Apparatus for controlling a hydraulic elevator

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United States of America Patent

PATENT NO 5243154
SERIAL NO

07775555

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ATTORNEY / AGENT: (SPONSORED)

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Abstract

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An apparatus for controlling a car of a hydraulic elevator by variable-speed-driving an electric motor directly coupled to a hydraulic pump so as to adjust the rate at which oil is supplied from the hydraulic pump to a hydraulic jack system, the apparatus having a speed controller for variable-speed-driving the electric motor, a first detector for detecting the speed of the car, a second detector for detecting the rotational speed of the electric motor, a third detector for detecting a pressure in the hydraulic jack system, a feedback circuit for returning a control signal for limiting vibration of the car as a feedback signal to the speed controller. The feedback circuit forms the control signal from a differential signal representing the difference between a car speed value converted from the rotational speed of the electric motor detected by the second detector and the car speed detected by the first detector and a pressure signal representing the pressure detected by the third detector.

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Patent Owner(s)

Patent OwnerAddress
MITSUBISHI DENKI KABUSHIKI KAISHA2-3 MARUNOUCHI 2-CHOME CHIYODA-KU TOKYO 100-8310

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Kubota, Takehiko Inazawa, JP 53 394
Tomisawa, Masao Amagasaki, JP 3 23

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