Servo actuator

Claim 1

A SERVO ACTUATOR COMPRISING HOUSING MEANS, A CYLINDRICAL CHAMBER FORMED IN SAID HOUSING, PISTON MEANS MOUNTED FOR RECIPROCATION WITHIN SAID CYLINDRICAL CHAMBER TO FORM VARIABLE VOLUME CHAMBERS AT OPPOSITE SIDES OF SAID PISTON, AN ARMATURE ASSEMBLY FLEXIBLY MOUNTED IN SAID HOUSING, SAID ARMATURE ASSEMBLY INCLUDING AN ARMATURE AND A JET PIPE MOVABLE WITH SAID ARMATURE ASSEMBLY, A PAIR OF RECEIVING PASSAGES IN SAID HOUSING ADJACENT THE DISCHARGE END OF SAID JET PIPE FOR DIRECTING PROPORTIONALLY VARIABLE AMOUNTS OF FLUID UNDER PRESSURE TO SAID PISTON CHAMBERS FOR CONTROLLING THE POSITION OF SAID PISTON, SAID JET PIPE WHEN IN A NULL POSITION HAVING ITS DISCHARGE END SYMMETRICALLY LOCATED RELATIVE TO SAID RECEIVING PASSAGES FOR SUPPLYING SUBSTANTIALLY EQUAL QUANTITIES OF FLUID THERETO, MEANS PROVIDING AN ELECTRICAL SIGNAL TO BIAS SAID ARMATURE FOR VARIABLY POSITIONING SAID JET PIPE TO DELIVER DISPROPORTIONATE AMOUNTS OF FLUID TO SAID RECEIVING PASSAGES, A FEEDBACK ROD MOUNTED WITHIN SAID HOUSING AND OPERATIVELY CONNECTED TO SAID PISTON FOR MOVEMENT THEREWITH, AND PLURAL SPRING MEANS RESPONSIVE TO MOVEMENT OF SAID FEEDBACK ROD IN EITHER DIRECTION TO RETURN SAID JET PIPE TO A NULL POSITION FOLLOWING MOVEMENT THEREOF IN RESPONSE TO SAID ELECTRICAL SIGNAL, THE PISTON THEREBY BEING MAINTAINED IN ITS ADJUSTED POSITION.