Can container

Abstract

An easily rupturable portion, which is ruptured when an inner pressure of a can container is raised extraordinary and the domed portion is thereby deformed to protrude outwardly of the can container, is formed on an outer face side of the domed portion and situated in the close vicinity of an outer circumferential portion of the domed portion continuing into a seamed portion. For example, the easily rupturable portion is ruptured to release the contents of the can container when an inner pressure of a can container is raised extraordinary by heat or the like to deform the domed portion of a bottom lid to protrude outwardly within the outer circumferential portion of the domed portion. Therefore, a gas can be released without blowing off a portion of the can container.

Description

TECHNICAL FIELD[0001]This invention relates to a can container such as an aerosol can to be filled with contents.BACKGROUND ART[0002]Aerosol cans filled with a propellant as a high pressure gas are used in the prior art of this kind of aerosol can is thrown into the fire or left in a hot place over a prolonged period of time, an inner pressure of the can container is raised extraordinarily due to thermal expansion of a propellant. In this case, a seamed portion where a can body and a bottom lid are seamed, or an installation portion of the can body where a mountain cap is mounted thereon may be demolished and the bottom lid of the can container or the mountain cap is thereby blown off. In order to prevent such an explosion of the can container resulting from a pressure rise, a weakened portion is formed to release the inner pressure of the can container. The weakened portion is to be ruptured when the inner pressure of the can container exceeds a certain value so that the can contai...

AI Technical Summary

Benefits of technology

[0008]In order to achieve the above-mentioned object, according to the invention, there is provided a can container, which has an annular ground contacting portion formed at a lower end of the can container and a domed portion protruding inward of the can container from an inner circumferential face of the annular ground contacting portion, characterized in that: an easily rupturable portion, which is ruptured when an inner pressure of the can is raised extraordinary and the domed portion is thereby deformed to protrude outward of the can container, is formed on an outer face side of the domed portion and situated in the close vicinity of an outer circumferential portion of the domed portion continuing into the annular ground contacting portion.

[0012]Therefore, according to the invention, when the inner pressure of the can container is raised extraordinary by heat or the like the domed portion is inflated and deformed to protrude outwardly of the can container, within the outer circumferential portion of the domed portion formed on the bottom side of the can container (i.e. a lower edge of the domed portion continuing into the annular ground contacting portion which is to be contacted directly with the ground when the can container stands upright). As a result the easily rupturable portion is ruptured to release the contents of the can container For this reason a gas venting can be achieved without blowing apart a piece of the can container, when the inner pressure is raised extraordinary. In addition since the easily rupturable portions are formed in the close vicinity of the outer circumferential portion of the domed portion where the degree of deformation resulting from inflation is great the easily rupturable portions can be ruptured certainly when the domed portion is inflated. The easily rupturable portions can be prevent from being ruptured unexpectedly by dropping impact by forming them on the outer face side of the domed portion in the close vicinity of the outer circumferential portion of the domed portion in comparison with the case in which the easily rupturable portions are formed on the annular ground contacting portion which is likely to collide directly with the ground if the can container is dropped accidentally.

[0015]Further, according to the invention, since a planar shape of the easily rupturable portion is an approximate semicircular shape and end portions thereof are extended approximately in the radial direction of the can container, the semicircular portion enclosed by the ruptured easily rupturable portion is easy to pop up outwardly when the domed portion is deformed to protrude outwardly and the easily rapturable portion is thereby ruptured, in comparison with the case in which the easily rapturable portion is formed linearly. For this reason, the pressure in the can container can be relieved promptly. Additionally, since the end portions of the easily rupturable portion are not directed to the adjoining easily rupturable portion in the circumferential direction, the rupture of the easily rupturable portion will not attack to the adjoining easily rupturable portion even if the propagation of the rupture extends beyond the end portion of the easily rupturable portion For this reason, the domed portion will not be fractured partially.

Problems solved by technology

However, in case of the invention disclosed in Japanese Patent Laid-Open No 47-7686, the scores are formed on the seamed portion of the metal can container so that sealing characteristics of the seamed portion is unstable.

Moreover, a rupture of the scores may be induced by an impact or vibration in transit and this also results in a leakage of the contents or propellant from the ruptured portion.

Further, if the can container is dropped accidentally, the seamed portion may collide directly with the ground and this makes the score lines formed on the seamed portion easy to be ruptured.

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