| 摘要 |
PURPOSE:To equalize the elongations of the upper and lower parts of the bellows substantially by a method wherein the upper flange of the uppermost bellows and an intermediate flange connecting a plurality of bellows are engaged with an upper plate through a wire and a pulley. CONSTITUTION:When a screw shaft 11 is rotated, the upper flange 8 of the upper bellows 3 moves upwardly or downwardly. The intermediate flanges 1, 2, connecting the upper and lower bellows 3, 4, are engaged with the upper plate 6 through the pulley 10 and the wire 9, therefore, the flanges 1, 2 move by the half of the moving amount of the upper flange 8. The ratio of the deflecting amounts of the upper bellows 3 and the lower bellows 4, which are predetermined initially, is kept constant at all times and, therefore, the elongations of the upper and lower bellows 3, 4 may be equalized substantially. |
