Abstract: A servo valve comprises a first spool extending along a first spool axis, a second spool extending along a second spool axis, a first piezoelectric actuator, and a second piezoelectric actuator. The first piezoelectric actuator is operatively connected to the first spool for translating the first spool in response to a voltage applied thereto. The second piezoelectric actuator is operatively connected to the second spool for translating the second spool in response to a voltage applied thereto.

Abstract: A servo valve comprises a first spool extending along a first spool axis, a second spool extending along a second spool axis, a first piezoelectric actuator, and a second piezoelectric actuator. The first piezoelectric actuator is operatively connected to the first spool for translating the first spool in response to a voltage applied thereto. The second piezoelectric actuator is operatively connected to the second spool for translating the second spool in response to a voltage applied thereto.

Abstract: A servo valve comprising: a fluid transfer valve assembly comprising a supply port and a control port (PA, PB); a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive means configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow; wherein the drive means comprises a piezo actuator element mounted within and axially movable with the valve spool, the piezo actuator configured to extend axially in response to the control signal to cause corresponding axially movement of the spool

Abstract: A hydraulic servo valve comprising a pair of opposing receiving ports, a piston disposed between the pair of opposing receiving ports and an actuator in contact with the piston. The actuator is configured to provide axial movement of the piston in response to being actuated. The piston comprises a pair of opposed openings that are in operable fluid communication with a respective one of each of the receiving ports, and the axial movement of the piston is configured to vary the amount of a fluid pressure communicated between a respective one of the openings and receiving ports.

Abstract: A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive assembly configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The drive assembly comprises a steerable jet pipe moveable by an amount determined by the control signal to cause corresponding movement of the valve spool. The jet pipe terminates at one end in a nozzle and at the other end being in fluid flow engagement with and fixedly connected to a fluid supply torsion tube arranged to receive fluid from a fluid source. Movement of the valve spool is caused by fluid flowing from the nozzle to engage with the valve spool.

Abstract: The present disclosure relates to an aircraft comprising a passenger module, and also a method of protecting a passenger on an aircraft. The passenger module is configured to be ejected through a skin of the aircraft in response to an ejection command. The ejection command may be given in response to a fatal condition to the aircraft being detected or manually indicated.