| 摘要 |
<p>The hydraulic mechanism gives even lifting of loads by means of a series of jacks supplied by a hydraulic pump. To give equal movement of all jacks a metering cylinder unit is provided, with cylinders of the same number as the jacks. The cylinders are similar, coaxial and separate from each other, each cylinder being divided by a piston into first and second chambers. The first chambers are connected in parallel by a control valve either with the pump or the return pipe, and the second chambers are each connected with one of the jacks. The metering cylinder pistons are mechanically coupled together by a common rod, passing through seals between the cylinders.</p> |
