Abstract: An electromagnetic device is disclosed, the electromagnetic device comprising a core support having an exterior surface comprising at least one radial protrusion, a tubular magnetic core positioned around a portion of the length of the core support, the tubular magnetic core having an interior surface, at least one indent located in the interior surface of the tubular magnetic core, wherein the at least one protrusion is located within the at least one indent to prevent relative longitudinal movement between the core support and tubular magnetic core, and a primary coil and at least one secondary coil, each coil positioned around a portion of a length of the tubular magnetic core.

Abstract: A plug for sealing a passage extending about a longitudinal axis (A) comprises a shell having a circumferential wall extending between an end wall and an opening, and an internal cavity extending axially within the shell, and an expander having a head and a shank extending axially from the head, the head retained with the cavity and the shank extending axially through the opening of the cavity, wherein the circumferential wall comprises an inner surface having at least a first region and a second region, the second region proximate the opening and the first region adjacent to the second region and extending therefrom towards the end wall, the inner surface in the first region tapering inwardly relative to the longitudinal axis (A) to provide a first angled ramp, and the inner surface in the second region tapering further inwardly to provide a second angled ramp.

Abstract: A linear variable differential transducer is disclosed comprising a tubular magnetic core formed from a sheet, a primary coil and at least one secondary coil, each coil positioned around a portion of a length of the magnetic core.

Abstract: A new method of forming a torsion spring for use in a servovalve is described. The method comprises individually forming the different components of the torsion spring and then connecting the individual components together using a brazing process. The torsion spring created by this method is also described.

Abstract: A spool for a spool valve having a longitudinal axis (L). The spool comprising: a plurality of lands each having a substantially radially extending metering edge and an axially extending circumferential surface; a plurality of grooves separating each of the plurality of the lands; and a guiding section located axially between at least one land and an adjacent groove. The guiding section comprising a plurality of circumferentially spaced guiding surfaces being substantially flush and contiguous with the circumferential surface of the land, wherein the guiding section allows fluid communication between the groove and the metering edge of the land.

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 jet pipe 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 spool includes a tubular body defining a path for fluid flow, the tubular body closed at each end by a respective end cap having openings via which, in use, fluid enters the interior of the spool. The end caps extend within the tubular body at least to an extent that they overlap the openings, and wherein the end caps are provided with filter means for filtering the fluid from the openings as it enters the spool.

Abstract: A torque limiter assembly is disclosed comprising a housing having at least one first engagement member, an input shaft that is rotatable relative to the housing and having at least one second engagement member; and an electromagnet. The electromagnet 10 is arranged and configured such that when activated it generates a magnetic field that moves the at least one first engagement member relative to the at least one second engagement member, such that the first and second engagement members engage each other and stop or inhibit rotation of the input shaft relative to the housing.

Abstract: A servovalve includes a fluid transfer valve assembly comprising a supply port and a control port and a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal. The servovalve also includes a jet pipe assembly configured to direct fluid to the ends of the spool to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The jet pipe assembly comprises a jet pipe a connector header fluidly connecting the jet pipe to a nozzle. The spool has one or more openings 28 is provided in the spool such that fluid from the supply port flows into the interior of the spool and into the jet pipe.

Abstract: The present disclosure relates to a nozzle assembly for use in a servo valve. The nozzle assembly comprises three nozzle parts and a housing. The second part is coaxial with the first part and surrounds at least a first portion of the first part. The third part is coaxial with the first part, and a first portion of the third nozzle part surrounds a first portion of the second nozzle part, and a second portion of the third part is attached to a second portion of the first part. First and second nozzle parts are made of materials having approximately the same first coefficient of thermal expansion (TE1), and third part and housing are made of materials having approximately the same second coefficient of thermal expansion (TE2). TE1 is different from TE2. The interaction between the portions due to the differences in TE1 and TE2 allow the nozzle assembly to compensate for temperature fluctuations during and operation whilst remaining firmly held in position.

Abstract: There is provided a method of manufacturing a torsion spring, comprising providing a section of sheet metal, and forming the torsion spring from the section of sheet metal.

Abstract: A method of manufacturing a hydraulic plug. A shell with a circumferential wall, a sealed end, an open end and an axially extending cavity within is provided in which the cavity is defined by an internal surface with an inner diameter which narrows towards the open end. A head of an expander is inserted into the cavity, the expander further comprising a stem extending from the cavity for applying a tensile force (T) to the head. A sleeve is provided on a stem side of the head extending into the cavity, an end of the sleeve adjacent the head having an inner diameter which is less than a maximum outer diameter of the head. The sleeve is formed by expanding the sleeve by forcing the head into the end of the sleeve through urging the sleeve and/or expander towards the other in an axial direction.

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 jet pipe assembly configured to direct fluid to the ends of the spool to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow. The jet pipe assembly includes a jet pipe and a connector header fluidly connecting the jet pipe to a nozzle via which fluid is directed to the spool ends. One or more openings is provided in the spool such that fluid from the supply port flows into the interior of the spool and into the jet pipe and to the nozzle via the connector header.

Abstract: A method of manufacturing a hydraulic plug includes providing a shell comprising a circumferential wall, a sealed end, an open end and a cylindrical cavity opening to the open end is provided. The open end of the shell is wider externally than the sealed end. A head of an expander is inserted into the cavity. The head of the expander has a convex contact surface which is rounded in an axial direction (A) of the cavity. A region of the shell adjacent its open end is plastically deformed causing material from the circumferential wall of the shell to be displaced radially inward around the head of the expander to form a constricted opening retaining the expander within the cavity. The deforming reshapes an internal surface of the cavity from a cylindrical to a non-linear shaped ramp leading up to a constricted opening.

Abstract: A system is described for positioning and locking in place a nozzle within a cylindrical bore of a body, and a method for positioning and locking in place a nozzle within a cylindrical bore of a body is also described. The system has a nozzle having a tubular shape extending between a first end and a second end with an outer cylindrical surface and an inner surface, said inner surface comprising a thread. The system also has a locking member provided within said nozzle and comprising an outer circumferential surface having a thread that corresponds to the thread of the inner surface of the nozzle. The system also has means for providing torque to said locking member to screw said locking member into and within said nozzle via said threaded surfaces to thereby create a press-fit between said outer cylindrical surface and an inner surface of said cylindrical bore.