Telescopically sliding tube catheter - has outer tube pushed forward on inner one and gap sealed liq. tight at proximal end

摘要

The catheter consists of two co-axial tubes fastened together at their distal ends. The outer tube can be pushed forward on the inner: it bulges out at its distal end as it moves down. The gap between the tubes is to be sealed liquid-tight at the proximal end, at least when the outer tube is forward, in which position a latch is to be come effective. Three methods are described, using respectively a sealing flange in a bulbous cavity, a clamp to pinch the tubes together, and a bellows.