The present invention relates to an expandable, externally-threaded collar member which is adapted to cooperate with an internally-threaded cap member to form a closure for a container. More particularly, the present invention is directed to a closure unit wherein both the threaded collar member and the threaded cap member which cooperate together to form the closure unit are separable from the container which is to be closed.
A number of types of closures utilized for sealing the contents of a container are well known in the art. However, most of the presently utilized closures do not provide an effective seal and, accordingly, the substances stored within the container readily spoil or become contaminated because of the loss of the sealing capability of the container.
One of the most effective means for sealing a particular container is through the use of a screw-threaded closure. However, since many containers are not provided with a suitable threaded portion which can be used for engaging a threaded cap, such containers, such as for example, can containers, cannot be sealed by utilizing a screw-thread type of sealing means.
Accordingly, an object of the present invention is to provide a screw-type closure unit for a container which is not provided with a threaded portion which is integral with the container itself.
Another object of the present invention is to provide an expandable, externally-threaded collar member which is applied to the top portion of a container and an internally-threaded cap member which is adapted to cooperate with the collar member to form a closure for a container.
A further object of the present invention is to provide an expandable, externally-threaded collar member which is so constructed that it can be readily slipped over the top lip of the container and positioned around the neck of said container beneath said lip for receiving the internally-threaded cap member.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter, it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Pursuant to the present invention, the above disadvantages may be eliminated and a closure unit has been developed wherein a container can be provided with a screw-type seal even though the container does not possess a screw-threaded portion which is integral with the top portion of the container itself. According to the present invention, a container, for example a can, can be provided with a screw-type closure by mounting a threaded collar to the can, said collar cooperating with a threaded cap to form said closure unit. The threaded collar member is made of an expandable material, for example, a plastic material, and contains at least one slot which extends for a distance from one opened end of the collar, the expandable nature of the threaded collar and the presence of said slot enabling said collar to be mounted over a top lip of the container and positioned around the neck of said container beneath said lip. Advantageously, a plurality of slots are positioned equidistantly along the threaded collar, said slots increasing the overall flexibility of said collar, thereby enabling the collar to be stretched over the lip of the container and positioned around the neck of said container.