Digital servo actuators

Claim 1

AN APPARATUS FOR CONVERTING INPUT ELECTRICAL DIGITAL SIGNALS INTO CORRESPONDING MECHANICAL LINEAR DISPLACEMENTS WITH POWER AMPLIFICATION, SAID APPARATUS COMPRISING: A STATIONARY HOUSING DEFINING A STATIONARY REFERENCE ELEMENT AND HAVING A FIRST SUBSTANTIALLY CYLINDRICAL BORE CLOSED AT ONE END AND OPEN AT THE OTHER END; A SLIDABLE OUTPUT MEMBER DEFINING A FIRST MOVABLE REFERENCE ELEMENT WHICH IS MOVABLE THROUGH THE OPEN END OF SAID HOUSING; A PLURALITY OF CASCADED MOTOR STAGES SLIDABLY DISPOSED END-TO-END WITHIN SAID FIRST BORE INTERMEDIATE THE CLOSED END OF SAID BORE AND SAID OUTPUT MEMBER, EACH OF SAID MOTOR STAGES COMPRISING: A PISTON MEMBER HAVING A BODY ADAPTED TO SLIDABLY FIT WITHIN SAID FIRST BORE IN THE HOUING AND HAVING A FIRST AND A SECOND L-SHAPED EXTENSIONS PROJECTING FROM THE OPPOSITE FACES OF SAID BODY; THE FIRST OF SAID EXTENSIONS BEING A PUSH-ROD ELEMENT ADAPTED TO ABUT AGAINST THE END FACE OF THE PISTON BODY IMMEDIATELY PRECEDING, AND THE SECOND OF SAID EXTENSIONS BEING A CONNECTING LINK ELEMENT HAVING AN END FLANGE PORTION ADAPTED TO PROJECT INTO A CORRESPONDING RECESS OF THE PUSH-ROD ELEMENT OF THE NEXT CONSECUTIVE PISTON MEMBER; SAID END FLANGE PORTION HAVING ITS INNER END DEFINING AN ABUTMENT FOR THE INNER END FACE OF THE RECESS IN THE PUSH-ROD ELEMENT OF THE NEXT CONSECUTIVE ANNULAR MOTOR CHAMBER DISPOSED A SUBSTANTIALLY ANNULAR MOTOR CHAMBER DISPOSED BETWEEN EACH TWO CONSECUTIVE PISTON MEMBER BODIES; CONDUIT MEANS TO ADMIT SUPPLY PRESSURE FLUID INTO SAID ANNULAR MOTOR CHAMBER THEREBY CAUSING SAID PISTON BODY TO BE DISPLACED, DISPLACING AT THE SAME TIME THE PISTON MEMBERS BETWEEN IT AND THE OUTPUT MEMBER BY PUSHING AGAINST THE PUSHROD OF THE NEXT CONSECUTIVE PISTON MEMBER; STOP MEANS DEFINED BY THE INNER END FACE OF THE RECESS IN THE PUSH-ROD ELEMENTS AND THE ABUTMENT OF THE FLANGE PORTION OF THE CONNECTING LINK ELEMENTS; THE FIRST CONNECTING LINK ELEMENT BEING AN INTEGRAL PORTION OF THE END PLATE CLOSING THE CLOSED END OF SAID FIRST BORE IN THE HOUSING AND THE LAST PISTON MEMBER DISPLACING DIRECTLY SAID OUTPUT MEMBER; BIASING MEANS EXERTED UPON SAID LAST PISTON MEMBER IN A DIRECTION THAT TENDS TO MAINTAIN THE END FACE OF THE PUSH ROD OF EACH PISTON MEMBER IN CONTACT WITH THE CORRESPONDING END FACE OF THE NEXT PRECEDING PISTON BODY AND THE END FACE OF THE PUSH-ROD OF THE FIRST PISTON MEMBER IN CONTACT WITH THE INNER FACE OF SAID END PLATE, THEREBY BIASING THE OUTPUT MEMBER TO ITS RETRACTED POSITION; A SOLENOID-OPERATED VALVE FOR EACH OF SAID MOTOR STAGES, SAID VALVE COMPRISING: A SUBSTANTIALLY CYLINDRICAL CAVITY WITH PRESSURE, RETURN AND CONTROL PORTS IN COMMUNICATION RESPECTIVELY WITH A PRESSURE FLUID CHANNEL, A RETURN FLUID CHANNEL, AND CONTROL PASSAGEWAY AT ALL TIMES CONNECTED TO THE MOTOR CHAMBER OF ONE OF SAID MOTOR STAGES; A SPOOL MEMBER WITH TWO INTEGRAL ENLARGED LAND PORTIONS SLIDABLE WITHIN SAID CYLINDRICAL CAVITY; A SPRING BIAS URGING SAID SPOOL MEMBER TO ONE EXTREME POSITION WHERE SAID PRESSURE PORTS ARE DISCONNECTED FROM AND SAID RETURN PORTS ARE CONNECTED TO SAID CONTROL PORTS;

Claim 2

AN APPARATUS FOR CONVERTING INPUT ELECTRICAL DIGITAL SIGNALS INTO CORRESPONDING MECHANICAL LINEAR DISPLACEMENTS WITH POWER AMPLIFICATION, SAID APPARATUS COMPRISING: A STATIONARY HOUSING DEFINING A STATIONARY REFERENCE ELEMENT AND HAVING A FIRST SUBSTANTIALLY CYLINDRICAL BORE CLOSED AT ONE END AND OPEN AT THE OTHER END; A SLIDABLE OUTPUT MEMBER DEFINING A FIRST MOVABLE REFERENCE ELEMENT WHICH IS MOVABLE THROUGH THE OPEN END OF SAID HOUSING; A PLURALITY OF CASCADED MOTOR STAGES SLIDABLY DISPOSED END-TO-END WITHIN SAID FIRST BORE INTERMEDIATE THE CLOSED END OF SAID BORE AND SAID OUTPUT MEMBER, EACH OF SAID MOTOR STAGES COMPRISING: A PISTON MEMBER HAVING A BODY ADAPTED TO SLIDABLY FIT WITHIN SAID FIRST BORE IN THE HOUING AND HAVING A FIRST AND A SECOND L-SHAPED EXTENSIONS PROJECTING FROM THE OPPOSITE FACES OF SAID BODY; THE FIRST OF SAID EXTENSIONS BEING A PUSH-ROD ELEMENT ADAPTED TO ABUT AGAINST THE END FACE OF THE PISTON BODY IMMEDIATELY PRECEDING, AND THE SECOND OF SAID EXTENSIONS BEING A CONNECTING LINK ELEMENT HAVING AN END FLANGE PORTION ADAPTED TO PROJECT INTO A CORRESPONDING RECESS OF THE PUSH-ROD ELEMENT OF THE NEXT CONSECUTIVE PISTON MEMBER; SAID END FLANGE PORTION HAVING ITS INNER END DEFINING AN ABUTMENT FOR THE INNER END FACE OF THE RECESS IN THE PUSH-ROD ELEMENT OF THE NEXT CONSECUTIVE ANNULAR MOTOR CHAMBER DISPOSED A SUBSTANTIALLY ANNULAR MOTOR CHAMBER DISPOSED BETWEEN EACH TWO CONSECUTIVE PISTON MEMBER BODIES; CONDUIT MEANS TO ADMIT SUPPLY PRESSURE FLUID INTO SAID ANNULAR MOTOR CHAMBER THEREBY CAUSING SAID PISTON BODY TO BE DISPLACED, DISPLACING AT THE SAME TIME THE PISTON MEMBERS BETWEEN IT AND THE OUTPUT MEMBER BY PUSHING AGAINST THE PUSHROD OF THE NEXT CONSECUTIVE PISTON MEMBER; STOP MEANS DEFINED BY THE INNER END FACE OF THE RECESS IN THE PUSH-ROD ELEMENTS AND THE ABUTMENT OF THE FLANGE PORTION OF THE CONNECTING LINK ELEMENTS; THE FIRST CONNECTING LINK ELEMENT BEING AN INTEGRAL PORTION OF THE END PLATE CLOSING THE CLOSED END OF SAID FIRST BORE IN THE HOUSING AND THE LAST PISTON MEMBER DISPLACING DIRECTLY SAID OUTPUT MEMBER; BIASING MEANS EXERTED UPON SAID LAST PISTON MEMBER IN A DIRECTION THAT TENDS TO MAINTAIN THE END FACE OF THE PUSH ROD OF EACH PISTON MEMBER IN CONTACT WITH THE CORRESPONDING END FACE OF THE NEXT PRECEDING PISTON BODY AND THE END FACE OF THE PUSH-ROD OF THE FIRST PISTON MEMBER IN CONTACT WITH THE INNER FACE OF SAID END PLATE, THEREBY BIASING THE OUTPUT MEMBER TO ITS RETRACTED POSITION; A SOLENOID-OPERATED VALVE FOR EACH OF SAID MOTOR STAGES, SAID VALVE COMPRISING: A SUBSTANTIALLY CYLINDRICAL CAVITY WITH PRESSURE, RETURN AND CONTROL PORTS IN COMMUNICATION RESPECTIVELY WITH A PRESSURE FLUID CHANNEL, A RETURN FLUID CHANNEL, AND CONTROL PASSAGEWAY AT ALL TIMES CONNECTED TO THE MOTOR CHAMBER OF ONE OF SAID MOTOR STAGES; A SPOOL MEMBER WITH TWO INTEGRAL ENLARGED LAND PORTIONS SLIDABLE WITHIN SAID CYLINDRICAL CAVITY; A SPRING BIAS URGING SAID SPOOL MEMBER TO ONE EXTREME POSITION WHERE SAID PRESSURE PORTS ARE DISCONNECTED FROM AND SAID RETURN PORTS ARE CONNECTED TO SAID CONTROL PORTS;