(1) Field of the Invention
The present invention relates to an aerosol dip tube for conveying the contents of an aerosol container to a valve mechanism provided on the aerosol container.
(2) Description of Related Art
An aerosol dip tube is provided in an aerosol container with one end portion thereof connected to a valve mechanism. The dip tube conveys the contents of the container to the valve mechanism so that it can be sprayed as an aerosol. Such dip tubes include those made from relatively rigid resins which can hardly be bent and those made from soft and elastic resins which can easily be bent.
If a dip tube made from a rigid resin is used in an aerosol container, the dip tube cannot follow the aerosol content, which moves when the aerosol container is slanted or inverted, because the container is not designed to be used in such slanted or inverted state. Accordingly, such an aerosol container suffers because some of the aerosol content remains unused while only the propellant gas is exhausted. Therefore, although some of the aerosol content may still remain in the container, it is impossible to spray it.
Dip tubes made from bendable, soft and elastic materials are being explored to solve the problems described above. A dip tube made from such a soft and elastic material is designed to follow the aerosol content as the aerosol container is slanted, and is therefore constantly brought into contact with the aerosol content within the aerosol container.
For example, in Japanese Unexamined Utility Model Publication No. Sho 62-118552, a thick weight is fixed to the free end portion of a dip tube made from a soft and elastic material. According to this arrangement, the dip tube bends because of the weight as the aerosol container is slanted. This allows the free end portion of the dip tube to move such that it can constantly be brought into contact with the aerosol content. Thus, the aerosol content in the container may be assuredly consumed.
Another dip tube with a similar objective is disclosed in Japanese Utility Model Publication No. Sho 56-39578. According to this device, a holding frame is attached to a free end of a dip tube made from a soft and elastic material. A thick weight is embedded in this holding frame. This arrangement enables the dip tube to bend as the aerosol container is slanted and moves the free end portion of the dip tube into constant contact with the aerosol content.
Another dip tube is disclosed in Japanese Unexamined Utility Model Publication No. Sho 55-13626. A thick weight is attached to the free end portion of a soft and elastic dip tube. The weight is covered on its circumference thereof with a shock absorbing material.
However, in a dip tube having a thick weight fixed at the free end portion thereof, as disclosed in Japanese Unexamined Utility Model Publication No. Sho 62-118552, the free end of the dip tube cannot reach nooks at the bottom of the aerosol container because the weight strikes the side of the aerosol container. This causes the contents of the aerosol container to remain not fully used. In addition, in the dip tube having a weight fixed at the free end portion thereof, the weight hits the inner surface of the aerosol container when the weight moves as the aerosol container is slanted. This may damage a coating etc. applied on the inner surface of the aerosol container. If the aerosol content is corrosive, for example, the aerosol container could corrode due to this damage. This could cause the properties of the aerosol content to change or cause accidents such as gas leakage due to the damage to the aerosol container.
Japanese Utility Mode Publication No. Sho 56-39578 discloses a dip tube having a free end to which a holding frame made from a soft and elastic material is attached. A thick weight is embedded in this holding frame. This arrangement has disadvantages because the structure of the tube is relatively complicated. This complicates manufacture of the dip tube and raises the production costs. Further, the weight provided at the free end portion of the dip tube strikes the side of the aerosol container, thereby preventing the free end of the dip tube from assuredly reaching the nooks at the bottom of the aerosol container and causing the contents to be not fully used.
In the dip tube disclosed in Japanese Unexamined Utility Model Publication No. Sho 55-13626, the outer periphery of a thick weight is attached to the free end of a dip tube and is covered with a shock absorbing material. Therefore, the inner surface of the aerosol container is not damaged, but other previously mentioned disadvantages, such as the complicated structure of the dip tube increasing the production unit cost, or the content of the aerosol remaining not fully used, are not completely avoided.