Hydraulic control valve for selectively supplying fluid to hydraulic services

A hydraulic control valve comprising:

• a body having a plurality of faces including at least one pair of opposed faces and adjacent first and second bores extending between said opposed faces;
• each of said bores having a plurality of chambers spaced longitudinally thereof and communicating therewith;
• a landed valve spool in each of said bores slidable between a neutral position and at least one effective position in which selected communication is provided between adjacent chambers along said bore;
• a fluid pressure supply port in one of said faces which communicates with said first bore by way of first and second of said chambers spaced longitudinally of said first bore, whereby the increased flow area provided by said two chambers reduces the pressure drop occassioned by flow through them;
• a check valve disposed between said supply port and one of said two chambers adapted to control admission of pressure fluid from said supply port to that said one chamber and to prevent reverse flow from that said one chamber to said supply port;
• a tank port in one of said faces;
• tank passages connecting certain of said chambers to said tank port;
• fluid supply passages connecting said supply port, said first and second chambers, a third one of said chambers connected to said first bore and also having connection with said second bore and arranged that when said valve spools are in their neutral positions said supply port is connected to said tank port through said fluid supply passages said first, second and third chambers, and said tank passages;
• service ports connected to others of said chambers and connectable to said fluid supply and tank passages when said valve spools are in said effective positions, said valve spool in said first bore when in said effective position selectively connecting that one of the first and second chambers between which and said supply port said check valve is disposed with one of said service ports by way of said first bore;
• restrictor means in one said fluid supply passage downstream of said first bore, and valve means having a fluid pressure responsive member and being in communication with one said fluid supply passage and with one said tank passage and being constructed and arranged to respond to a pre-determined pressure drop across said restrictor means to cause a portion of fluid in said supply passage to spill to said tank port when said first spool is in said neutral position.