A polishing apparatus has a polishing pad, a top ring for holding a semiconductor wafer, and a vertical movement mechanism operable to move the top ring in a vertical direction. The polishing apparatus also has a distance measuring sensor operable to detect a position of the top ring when a lower surface of the top ring is brought into contact with the polishing pad, and a controller operable to calculate an optimal position of the top ring to polish the semiconductor wafer based on the position detected by the distance measuring sensor. The vertical movement mechanism includes a ball screw mechanism operable to move the top ring to the optimal position.

A grinding robot for grinding an electrically conducting workpiece. The grinding robot includes a grinding wheel, an actuation device for actuating grinding wheel, and a control system. The grinding wheel including an undulated tool receptacle which defines an axis of rotation about which the grinding wheel can rotate during grinding, and a head which is rotationally symmetrical with respect to the axis of rotation, and which contains abrasive material and has a grinding surface which is in contact with workpiece during grinding. The grinding wheel also includes a measuring and transmission unit and at least one conductor strand pair with two conductor strands which are electrically insulated from one another. The conductor strands are embedded in the rotationally symmetrical head and extend from the grinding surface of the head into the interior of the head and are electrically connected with measuring and transmission unit.

An apparatus for checking the diameter of crankpins (15) of a crankshaft in orbital motion about a geometrical axis in a numerical control machine tool includes a V-shaped reference device (10), a measuring device (6) and a support device (4) fixed to the tool holding slide (2) that movably supports the reference device and the measuring device. A control device (50) for controlling automatic displacements of the apparatus towards and away from a checking condition, includes a programmable electric motor (60) and a transmission mechanism (62). The programmable electric motor is programmed to define a start position in which the automatic displacement of the apparatus away from the checking condition can be stopped, for instance a rest position or an intermediate position between the rest position and the checking condition. The programmable electric motor is also programmed to define a displacement speed and a checking method includes steps for controlling the automatic displacements towards the checking condition.

An apparatus for checking the diameter of crankpins (15) of a crankshaft in orbital motion about a geometrical axis in a numerical control machine tool includes a V-shaped reference device (10), a measuring device (6) and a support device (4) fixed to the tool holding slide (2) that movably supports the reference device and the measuring device. A control device (50) for controlling automatic displacements of the apparatus towards and away from a checking condition, includes a programmable electric motor (60) and a transmission mechanism (62). The programmable electric motor is programmed to define a start position in which the automatic displacement of the apparatus away from the checking condition can be stopped, for instance a rest position or an intermediate position between the rest position and the checking condition. The programmable electric motor is also programmed to define a displacement speed and a checking method includes steps for controlling the automatic displacements towards the checking condition.

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 grinding robot for grinding an electrically conducting workpiece. The grinding robot includes a grinding wheel, an actuation device for actuating grinding wheel, and a control system. The grinding wheel including an undulated tool receptacle which defines an axis of rotation about which the grinding wheel can rotate during grinding, and a head which is rotationally symmetrical with respect to the axis of rotation, and which contains abrasive material and has a grinding surface which is in contact with workpiece during grinding. The grinding wheel also includes a measuring and transmission unit and at least one conductor strand pair with two conductor strands which are electrically insulated from one another. The conductor strands are embedded in the rotationally symmetrical head and extend from the grinding surface of the head into the interior of the head and are electrically connected with measuring and transmission unit.

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 grinding device is operated by grinding of a surface of the workpiece with at least one grinding medium while recording actual data of the surface after grinding with at least one data collection device. Actual data recorded during grinding is then compared with target data stored in an electronic memory in an electronic data processing device. Based on the comparison, adjustments are made to at least one grinding parameter if a deviation of the actual data from the target data exceeds a predetermined limit.

A polishing apparatus has a polishing pad, a top ring for holding a semiconductor wafer, and a vertical movement mechanism operable to move the top ring in a vertical direction. The polishing apparatus also has a distance measuring sensor operable to detect a position of the top ring when a lower surface of the top ring is brought into contact with the polishing pad, and a controller operable to calculate an optimal position of the top ring to polish the semiconductor wafer based on the position detected by the distance measuring sensor. The vertical movement mechanism includes a ball screw mechanism operable to move the top ring to the optimal position.

A grinding apparatus including a robot, a grinding tool attached to the robot, a force sensor configured to detect a force exerted on the grinding tool, and a controller connected with the force sensor and configured to control the robot. The controller includes a variation acquiring section configured to acquire the present position of the robot by pressing the grinding tool against a reference surface in such a manner that a pressing force detected by the force sensor is constant, and to acquire a difference between the acquired present position and a reference position of the robot stored in advance, the difference being acquired as a variation of the grinding tool.