Pressure sensing passages of load responsive control valves

Claim 1

A valve assembly comprising a housing having a fluid load chamber and two other chambers, said two other chambers being a fluid inlet chamber and a fluid outlet chamber, partitions separating said chambers and having extension means projecting into said chambers, valve bore means extending through said partitions and in direct communication with all of said chambers, differential pressure control valve means operable to maintain a constant pressure differential between adjacent chambers, an opening on the surface of said valve bore means passing through extension means of one of said partitions adjacent to said load chamber, pressure signal passage means connecting said differential pressure control valve means to said opening, said opening having a width parallel to axis of said valve bore means, said valve bore means axially guiding a valve spool having land means, said valve spool having a neutral position in which said land means isolate said chambers and block said opening to said pressure signal passage means, and sequencing means on said valve spool to determine a first actuating distance in one direction from neutral position of said valve spool to interconnect said load chamber with said pressure signal passage means, synchronizing means on said valve spool to determine a second actuating distance in the same direction from neutral position of said valve spool to interconnect said load chamber and said pressure signal passage means with one of said other chambers, whereby said first and second actuating distance can be selected with respect to each other in a manner independent of width of said opening to determine the dead band of the valve assembly.