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A fuel injector uses two or more individual piezoelectric devices. A first piezoelectric device is used to actuate a valve which allows pressurized fuel to pass from a pressure chamber through an outlet port. The fuel is pressurized by a second piezoelectric device. In certain applications, a return

A fuel injector uses two or more individual piezoelectric devices. A first piezoelectric device is used to actuate a valve which allows pressurized fuel to pass from a pressure chamber through an outlet port. The fuel is pressurized by a second piezoelectric device. In certain applications, a return piezoelectric device is arranged in opposing configuration to the first piezoelectric device so that the valve can be positively moved both into its opened and closed positions rather than depending on the return force of a spring.

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I claim: 1. A fuel injection system, comprising: an outlet port; a valve which is movable along a path between a first position and a second position, said outlet port being blocked by said valve when said valve is in said first position, said outlet port being unblocked by said valve when said val

I claim: 1. A fuel injection system, comprising: an outlet port; a valve which is movable along a path between a first position and a second position, said outlet port being blocked by said valve when said valve is in said first position, said outlet port being unblocked by said valve when said valve is in said second position; a first piezoelectric device disposed in force transmitting association with said valve to selectively move said valve along said path; a pressure chamber; and a second piezoelectric device disposed in pressure affecting association with said pressure chamber, whereby movement of said second piezoelectric device changes the pressure of a fuel within said pressure chamber by exerting a force on said fuel within said pressure chamber and movement of said valve under the influence of said first piezoelectric device causes said fuel, which is pressurized within said pressure chamber, to flow from said pressure chamber and through said outlet port; wherein said second piezoelectric device is a transducer exerting a force directly on the fuel within the pressurization chamber to create the pressurized fuel. 2. The system of claim 1, further comprising: a first resilient member configured to urge said valve toward said first position. 3. The system of claim 1, wherein: said first piezoelectric device is configured to cause said valve to move toward said second position when said first piezoelectric device is activated. 4. The system of claim 1, wherein: said second piezoelectric device is configured to increase a pressure of said fuel within said pressure chamber during each actuation of said second piezoelectric device. 5. The system of claim 1, wherein: said fuel injection system is a fuel injector which contains said first and second piezoelectric devices within a common structure. 6. The system of claim 1, wherein: said first piezoelectric device comprises a first piezoceramic element; said first piezoceramic element comprises a first lead zirconate titanate component; said second piezoelectric device comprises a second piezoceramic element; and said second piezoceramic element comprises a second lead zirconate titanate component. 7. The system of claim 1, further comprising: a return piezoelectric device disposed in force transmitting association with said valve to selectively move said valve along said path, said return piezoelectric device being configured to provide a force in a direction which is opposite to the direction of force provided by said first piezoelectric device to selectively move said valve along said path. 8. The system of claim 7, wherein: said first piezoelectric device is configured to move said valve toward said second position and said return piezoelectric device is configured to move said valve toward said first position. 9. A fuel injection system, comprising: a piezoelectric driven pressurizing chamber; an outlet port disposed in fluid communication with said piezoelectric driven pressurizing chamber; and a piezoelectric actuated valve which is movable from a first position in which said piezoelectric actuated valve closes said outlet port and a second position in which said piezoelectric actuated valve opens said outlet port, wherein the piezoceramic driven pressurizing chamber includes a piezoelectric device which is a transducer exerting a force directly on the fuel within the piezoceramic driven pressurizing chamber to create pressurized fuel. 10. The system of claim 9, wherein: said piezoelectric actuated valve is movable along a path between said first position and said second position. 11. The system of claim 10, wherein: a first piezoceramic device is disposed in force transmitting association with said piezoelectric actuated valve to selectively move said valve along said path; said piezoelectric device a second piezoceramic device is disposed in pressure changing association with said piezoelectric driven pressurizing chamber; and whereby movement of said second piezoceramic device changes the pressure of a fuel within said piezoelectric driven pressurizing chamber by exerting a force on said fuel within said pressurizing chamber and movement of said piezoelectric actuated valve under the influence of said first piezoceramic device causes said fuel, which is pressurized within said piezoelectric driven pressurizing chamber, to flow from said piezoelectric driven pressurizing chamber and through said outlet port. 12. The system of claim 11, further comprising: a first resilient member configured to urge said piezoelectric actuated valve toward said first position, said first piezoceramic device being configured to cause said piezoelectric actuated valve to move toward said second position when said first piezoceramic device is activated. 13. The system of claim 12, wherein: said second piezoceramic device is configured to sequentially increase a pressure of said fuel within said piezoelectric driven pressurizing chamber during each of a plurality of actuations of said second piezoceramic device. 14. A method for injecting fuel for an internal combustion engine, comprising the steps of: providing a first piezoelectric device associated in force transmitting relation with a valve; providing a second piezoelectric device associated in pressure affecting relation with a pressure chamber, said pressure chamber having an outlet port; changing the pressure of a fluid within said pressure chamber by actuating said second piezoelectric device and thereby exerting a force on said fluid to change said pressure on said fluid; and moving said valve from a first position, which blocks said outlet port, toward a second position, which does not block said outlet port, by actuating said first piezoelectric device, whereby pressurized fluid flows through said outlet port from said pressure chamber when said valve moves away from said first position wherein said second piezoelectric device is a transducer exerting a force directly on the fuel within the pressurization chamber to create the pressurized fuel. 15. The method of claim 14, further comprising: actuating said second piezoelectric device when said valve is in said second position. 16. The method of claim 15, wherein: said fluid is pressurized and caused to flow through said outlet port while said valve is in said second position. 17. The method of claim 14, wherein: said pressure increasing step is performed while said valve is in said first position. 18. The method of claim 17, wherein: said pressure increasing step is performed, while said valve is in said first position, by actuating said second piezoelectric device a plurality of times. 19. The method of claim 14, wherein: said fluid is drawn into said pressure chamber in response to actuation of said second piezoelectric device. 20. The method of claim 14, wherein: said fluid is a liquid fuel. 21. The method of claim 14, wherein: said pressure increasing step is performed, while said valve is in said second position, by actuating said second piezoelectric device a plurality of times. 22. The method of claim 14, wherein: said first and second piezoelectric devices are both piezoceramic devices.