Push-Tab Hinge for a Container Closure Apparatus

The present invention relates generally to containers useful for products that may be poured from the container and, more particularly, to improved closures secured to said containers. For example, paperboard cartons are generally well known. A familiar type is the milk carton which has a gabled top. Also, becoming ever more popular are rectangular shaped cartons, some of aseptic quality, for containing beverages, powdered goods, and practically any other pourable substance. To prevent waste and provide for ease of pouring, improved pouring-through closure apparatus for securing openings in said containers are needed. Practically any container to be used to hold pourable contents may benefit from the improved closure of the present invention.

Push-tabs have been used in combination with container closure apparatus, which are designed to be depressed into the material of the container or package. The push-tabs serve to open a partially pre-cut area on the surface of the package below the closure. The push-tab separates the material of the package and may serve to hold the material apart to maintain the opening during pouring.

Previous closure push-robs have been hinged directly to an inner wall that defined a central opening in the closure apparatus. The present invention recognizes a need for improved force distribution through the hinge, when the push-tab is depressed by a user of the container. By improving the push-tab hinge design, stress distribution through the hinge is improved. As a result of the hinge design improvements, the closure apparatus may be manufactured from a broader range of materials, some of which may be less expensive.

The present invention provides a push-tab hinge which distributes stresses more effectively than previous hinge designs. In particular, the present invention provides a landing which extends from the closure central opening to a spring face which depends from the push-tab. The junction between the landing and the spring face provides a first flexible joint through which the hinge acts. The junction between the spring face and the push-tab provides a second flexible joint through which the hinge acts. Furthermore, the spring face may be flexible through its entire length, thereby providing additional means by which the hinge may flex as the push-tab is depressed.

The entire apparatus may be made as a one-piece injection molded plastic unit, having movable parts. Reference is made to U.S. Pat. No. 5,101,999, which is hereby incorporated by reference into the present application.

These and other advantages will be apparent from the following detailed description of the invention, drawings, and claims.

The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:

FIG. 1 is a perspective view of one embodiment of the closure apparatus of the present invention attached to the top of a package or container;

FIG. 2 is a plan view of the closure apparatus of FIG. 1 with a cover rotated to its open position;

FIG. 3 is an enlarged section view taken along line 3--3 in FIG. 1;

FIG. 4 is a cut away, side elevational view showing the push-tab in its open position and material of the package top broken into the package;

FIG. 5 is a plan view showing the bottom surface of a preferred embodiment of the closure apparatus of the present invention; and

FIG. 6 is a detail view of the hinge of FIG. 3.

Referring to FIG. 1, a closure apparatus 10 for opening and resealing a package 12 is shown. The package 12 may be made from a penetrable material, and may contain a dispensable fluid, powder, particulate solid substance, or any other pourable contents.

As shown in FIG. 2, the closure apparatus 10 may have a base 13 having a forward portion 14 and a rearward portion 16. The bottom surface 18 of the base 12 (as shown in FIG. 5) may be attached to the package top 20 by any suitable means, such as an adhesive 22 applied to the bottom surface 18. The closure apparatus is shown secured to the package 12 in FIG. 3.

On a top surface 24 of the base 12 there may be a formed pour wall 26. Interiorally of the pour wall 26 there may be formed an inner side wall 28 that defines a central opening 30. In the preferred embodiment, a landing 32 extends from the rear portion 34 of the inner side wall 28. It is to be recognized that the landing 32 may extend from elsewhere, such as from pour wall 26, on the apparatus 10 and remain within the scope of the present invention. The present invention may also be accomplished without a landing.

A push-tab 36 is formed to initially reside within the inner side wall 28 directly over the central opening 30. The push-tab 36 has a spring face (best shown in FIG. 3) extending from the push-tab 36. The spring face 38 is also integrally connected with the landing 32. The junction 40 between the spring face 38 and the landing 32 forms a first flexible joint. The junction 42 between the spring face 38 and the push-tab 36 forms a second flexible joint. Both flexible joints 40, 42 may be seen best in FIG. 6. The spring plate 38 and the first and second junctions 40 and 42 in combination with the landing 32 provides a robust hinge which distributes stress more effectively than previous designs.

The spring face 38 may, in another embodiment of the present invention, extend directly from the inner side wall 28. In this case, the first junction 40 would reside at the location where the side wall 28 and the spring face 38 meet.

Referring to FIG. 4, the push-tab 36 is shown in its depressed position, having broken through the material 46 of the package 12. As the push-tab 36 is depressed, junctions 40 and 42 are placed in flexion, as is spring face 38.

The closure apparatus 10 may be provided with a vent hole 60 to allow air to enter and exit the package when the contents are poured from the package 12. The vent hole 60 allows for a more even flow rate of the contents out of the package. Vent hole 60 may be provided in several places, including spring plate 38, in landing 32, or the vent hole 60 may straddle the junction 40.

Referring to FIG. 2, if the vent hole 60 is supplied where shown, in the center of junction 40, it effectively divides the junction into two halves. The two halves 61, 62 act as hinge straps. The dual hinge strap embodiment results in practically having two hinges (61 and 62) in place of one continuous junction hinge 40.

The present invention has been described in the form of preferred embodiments, but it is to be recognized that several modifications and variations to the invention could be made and fall within the scope of the subjoined claims.