Container and Closure With Sealing Threads

The present invention relates to a container, particularly a container made of synthetic material or to a container coated inside with synthetic material, the container having a filling-hole with an essentially cylindrical neck and a closing device, the closure having a portion extending into the neck, the portion having a sealing ring, in which the closure with a thread may engage with the thread of the neck, and in which the sealing ring is positioned between the neck and the closure. A container of this kind is known from the German Patent Application No. 2143801.7 laid open to public inspection. A disadvantage of the known container is that the liquid contained in the container may creep upwards in the thread between the neck and the closure and may come in contact with the sealing ring.

With aggressive fluids in particular, this means that the sealing ring should meet high demands so that said ring must be made from expensive material.

It is the object of the present invention to eliminate said disadvantage.

In accordance with the invention, said object is achieved in that at least one radially directed bar or rib is present in the thread of the closure, said bar sealing completely the play between the thread of the closure and the thread of the neck. With said bar or rib it is achieved that the liquid contained in the container cannot come in contact any longer with the sealing ring. As a result thereof the sealing ring may be made from considerably less expensive material.

An additional disadvantage of the known container is that after the filling with e.g. adhesive fluids it is found often that one runs into difficulties in removing the closure.

In accordance with the invention, said drawback is eliminated in that the bar is positioned at the end of the thread of the closure facing the contents of the container. In this embodiment the bar will clean the thread in the neck of the container of any liquid present on said thread during the screwing-in of the closure.

Moreover, the bar may consist of two or more parts being slightly displaced in circumferential direction, said parts being connected to each other. This connection does increase the flexibility of the bar.

In accordance with a preferred embodiment the bar comprises two parts, one part of which connects to the core of the thread of the closure and the other part to the bottom side of the thread and both parts are bevelled at opposite sides.

For reasons of manufacture, generally two bars will be arranged diametrically opposite to each other in the thread of the closure according to a mid-section plane of the closure.

The invention will now be described more in detail in a preferred embodiment with reference to the accompanying drawings, wherein:

FIG. 1 illustrates one part of the container with the filling-hole and the closing device;

FIG. 2 illustrates a top view of the closing device in accordance with FIG. 1; and

FIG. 3 gives a perspective view of part of the closing device.

The container is generally indicated by reference numeral 1 and consists of a metal wall 2 with an inner coating 3 of synthetic material. Said coating forms a cylindrical neck 4 which is internally provided with thread 5. A closure 10 is present in neck 4 of the container 1. Said closure 10 has a cylindrical jacket portion 11, said portion being externally provided with thread 12. A sealing ring 20 has been provided in this embodiment. The sealing comprises in addition two truncated cone surfaces 6 and 7. Two bars 30 have been provided at two points diametrically opposite each other in thread 12 of the closure 10. Each bar comprises two portions 31 and 32, in which part 31 connects to the cylindrical core of the thread and the other part 32 to the tapered bottom side of the thread. Arrow A in FIG. 1 shows a sectional area of part 32 of bar 30 on an enlarged scale. Both parts 31 and 32 are staggered slightly in circumferential direction relatively to each other and they are connected to each other at the transition point between core and underside of the thread. Since both parts are displaced with reference to each other, their area of contact is very small. As a result thereof, they do not obstruct each other as to the flexibility.

FIG. 2 illustrates the beginning of thread 12 at the top edge of the closure by reference numeral 13 and the and of thread 12 at the underside of the closure 10 is indicated by reference numeral 14. It will be evident from FIG. 2 that the bar 30, which is present in the thread chamfer of the closure 10, has been positioned at some distance from the end 14 of the thread in such a manner that the bar 30 can fulfill its sealing function.

A perspective view of the position of the bar 30 with the parts 31 and 32 is given in FIG. 3. In observing said Figure it will be evident that during the screwing-in of the closure 10 to the right with a right-hand thread the bar 30 will wipe-off the thread in the neck of the container and, as a result thereof, will clean said thread.

In accordance with another preferred embodiment of the invention the bar 30 will act together with thread 12 according to FIGS. 1 and 3.