Differential pressure transmitters

Claim 1

A DIFFERENTIAL PRESSURE TRANSMITTER, WHICH COMPRISES A MAIN BODY PROVIDED WITH A CENTRAL CHAMBER, FLANGES FIXED TO THE OPPOSITE SIDE OF SAID MAIN BODY FOR FORMING A HIGH PRESSURE CHAMBER AND A LOW PRESSURE CHAMBER THEREIN, ONE SET OF HIGH AND LOW PRESSURE RESPONSIVE BELLOWS FIXED AT ONE END AND MOVABLE AT THE OTHER END AND FITTED TO THE OPPOSITE SIDES OF SAID MAIN BODY IN SPACES PROVIDED INSIDE OF SAID HIGH AND LOW PRESSURE CHAMBERS RESPECTIVELY, A DIFFERENTIAL PRESSURE RESPONSIVE BELLOWS FIXED AT ONE END TO A PART OF THE MAIN BODY AND MOVABLE AT THE OTHER END, THE INSIDE OF SAID DIFFERENTIAL PRESSURE RESPONSIVE BELLOWS COMMUNICATING WITH THE CENTRAL CHAMBER WHICH IS IN COMMUNICATION WITH THE INSIDE OF SAID HIGH PRESSURE RESPONSIVE BELLOWS THROUGH A DUCT, THE OUTSIDE OF SAID DIFFERENTIAL PRESSURE RESPONSIVE BELLOWS BEING IN COMMUNICATION WITH THE INSIDE OF SAID LOW PRESSURE RESPONSIVE BELLOWS, LIQUID ENCLOSED INSIDE AND OUTSIDE OF SAID BELLOWS, A MOVABLE END PLATE DISPOSED IN SAID DIFFERENTIAL PRESSURE RESPONSIVE BELLOWS, A FLEXIBLE SPRING FIXED AT ONE END TO SAID MOVABLE END PLATE FOR TRANSMITTING THE DEFLECTION OF SAID MOVABLE END PLATE TO THE OTHER END, A CANTILEVER ARM FIXED AT ONE END TO THE OTHER END OF SAID SPRING WHICH OTHER END CONVERTS THE DEFORMATION OF SAID MOVABLE END PLATE TO A ROTARY DEFORMATION THEREOF, A TORQUE TUBE FIXED AT ONE END TO THE OTHER END OF SAID CANTILEVER AND FIXED AT THE OTHER END TO A HOLDING MEMBER SECURED TO SAID MAIN BODY, SAID ONE END OF SAID TORQUE TUBE BEING TWISTED, A SPINDLE INSERTED INTO SAID TORQUE TUBE AND FIXED THERETO AT ITS ROOT FOR TRANSMITTING THE PRESSURE DIFFERENCE ACTING ON ONE SET OF THE COOPERATING BELLOWS BY CONVERTING IT TO A ROTARY DEFLECTION TO THE OUTSIDE OF THE MAIN BODY, A MEASURING MECHANISM OPERATIVELY CONNECTED TO SAID SPINDLE SO AS TO BE OPERATED BY THE ROTARY DEFLECTION TRANSMITTED THERETO, AND A COMPENSATING ELEMENT PROVIDED IN THE CENTRAL CHAMBER FOR COMPENSATING THE TEMPERATURE VARIATION BY ADJUSTING ITS VOLUME TO MAKE THE QUANTITIES OF LIQUID SEALED INSIDE AND OUTSIDE OF SAID DIFFERENTIAL PRESSURE RESPONSIVE BELLOWS EQUAL.