Control system for hydraulic presses comprising a plurality of press rams

A control system for hydraulic presses comprising a plurality of press rams, which are movable in a forward direction toward each other and in a rearward direction away from each other in alternation, comprising a high-pressure conduit and a low-pressure conduit, said high-pressure conduit incorporating an intensifier and communicating with first chambers, which are associated with respective press rams and adapted to apply pressure to said press rams so as to urge them in said forward direction, said low-pressure conduit communicating with second chambers, which are associated with respective press rams and adapted to apply pressure to said press rams so as to urge them in said rearward direction, said intensifier comprising a piston which is displaceable in a housing under the action of the pressure fluid in the high-pressure conduit and which defines in said housing a primary chamber and at least one secondary chamber, said primary chamber being constantly supplied with high-pressure liquid from said high-pressure conduit throughout the operation of the press, said secondary chamber communicating with said first chambers associated with said press rams, said primary chamber being connected by a first valve to a control conduit, and a second valve being provided, which is adapted to connect said control conduit in alternation to said low-pressure conduit and a return conduit in synchronism with the reciprocating motion of said press rams.