An industrial truck (2) with a lift mast (4), a hydraulic system (10), and a method for operating a hydraulic system (10). The lift mast (4) of the industrial truck (2) is driven by a mast lift cylinder (12) and includes at least one mast lift stage (42). A free lift stage is present that is driven by a free lift cylinder (8) with which a load receiving means (6) can be displaced along the lift mast (4). The industrial truck (2) includes a hydraulic system (10) for supplying the at least one mast lift cylinder (12) and the at least one free lift cylinder (8) with a hydraulic fluid (14). The hydraulic system (10) is configured to at least at times simultaneously actuate the at least one mast lift cylinder (12) and the at least one free lift cylinder (8) in load lifting operation and/or in load lowering operation.

Disclosed is system, method, and rack stand portion for the advantageous cooling of computer equipment 305. The rack stand 200 includes a hollow body 210, 212 that may be formed of cartridges 2416. Gas from an airflow source 5204 is guided into the rack stand body and then into a sealed case of the computer equipment. Air flow is then guided out of the computer equipment for recirculation, exhaust, or other purpose.

The present invention includes a lateral support member for a server computer constructed to permit advantageous airflow. The present invention can be operated to shunt organized airflow into multiple computer cases and/or organized airflow from multiple computer cases to a dedicated heat reservoir.

The invention relates to an industrial truck (2) with a lift mast (4), a hydraulic system (10) as well as a method for operating a hydraulic system (10). The lift mast (4) of the industrial truck (2) is driven by a mast lift cylinder (12) and comprises at least one mast lift stage (42, 42). Furthermore, a free lift stage is present that is driven by a free lift cylinder (8) with which a load receiving means (6) can be displaced along the lift mast (4). The industrial truck (2) comprises a hydraulic system (10) for supplying the at least one mast lift cylinder (12) and the at least one free lift cylinder (8) with a hydraulic fluid (14), wherein the hydraulic system (10) is configured to at least at times simultaneously actuate the at least one mast lift cylinder (12) and the at least one free lift cylinder (8) in load lifting operation and/or in load lowering operation.

A fluid pressure control device for a power shovel includes: a first switching valve configured to permit or prohibit communication between a first pump and a first cylinder; a second switching valve configured to permit or prohibit communication between a second pump and a second cylinder; a third pump configured to allow to supply working fluid to the first cylinder and the second cylinder; a first junction control valve configured to permit or prohibit communication between the third pump and the first cylinder or the second cylinder; and a communication control valve configured to prohibit communication between the third pump and the first cylinder to guide the working fluid discharged by the third pump to the second cylinder by controlling the first junction control valve in a case where the second pump is communicated with the second cylinder by the second switching valve regardless of whether or not the first pump is communicated with the first cylinder by the first switching valve.

A hydrostatic drive includes a hydraulic machine, a hydraulic adjusting device, a high-pressure accumulator, an accumulator-closing valve, and an electronic control unit. The hydraulic machine has a swept volume that is adjustable via the hydraulic adjusting device from a maximum positive swept volume to a maximum negative swept volume via a zero swept volume. The hydraulic machine is operated as a pump with positive swept volume and as a motor with negative swept volume. The high-pressure accumulator supplies the hydraulic machine with pressure medium for operation as a motor via a pressure line. The accumulator-closing valve has a first position and a second position and is arranged in the pressure line. A fluidic connection from the high-pressure accumulator to the hydraulic machine is open in the first position and closed in the second position. The accumulator-closing valve is actuated in accordance with signals from the electronic control unit.

A work vehicle for cutting crops includes a header a supported by a chassis of the work vehicle. The header includes a cutter assembly having a cutter bar frame supporting a series of rotary cutters arranged in a lengthwise direction. A gear train, having a first gear and a second gear, is coupled to the series of rotary cutters to transfer power thereto. A cutter control system includes a first motor coupled to the first gear of the gear train and a second motor coupled to the second gear of the gear train. A controller, including a processor and memory architecture, is operably connected to the first motor and the second motor to control operation thereof. The cutter control system drives the first gear at a first speed via the first motor and drives the second gear at a second speed via the second motor. The second speed is different than the first speed to pre-load the gear train into enmeshing engagement with each other in one rotational direction.

Saturation of a secondary system pressure circuit (18) of a hydraulic system (4) of a motor vehicle transmission is earlier, in that an excess amount of oil from a primary system pressure circuit (16) of the hydraulic system (4) is not directed to a suction charging (40), but rather into the secondary system pressure circuit (18). This can take place via a system pressure valve (9) for the primary system pressure circuit (16), which is configured for this function.

A pressurized fluid supply system capable of favorably resuming the supply of a pressurized fluid to a support member when the supply of the pressurized fluid from a fluid supply source returns to a normal state, includes: a fluid supply path for supplying the pressurized fluid from the fluid supply source to the support member that supports a member using the pressurized fluid; a solenoid valve provided on the fluid supply path; a pressure sensor that is provided on the fluid supply path between the fluid supply source and the solenoid valve and detects the pressure of the pressurized fluid; a flow rate sensor that is provided on the fluid supply path between the solenoid valve and the support member and detects the flow rate of the pressurized fluid; and a control unit that controls opening/closing of the solenoid valve.

The present invention includes a server system that uses an airflow source that can be external to the computer that the airflow source cools. The computer may be sealed such that the conduits are the primary source of fluid ingress and egress. The airflow source can be positioned in a case of the computer, support members affixing the computer to a rack stand, the rack stand, or beyond conduit that conducts fluid to the rack stand.