Controlling apparatus

Claim 1

AN APPARATUS FOR POSITIONING A FLUID PRESSURE OPERATED CONTROL MEMBER IN ACCORDANCE WITH THE MAGNITUDE OF A DIGITAL CONTROL SIGNAL, COMPRISING AN ELECTRO-MECHANICAL MEANS TO TRANSFORM THE DIGITAL CONTROL SIGNAL INTO SUBSTANTIALLY PROPORTIONAL STRAIGH-LINE MOTION, A PILOT VALVE HAVING A NON-RESTRICTED SPRING LOADED FLAPPER NOZZLE FLUID EXHAUST VALVE AND A SPRING LOADED FLAPPER NOZZLE FLUID SUPPLY VALVE FOR SIMULTANEOUSLY SUPPLYING AND EXHAUSTING REGULATED AMOUNTS OF A FLUID UNDER PRESSURE INTO A COMMON CHAMBER, THE FLAPPERS OF THE VALVE BEING OPERABLY CONNECTED FOR SIMULTANEOUS OPPOSITE OPENING AND CLOSING MOVEMENT WITH A CONNECTING ROD PASSING THROUGH THE PIVOT VALVE, A FIRST COMPRESSION SPRING POSITIONED BETWEEN THE ELECTRO-MECHANICAL MEANS AND ONE END OF THE CONNECTING ROD FOR TRANSMITTING THE STRAIGHT-LINE MOTION IN THE FORM OF A SPRING LOAD TO THE ROD, A FLUID PRESSURE ACTUATOR OPERABLY CONNECTED TO APPLY A FORCE PROPORTIONAL TO THE MAGNITUDE OF THE FLUID PRESSURE GENERATED IN THE CHAMBER BY THE SIMULTANEOUS OPENING AND CLOSING OF THE NOZZLE TO BE CONTROLLED MEMBER, A NEGATIVE FEEDBACK LINKAGE OPERABLY CONNECTED FOR MOVEMENT WITH THE CONTROLLED MEMBER AT ONE END AND BEING OPERABLY CONNECTED AT ITS OTHER END TO CHANGE THE FORCE APPLIED TO THE END OF A SECOND COMPRESSION SPRING, AND THE OTHER END OF THE LASTMENTIONED SPRING BEING OPERABLY CONNECTED TO THE CONNECTING ROD TO TRANSMIT THE MOTION OF THE FEEDBACK LINKAGE IN THE FORM OF A SPRING LOAD TO AN OPPOSITE END OF THE ROD THEREBY BALANCE THE FORCE BEING APPLIED TO THE PILOT VALVE BY THE FIRST COMPRESSION SPRING.

Claim 2

AN APPARATUS FOR POSITIONING A FLUID PRESSURE OPERATED CONTROL MEMBER IN ACCORDANCE WITH THE MAGNITUDE OF A DIGITAL CONTROL SIGNAL, COMPRISING AN ELECTRO-MECHANICAL MEANS TO TRANSFORM THE DIGITAL CONTROL SIGNAL INTO SUBSTANTIALLY PROPORTIONAL STRAIGH-LINE MOTION, A PILOT VALVE HAVING A NON-RESTRICTED SPRING LOADED FLAPPER NOZZLE FLUID EXHAUST VALVE AND A SPRING LOADED FLAPPER NOZZLE FLUID SUPPLY VALVE FOR SIMULTANEOUSLY SUPPLYING AND EXHAUSTING REGULATED AMOUNTS OF A FLUID UNDER PRESSURE INTO A COMMON CHAMBER, THE FLAPPERS OF THE VALVE BEING OPERABLY CONNECTED FOR SIMULTANEOUS OPPOSITE OPENING AND CLOSING MOVEMENT WITH A CONNECTING ROD PASSING THROUGH THE PIVOT VALVE, A FIRST COMPRESSION SPRING POSITIONED BETWEEN THE ELECTRO-MECHANICAL MEANS AND ONE END OF THE CONNECTING ROD FOR TRANSMITTING THE STRAIGHT-LINE MOTION IN THE FORM OF A SPRING LOAD TO THE ROD, A FLUID PRESSURE ACTUATOR OPERABLY CONNECTED TO APPLY A FORCE PROPORTIONAL TO THE MAGNITUDE OF THE FLUID PRESSURE GENERATED IN THE CHAMBER BY THE SIMULTANEOUS OPENING AND CLOSING OF THE NOZZLE TO BE CONTROLLED MEMBER, A NEGATIVE FEEDBACK LINKAGE OPERABLY CONNECTED FOR MOVEMENT WITH THE CONTROLLED MEMBER AT ONE END AND BEING OPERABLY CONNECTED AT ITS OTHER END TO CHANGE THE FORCE APPLIED TO THE END OF A SECOND COMPRESSION SPRING, AND THE OTHER END OF THE LASTMENTIONED SPRING BEING OPERABLY CONNECTED TO THE CONNECTING ROD TO TRANSMIT THE MOTION OF THE FEEDBACK LINKAGE IN THE FORM OF A SPRING LOAD TO AN OPPOSITE END OF THE ROD THEREBY BALANCE THE FORCE BEING APPLIED TO THE PILOT VALVE BY THE FIRST COMPRESSION SPRING.