Speed sensing apparatus

Claim 1

APPARATUS INCLUDING A ROTATABLE ELEMENT AND A DEVICE FOR DETECTING THE DIRECTION OF ROTATION AND THE ROTATIONAL SPEED OF SAID ROTATING ELEMENT, SAID DEVICE COMPRISING A FLUID PRESSURE RESPONSIVE DEVICE, A FLUID PRESSURE IMPACT RECEIVER PROVIDING A FLUID PASSAGEWAY COMMUNICATING AT ONE END WITH SAID PRESSURE RESPONSIVE DEVICE AND HAVING A FLUID INLET, A SINGLE NOZZLE MEMBER DISPOSED IN SPACED AXIAL ALIGNMENT WITH SAID INLET, MEANS FOR PASSING PRESSURIZED FLUID THROUGH SAID NOZZLE TOWARD SAID IMPACT RECEIVER INLET IN A FREE JET, A DISC MEMBER INTERPOSED BETWEEN SAID NOZZLE AND SAID INLET AND ROTATABLY DRIVEN BY SAID ROTATING ELEMENT, SAID DISC MEMBER HAVING AN ANNULAR ARRAY OF EQUALLY SPACED RADIAL VANES DISPOSED ABOUT ITS CIRCUMFERENTIAL PERIPHERY, SAID VANES HAVING LEADING EDGES DISPOSED ADJACENT SAID NOZZLE AND TRAILING EDGES DISPOSED ADJACENT SAID INLET, SAID VANES BEING SKEWED AND DEFINING AN ANNULAR ARRAY OF SKEWED PASSAGES, SAID PASSAGES PERMITTING IMPINGEMENT OF THE FLUID JET IN SAID INLET AND SAID VANES DEFLECTING THE FLUID JET FROM SAID INLET DURING ROTATION OF SAID DISC MEMBER, SAID LEADING EDGES BEING IN ADVANCE OF SAID TRAILING EDGES WHEN SAID DISC MEMBER IS DRIVEN IN ONE DIRECTION AND SAID TRAILING EDGES BEING IN ADVANCE OF SAID LEADING EDGES WHEN SAID DISC MEMBER IS DRIVEN IN THE OPPOSITE DIRECTION.