| 摘要 |
<p>PROBLEM TO BE SOLVED: To switch over liquid-operated passages at the normal and fail times by a simple constitution. SOLUTION: This device has a motor 19, a conversion mechanism part 20 for converting the rotation movement of the motor 19 into the rectilinear movement, and a motor driven piston 21 to be rectilinearly moved by the conversion mechanism part 20, and generates a braking force by pressing a pad 13 abutting on the piston 21 to a disk 12 through the rectilinear movement of the piston. This device has a liquid-operated piston 39 which is reciprocated rectilinearly by a liquid pressure to abut on the pad 13 other than the piston 21 to press the pad 13 to the disk 12. Consequently the piston 21 to be stroked at normal time need not to be stroked at fail time, and liquid-operated passages 46, 51, and 55 can be switched over at the time of normal and fail at the position of such the piston.</p> |
