Abstract: A tamper indicating plastic cap for twist application to a threaded container neck comprises cap, body and a band interconnected to the cap by a plurality of bridges. Each of the bridges slopes upwardly in the direction of twist application of the cap to the container. A plurality of drive devices have co-operating abutments on the cap and band which are normally disengaged. The bridges flex as the band is snap-fitted over a bead on a threaded container shoulder in a manner which enhances the movement of the cooperating abutments towards one another as the band moves upwardly towards the cap. The abutments engage to drive the band with the cap to prevent breaking of the bridges as the band is snap-fitted over the threaded container neck. The bridges readily break when the cap is unthreaded from the container neck with the band engaged with the container bead. Such arrangement substantially facilitates the injection moulding of the cap because the band is significantly spaced from the cap underside.

Abstract: A plastic screw-on closure adapted for use with containers and having provision to indicate when the sealed container closure has been tampered with. The closure has a cap, a band for application over the shoulder of a container, means for connecting the cap and band and drive means for controlling relative rotation of the cap and band as the band is applied over a shoulder on a container. The drive means provides engagement between the cap and band during application of the closure, thereby ensuring the integrity of the connecting means during application of the closure. However, the drive means is ineffective during removal of the cap, such that the connecting means fractures due to axial separation of the cap and band.