Air velocity meters

Claim 1

AN AIR PRESSURE MEASURING INSTRUMENT OF THE MOVING COIL TYPE, COMPRISING A CYLINDRICAL POLE PIECE, THREADED MEANS PASSING THROUGH SAID POLE PIECE PARALLEL TO THE AXIS THEREOF, A CORE BRACKET, COMPRISING A METAL MEMBER OF SUBSTANTIALLY U-SHAPE, HAVING A CYLINDRICAL BORE IN THE U PORTION THEREOF, AND A THREADED BORE IN THE BOTTOM WALL THEREOF, A PAIR OF OUTWARDLY EXTENDING BRIDGE FLANGES CARRIED BY THE UPPER END OF SAID CORE BRACKET, SECURED BY SAID THREADED MEANS, A CYLINDRICAL CORE MAGNET FITTING IN THE BORE OF SAID CORE BRACKET, MEANS FOR SECURING THE CORE MAGNET IN SAID CORE BRACKET, A BRIDGE EXTENDING FROM FLANGE TO FLANGE OF SAID CORE BRACKET AND SECURE BY SAID THREADED MEANS, AND HAVING A THREADED BORE THEREIN ALIGNED WITH THE THREADED BORE IN SAID CORE BRACKET, SAID CORE BRACKET HAVING AN ARCUATE ANNULAR AIR GAP ON EACH SIDE THEREOF, BETWEEN THE POLE PIECE AND THE CORE MAGNET, A MOVING COIL MOUNTED SAID AIR GAP, AND HAVING A PIVOT PIN AT EACH END OF SAID COIL, A THREADED SLEEVE MOUNTED IN THE END OF THE CORE BRACKET, AND IN THE BORE OF THE BRIDGE, THE THREADED SLEEVE BEING ADAPTED TO THE MOVEMENT INTO CLOSE PROXIMITY WITH EACH PIVOT PIN TO LIMIT THE MOVEMENT OF BOTH PIVOT PINS AXIALLY AND OUT OF AXIAL POSITION, A SPRING BOW MOUNTED ON THE THREADED SLEEVE AT EACH END OF THE MOVING COIL, SAID BOW SUPPORTING A TRANSVERSE SPRING IN EACH CASE, AND A RIBBON ANCHORED IN THE CENTER OF EACH TRANSVERSE SPRING, AND EXTENDING AXIALLY THROUGH THE THREADED SLEEVE IN EACH CASE EACH RIBBON BEING ANCHORED IN THE PIVOT PIN ON EACH END OF THE MOVING COIL, AND PROVIDING A RESILIENT SPRING MOUNTING FOR THE MOVING OVER A SCALE ARM CARRIED BY THE MOVING COIL AND MOVING OVER A SCALE PAN HAVING A SCALE, CARRIED BY THE INSTRUMENT, AN AIR VANE CARRIED BY THE POINTER ARM, AN ADJUSTABLE RESISTANCE AND A STANDARD CELL IN SERIES WITH THE RESISTANCE, AND CONNECTED ACROSS THE TERMINALS OF THE MOVING COIL, TO DAMP THE MOVEMENT OF THE MOVING COIL AND POINTER THE SAID NEEDLE AND MOVING COIL BEING MOVED BY THE AIR VANE, ACCORDING TO AIR FLOW.