Abstract: The invention relates to a sub-aperture polishing tool, comprising a support member including an attachment feature for attachment to a sub-aperture polishing machine. At an end of the support member is a polishing head comprising: a base structure attached to or integral with the support member, the base structure being arranged to provide a non-flat surface. The polishing head also comprises an outer shell, at least part of the outer surface of which defines the working surface of the polishing tool, the outer shell being affixed to the base structure so as to enclose a cavity between the outer shell and the non-flat surface. A viscoelastic material filling the cavity, located between the outer shell and the base structure.

Abstract: Methods and apparatus for shaping workpieces are described in which data representing the surface form of the workpiece is analysed to determine characteristics of curvature of the surface, and these characteristics are used to determine the size and form required for a tool to apply shaping treatment to all parts of the workpiece surface. Measurements of the actual workpiece are then compared with data relating to the required workpiece form, to determine the amount and distribution of material to be removed from the workpiece. A tool path for moving the tool over the workpiece to achieve the required shaping operation is then determined, and the tool and tool path data are provided to a shaping machine to carry out the shaping operation. The shaping tool may comprise an elastomeric body covered in a flexible cloth on which rigid pellets containing abrasive material are fixed. The specification discloses methods of manufacturing such tools, and also discloses methods for conditioning the pelleted cloth.

Abstract: Methods and apparatus for shaping workpieces are described in which data representing the surface form of the workpiece is analysed to determine characteristics of curvature of the surface, and these characteristics are used to determine the size and form required for a tool to apply shaping treatment to all parts of the workpiece surface. Measurements of the actual workpiece are then compared with data relating to the required workpiece form, to determine the amount and distribution of material to be removed from the workpiece. A tool path for moving the tool over the workpiece to achieve the required shaping operation is then determined, and the tool and tool path data are provided to a shaping machine to carry out the shaping operation. The shaping tool may comprise an elastomeric body covered in a flexible cloth on which rigid pellets containing abrasive material are fixed. The specification discloses methods of manufacturing such tools, and also discloses methods for conditioning the pelleted cloth.

Abstract: A polishing machine is described in which a surface treatment tool is moved across the surface of a workpiece in accordance with a predefined tool-path, in order to carry out the desired treatment process. The tool-path is non-periodic and preferably pseudo-random. Various techniques are described for generating data representing the tool-path to be followed. A technique is also described for determining optimum control parameters used to control the polishing machine for a given tool-path. The surface treatment may be a shaping technique in which material is removed from the surface, or a technique for adding material to the surface of the workpiece, or a technique for modifying the surface or a region under the surface of the workpiece.

Abstract: A polishing machine is described in which a surface treatment tool is moved across the surface of a workpiece in accordance with a predefined tool-path, in order to carry out the desired treatment process. The tool-path is non-periodic and preferably pseudo-random. Various techniques are described for generating data representing the tool-path to be followed. A technique is also described for determining optimum control parameters used to control the polishing machine for a given tool-path. The surface treatment may be a shaping technique in which material is removed from the surface, or a technique for adding material to the surface of the workpiece, or a technique for modifying the surface or a region under the surface of the workpiece.

Abstract: A polishing machine is described in which a surface treatment tool is moved across the surface of a workpiece in accordance with a predefined tool-path, in order to carry out the desired treatment process. The tool-path is non-periodic and preferably pseudo-random. Various techniques are described for generating data representing the tool-path to be followed. A technique is also described for determining optimum control parameters used to control the polishing machine for a given tool-path. The surface treatment may be a shaping technique in which material is removed from the surface, or a technique for adding material to the surface of the workpiece, or a technique for modifying the surface or a region under the surface of the workpiece.

Abstract: A polishing machine is described in which a surface treatment tool is moved across the surface of a workpiece in accordance with a predefined tool-path, in order to carry out the desired treatment process. The tool-path is non-periodic and preferably pseudo-random. Various techniques are described for generating data representing the tool-path to be followed. A technique is also described for determining optimum control parameters used to control the polishing machine for a given tool-path. The surface treatment may be a shaping technique in which material is removed from the surface, or a technique for adding material to the surface of the workpiece, or a technique for modifying the surface or a region under the surface of the workpiece.