Servomotor with monitor

Claim 1

IN A FLUID TYPE SERVOMECHANISM HAVING AN OUTPUT MEMBER AND COMPRISING AT LEAST THREE CYLINDERS AND INTEGRALLY CONNECTED RAMS, ONE FOR EACH CYLINDER, CONNECTED ALSO TO SAID OUTPUT MEMBER; A SERVO CONTROL VALVE FOR EACH CYLINDER; AN ENGAGE VALVE INTERMEDIATE EACH SAID SERVO VALVE AND CYLINDER TO EFFECT TANSMISSION OF FLUID FROM THE VALVE AND CYLINDER OPERATED TO ITS RESPECTIVE CYLINDER; PRESSURE RESPONSIVE MEANS CONNECTED TO EACH ENGAGE VALVE FOR OPERATING EACH SAID ENGAGE VALVE TO ITS OPERATED POSITION; COMMUNICATING WITH SAID FIRST OPENING; A SLIDE MEMBER IN OPERATING OR DISPLACING EACH LIMIT VALVE IN RESPONSE TO DIFFERENTIAL PRESSURE ON OPPOSITE SIDES OF THE RAM IN EACH INDIVIDUAL CYLINDER; AND MEANS RESPONSIVE TO UNEQUAL DIFFERENTIAL PRESSURES IN THE THREE CYLINDERS OPEATING ONE OF SAID LIMIT VALVES TO RELIEVE THE PRESSURE ON THE ENGAGE VALVE ND CAUSING RETURN OF SAID ONE ENGAGE VALVE TO UNOPERATED POSITION WHEREBY THE OPPOSIED ENDS OF THE CYLINER CORRESPONDING TO SAID RETURNED ENGAGE VALVE BECAUSE OF A MALFUNCTION, INDICATED BY NONCONFORMANCE OF ITS DIFFERENTIAL PRESSURE WITH THE OTHER TWO CYLINDERS, ARE BROUGHT INTO COMMUNICATION WITH EACH OTHER.