대표
청구항
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1. An apparatus for eliminating back drive in a push pull type control system, the apparatus comprising: a control rod including a rod end assembly comprising a pair of spaced apart piston displacement members, each piston displacement member having a check valve aperture configured to receive a check valve;a first check valve of a set of opposite-facing check valves having a body connected to a first of the pair of piston displacement members and having an aperture extending through a piston-facing surface of the first check valve for receiving hydrauli...
1. An apparatus for eliminating back drive in a push pull type control system, the apparatus comprising: a control rod including a rod end assembly comprising a pair of spaced apart piston displacement members, each piston displacement member having a check valve aperture configured to receive a check valve;a first check valve of a set of opposite-facing check valves having a body connected to a first of the pair of piston displacement members and having an aperture extending through a piston-facing surface of the first check valve for receiving hydraulic fluid; anda second check valve of the set of opposite-facing check valves having a body connected to a second of the pair of piston displacement members and having an aperture extending through a piston-facing surface of the second check valve for receiving hydraulic fluid;wherein the first check valve body is oriented so that when the first of the pair of piston displacement members is retracted into a direction of a piston head positioned between the set of opposite-facing check valves and the piston-facing surface of the first check valve lands upon an opposing surface of the piston head, the aperture of the first check valve forms an at least substantially sealed pathway through an aperture in the piston head; andwherein the second check valve body is oriented so that when the second of the pair of piston displacement members is extended into a direction of the piston head and the piston-facing surface of the second check valve lands upon an opposing surface of the piston head, the aperture in the second check valve forms an at least substantially sealed pathway through the second aperture in the piston head. 2. An apparatus as defined in claim 1, further comprising: a piston located within a chamber of a piston housing, the piston comprising a piston head and a piston body having inner surface portions defining a piston chamber configured to receive hydraulic fluid, the piston head including a first aperture for receiving a portion of the control rod, a first of the pair of piston displacement members located within the piston chamber and a second of the pair of piston engagement members located outside the piston chamber, the piston head further including a second aperture for passing portions of the hydraulic fluid into the piston chamber and for passing portions of the hydraulic fluid out of the piston chamber. 3. An apparatus as defined in claim 2, wherein the first and the second check valves are separated a sufficient distance so that when the respective piston-facing surface of one of the pair of opposite-facing check valves is in sealing contact with the piston head, the piston-facing surface of the other of the pair of opposite-facing check valves is separated from the piston head. 4. An apparatus as defined in claim 2, wherein the piston is operably coupled to an object to be controlled, and wherein the piston head and the first check valve are complementarily configured so that when the piston encounters forces emanating from the object that cause the piston to retract in the direction of the piston-facing surface of the first check valve and the corresponding opposing surface of the piston head sealingly engages the piston-facing surface of the first check valve, the sealing engagement of the opposing surface of the piston head with the first check valve causes a hydraulic lock that prevents further retraction of the piston head as a result of the forces emanating from the object to be controlled, thereby preventing back drive of the object to be controlled. 5. An apparatus as defined in claim 2, wherein the piston is operably coupled to an object to be controlled, and wherein the piston head and the second check valve are complementarily configured so that when the piston encounters forces emanating from the object to be controlled that cause the piston to extend in the direction of the piston-facing surface of the second check valve and the corresponding opposing surface of the piston head sealingly engages the piston-facing surface of the second check valve, the sealing engagement of the opposing surface of the piston head with the piston-facing surface of the second check valve causes a hydraulic lock that prevents further extension of the piston head as a result of the forces emanating from the object to be controlled, thereby preventing back drive of the object to be controlled. 6. An apparatus as defined in claim 2, further comprising a pair of centering springs positioned to maintain the piston head between the pair of opposite-facing check valves so that when no substantial external forces are applied to the piston or to the control rod, hydraulic fluid can flow into and out of the piston chamber through the second aperture of the piston head, effectively bypassing the check valves. 7. An apparatus as defined in claim 6, wherein a first of the pair of centering springs extends between a piston-facing outer surface portion of first piston displacement member and an opposing distal-facing outer surface portion of the piston head, and a second of the pair of centering springs extending between a piston-facing outer surface portion of the second piston displacement member and a proximal-facing outer surface portion of the piston head. 8. An apparatus as defined in claim 2, wherein the piston head includes a third aperture and fourth aperture, the apparatus further comprising: a first pressure relief valve having a body slidably positioned within the third aperture; anda second pressure relief valve having a body slidably positioned within the fourth aperture, the second pressure relief valve oriented to function in an opposite direction than that of the first pressure relief valve,the first and the second pressure relief valves together configured to prevent excessive pressure buildup on both proximal and distal facing sides of the piston head. 9. An apparatus as defined in claim 2, wherein the piston housing is a cylindrical housing having a first end portion, a second end portion, and a medial body portion extending therebetween, the medial body portion having an inner body surface defining a chamber containing hydraulic fluid, the first end portion configured to connect to a main aircraft structure;wherein the piston is slidably positioned within the chamber of the cylindrical housing and having an outer surface in sealed contact with inner surface portions of the medial body portion of the cylindrical housing;wherein the control rod is a first control rod extending from the second end of the housing and configured to be operably controlled by a user; andwherein the apparatus further comprises a second control rod connected to a piston tail section of the piston, extending from the first end portion of the housing, and configured to operably interface with the object to be controlled. 10. An apparatus for eliminating back drive in a push pull type control system, the apparatus comprising: a control rod including a rod end assembly comprising a pair of spaced apart piston displacement members, each piston displacement member having a check valve aperture configured to receive a check valve;a piston located within a chamber of a piston housing, the piston comprising a piston head and a piston body having inner surface portions defining a piston chamber configured to receive hydraulic fluid, the piston head including a first aperture for receiving a portion of the control rod, a first of the pair of piston displacement members located within the piston chamber and a second of the pair of piston engagement members located outside the piston chamber, the piston head further including a second aperture for passing portions of the hydraulic fluid into the piston chamber and for passing portions of the hydraulic fluid out of the piston chamber;a first check valve of a pair of opposite-facing check valves having a body connected to the first of the pair of piston displacement members and having an aperture extending through a piston-facing surface of the first check valve for receiving hydraulic fluid, the first check valve body oriented so that when the first of the pair of piston displacement members is retracted into a direction of the piston head and the piston-facing surface of the first check valve lands upon an opposing surface of the piston head, the aperture of the first check valve forms a sealed pathway through the second aperture in the piston head; anda second check valve of the pair of opposite-facing check valves having a body connected to the second of the pair of piston displacement members and having an aperture extending through a piston-facing surface of the second check valve for receiving hydraulic fluid, the second check valve body oriented so that when the second of the pair of piston displacement members is extended into a direction of the piston head and the piston-facing surface of the second check valve lands upon an opposing surface of the piston head, the aperture in the second check valve forms a sealed pathway through the second aperture in the piston head. 11. An apparatus as defined in claim 10, wherein the first and the second check valves are separated a sufficient distance so that when the respective piston-facing surface of one of the pair of opposite-facing check valves is in sealing contact with the piston head, the piston-facing surface of the other of the pair of opposite-facing check valves is separated from the piston head. 12. An apparatus as defined in claim 10, wherein the piston is operably coupled to an object to be controlled, and wherein the piston head and the first check valve are complementarily configured so that when the piston encounters forces emanating from the object that cause the piston to retract in the direction of the piston-facing surface of the first check valve and the corresponding opposing surface of the piston head sealingly engages the piston-facing surface of the first check valve, the sealing engagement of the opposing surface of the piston head with the first check valve causes a hydraulic lock that prevents further retraction of the piston head as a result of the forces emanating from the object to be controlled, thereby preventing back drive of the object to be controlled. 13. An apparatus as defined in claim 10, wherein the piston is operably coupled to an object to be controlled, and wherein the piston head and the second check valve are complementarily configured so that when the piston encounters forces emanating from the object to be controlled that cause the piston to extend in the direction of the piston-facing surface of the second check valve and the corresponding opposing surface of the piston head sealingly engages the piston-facing surface of the second check valve, the sealing engagement of the opposing surface of the piston head with the second check valve causes a hydraulic lock that prevents further extension of the piston head as a result of the forces emanating from the object to be controlled, thereby preventing back drive of the object to be controlled. 14. An apparatus as defined in claim 10, further comprising a pair of centering springs positioned to maintain the piston head between the pair of opposite-facing check valves so that when no substantial external forces are applied to the piston or to the control rod, hydraulic fluid can flow into and out of the piston chamber through the second aperture of the piston head, effectively bypassing the check valves. 15. An apparatus as defined in claim 14, wherein a first of the pair of centering springs extends between a piston-facing outer surface portion of first piston displacement member and an opposing distal-facing outer surface portion of the piston head, and a second of the pair of centering springs extending between a piston-facing outer surface portion of the second piston displacement member and a proximal-facing outer surface portion of the piston head. 16. An apparatus as defined in claim 10, wherein the piston head includes a third aperture and fourth aperture, the apparatus further comprising: a first pressure relief valve having a body slidably positioned within the third aperture and connected to the second of the pair of piston displacement members; and a second pressure relief valve having a body slidably positioned within the fourth aperture and connected to the first of the pair of piston displacement members, the second pressure relief valve oriented to function in an opposite direction than that of the first pressure relief valve,the first and the second pressure relief valves together configured to prevent excessive pressure buildup on both proximal and distal facing sides of the piston head. 17. An apparatus as defined in claim 10, wherein the piston housing is a cylindrical housing having a first end portion, a second end portion, and a medial body portion extending therebetween, the medial body portion having an inner body surface defining a chamber containing hydraulic fluid, the first end portion configured to connect to a main aircraft structure;wherein the piston is slidably positioned within the chamber of the cylindrical housing and having an outer surface in sealed contact with inner surface portions of the medial body portion of the cylindrical housing;wherein the control rod is a first control rod extending from the second end of the housing and configured to be operably controlled by a user; andwherein the apparatus further comprises a second control rod connected to a piston tail section of the piston, extending from the first end portion of the housing, and configured to operably interface with the object to be controlled. 18. An apparatus as defined in claim 10, wherein the push pull system is a push pull system for a rotary wing aircraft that provides pilot control to a rotor control head; andwherein the piston is operably coupled to the rotor control head via the push pull system. 19. An apparatus for eliminating back drive in a push pull type flight control system for an aircraft, the apparatus comprising: a cylindrical housing having a first end portion, a second end portion, and a medial body portion extending therebetween, the medial body portion having an inner body surface defining a housing chamber containing hydraulic fluid, the first end portion configured to connect to a main aircraft structure;a first control rod extending from the first end portion of the housing and configured to operably interface with a rotor control head; a second control rod extending from the second end of the housing and configured to be operably controlled by a user, the second control rod including a rod end assembly comprising a pair of spaced apart piston displacement plates, each piston displacement plate having a check valve aperture configured to support a check valve;a piston slidably positioned within the chamber of the cylindrical housing and having an outer surface in sealed contact with inner surface portions of the medial body portion of the cylindrical housing, the piston comprising a first end portion, a second end portion defining a piston head, and a medial body portion extending therebetween, the medial body portion defining a piston chamber containing portions of the hydraulic fluid, the piston head including a first aperture for receiving a portion of the second control rod, a first of the pair of piston displacement plates located within the piston chamber and a second of the pair of piston displacement plates located outside the piston chamber and inside the chamber of the cylindrical housing, the piston head further including a second aperture for passing portions of the hydraulic fluid into the piston chamber and for passing portions of the hydraulic fluid out of the piston chamber;a first check valve of a pair of opposing check valves having a body connected to the first of the pair of piston displacement plates and having an aperture extending through a piston-facing surface of the check valve for receiving hydraulic fluid, the first check valve body oriented so that when the first of the pair of piston displacement plates is retracted into a direction of the piston head and the piston-facing surface of the first check valve lands upon an opposing surface of the piston head, the aperture of the first check valve forms a sealed pathway through the second aperture in the piston head; and a second check valve of the pair of opposing check valves having a body connected to the second of the pair of piston displacement plates and having an aperture extending through a piston-facing surface of the check valve for receiving hydraulic fluid, the second check valve body oriented so that when the second of the pair of piston displacement plates is extended into a direction of the piston head and the piston-facing surface of the second check valve lands upon an opposing surface of the piston head, the aperture in the second check valve forms a sealed pathway through the second aperture in the piston head,the first and the second check valves being separated a sufficient distance so that when the respective piston-facing surface of one of the pair of opposing check valves is in sealing contact with the piston head, the piston-facing surface of the other of the pair of opposing check valves is separated from the piston head. 20. An apparatus as defined in claim 19, wherein the piston head separates the housing chamber into an input side chamber and an output side chamber;wherein when the piston-facing surface of the first check valve is in sealing contact with the piston head, hydraulic fluid cannot pass between the input side chamber and the output side chamber or pass out of the piston chamber; andwherein when the piston-facing surface of the second check valve is in sealing contact with the piston head, hydraulic fluid cannot pass between the input side chamber and the output side chamber or pass into of the piston chamber.
