Actuating member for varying length of vacuum chamber

摘要

Length is adjusted in a vacuum chamber by a vacuum-tight linear drive (30, 40) fitted between first (20) and second (50) closing members at mutually variable spacing. Preferably, the linear drive comprises a rotary drive (30) and a rotary converter (40), the second closure member having at least one contact point with the converter, which is moved on a cam-like surface of the converter when it turns, so that the distance of the closure member from the first closure member is varied. Preferably, the converter has a corrugated plate (41) with a surface (42), on which a spacer (52) of the closure member runs via rollers (53).