| 摘要 |
<p>PROBLEM TO BE SOLVED: To construct a bed with lifting mechanisms at low cost and precisely determine whether or not driving portions are in trouble. SOLUTION: In a lifting drive mechanism for driving lifting frames 5a and 5b for raising or lowering, the numbers of rotations of speed reducers 12a and 12b or portions downstream of the speed reducers 12a and 12b are detected by means of detecting sensors 17a and 17b. Since the numbers of rotations after speeds are reduced by the speed reducers 12a and 12b are detected, the need for detecting high-speed rotations is eliminated, and inexpensive sensors using general counters can be used. A determination can also be made as to whether or not portions upstream of the speed reducers 12a and 12b are in trouble.</p> |
