摘要 |
A distributor for hydraulic cylinders (2), especially applicable to crane drive cylinders, which comprises an axial sliding runner (4) for selection of the oil circuit. Said runner (4) is hollow, forming two separate chambers (19,20) adjacent to the cylinder chamber supply and return ducts with which it is connected through holes in the wall of the said runner. One of the chambers (19) includes means for varying the degree to which the holes are opened, according to the return oil pressure from the cylinder withdrawal chamber. The other chamber (20) incorporates means for opening or closing the connection through it, according to the pressure being delivered by the pump, to the cylinder withdrawal chamber oil supply duct. Thus it is possible to regulate the flow as an inverse function of the load and to reduce the effect of induced pressure. |