Patent ID: 7743789

Claim:
A valve for the hydraulic braking of work machines, comprising: an outer casing provided with a second abutment element thereinside, with a longitudinal seat and with at least one first port for connection of said seat to a pumping assembly for feeding pressurized fluid; at least one second port for connecting said seat to a fluid discharge and recovery tank; at least one third port for connecting said seat to a braking system of a work machine; a slider which is slideable along said seat and provided with a contoured portion, for allowing/preventing passage of the fluid through said first, second and third connecting ports; and with a first abutment element; a reaction surface connected to said third connecting port; and actuation means for actuating sliding of said slider in said seat in contrast with said pressurized fluid that contacts said reaction surface; and wherein said actuation means comprise: first elastic means, which are interposed between said casing and said slider and are adapted to contrast a thrust of said pressurized fluid against said reaction surface; second elastic means which are interposed between said first abutment element and said second abutment element to contrast the thrust of said first elastic means, and manual actuation means for manually actuating loading/unloading of said second elastic means, and wherein said slider comprises at least one abutment surface, which is movable by said second abutment element at a stroke limit configuration.