Patent Application
20100200605
1. Field of the Invention
This invention relates generally to the field of plastic containers, and more specifically to plastic containers that are designed to receive a snap fit lid that forms a seal with the container for securing product within the container.
2. Description of the Related Technology
Containers for compositions such as paint and similar substances are required to be designed so as to ensure that a reliable and secure seal is formed between the container and the lid. Such as seal is required not only to prevent spoilage of the contents of the container, but also to prevent potentially harmful vapors from escaping the container assembly during transportation and storage. Such containers also must be constructed so as to have high degree of reliability and durability under extreme temperature conditions and for prolonged periods of storage.
Accordingly, paint containers conventionally have been fabricated from steel or other metallic materials and have utilized lids that also were fabricated from a metallic material. The use of plastic materials for such applications has also been proposed. However, it has been difficult to achieve the required sealing and performance characteristics that are briefly described above using plastic containers.
However, plastic containers offer benefits in terms of economy of manufacture, shapeability and lightweighting that make them potentially attractive for use as paint containers if the prerequisite sealing and performance characteristics can be achieved. Accordingly, a need exists in this area of technology for an improved plastic container assembly for packaging paints and similar materials that possesses a high degree of reliability and durability under extreme conditions and that ensures that a reliable and secure seal is formed between the container and the lid.
Accordingly, it is an object of the invention to provide an improved plastic container assembly for packaging paints and similar materials that possesses a high degree of reliability and durability under extreme conditions. It is also an object of the invention to provide an improved plastic container assembly that ensures that a reliable and secure seal is formed between the container and the lid.
In order to achieve the above and other objects of the invention, a plastic container according to a first aspect of the invention includes a container main body portion; and a lid mounting portion, the lid mounting portion including a sealing flange and a flexible transition portion connecting the sealing flange to the container main body portion, the flexible transition portion having at least one notch defined therein so as to form a hinge permitting downward movement of the sealing flange.
A method of making a plastic container according to a second aspect of the invention includes steps of blow molding a container blank having a main body portion and a lid mounting portion, the lid mounting portion comprising a sealing flange blank and a flexible transition portion connecting the sealing flange blank to the container main body portion, the flexible transition portion having at least one notch defined therein so as to form a hinge; and trimming the sealing flange blank to form a sealing flange.
These and various other advantages and features of novelty that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings which form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views, and referring in particular to
The blow molded plastic container 12 is preferably manufactured according to the extrusion blow molding process, and is preferably fabricated from a plastic material such as polypropylene, polyethylene or high-density polyethylene. The blow molded plastic container 12 may also be constructed from a multi-layer plastic material that is co-extruded as a multilayered parison and then is molded into the preferred container, preferably although not necessarily by using a shuttle or a wheel molding apparatus.
Container assembly 10 further includes a lid member 18, which is preferably fabricated from a plastic material such as polypropylene, polyethylene or high-density polyethylene. Lid member 18 may be fabricated from a softer material than is used to fabricate the blow molded plastic container 12, and may in the preferred embodiment be fabricated so as to have a wall thickness that is less than the wall thickness of the blow molded plastic container 12. The lid member 18 is preferably fabricated using an injection molding process.
Alternatively, the lid member 18 can be fabricated from a metallic material such as steel or aluminum.
Referring to
As
The outer wall 30 preferably includes at least one annular snap bead 34 that is provided on inner surface thereof in order to engage corresponding structure on the container 12 to facilitate a snap fit. Alternatively, a plurality of snap bead members 34 could be provided instead of a continuous annular bead. The inner surface of the outer wall 30 further includes an oblique contact surface 35 that is constructed and arranged to contact structure on the container 12 to facilitate the snap fit, as will be described in greater detail below. The oblique contact surface 35 intersects with an upstanding vertical portion of the inner surface of the outer wall 30 to define an annular sealing ridge portion 37, as is best shown in
Referring now to
In the embodiment that is shown in
Referring back to the embodiment of
A first continuous annular or circumferential seal 50 is formed between the inner end of the sealing flange 38 and the inner surface 36 of the inner wall 28 of the lid member 18 in order to prevent leakage from the container 12. A second circumferential annular seal 52 is formed by the contact of the outermost portion of the annular mounting bead 46 and the inner surface of the outer wall 30 just beneath the oblique contact surface 35 in order to further prevent leakage from the container 12. In addition, a third circumferential contact area 54 may be created by the contact of the annular sealing ridge portion 37 of the inner surface of the outer wall 30 of the lid member 18 with a portion of the outer sidewall of the flexible transition portion 40 between the notch 42 and the annular mounting bead 46. The third circumferential contact area 54 in the preferred embodiment does not create a seal, although this may be possible in an alternative embodiment. The compound seal that is created by the individual continuous annular seals 50, 52 is expected to be comparable to the seal that is achieved using metallic paint container assemblies, and provides redundancy that will provide additional security against leakage that might otherwise occur due to unwanted deformation of the plastic material that is used to fabricate the lid member 18 and the container 12.
When the lid 18 is fastened onto the container 12, the flange 46 is preferably in contact with the lip 34, which holds the lid 18 onto the container 12.
The embodiment of the invention that is depicted in
According to aspect of the invention, the hinge 44 in the embodiment of the invention that is depicted in
A making a blow molded plastic container according to one aspect of the invention is shown schematically in
Preferably, the sealing flange 38 will be formed and folded over by the capping machine as the cap is being applied. As an alternative option, after the trimming operation depicted in
The container is then filled and sealed by snapping on the lid 18 as is shown schematically in
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
