Patent ID: 6971481
Filing Date: 2005-12-06
Classification: B66B,Y02B

Abstract:
1. A hydraulic elevator, comprising: a hydraulic drive for moving a car; a pressure accumulator; a pressure switch connected for detecting pressure in said pressure accumulator; a pump connected to said pressure accumulator by an accumulator line and connected to said hydraulic drive by a cylinder line for producing a flow of hydraulic fluid between said hydraulic drive and said pressure accumulator for moving the car, wherein said pump is directly connected to said pressure accumulator by said accumulator line; a motor connected to said pump and driven by a power regulating unit for driving said pump; a control/automatic regulation unit generating a signal for controlling said power regulating unit; a tank holding a hydraulic fluid; a charging pump driven by an electric motor for charging said pressure accumulator with hydraulic fluid from said tank in response to said pressure switch; a cylinder line stop valve comprising an electrically switchable on-off valve connected between said cylinder line and said pump; and means for preventing discharge of said pressure accumulator when said elevator is stopped.