| 摘要 |
PROBLEM TO BE SOLVED: To improve operability in the case of mounting or removing a side plate from above. SOLUTION: An engaging protrusion 38a of a sectional ridge shape is provided at a lower end of a right side plate 3, and an upward recessed locking groove 45 is provided above a bottom frame 7. The protrusion 38a is engaged with the groove 45 in the case of operating to assemble the plate 3 by sliding upward, thereby obtaining a fixed state of a lower end side of the plate 3. Thus, it is not necessary to clamp the lower end side of the plate 3 to the frame 7 with a clamping screw, but when a peripheral edge of the upper side is clamped with a screw, an entire clamping state can be obtained and hence an operation of mounting or removing the plate 3 can be facilitated. |
