Smiths Industries Plc

Smiths Group Plc

David Woodroffe

Norman Stewart Jones

A seal arrangement provides a seal between a bore and a rod movable in the bore with a gap formed between the bore and the rod. The seal arrangement includes a floating elastomeric sealing ring which is accommodated in a circumferential groove around the rod. The sealing ring sealingly engages the wall of the bore. An annular resilient biasing device is also accommodated in the groove. The biasing device acts between one wall of the groove and the sealing ring to urge the sealing ring against an opposing wall of the groove. In addition, the biasing device is configured to allow passage of fluid past the biasing device between a region of the groove disposed radially inwardly of the sealing ring and the gap between the rod and the bore on the side of the sealing ring opposite the opposing wall. The biasing device has, at least at some circumferential positions therearound, a cross-sectional profile that reduces in radial width towards one wall of the groove. The biasing device can be provided as an elastomeric loading ring that provides at least one passage for fluid flow between its radially outer side and its radially inner side.

Seal arrangement providing a seal between a bore and a rod moveable in the bore

A seal arrangement is disclosed that provides a seal between a bore and a rod movable in the bore with a gap formed between the bore and the rod. The seal arrangement includes a floating elastomeric sealing ring which is accommodated in a circumferential groove around the rod. The sealing ring sealingly engages the wall of the bore. An annular resilient biasing device is also accommodated in the groove. The biasing device acts between one wall of the groove and the sealing ring to urge the sealing ring against an opposing wall of the groove. In addition, the biasing device is configured to allow passage of fluid past the biasing device between a region of the groove disposed radially inwardly of the sealing ring and the gap between the rod and the bore on the side of the sealing ring opposite the opposing wall. The biasing device has, at least at some circumferential positions therearound, a cross-sectional profile that reduces in radial width towards one wall of the groove. The biasing device can be provided as an elastomeric loading ring that provides at least one passage for fluid flow between its radially outer side and its radially inner side.

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Luton, United Kingdom

David Woodroffe