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. There is also described a method of determining permissible amounts of tool offset to ensure smooth cutting of the workpiece.

A method of manufacturing a rotary abrasive machining tool, the rotary abrasive machining tool including a hub and a plurality of abrasive segments mounted to the hub, the method including the steps of: mounting each abrasive segment on the hub; machining an abrading edge on each abrasive segment while the abrasive segment is mounted on the hub.

A method of manufacturing a rotary abrasive machining tool, the rotary abrasive machining tool including a hub and a plurality of abrasive segments mounted to the hub, the method including the steps of: mounting each abrasive segment on the hub; machining an abrading edge on each abrasive segment while the abrasive segment is mounted on the hub.

There is described a method, apparatus and shaping tool for shaping a workpiece. The tool comprises a flexible support surface on which are mounted a number of rigid pellets (84) carrying abrasive material. The tool is driven, in contact with the workpiece surface (S), to perform a ductile grinding operation which results in a finished surface of reduced roughness as compared to conventional grinding operations, while achieving significantly higher material removal rates than comparable ultra-precision grinding techniques. A procedure for preparing the tool for operation by conditioning the tool against a conditioning surface is also described. An exemplary application for the method and apparatus is in the preparation of moulds for moulding curved glass components for use in display screens, in which process a silicon carbide mould cavity surface is shaped using the method to produce a mould cavity surface with a smooth surface finish.

There is described a method, apparatus and shaping tool for shaping a workpiece. The tool comprises a flexible support surface on which are mounted a number of rigid pellets (84) carrying abrasive material. The tool is driven, in contact with the workpiece surface (S), to perform a ductile grinding operation which results in a finished surface of reduced roughness as compared to conventional grinding operations, while achieving significantly higher material removal rates than comparable ultra-precision grinding techniques. A procedure for preparing the tool for operation by conditioning the tool against a conditioning surface is also described. An exemplary application for the method and apparatus is in the preparation of moulds for moulding curved glass components for use in display screens, in which process a silicon carbide mould cavity surface is shaped using the method to produce a mould cavity surface with a smooth surface finish.

A method which is executed in a grinding machine comprising a) rotationally driving a cup grinding wheel around an axis of rotation of a tool spindle at a first speed, b) rotationally driving a dressing tool around an axis of rotation of a dressing spindle at a second speed, c) carrying out a dressing method using the dressing tool, wherein a predetermined, fixed speed ratio is specified between the first speed and the second speed, and after steps (a), (b), and (c): i. eccentrically rotationally driving the cup grinding wheel around the axis of rotation of the tool spindle at a first machining speed using the eccentric drive, ii. carrying out a grinding method, wherein the bevel gear workpiece is machined by grinding using the cup grinding wheel.

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. There is also described a method of determining permissible amounts of tool offset to ensure smooth cutting of the workpiece.

The method of the present invention comprises the steps of: previously obtaining correlation data between surface properties of the polishing pad dressed under a plurality of stages of dressing conditions and polishing effects of the work polished by the polishing pad dressed under the dressing conditions; determining an assumed dressing condition capable of achieving an object polishing effect from the correlation data; dressing the polishing pad under the assumed dressing condition determined; polishing the work; cleaning the polishing pad which has been used for polishing the work; and measuring a surface property of the cleaned polishing pad.

The method of the present invention comprises the steps of: previously obtaining correlation data between surface properties of the polishing pad dressed under a plurality of stages of dressing conditions and polishing effects of the work polished by the polishing pad dressed under the dressing conditions; determining an assumed dressing condition capable of achieving an object polishing effect from the correlation data; dressing the polishing pad under the assumed dressing condition determined; polishing the work; cleaning the polishing pad which has been used for polishing the work; and measuring a surface property of the cleaned polishing pad.

Method for the grinding of a gear wheel workpiece using a dressable worm grinding wheel, wherein the worm grinding wheel is rotationally driven about a tool axis of rotation and the gear wheel workpiece is rotationally driven about a workpiece axis of rotation, and relative movements are executed between the worm grinding wheel and gear wheel workpiece, and wherein after the execution of a dressing procedure of the worm grinding wheel, which is carried out by means of a rotationally-drivable dressing unit, the following steps are carried out: executing a relative shift movement between the worm grinding wheel and gear wheel workpiece parallel to the tool axis of rotation, executing an axially-parallel relative movement between the worm grinding wheel and gear wheel workpiece in parallel or diagonally to the workpiece axis of rotation,
wherein a ratio between the shift movement and axially-parallel relative movement is specified, which is variable.