Flow meter

Claim 1

IN APPARATUS OF THE CLAS DESCRIBED, A CONDUIT HAVING A PASSAGE THERETHROUGH; RESTRICTING MEANS IN THE PASSAGE, SAID MEANS, IN RESPONSE TO THE PASSING OF FLUID THROUGH THE PASSAGE, CREATING THEREIN A REGION OF RELATIVELY HIGHER FLUID VELOCITY AND LOWER FLUID PRESSURE AS COMPARED TO FLUID PRESSURE AND VELOCITY ON THE DOWNSTREAM SIDE OF SAID RESTRICTING MEANS; A BALANCE MEMBER POSITIONED NEAR AND ON THE DOWNSTREAM SIDE OF SAID RESTRICTING MEANS; A ROTOR MOUNTED UPON A SHAFT SUBSTANTIALLY COAXIALLY WITH SAID CONDUIT, SAID ROTOR HAVING BLADES FOR CAUSING ROTATION BY COACTION WITH THE FLUID FLOWING IN SAID CONDUIT, SAID ROTOR ALSO BEING FREE TO SHIFT AXIALLY OF THE CONDUIT WITHIN PRESELECTED LIMITS; MEANS FOR INTERCONNECTING SAID ROTOR AND BALANCE MEMBER FOR MOVEMENT TOGETHER IN ROTATION AND AXIALLY OF SAID CONDUIT, SAID ROTOR PASSING THROUGH THAT PORTION OF THE PASSAGE WHICH IS RESTRICTED BY SAID RESTRICTING MEANS; AND A SHIELD POSITIONED UPSTREAM RELATIVE TO SAID BALANCE MEMBER FOR COUNTERACTING TO A PRESELECTED EXTENT THE EFFECT OF DYNAMIC FLUID PRESSURE THEREON, THERE BEING IN RESPONSE TO FLUID FLOW THROUGH THE CONDUIT A PRESSURE HEAD ACTING UPON THE DOWNSTREAM FACING AREAS INCLUDING THE DOWNSTREAM END AREAS OF SAID BALANCE MEMBER URGING SAME UPSTREAM, WHICH HEAD IS BALANCED AGAINST THE PRESSURE AND VELOCITY HEADS URGING SAID BALANCE MEMBER DOWNSTREAM, THE PITCH OF SAID BLADES BEING SELECTED TO ACHIEVE SUCH BALANCE; AND MEANS FOR PRODUCING A SIGNAL RESPONSIVE TO THE SPEED OF ROTATION OF SAID ROTOR.