Abstract: A method for enshrouding an actuator for use in a fuel injector, comprising the steps of providing an actuator having a body section, a first end piece and a second end piece; providing a shroud having first and second ends; applying a sealant material to at least one portion of an exterior surface of the end pieces, and/or to at least one part of the shroud; and enshrouding the actuator with the shroud, such that the sealant material provides an intermediate layer between the end pieces and the shroud and forms a fluid-tight seal between them.

Abstract: A clip for securing a sleeve to the body of a piezoelectric actuator in an actuator assembly, the clip taking the form of a band comprising first and second axially spaced ring-like members joined by a plurality of inwardly facing substantially arch shaped sections, the arch shaped sections defining the minimum inner diameter of the band, whereby axial displacement of the ring-like members way from one another causes flexing of the arch shaped sections to increase the minimum inner diameter of the band while axial displacement of the ring-like members towards one another causes flexing of the arch shaped sections to reduce the minimum inner diameter of the band thereby, when in use, to increase a clamping force applied to the sleeve.

Abstract: A method for enshrouding an actuator for use in a fuel injector, comprising the steps of providing an actuator having a body section, a first end piece and a second end piece; providing a shroud having first and second ends; applying a sealant material to at least one portion of an exterior surface of the end pieces, and/or to at least one part of the shroud; and enshrouding the actuator with the shroud, such that the sealant material provides an intermediate layer between the end pieces and the shroud and forms a fluid-tight seal between them.

Abstract: A clip for securing a sleeve to the body of a piezoelectric actuator in an actuator assembly, the clip taking the form of a band comprising first and second axially spaced ring-like members joined by a plurality of inwardly facing substantially arch shaped sections, the arch shaped sections defining the minimum inner diameter of the band, whereby axial displacement of the ring-like members way from one another causes flexing of the arch shaped sections to increase the minimum inner diameter of the band while axial displacement of the ring-like members towards one another causes flexing of the arch shaped sections to reduce the minimum inner diameter of the band thereby, when in use, to increase a clamping force applied to the sleeve.

Abstract: A method of operating an injector having an injector valve needle and a piezoelectric actuator for controlling movement of the injector valve needle, the method comprising reducing the voltage across the actuator at a first rate (RT1) in order to initiate an initial injection, increasing the voltage across the actuator in order to terminate the injection, and once the initial injection has terminated and before a subsequent injection is initiated, reducing the voltage across the actuator at a second rate (RT2; RT3), which is lower than the first rate (RT1), so as to de-energise the actuator but without initiating an injection. The invention ensures the injector spends a significantly reduced period of its life with a high voltage across its actuator.

Abstract: A method of operating an injector having an injector valve needle and a piezoelectric actuator for controlling movement of the injector valve needle, the method comprising reducing the voltage across the actuator at a first rate (RT1) in order to initiate an initial injection, increasing the voltage across the actuator in order to terminate the injection, and once the initial injection has terminated and before a subsequent injection is initiated, reducing the voltage across the actuator at a second rate (RT2; RT3), which is lower than the first rate (RT1), so as to de-energise the actuator but without initiating an injection. The invention ensures the injector spends a significantly reduced period of its life with a high voltage across its actuator.