Patent Number: 047643331
Section: summary

The present invention concerns end closures for containers, in particular end closures for nuclear fuel transport flasks. BACKGROUND OF THE INVENTION One form of flask for the transport of nuclear fuel comprises a vessel having a removable closure member at one end. The flask accommodates a bottle or magazine containing the fuel and the flask is emptied by setting in an upright position with the removable closure member at its lower end whereby upon removal of the closure member the bottle or magazine can be lowered out of the flask. As the fuel within the bottle or magazine is submerged in water which can leak out of the bottle it is necessary as a safety feature to ensure that the end closure member effect a liquid tight seal at the end of the flask. It has been proposed to utilise a wedge-shaped member to effect a seal whereby lateral movement of the wedge-shaped member across the end of the flask causes an initial vertical displacement of the end closure member to break the seal at the end of the flask. This has the advantage of reducing damage to the seal by a tearing action which could arise if the closure member was moved laterally across the end of the flask seal face without any initial separation. However the use of a single wedge-shaped member results in an end closure member of a non-uniform thickness. FEATURES AND ASPECTS OF THE INVENTION According to the present invention there is provided an end closure for a container, in particular an end closure for a nuclear fuel transport flask, comprising a gate movable between open and closed positions across an end of the flask, the gate having first and second portions continuously urged apart, a door releasably mounted on the gate and sealingly engageable with an opening in the end of the flask, the door having upper and lower cooperable wedge-shaped members releasably mounted on the first and second gate portions respectively for movement therewith between the open and closed positions, the assembly being arranged such that a lateral displacement of the gate into or out of its fully closed position effects movement of the second gate portion only and corresponding movement of the associated lower wedge-shaped door member, with the first gate portion and its associated upper wedge-shaped door member remaining stationary whereby to effect a vertical displacement of the upper wedge-shaped door member into or out of sealing engagement with the opening in the end of the fuel flask.