Anti-cavitation and overload relief valve for a hydraulic system

In a hydraulic overload relief and anti-cavitation protection system for hydraulic equipment having a hydraulic cylinder;

• a hydraulic valve having a housing;
• a first chamber within said housing in fluid communication with one end of said hydraulic cylinder;
• a second chamber within said housing in fluid communication with a fluid reservoir;
• a fluid passageway within said housing connecting said first and second chambers;
• a movable valve assembly positioned within said fluid passageway for operating in a first mode to block fluid flow between said first and second chambers, for operating in a second mode to permit fluid flow from said first chamber to said second chamber only when the pressure in said first chamber exceeds the pressure in said second chamber by a first predetermined amount, and for operating in a third mode to permit fluid flow from said second chamber only when the pressure in second chamber exceeds the pressure in said first chamber by a second predetermined amount;
• said valve having a stationary portion positioned within said fluid passageway between said first and second chambers, said stationary portion including a valve seat;
• said movable valve assembly including a movable valve element having a sealing portion for engaging said valve seat of said stationary portion when said movable valve assembly is operating in said first and second modes, said movable valve assembly further having a valve seat, and a poppet mechanism including a poppet for sealingly engaging said valve seat of said movable valve element when said movable valve assembly is operating in said first and third modes;
• said poppet mechanism including a poppet which is substantially solid in cross-section, has a head located at one end thereof, and a tang axially projecting from said head, said tang being comprised of a single axial projection,
• said stationary portion further includes a tapered reduced diameter portion for engaging the tang of the poppet in order to limit the travel thereof, whereby said tang intersects said tapered reduced diameter portion to maintain flow past said tapered portion and through said stationary portion to said second chamber from said first chamber.