Patent ID: 8413688
Filing Date: 2013-04-09
Classification: F15B,Y10T

Abstract:
1. A device for controlling a pilot pressure of hydraulic valves, operating between two pilot lines between said valve and the feeding line of a hydraulic actuator, comprising a two-way valve and two positions for the communication between the actuator-side pilot line and the valve side pilot line, characterized in that said two-way valve and two positions is capable of taking different positions such as to never completely close the passage of fluid between the pilot lines wherein said device comprises: a cartridge having a respective hole and a transverse hole which is in fluid communication with the valve side pilot line; a continuous positioning slider, with communication ducts comprising transverse and axial communication duct between the pilot lines, which precisely slides within the respective hole and is moved by the difference between the pressure in the actuator-side pilot line and the atmospheric pressure, which counteracts the force applied by an elastic element; when the communication ducts allow the communication between said actuator-side pilot line and said valve-side pilot line, the fluid can flow freely from said actuator-side pilot line to said valve-side pilot line via the transverse hole and communication ducts, and vice versa; and when the transverse communication duct is not in fluid communication with the transverse hole of the cartridge, the passage of the fluid between said actuator-side pilot line and said valve-side pilot line is allowed only by leakage between the slider and the respective hole.