Abstract: An actuator includes an actuator piston movable along an axis, a first stop member rotatable about the axis and configured to limit the movement of the actuator piston in a first direction along the axis, a second stop member movable along the axis and configured to limit the movement of the actuator piston in a second direction along the axis, wherein the first direction is opposite to the second direction. A first screw connection is present between the first stop member and the second stop member such that rotation of the first stop member about the axis causes movement of the second stop member along the axis to vary the amount by which the actuator piston can move along the axis in use.

Abstract: A method for manufacturing a spring is disclosed that comprises: forming the spring from a material; heat treating the spring; performing a first machining step to the ends of the spring; subjecting the spring to a first stress relief heat treatment; performing a second machining step to the ends of the spring; and subjecting the spring to a second stress relief heat treatment step. A spring that is manufactured by this method is also described. This spring may then be used in a pressure relief valve, as well as in other assemblies.

Abstract: A locking device for use in a rotor blade, said locking device comprising: a locking member that is arranged to be movable from an unlocked position to a locking position upon experiencing sufficiently fast rotation; and a selectively engagable retaining device arranged when engaged to retain the locking member in the unlocked position. The locking device will typically default to an unlocked position during normal rotation and will only be locked so as to prevent movement when the retaining device is de-activated. A method of locking an actuator is also disclosed. The locking device has applications in helicopter rotor blades and wind turbine blades amongst others.

Abstract: There is provided a pressure regulating shut-off valve comprising a valve body, at least one piston serving as a regulating piston and/or a shut-off piston, a solenoid valve, and a pressure relief valve; wherein the valve body defines an inlet and an outlet, and comprises at least a portion formed by an additive manufacturing process.

Abstract: A mount for a sensor includes a first mount part for mounting a sensor part and a second mount part for mounting the first mount part. A first adjustment mechanism is provided to adjust the first mount part relative to the second mount part and a second adjustment mechanism is provided to adjust the second mount part relative to a support. At least one of the first adjustment mechanism and the second adjustment mechanism is a vernier adjustment mechanism.

Abstract: A double-walled pipe includes an inner wall, which bounds a flowpath for a first fluid such as air, an outer wall radially spaced from the inner wall so that there is an annular gap between the inner wall and the outer wall; and walls extending in the annular gap between the inner wall and the outer wall, such that flow passages are formed in the annular gap, through which a temperature-controlled fluid can be circulated to control the temperature of the inner wall. The double-walled pipe is formed by an additive manufacturing process. The walls may be helical walls, defining helical flow passages.

Abstract: A pneumatic pressure regulation valve comprising: a valve inlet; a valve outlet; a piston arranged to control gas flow from the inlet to the outlet; a sense line fluidly connecting the inlet to a pressure regulation chamber and with a pressure relief valve connected thereto to limit the pressure in the pressure regulation chamber; wherein the piston is arranged between the pressure regulation chamber and the valve outlet such that the position of the piston is determined by the relative pressures in the regulation chamber and the valve outlet and the position of the piston controls the flow from the valve inlet to the valve outlet; wherein the sense line comprises a flow restriction upstream of the pressure relief valve. The flow restriction addresses instability that can arise from large volumes of connecting tubes or pipes in the sense line.

Abstract: A rotor blade includes an actuator comprising an electric motor having a rotary drive shaft, a bearing for mounting the rotary drive shaft along an axis extending along the length of the rotor blade, and a lubrication system for lubricating the bearing. The lubrication system includes a sump closer to the tip of the blade than the bearing, and a pump for pumping lubricant from the sump to the bearing.

Abstract: A rotary seal comprising: a shaft with a chromium oxide coating provided at a seal contact area; wherein said coating has a hardness of at least 55 Rockwell-C. The coating may have a surface roughness parameter (Ra) of between 0.2 and 0.4 circular. The coating may have a thickness of at least 0.1 mm. The coating layer forms part of a rotary seal with a flexible seal element that is biased into contact with the surface of the coating. The flexible seal element may be biased against the shaft by a spring to increase the pressure of the flexible seal element against the coating. The coating is preferably deposited by a plasma spray process.

Abstract: A rotor blade includes an actuator comprising an electric motor having a rotary drive shaft, a bearing for mounting the rotary drive shaft along an axis extending along the length of the rotor blade, and a lubrication system for lubricating the bearing. The lubrication system includes a sump closer to the tip of the blade than the bearing, and a pump for pumping lubricant from the sump to the bearing.

Abstract: An electromagnetic brake or clutch includes a first face confronting a first face of a rotor disc, the discs being mounted for movement towards and away from the other; and a stator coil energized to urge the first face of the disc away from the first face of the rotor disc. In a first set of rotational positions, magnetic regions of one polarity on the first face of the brake or clutch disc confront magnetic regions of the opposite polarity on the first face of the rotor disc, and, in a second set of rotational positions of the shaft interposed between respective ones of the first set of rotational positions, magnetic regions of one polarity on the first face of the brake or clutch disc confront magnetic regions of the same polarity on the first face of the rotor disc.