Abstract: A powder bed fusion apparatus for building an object, including a processing chamber having a processing chamber aperture, scanner arranged to direct an energy beam to locations in a plane of the aperture and debuilding chamber having a debuilding chamber aperture. The apparatus includes a build chamber including a build sleeve and platform movable therein for supporting powder, the platform including a seal for engaging with the sleeve walls to prevent flow of powder past the platform; and at least one drive mechanism for driving movement of the platform. A translation mechanism moves the chamber between a building position, wherein the sleeve aligns with the processing aperture so an energy beam can be delivered to consolidate powder to build the object, and debuilding position, wherein the sleeve aligns with the debuilding aperture so the object and powder can be inserted into the debuilding chamber through movement of the platform.

Abstract: An apparatus including an inspection apparatus for inspecting an artefact, and a transfer mechanism for moving a pallet on which an artefact is located relative to the inspection apparatus so as to move the pallet to and from an inspection location, and further including at least one pallet lifter which can be actuated between a retracted and an extended configuration, configured such that when a pallet is at the inspection location the at least one pallet lifter can be actuated to its extended configuration so as to engage with and lift the pallet and thereby decouple the pallet from the transfer mechanism.

Abstract: A pallet loader for a positioning apparatus, including at least two pallet bays and at least one intermediate member, arranged such that at least two pallet bays are located on different sides of the intermediate member, such that at least one pallet can be driven i) from one pallet bay to another, and ii) from one pallet bay to a positioning apparatus, in which the apparatus includes cooperating guide features on the underside of the at least one pallet and on one or more of the intermediate member and pallet bays for guiding the pallet along a predetermined path and/or for controlling the rotational orientation of the pallet about a vertical axis, as the pallet moves across the intermediate member/pallet bay.

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.

Abstract: A positioning apparatus, having first and second members relatively moveable in a substantially vertical degree of freedom. At least one energy conduit is mounted to at least one of the first and second members, which imparts a load on at least one of the members it is mounted to that varies dependent on the relative position of the first and second members. A compensatory member is configured to apply a load that varies, dependent on the relative position of the first and second members, inversely to the variation in load applied by the at least one energy conduit, so as to at least partially counteract the variation in load applied by the at least one energy conduit on said at least one of the members.

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: 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: 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.

Abstract: A coordinate positioning apparatus comprising first and second relatively moveable bodies, at least the first body comprising at least one sheet or plate of material arranged to provide a load-bearing structure comprising a plurality of planar load-bearing members and on which at least one member is mounted to the first body via a mount which is coupled to at least three, non-parallel planar load-bearing members of the first body, such that the planes of said at least three non-parallel planar load-bearing members intersect each other at a common point.

Abstract: A positioning apparatus, having first and second members relatively moveable in a substantially vertical degree of freedom. At least one energy conduit is mounted to at least one of the first and second members, which imparts a load on at least one of the members it is mounted to that varies dependent on the relative position of the first and second members. A compensatory member is configured to apply a load that varies, dependent on the relative position of the first and second members, inversely to the variation in load applied by the at least one energy conduit, so as to at least partially counteract the variation in load applied by the at least one energy conduit on said at least one of the members.

Abstract: A positioning apparatus including a quill on which a probe apparatus can be mounted, at least one motor for positioning the quill in a substantially vertical dimension, and a pneumatic counterbalance mechanism for the quill. The positioning apparatus is configured, based on at least one factor relating to the quill, to automatically effect a change in the pneumatic counterbalance mechanism's pressure so as to thereby adapt the counterbalance force on the quill provided by the pneumatic counterbalance mechanism.

Abstract: A coordinate positioning apparatus having first and second relatively moveable bodies, at least the first body having at least one sheet or plate of material arranged to provide a load-bearing structure having a plurality of planar load-bearing members and on which at least one member is mounted to the first body via a mount which is coupled to at least three, non-parallel planar load-bearing members of the first body, such that the planes of the at least three non-parallel planar load-bearing members intersect each other at a common point.

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: 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: 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: A metrology apparatus including a body and a first member rotatable relative to the body about a first axis of rotation, said first axis being defined by first bearing and a first motor for actuating rotation of the first member relative to the body about the first axis of rotation. A surface sensing device is attachable to the first member such that the surface sensing device can move with the first member, relative to the body. The first motor may include a first magnet and at least one metal coil spaced apart along the first axis and mounted such that the first magnet and the at least one metal coil are moveable relative to one another.

Abstract: A head clamp for neurosurgery is described that includes a member for at least partially encircling the head of a subject. The first end and second end of the head clamp include first and second skull attachment portions for attaching the member to the head of a subject. A position setter, such as an indexing mechanism, is also provided that allows the member to be moved or indexed between at least two repeatable relative positions.

Abstract: A head clamp for neurosurgery is described that includes a member for at least partially encircling the head of a subject. The first end and second end of the head clamp include first and second skull attachment portions for attaching the member to the head of a subject. A position setter, such as an indexing mechanism, is also provided that allows the member to be moved or indexed between at least two repeatable relative positions.

Abstract: A method of fabricating a bearing surface for a gas or air bearing is described. The method comprises taking a bulk bearing portion having at least one bearing surface region and providing a coating on the bearing surface region to define at least one gas pocket. The at least one gas pocket has a depth substantially equal to the thickness of the coating. In one example, laser ablation is used to remove part of the coating to form the gas pockets. The coating may be an anodized coating and the bulk bearing portion may be formed from aluminum. An air bearing component formed using the method is also described.

Abstract: A rotary gas bearing is described that comprises a first part rotatable relative to a second part. The first part comprises a support member and a first portion and a second portion attached to the support member. The first portion comprises a first bearing surface and the second portion comprising a second bearing surface. Both the first portion and the second portion are attached to the support member by screw thread connections. The second part may comprise complimentary bearing surfaces. Epoxy may be used to fix the first and/or second portions to the support member. A method of determining the bearing working gap by measuring gas flow through the bearing is also described.