| 摘要 |
A hydraulic elevator has a cage 5 being moved upwardly and downwardly by a hydraulic cylinder 2, and an induction motor driven hydraulic pump 13 supplying pressured hydraulic oil to the cylinder 2 through a electromagnetic change-over valve 12. The induction motor speed is controlled on the basis of a output signals of a speed instruction generating circuit 33 and start compensation instruction circuit 34 which generates a compensation signal in response to the difference between the discharge pressure oil of the hydraulic pump 13 and oil pressure in the cylinder 2 so as to prevent jerky movement of cage 5 when the discharge pressure first exceeds the cylinder pressure and valve 12 becomes conductive. <IMAGE>
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