| 摘要 |
<p>Bellows (14) for optical equipment comprising a tubular concertina structure of adjustable axial length, the folds of the concertina structure acting as hinges, said structure having portions of laminated construction, a first layer of said construction being of flexible light-inhibiting material (66) and a further layer (70) being of load-bearing material which stiffens the folds whereby upon axial adjustment the bellows retain its configuration without external support or restraint.</p> |
