The present invention relates to a container end which provides venting during emptying of contents and, in particular, a container with an end having a score defining a vent area providing good pouring characteristics without undue increase in the opening""s size.
A number of containers are configured to achieve easy opening, such as without the need for a can opener or other tool and preferably which does not involve separation of any parts (so that there is no separate tab or cover piece to dispose of). A number of features of such containers and container ends affect the level to which end users, as well as bottlers, manufacturers, distributors, shippers and retailers, are satisfied with the container. One factor believed to be of some importance to consumers is the pour characteristics of the container. In general, it is believed that consumers prefer to use containers capable of providing a relatively high pour rate, such as pouring about 350 ml in less than about 10 seconds, preferably less than about 8 seconds, and more preferably less than about 7 seconds (e.g., measured using pour rate testing as described below). Additionally, it is believed consumers prefer containers that provide a smooth or substantially laminar pour, i.e. a pour which is not characterized by a series of surges (which can cause splashing and/or can affect a beverage head, fizz or other carbonation or pressurization-related characteristics of the contents, after pouring).
Certain previous containers have been configured in an attempt to address these concerns by providing relatively large openings, e.g. openings covering greater than about 0.5 square inches (about 3.2 cm2). Unfortunately, such larger openings tend to be associated with a higher rate of problems such as bursting, buckling, leakage, opening failures and the like, particularly when the contents are pressurized, such as being provided with an over-pressure of about 35 psi (about 250 kPa) or more. In some cases, large opening panels are provided in designs having relatively smaller hinge or xe2x80x9cgatexe2x80x9d regions, which can, in some instances, be associated with container leakage and/or separation of the panel, or other components, upon opening, sometimes causing parts to be expelled (xe2x80x9cmissileingxe2x80x9d). Furthermore, such larger openings are difficult or infeasible to provide in container ends which are relatively small, such as round container ends having a diameter of than about 2 inches (about 5 cm). Furthermore, certain previous approaches to improving pouring characteristics have involved major changes to the design of the container end, thus involving relatively high tooling or other equipment costs, design costs, testing costs and the like.
Accordingly, it would be useful to provide a container or container end with improved pouring characteristics while retaining a relatively small opening area, which is preferably compatible with relatively small-sized container ends, and which can be achieved with only modest changes in tooling, procedures and/or testing.
The present invention relates to a container and container end of a type where an opening area is at least partially defined by a score line. First and second endpoints of the score line are spaced apart along the score line, and the opening area is bent inward, following rupture (e.g. via a tab pivoted about a rivet, along an opening axis). The pivot point defined by the rivet is generally at about the center or centroid of the container end. The spaced-apart ends of the rupture define an opening or xe2x80x9cgatexe2x80x9d axis about which the bent-in region bends or pivots. The present invention involves configuring the score line so that the area which is bent-in provides an opening which defines not only a pouring region but also a vent region. In one embodiment the vent region is shaped (substantially triangular) with an edge of the vent region defined by the gate region. The vent region has an apex pointing generally away from the pour area. In one embodiment, both termination points at the rupture line are located on the same side of the opening axis but on opposite sides of a pivot axis (which is perpendicular to the opening axis and substantially passes through the pivot point of the tab). Preferably a first end of the rupture line extends substantially from a region adjacent a pivot point to the apex of the triangular vent region, forming one side of the triangular vent region. The gate axis, forming a second side of the triangular vent region, extends from this rupture line termination point to the other rupture line termination point. Preferably at least a portion of the end initially covering the vent region is reinforced with a stiffening shape, preferably triangular in shape, and preferably having an edge of the stiffening shape generally adjacent or colinear with the gate defined between the two rupture line end points. The present invention provides a desirably fast, smooth pour while maintaining a relatively small total opening area (pour opening plus vent opening) and otherwise avoiding undesirable bursting, buckling and opening failures.