Abstract: A surface finish stylus and associated methods for a multi-directional scanning probe the stylus having an elongate stylus shaft having a longitudinal axis and one or more contact elements protruding from the elongate shaft for contacting a surface to be measured. The one or more contact elements are configured to enable measurement of surface finish during motion of the stylus shaft relative to a surface along a measurement direction that is non-parallel to the longitudinal axis. The multi-directional scanning probe may be carried by a coordinate measuring machine or machine tool.

Abstract: A non-Cartesian coordinate positioning machine that includes an extendable leg assembly for positioning a component such as a measurement probe within a working volume of the machine. The extendable leg assembly includes a first member and a second member which move relative to one another when the extendable leg assembly changes length. The first member including an axial arrangement of magnets forming part of a linear motor for extending and retracting the extendable leg assembly, and at least one resilient member for absorbing at least some of any axial thermal expansion or contraction of the magnets in use.

Abstract: A method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by, repeatedly, depositing a layer of powder on a powder bed and scanning a plurality of laser beams over the deposited powder to selectively solidify the powder layers, wherein a gas flow is passed over the powder bed in a gas flow direction. The method including selecting a scanning sequence for the plurality of laser beams to include the simultaneous exposure of an upstream point together with a downstream point located downstream of a flow of debris carried from the upstream point by the gas flow, the downstream and upstream points selected for simultaneous exposure based upon the downstream point being within a maximum separation distance from the upstream point.

Abstract: An encoder apparatus comprising a scale and a readhead assembly comprising a scale signal receiver. The scale and the scale signal receiver are located within a protective housing which is configured to protect them from contamination located outside the protective housing and comprises a seal through which the scale signal receiver can be connected to a part outside the protective housing. The arrangement of the scale signal receiver inside the protective housing is independent of the scale and protective housing.

Abstract: A surface finish stylus is described that includes an elongate stylus shaft and a contact element protruding from the elongate shaft for contacting a surface to be measured. The contact element is deformable and the stylus shaft includes a clamp for retaining the contact element, the contact element being deformed by the clamp. The contact element may comprise a metal, such as chromium steel or nitinol. The contact element includes one or more regions of weakness to cause a required deformation when retained by the clamp. The surface finish stylus may be used with a surface finish measurement probe or the like.

Abstract: A calibration device for a machine tool is described that includes a base attachable to a machine tool and a calibration artefact, such as a sphere of known radius. A deflection mechanism attaches the calibration artefact to the base and allows movement of the calibration artefact relative to the base when an external force is applied to the calibration artefact. The deflection mechanism also maintains the calibration artefact in a defined rest position relative to the base in the absence of an applied external force. A sensor is provided for sensing the extent of movement of the calibration artefact relative to the base. A method of using the device with a reference tool to accurately determine a position of a calibration artefact is also described.

Abstract: A non-Cartesian coordinate positioning machine is provided that comprises an extendable leg assembly for positioning a component such as a measurement probe within a working volume of the machine, and a constraint member associated with the extendable leg assembly for providing a predetermined part of the extendable leg assembly with substantially a same orientation relative to gravity for a same position of the component within the working volume. In a preferred embodiment, the orientation relative to gravity is maintained substantially constant, so that a plane defined by the predetermined part is substantially aligned with gravity, as the component is moved around the working volume.

Abstract: An apparatus and methods for generating geometric data for use in an additive manufacturing process. The apparatus includes a processing unit. The processing unit may be arranged for receiving data defining surface geometry of a plurality of objects to be built together in an additive manufacturing process, providing a user interface that allows a user to define a location of each object within a common build volume and carrying out a slicing operation on at least one of the objects located in the common build volume independently from another one of objects located in the common build volume. The slicing operation determines sections of the at least one object to be built in the additive manufacturing process. In one embodiment, the objects are defined in a hierarchical data structure. Supports for supporting the objects during the build may be defined with reference to a 2-dimensional support cross-section.

Abstract: A transmission Raman spectroscopy apparatus has a light source for generating a light profile on a sample, a photodetector having at least one photodetector element, collection optics arranged to collect Raman scattered light transmitted through the sample and direct the Raman light onto the at least one photodetector element and a support for supporting the sample. The support and light source are arranged such that the light profile can be moved relative to the sample in order that the at least one photodetector element receives Raman scattered light generated for different locations of the light profile on the sample.

Abstract: A catheter assembly for insertion into the brain. The assembly comprises a first length of tubing made of a first material. A second material surrounds the first length of tubing, the second material being more flexible than the first material and having a hardness of less than 50 Rockwell E. The second material provides damping to the first length of tubing.

Abstract: Apparatus for delivering therapeutic agents to the central nervous system of a subject is described. The apparatus includes at least one intracranial catheter and a percutaneous access device. The percutaneous access device includes a body having at least one extracorporeal surface and at least one subcutaneous surface, the body defining at least one port for connection to an implanted intracranial catheter. The port is accessible from the extracorporeal surface of the device, but is provided with a seal such as a rubber bung between the lumen of the port and the extracorporeal surface. The percutaneous access device may have more than two ports and/or a flange. A method of implanting the percutaneous access device is also described.

Abstract: This invention concerns a laser solidification apparatus for building objects by layerwise solidification of powder material. The apparatus including a build chamber containing a build platform, a device for depositing layers of powder material on to the build platform, an optical unit for directing a laser beam to selectively solidify areas of each powder layer and a spectrometer for detecting characteristic radiation emitted by plasma formed during solidification of the powder by the laser beam. The invention also relates to a spectrometer for detecting characteristic radiation generated by interaction of the metal with the or a further laser beam. The spectra recorded using the spectrometer may be used for feedback control during the solidification process.

Abstract: An additive manufacturing apparatus and corresponding method for building an object by layerwise consolidation of material, where the apparatus includes a build enclosure containing a build support for supporting the object during the build, a material source for providing material to selected locations for consolidation, a radiation device for generating and directing radiation to consolidate the material at the selected locations and an acoustic sensing system. The acoustic sensing system may be arranged to detect acoustic signals generated in the build enclosure by consolidation of the material with the radiation. The acoustic sensing system may be a passive acoustic sensing system arranged to detect acoustic signals generated in the build enclosure that are indicative of at least one condition of the building process and/or the object.

Abstract: A non-Cartesian coordinate positioning machine that includes an extendable leg assembly for positioning a component such as a measurement probe within a working volume of the machine. The extendable leg assembly includes a first member and a second member which move relative to one another when the extendable leg assembly changes length. The first member including an axial arrangement of magnets forming part of a linear motor for extending and retracting the extendable leg assembly, and at least one resilient member for absorbing at least some of any axial thermal expansion or contraction of the magnets in use.

Abstract: A positioning apparatus comprising first and second relatively moveable members, and a linear motor comprising at least one elongate stator assembly and at least one armature assembly respectively mounted to the first and second moveable members for effecting relative movement of the first and second moveable members, configured so at to permit longitudinal expansion and/or contraction of the at least one elongate stator assembly and/or of the at least one armature assembly relative to its respective member.

Abstract: An encoder apparatus including a scale including a series of features defining at least one scale track and a readhead for reading the scale's features. The readhead includes at least one light source for illuminating the scale and at least one detector. The configuration of the at least one light source is such that there is a structure in the light projected toward the scale. The readhead is configured such that the structure is angled so that it is substantially misaligned with respect to the scale's features so as to reduce measurement error in the signal output by the readhead.

Abstract: A non-Cartesian coordinate positioning machine is provided that comprises an extendable leg assembly for positioning a component such as a measurement probe within a working volume of the machine, and a constraint member associated with the extendable leg assembly for providing a predetermined part of the extendable leg assembly with substantially a same orientation relative to gravity for a same position of the component within the working volume. In a preferred embodiment, the orientation relative to gravity is maintained substantially constant, so that a plane defined by the predetermined part is substantially aligned with gravity, as the component is moved around the working volume.

Abstract: This invention concerns a neurosurgical kit comprising a catheter (1) and a guide tube (2). The catheter (1) comprises a distal section of tubing (11) having a distal end with a port or ports for delivering fluid to a target site within the brain. The distal section of tubing (11) has an outer diameter that is smaller than an internal diameter of the guide tube (2). The catheter (1) and guide tube (2) are arranged such that, when the catheter (1) is inserted into the guide tube (2) to locate the port or ports at the target site, a recess (14) is provided in a distal end section of the guide tube (2) between the guide tube (2) and the distal section of tubing (11) of the catheter (1).

Abstract: A method for assessing the profile of a tool using a non-contact tool setting apparatus that includes a transmitter for emitting a light beam and a receiver for receiving the beam. The receiver generates a beam intensity signal describing the intensity of received light. The setting apparatus is mounted to a coordinate positioning apparatus that allows the tool to be moved relative to the setting apparatus. The method includes using the coordinate positioning apparatus to move the tool relative to the setting apparatus along a tool inspection path, the tool inspection path being selected so that the light beam is traced substantially along a periphery of the tool to be inspected. Beam intensity data is collected describing the beam intensity signal that is generated by the receiver as the tool inspection path is traversed and analysis of the collected beam intensity data is used to assess the tool profile.

Abstract: A coordinate positioning apparatus having a load bearing structure. The load bearing structure has at least one elongate corner piece providing at least two bearing surfaces, one on each side of the corner, for a carriage moveable along the load bearing structure, and at least one piece of sheet material which extends along the at least one elongate corner piece and provides at least one load bearing facet.