| 摘要 |
PROBLEM TO BE SOLVED: To ensure an insulation distance and facilitate accommodation of a shutter in the case of connection by overlapping an upper plate and a lower plate and making the height in the vertical direction about a half. SOLUTION: A frame 11 having a window 11a is installed movably between portions P and Q. A shutter 18, constituted of an upper plate 19 and a lower plate 20, is installed movable vertically in the frame 11. When the frame 11 is at the positioned P, the upper plate 19 is caught by a stopper 32, and the shutter 18 turned into a state of one plate closes the window 11a. When the frame 11 moves to the position Q, a follower 28 rolls along a rail 30, and the lower plate 20 overlaps with the upper plate 19 and moves to a part above a bushing 5. As a result, the window 11a is opened. |
