ES415981A1 - Improvements introduced in a separate control valve device for arms of load handling machines. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Perfections introduced in a separate control valve device for arms of load handling machines, for the control by hydraulic jack of the gravity descent movement of a mobile work organ, characterized in that said device comprises: a first pressurized chamber that receives a first fluid under pressure, or control fluid; a control piston, which slides in the first chamber under the pressure of the first fluid; a second pressurized chamber that receives a second fluid under pressure or working fluid from the jack, this second chamber being constituted by an intake part, and an exhaust part, and constituting the seat of a valve member that slides in the part of admission, the separation between the intake part and the exhaust part; a rod integral with the piston, and sliding tightly and tightly in a hole made through the wall separating the first pressurized chamber of the second pressurized chamber, allowing this stem to separate the valve member from its seat, in the course of a piston displacement of the first pressurized chamber, under the action, of the first control fluid or fluid, which allows the second fluid contained in the lower capacity of the circular descent jack, through the valve member thus separated from its seat, in return to an appropriate tank, and this valve member being normally held against its seat, in the absence of the pressure of the first fluid on the control piston, by the counter-pressure of the second fluid that reigns in the of admission of the second pressurized chamber and in the lower capacity of the lowering jack, and/or by an appropriate spring means; a calibrated orifice located at the exit of the exhaust part of the second pressurized chamber, which allows to regulate by preselection of the outlet section of the second fluid through this orifice, the speed of descent of the work organ by simple gravity; and in that the active surface of the control piston receiving the pressure of the first fluid is sufficient to cause a force capable of separating the valve member from its seat, despite the counter-pressure exerted on this valve by the second fluid; and because the natures and levels of pressure of the first and second fluids are independent, which allows using two completely separate fluid circuits for the control of the valve organ, on the one hand, and for the work of the cat, on the other hand part. (Machine-translation by Google Translate, not legally binding)