Abstract: There is proposed a plastic closure which serves to close a container (3) with a mouth region (5). The closure (1) has a lid (7) allocated to the container mouth (5) and an annular side wall (9) connected with this. On the inner surface (15) of the side wall (9) there are provided fastening means (16) which coact with corresponding fastening means (14) on the outer surface (11) of the container (3) and are constructed, for example, as screw threads. The closure has, finally, also a sealing means. It is distinguished in that the sealing means (11) has a circumferential pivotable sealing lip (9) projecting from a support (15), which lip coacts with a side wall (25) surrounding the container mouth (21) of the container (19), which in the closing of the container is swung out of a rest position into a sealing position and which in its sealing position is clamped between support and side wall of the container so that it is subjected to a compression.

Abstract: The present invention is a seal for a container closure which is characterized by the fact that associated with the sealing lip (3) is an actuating arm (5) by which the sealing lip can be swiveled. The seal is part of a container closure (1) with a side wall (11) and a bottom (15). When the closure is screwed onto a container, the actuating arm is swiveled counterclockwise, this swivelling movement being facilitated by a deliberate attenuation (17) in the region of the bottom (15) of the closure (1). A counterclockwise swiveling movement of the actuating arm (5) also causes the sealing lip (3) to swivel counterclockwise and thus to lie against the outer wall of the container. A sealing surface is created not only between the container and the actuating arm (5), but also between the outside of the container and the sealing lip (3).