficiently flexible to deflect on installation of said plug to cover an opening, and wherein said ribs are sufficiently stiff to remain in a deflected position and to transmit a compressive force having a component substantially parallel to the direction of installation to oppose movement in the direction opposite to the direction of installation.
16. A container, comprising:
- at least one wall defining the container and defining at least one open end; and
- a plug, comprising: a floor defining a periphery; a wall extending from the periphery of the floor, the wall being structured to engage the container; at least one line of weakness defined in the wall or the floor of said plug; and said plug being structured to be retained over the opening of the container and to fail along the at least one line of weakness upon the application of a force exerted on said plug in a direction to remove said plug from said opening, and after failure of said at least one line of weakness at least a part of said plug is removable from said opening.
17. The container according to claim 16, further comprising ribs projecting from the wall of said plug, the ribs being structured to engage the sides of said container opening.
18. The container according to claim 17, wherein at least some of said ribs project from a surface of said plug oblique to said direction of installation, said at least some ribs being spaced apart in said direction of installation, said ribs further having free edges defining an imaginary surface that is more nearly parallel to said direction of installation than is said surface of said plug, said imaginary surface and said surface of said plug being furthest apart at the end of said plug that is intended to be installed furthest into said container opening.
19. The container according to claim 17, wherein the ribs are structured to present less resistance to installation of the plug to cover the container opening than to removal of the plug from the container opening.
20. The container according to claim 19, wherein said ribs are sufficiently flexible to deflect on installation of said plug to cover an opening, and wherein said ribs are sufficiently stiff to remain in a deflected position and to transmit a compressive force having a component substantially parallel to the direction of installation to oppose movement in the direction opposite to the direction of installation.
Type: Application
Filed: Feb 8, 2006
Publication Date: Aug 10, 2006
Inventors: James Johanson (Old Chatham, NY), Chad Lagace (Cohoes, NY), Keith Antal (Valatie, NY)
Application Number: 11/349,702
International Classification: B65D 17/34 (20060101); B65D 43/14 (20060101); B65D 43/04 (20060101);