| 摘要 |
<p>A vacuum chamber has its cover 11 adjustable in height by way of two rams 37 and 38 which lift a chamber cover ceiling 39 relative to a sidewall assembly 35, with the agency of an equalizing cylinder 41 to ensure identical lifting and lowering of the ceiling. During adjustment, an inflatable seal 33 around the periphery of the ceiling 39 is relaxed to allow the sliding movement and then after adjustment the seal 33 is re-inflated to ensure complete sealing between the ceiling 39 and the sidewall assembly 35. <IMAGE></p> |
