Patent Application
20110240673
1. Field of the Invention
This invention relates generally to the field of collapsible containers, which are commonly used in healthcare applications to administer parenteral nutrition and other fluids to patients. More specifically, this invention relates to an improved collapsible container that is shaped in a manner to facilitate efficient volumetric contraction and that may be fabricated using an extrusion blow molding process.
2. Description of the Related Technology
Collapsible containers such as flexible pouches are commonly used in healthcare applications to dispense such fluids as saline solution, parenteral solutions and other liquids to patients. Such containers are typically designed to be suspended from a hanging hook, with the fluid being withdrawn from a lower end of the container.
One such container is disclosed in U.S. Pat. No. 3,880,311 to McPhee. As the fluid is withdrawn from the container, the internal volume of the container is reduced, causing the flexible sidewalls to be drawn inwardly. However, as may be seen in
Collapsible containers are also disclosed in U.S. Pat. No. 3,926,341 to Lhoest. These containers include sidewalls that have inwardly extending hinge lines about which the sidewall is designed to collapse while fluid is being dispensed. While some of these designs may be more volumetrically efficient than the McPhee container, the shape of the container is difficult or impossible to fabricate using a conventional blow molding process. Specifically, the presence of the inwardly extending fold lines would make it difficult or impossible to withdraw the container from a mold.
A need exists for an improved collapsible container that is shaped in a manner to facilitate efficient volumetric contraction and that may be fabricated using an extrusion blow molding process.
Accordingly, it is an object of the invention to provide an improved collapsible container that is shaped in a manner to facilitate efficient volumetric contraction and that may be fabricated using an extrusion blow molding process.
In order to achieve the above and other objects of the invention, a blow molded collapsible container according to a first aspect of the invention includes a main body portion having a sidewall that defines an interior space that has a volume. The container further has a neck portion that is unitary with the sidewall. The neck portion has an opening defined therein that is in communication with the interior space. The main body portion includes opposing sides, with each of the opposing sides having an outwardly extending crease defined in a central portion thereof. The main body portion is constructed and arranged to collapse by folding along the outwardly extending creases when the volume of the interior space is reduced.
A method of making a collapsible container according to a second aspect of the invention includes steps of extruding a parison of plastic material; capturing a portion of the parison within a mold; inflating the portion of the parison that is within the mold against the walls of the mold to fabricate a collapsible container having a neck portion and a main body portion having opposing sides, with each of the opposing sides having an outwardly extending crease defined in a central portion thereof; and removing the collapsible container from the mold.
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
Collapsible container 10 includes a main body portion 12 having a sidewall 13 that defines an interior space having a volume. The collapsible container 10 further includes a neck portion 14 that in the preferred embodiment has at least one external thread 16 for receiving a closure or a coupling. An opening 18 is defined in the neck portion 14 and is in communication with the interior space of the collapsible container 10.
Container 10 preferably includes a tapered upper transition portion 22, an intermediate portion 24 and a tapered bottom transition portion 28. The tapered upper transition portion 22 includes an upper surface 20 that is unitary with the neck portion 14 and with the sidewall 13 of the main body portion 12. Container 10 further includes a bottom surface 26, which is best shown in
The main body portion 12, and specifically the intermediate portion 24, has a first side 30 and a second side 32, as is shown in
The presence of the outwardly extending creases 34, 36 and the hinge lines 38, 40 permit the main body portion 12 and specifically the intermediate portion 24 to collapse by folding along the outwardly extending creases 34, 36 when the volume of the interior space within the container 10 is reduced.
In the preferred embodiment, the tapered upper transition portion 22 includes a pair of upper oblique surfaces 44, 46, each of which is positioned between the upper surface 20 and a respective one of the sides 30, 32. The tapered bottom transition portion 28 includes a pair of lower oblique surfaces 48, 50, each of which is positioned between the bottom surface 26 and a respective one of the sides 30, 32. Preferably, the main body portion 12 is constructed and arranged so that the intermediate portion 24 will fold substantially flat on the volume of the interior space is sufficiently reduced. However, the tapered upper transition portion 22 and the tapered bottom transition portion 28 are both preferably constructed so that they substantially retained their shape when the intermediate portion 24 is folded flat.
The tapered bottom transition portion 28 is preferably substantially symmetrical in shape with respect to the tapered upper transition portion 22.
A hanging hook 54 is preferably attached to the bottom surface 26. The hanging hook 54 preferably has a hole 56 defined therein. Alternatively, a hook-shaped projection could be used in lieu of the hole 56. The hanging hook 54 is preferably integrally molded with a central rib 52 that is defined in the bottom surface 26. The central rib 52 is preferably aligned with the outwardly extending creases 34, 36 that are defined in the first and second sides 30, 32.
In the preferred embodiment, a pair of locking channels 58 may be molded into the bottom surface 26 in order to receive and releasably secure the hanging hook 54 in a nondeployed position as shown diagrammatically in
A container 10 according to the preferred embodiment of the invention is preferably manufactured by extruding a parison of plastic material, capturing a portion of the parison within a mold and inflating the portion of the parison that is within the mold against the walls of the mold to fabricate the specific shape of the container 10 that is described in detail above. Alternatively, other types of molding processes could be used.
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.
