Abstract: A device for preventing the self-unscrewing of a screw cap from a container, e.g. a bottle for use in pharmacy or perfumery and typically containing a volatile liquid product. The container has a neck having formed thereon a screwthread and a projection at or below the lower end of the neck screwthread. The cap screwthread has such a length that, during screwing of the cap onto the neck, the front or lower end of the cap screwthread strikes against the projection when the inside surface of the top portion of the cap is in contact with the top end of th neck. Final screw tightening of the cap causes the front or lower end of the cap screwthread to ride over the projection so that the cap is held more securely in a tightened condition on the container neck.

Abstract: An abutment face is provided in or adjacent the shoulder of a bottle or other container onto the neck of which a cap is screwed to seal the bottle. The cap has two parts--an inner part which screw-threadedly engages the neck and resiliently seals with it; and an outer part which is in driving engagement with the inner part. In order to ensure proper orientation of the outer part with the body of the bottle (if for example a flat surface on the outer part is to be aligned with a flat surface on the body of the bottle) while still ensuring a seal between the inner part and the bottle, a stop face is provided inside the outer part and, when the inner part has already sealed, abuts with the abutment face to cause such orientation. Upon initial capping of the bottle, the inner part is screwed tight onto the neck and the outer part is then forced over the inner part in a proper orientation until engagement between them is established.