An actuator is a device whose main purpose is the realization of great force for braking most often for the purpose of anchoring of large cranes. The pump sends pressurized oil into the chamber of the cylinder to retract and thus will overcome the force of the spring that performs anchoring, while allowing movement of the crane. All the time while the crane moves like the hydraulic power unit moves all the amount of oil via the overflow valve. Pulling the piston rod it overcomes the spring brake mechanism and thereby release the brake on the rail, which allows the smooth movement of the crane. Power limit brake release is achieved by using the pressure limiting valve oil. It is recommended that the force brake release is about 15-20% higher than the force necessary to overcome the force of the springs. We have to take care that the pressure does not exceed the maximum permissible value, to avoid damage to the device. After exclusion of aggregates, springs return connecting rod in the forward position and thus the crane anchors and prevents its movement. Brakes are controlled by adjusting the damping check valve. For operation at low temperatures, below -15 ° C ,heater and thermostat are embedded in aggregate to heat the oil before it starts. At the request of the customer, we make the actuators with other dimensions and operating parameters.