Background of the Invention
The invention relates to a tissue culture or cell cultivation container and closure. In the growing of tissue cultures or cells it is customary to use containers provided with an air tight screw cover in order to prevent contamination of the cell material and also to prevent the escape of cells or substrate to the surroundings. However, the use of such air tight screw covers involves various problems. During the autoclaving of such containers, the closure must be in a slightly open position in order to permit the ambient atmosphere of the autoclaving process to reach and sterilize the interior of the container. Further, it is necessary for the closure to be in a slightly open position during the heating phase in order to prevent an undesirable positive pressure within the container, and also during the cooling phase in order to prevent the generation of an undesirable negative pressure. Further, the positioning of the closure in a predetermined slightly opened position, permits a means for an atmospheric exchange during the tissue culture growth process.
Other container-closure assemblies have been provided in the past having means for an intermediate cooperative positioning of the closure with respect to the container; however, they have not been completely satisfactory since the cap or closure and the positioning mechanism did not provide for a stable positive positioning of the closure or cap. For example, U.S. Pat. No. 4,289,248 utilized a pair of detents on opposite sides of the neck of the container or closure, and a detent formed on opposite sides of the closure or container engagable therewith for positioning the closure in a predetermined open position on the container. Since the closures traditionally have a loose fit upon such containers, there is always a problem of the cap or closure flopping or cocking from side-to-side during the positioning of the closure on the container, and accordingly it was possible to completely miss the detents altogether.
U.S. Pat. No. 4,546,085 incorporated the use of a container having a stepped or offset neck portion and a closure having an annular bead for sealing the container. When the bead was moved to a zone adjacent the offset portion, venting of the container was possible, however, no positive positioning mechanism was employed. Again, such design did not necessarily provide a positive and stable cap placement upon the container as obtained in the present invention.
Summary of the Invention
In its simplest form, the present invention sets forth a novel closure-container assembly construction which facilitates a positive and stable cap or closure placement upon the container, while providing for a positive means of positioning the closure in a predetermined semi-open positionment on the container. The neck of the container is provided with radially-outwardly directed ring means at a predetermined distance below an upper open edge portion of the container, and a skirt portion of the cap or closure is provided with a plurality of inwardly extending projections which cooperate with the radially-outwardly directed ring means to positively position the cap in a predetermined semi-open position on the container.
Thus, it has been an object of the invention to provide a container and closure assembly having means for stably receiving and positively positioning the closure on the container in a predetermined semi-open positionment, while also permitting the complete sealing of the container by the closure.
Brief Description of the Drawings
FIG. 1 is a schematic isometric view of the neck of a container and a closure embodying the present invention.
FIG. 2 is a cross-sectional view in elevation showing the closure in a predetermined semi-open position on the neck of the container.
FIG. 3 is a cross-sectional view in elevation showing the closure in a sealed position on the container.
FIG. 4 is a further embodiment of a container and closure assembly of the present invention.
Description of the Preferred Embodiments
Referring now to the drawings, and particularly FIGS. 1, 2 and 3, a container 10 is shown having a substantially cylindrical neck portion 12 provided with external threads 14 which extend downwardly below an upper sealing edge surface portion 16 about the open mouth 18 of the container. An outwardly extending rim means 20, projecting radially-outwardly from the neck portion 12 at a predetermined distance below the upper sealing edge 16, is shown in FIG. 1 as a continuous rim 20a. The rim 20a encircles the neck portion 12 of the container 10 and lies within a plane extending perpendicular to the cylindrical axis of the neck portion 12. As shown, the rim 20a preferrably has an outwardly-downwardly tapered operating or abutment surface 22, which lies within a surface of a cone which intersects and is concentric with the axis of the cylindrical neck portion 12.
A cap or closure 30 is shown having a substantially cylindrical skirt portion 32 provided with internal threads 34 which engage the external threads 14 of the container 10. The cap 30 has a closed upper end including an annular U-shaped sealing portion 38, inwardly offset from the skirt portion 32, and providing an upper sealing surface portion 36 therebetween. The annular U-shaped portion 38 has an annular bead portion 39 for sealable engaging an inner surface 19 of the neck portion of container 10. In addition, the closure 30 is provided with a plurality of inwardly extending projections 40 positioned about the inner surface of the skirt portion 32 adjacent its lower extent. Although various geometric arrangements of such projections may be utilized, two pairs of opposed arcuately extending projections 40 are shown, having tapered upper and lower surface portions 42, 44, respectively, which lie within cones concentric with the axis of the cylindrical skirt 32. The closure may have a knurled gripping portion 46 about its outer surface, and the skirt portion may have a slight taper as may be necessitated in manufacturing the same.
In operation, the closure 30 is positioned upon the neck portion 12 of the container 10 and the internal threads 34 engage the external threads 14, allowing the cap or closure 30 to be screwed downwardly onto the container 10. As the closure is threaded toward its closed position upon the container 10, the inwardly extending arcuate projections 40 on the interior of the skirt portion 32 of cap 30, contact the outwardly extending rim means 20 formed on the exterior surface of the neck portion 12 of container 10. As the tapered surfaces 44 of the projections 40 engage the tapered surface 22 of the rim means 20, a binding action is occasioned therebetween within the surface of a cone concentric with the axes of the neck and skirt portions, which positively positions the cap in a predetermined slightly opened position on the container. That is, the contact between the projections 40 and the outwardly extending rim means 20 functions to detain the closure sealing surface portions 36 and 39 from contacting the sealing surfaces 16 and 19, respectively, of the container, and thereby prevent the formation of a seal between the container and the closure to allow air movement into and out of the container, as shown by arrows A in FIG. 2.
An additional torsional force on the cap 30 overcomes the binding between the tapered surfaces 22 and 44, causing a slight deformation of the closure and its inwardly extending projections 40 as they move past the outwardly extending rim means 20 on the container, allowing the closure sealing surfaces 36, 39 to engage and be secured against the container sealing surfaces 16, 19 respectively to seal the closure on the container and thereby prevent the container contents from exiting, or contaminants from entering, the closed system as shown in FIG. 3. Further, the cap 30 may be moved from the sealed positionment of FIG. 3 to a semi-open vented positionment, by unscrewing the cap until the tapered surfaces 42 of projections 40 engage the rim means 20, creating a binding action to positively position the cap in a semi-open position while locking the cap on the container and inhibiting it from becoming unscrewed. Preferrably, the closure is made of a plastic material, such as polypropylene which is plyable enough to permit some mechanical deformation and have a high enough softening point to permit steam autoclaving without thermal deformation.
As will be appreciated, the inwardly extending projections 40 on the inside of the closure 30 can contact the continuous rim 20a at any point on the rim means, and thereby provide a stable and definite positioning of the closure with its sealing surfaces above the sealing surfaces of the container, when it is desired to temporarily position the closure in a semi-open position. When additional torque is applied to the closure, the closure deforms and permits the tapered surfaces of the closure projections to slide over the tapered surfaces of the rim means on the container, and thereby allow the removal of the closure, or allow the closure and container sealing surfaces to contact one another and provide a seal therebetween.
Referring now to FIG. 4, a further embodiment of the invention is disclosed which is similar to that shown in FIGS. 1-3, but with the exception that the outwardly-extending rim means 20 is in the form of a plurality of partial neck projections 20b which have gap portions 21 therebetween, and may be equally spaced around the neck 12 of the container 10 in a plane extending perpendicular to the axis of the cylindrical neck portion 12. Each of the partial neck projections 20b also has an outwardly-downwardly tapered surface 22 for engaging the taper surfaces 44 of the inwardly extending projections 40 of cap 30. The operation of the embodiment shown in FIG. 4 is similar to that shown in FIGS. 1-3, with the exception that after the inwardly extending projections 40 have engaged the tapered surfaces 22 of the partial neck projections 20b to position the closure 30 in a predetermined slightly open position on the container 10, and additional torque is applied to the closure, the gap portions 21 between the partial neck projections 20b permit the closure projections 40 to slide therethrough, rather than over the continuous rim 20a of the embodiment of FIGS. 1-3, and permit the sealing surfaces of the closure to engage the sealing surfaces of the container for sealably closing the same. The same is true when unscrewing the cap from the closed position.
Although I have disclosed the now preferred embodiments of my invention, it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the spirit and scope of the invention as set forth in the following claims.