Abstract: A control valve unit for a hydraulic elevator includes two control valves wherein the flow of hydraulic oil from a tank to a lifting cylinder driving an elevator cabin and/or from the lifting cylinder to the tank can be controlled. In case of an upward movement of the elevator cabin, hydraulic oil is conveyed by a pump driven by an electromotor from the tank through the control valve unit to the lifting cylinder. In the case of a downward movement of the elevator cabin, the hydraulic oil flows through the control valve unit to the tank without the pump working. The control of the upward movement and the downward movement of the elevator cabin is achieved by one single pilotable control valve, respectively, that are provided to act as a check valve as well as a proportional valve.

Abstract: A method for controlling a hydraulic elevator whose car can be displaced by a hydraulic drive mechanism by hydraulic oil fed through a cylinder line or evacuated from said hydraulic drive mechanism by a pump that cooperates with a first control valve unit and a second control valve unit, wherein the flow the hydraulic oil is controlled by a measuring device and operation of the elevator can be controlled and regulated by a control apparatus. The load of the elevator car is determined by a load pressure sensor detecting pressure PZ in the cylinder line and is controlled preferably in a constant manner by changing the control of the second control valve unit in such a way that movement of the elevator car can be controlled in a very precise manner. When the elevator car is descending, the dropping pressure PZ in the cylinder line is regulated by changing the first control valve unit in such a way that the descending movement of the elevator-cabin can also be controlled in a very precise manner.

Abstract: The invention pertains to a control valve unit (28) for an hydraulic elevator. It contains two control valves (5, 15) with which the flow of hydraulic oil from a tank to a lifting cylinder driving an elevator cabin and/or from said lifting cylinder to said tank can be controlled. In case of upward movement of said elevator cabin hydraulic oil is conveyed by means of a pump driven by an electromotor, from said tank through said control valve unit (28) to said lifting cylinder, whereas in case of downward movement of said elevator cabin said hydraulic oil flows through said control valve unit (28) to the tank without the pump working. In accordance with the present invention for control of the upward movement and the downward movement of said elevator cabin in said control valve unit (28) one single pilotable control valve (5, 15) respectively is provided for, each of which acts as check valve as well as as proportional valve.

Abstract: The hydraulic or pneumatic drive for lifting and lowering loads, in particular for lifts, has a working cylinder (11) forming a pressure chamber (14) connected to a pressure fluid source (39) and subjected to a pressure fluid. It also has a lifting piston (1) tightly guided in the working cylinder and a guide rod (15) arranged in the working cylinder. The guide rod (15) projects into the interior of the lifting piston (1) which tightly encloses the guide rod (15). The end (4) of the lifting piston (1) which projects into the pressure chamber (14) forms an annular face (5) which is subjected to pressure fluid. The interior of the lifting piston (1) forms an additional pressure chamber (7) subjected to pressure fluid and which is connected to its own pressure fluid source (40).

Abstract: The invention relates to a method and an apparatus for controlling a hydraulic elevator, in which a car (2) is movable up and down in an elevator shaft (1). The car (2) is connected to a reciprocating piston. The car (2) is driven by an oil pump (40), with which pressurized oil is pumped between a tank (41) and a reciprocating cylinder (3). The oil pump (40) is driven by a motor (39), which is supplied by a controllable power supply part (28). The speed of the car (2) is detected by a sensor (13). A control and governing unit (10) controls and regulates the devices that affect the motion of the car (2), namely the motor (39) and a valve unit (43). In upward motion, the speed of the car (2) is controlled by regulation the motor (39). According to the invention, in downward motion, closed- or open-loop control is exerted on the valve unit (43).

Abstract: The actuator has a moving spool in a valve body for controlling the pressure medium inflow to and from an actuating cylinder. The pressure medium in the valve body is conducted to each end of the spool in order to use the pressure medium to move the spool when desired. A pair of piezo-electric or magnetostrictive servomotors are provided to actuate on/off valves, each of which controls a flow of pressure medium from each end of the spool. Upon actuation of a servomotor, a valve is opened so that the pressure at the corresponding end of the spool decreases causing a shift of the spool in that direction. The servomotors are triggered by brief electrical digital signals.