| 摘要 |
<p>A seal module (6) Fig 1 comprises a gas impermeable instrument seal 10 extending across a chamber and secured to make a substantially gas-tight seal with the internal wall of the chamber, said instrument seal has a central elastic disc shaped portion with an opening which can be stretched to accommodate the passage of elongate instruments of different cross-section to form a substantially gas-tight seal with such instruments. There is also provided a seal system which is active when no instrument is inserted. Two or more mechanically biased guides 1, 3 locate instruments of 6mm or less and are pivoted, but mechanically biased into the locating position. When a larger instrument is inserted, say 10mm in diameter, the guides, by use of pivots 5, 7 are pushed away to allow the entry of the 10mm instrument without difficulty. The gas is sealed by a flap valve 9 which seats on the guides which themselves seat on a support cap.</p> |
