| 摘要 |
In order to check the operation of highvoltage electric circuit-breakers, proximity detectors are housed in through-bores pierced in the wall of the hydraulic jack cylinder, the through-bores being disposed in spaced relation over a distance corresponding to the range of travel of the jack piston. Since no provision is made fox any piston ring or packing seal, the jack piston is not damaged as it passes against the outlets of the through-bores on the internal surface of the cylinder. The output signals of the proximity detectors are applied to a unit for measuring and controlling the position of the piston within the cylinder. |
