摘要 |
An hydraulic jack for an elevator installation comprises a pair of cylinders and a common plunger. One cylinder is fixedly mounted in a vertical position in a hoistway; while one end of the plunger is mounted within the fixed cylinder for vertical reciprocating movement therein. The other cylinder, which carries an elevator cab up and down in the hoistway, is slidably mounted about the other end of the plunger for vertical reciprocating movement thereon.
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