Abstract: In an electrohydraulic lifting control device (S) for stacker trucks, which comprises, for lifting control, an electrically operable three-way flow regulator (R1) in a lifting branch (1) between a pressure source (P) and a hydraulic cylinder (Z) as well as, for lowering control, an electrically operable two-way flow regulator (R2) in a lowering branch (2) which branches off from the lifting branch (1) and leads to the reservoir, a redundancy switching element (A) is provided, which is actively electrically operable between closed and open positions, said redundancy switching element (A) being provided between the control pressure circuit of the two-way flow regulator (R2) and/or the control pressure circuit of the three-way flow regulator (R1) and the reservoir (T).

Abstract: A seated-type valve S provided for the double-acted cylinder Z of an electric disconnector TS, comprises a housing G containing a slider closure element 7 and a separating actuating force generator C1 and a switch-on actuating force generator C2 for the slider closure element 7, respectively. At least the separating actuating force generator C1 is equipped with a piston D1 contained in an interior bore 23 of the slider closure element 7, which piston D1 abuts in the housing G without generating lateral forces for the slider closure element 7.

Abstract: An electromotor M of a electrohydraulic motor pump aggregate G drives at least one pump stage P, P1, P3. An attached element C is inserted between at least one pressure side port of the pump stage, a return line 13, and at least one consumer port A, B, 5, 6. A multiways control valve 3 is installed between the consumer port and the pressure side port. A pressure limiting valve R1, R2 constructed as a seated valve is installed between the consumer port A, B, 5, 6 and the return line 13. The motor pump aggregate G has an automatic hydraulic pressure relieving device D for relieving the system pressure whenever the electromotor M is switched off.

Abstract: A seated valve comprising a housing and a valve seat, a cylinder bushing for an actuation and a closure element provided in a bore of said housing, said closure element being adjustable in relation to said valve seat by means of the actuator, said closure element being a full sphere having a concentric waist portion the diameter of which being larger than the diameter of said valve seat but smaller than the inner guiding diameter of said cylinder bushing, which guiding diameter of said cylinder bushing being smaller than the diameter of said full sphere, such that said closure element can be inserted into or removed from said cylinder bushing from the out side of said housing.

Abstract: In a stacker control of a stacker (fork lift) for high storage racks comprising a swing-shift fork (G) which is pivotable about a vertical axis (7) and horizontally movable in computer-assisted fashion by hydraulically controlled hydraulic motors (H1, H2) via a directional control valve (W1, W2) which is connected to a joint source of pressure (15, P), a three-way pressure balance (D) is provided between the source of pressure (15) and the directional control valves (W1, W2) for giving priority to one of said hydraulic motors (H1, H2). the three-way pressure balance (D) being controlled by control pressures tapped upstream and downstream of the directional control valve, at least the directional control valve of the preferential hydraulic motor having an open zero position, and the three-way pressure balance (D) forming part of a neutral circulation circuit (U) led via the control piping of the further hydraulic motor from the source of pressure to tank.

Abstract: In a hydraulic control device for the direction control of at least one highest hydraulic pressure hydro-motor with working pressures above about 400 bar from a pressure source the hydro-motor is connectable via at least one consumer line and two leakage-free black/white directional seated valves selectively with said pressure source or a return line, within in said consumer line a load holding blocking valve is provided in leakage-free seated valve design and where in-between said pressure source and said return line a 2/2 idling or shunting directional seated valve having a hydraulic actuation is provided which in its blocking position is leakage-free from the pressure source towards said return line and in each switching position is leakage-free between said hydraulic actuation and said return line, and wherein said hydraulic actuation of said idling directional seated valve between said load holding blocking valve and one of said directional seated valves is connected with said consumer line.

Abstract: In a magnetically operated drain valve of an electrohydraulic lifting mod comprising a closing element which in the closing direction is assigned to a main valve seat, a pilot valve which is actuable by the magnet and arranged in a control chamber of the closing element, a throttle arranged upstream of the control chamber, and a closing member of the pilot valve which is adjustable by the magnet against a spring, the closing member being actuable by the magnet against the spring acting either in the closing adjustment direction or in the opening adjustment direction, a spring with a steep characteristic curve is used as the spring, and the closing element and the main valve seat form a lift-dependent flow-quantity adjusting device.

Abstract: In a load holding valve L, comprising a check valve R and a pressure limiting valve D in a housing chamber which is common to said two valves, a seat insert 13 has provided therein a valve seat 19 for a closure member 4 of the pressure-limiting valve D and a sealing surface 15 for a check-valve closure member 16, and an opening piston 9, which is coupled to the closure member 4, is provided in a pilot chamber 10, an effective area of said closure member 4 being, in a direction opposite to the direction of spring loading, adapted to be acted upon by the pressure to be limited, the opening piston 9 is formed integrally with the closure member 4 and is provided with a pressure surface in the pilot chamber 10 which is slightly smaller than the cross-sectional area of the valve seat 19, and the valve seat 19 defines in combination with control passages K formed in the closure member 4 a stroke-dependent quantity control device M.

Abstract: Correction coefficients which permit effective linearization of an electronic scale over a measurement range may be determined by loading the scale individually and in combination with loads, at least one of the loads being unknown and uncalibrated.

Abstract: In hydraulic control devices comprising a two-way flow regulator in a resoir return passage, in which the flow regulator comprises a metering restriction and a pressure equalizer including a control piston with the piston ends disposed in control chambers and subjected to the action of control pressures, the actuation of a single-acting hydraulic motor under load often results in an unavoidable switching shock, because the displacement of the control piston involves the consumption of a certain volume of the pressure fluid. In order to eliminate the switching shock with a simple construction, the end of the control piston subjected to the action of the load pressure is formed as a closure element cooperating with a valve seat in the manner of a poppet valve for holding the load pressure.

Abstract: The invention relates to a hydraulic control apparatus comprising a hydraulically adjustable throttle opening between an inlet passage and an outlet passage, a three-way pilot valve connected to an external actuator and having its inlet connected to a control pressure inlet passage, its control outlet being connected to the throttle valve in such a manner that the throttle valve element thereof is adapted to be biased in opposition to the pressure in the outlet passage and to the force of a spring. Known control apparatus require the employ of a displacement sensor for sensing the position or displacement of the throttle valve element and for correspondingly acting on the actuator to thereby vary the actuating force thereof for maintaining the opening degree of the throttle opening. This construction involves considerable complications. It is also disadvantageous that the pilot valve is subjected to the full operating pressure, requiring it to be of a highly accurate and therefor expensive construction.