Rotary closure for containers

摘要

A screw closure is provided which is composed of an annular part and a closure part. The closure part has the sealing compound which interacts with the container neck and is received in a snap-on manner in the annular part so as to be captive, but axially movable within limits and rotatable relative to said annular part so that, when the annular part is screwed onto the container neck, the closure part is pressed into a sealing position and, when it is released from the container neck by the screwing movement, is pushed off evenly over its circumference. In this case, the friction of the contact surface between the annular part and the closure part is considerably lower than the friction between the sealing compound and the sealing surface of the container neck interacting therewith, such that, in significant phases of the screwing-on and unscrewing movements of the annular part, the latter is relatively rotatable both in respect of the container neck and in respect of the closure part.