| 摘要 |
A pair of opposed finger pressure members (2, 2') is arranged at the upper surface of a basement (1) which is of rectangular-box shape. This basement (1) is provided at opposite end thereof with legs (3, 3') which horizontally extend substantially parallel to each other. The finger-pressure members (2, 2') are threadedly engaged with a feed screw rod (7) which is connected to any one of the legs (3, 3') and are mounted to a set of two frames (8, 8') which are mutually movable in the basement (1) so as to vary the distance between them. The finger-pressure members (2, 2') are threadedly engaged with a rotational shaft (7') which is connected to the other of the legs (3, 3'). Thus, the finger-pressure members are assembled so as to make the ascent and descent movement through the rise and fall mechanism which is driven in the frames (8, 8'). |
