Abstract: The present invention relates to an encoder readhead. The readhead includes a housing having an opening for capturing an encoder scale including an elongate rod having a substantially circular cross-section, the opening defining an axial direction along which a captured encoder scale can slide back and forth. A scale reader, which may include an array of Hall sensors, is provided for reading a portion of an encoder scale located in the opening. The housing includes an access portion that allows the encoder scale to be inserted into, and/or removed from, the opening by a relative movement between the housing and the encoder scale in a direction other than the axial direction.

Abstract: A method and apparatus is disclosed for producing precision marks for a metrological scale in the form of a stainless steel ribbon. A laser is used to produce ultra-short pulses which have a fluence at the ribbon such that ablation takes place. The laser light can be scanned via scanner and the pitch of the marks can be controlled. The ablative technique causes little thermal input and improves the accuracy of the scale.

Abstract: An object detector apparatus. The object detector apparatus comprises a receiver which is configured to receive a signal from an object having a repetitive motion, in which the signal repeats at a frequency that is dependent on the frequency of the repetitive motion of the object. The object detector apparatus further comprises an analyzer which is configured to sample a signal received by the receiver according to a first set of sampling parameters into a first sampled data set, and to produce an output based on a comparison of the first sampled data set with at least one previously sampled data set. The analyzer is also operable to sample a signal received by the receiver using a second set of sampling parameters which differs to the first set of sampling parameters into a second sampled data set, and to produce an output based on a comparison of the second sampled data set with at least one previously sampled data set.

Abstract: A tool setting or tool analysis device for a machine tool comprises a light source for producing a light beam. A light receiver receives the light beam and produces a signal indicative of the amount of light received. This is analyzed by a main analysis circuit to generate a trigger signal to a machine controller when the beam is at least partially occluded. To provide fail-safe operation should the main circuit not recognize the tool, a back-up trigger signal is produced after a delay by a delay circuit. In one preferred form, the back-up trigger signal may oscillate, providing repeated edges which can ensure fail-safe operation even if the machine controller suffers from a blind window and therefore misses the initial trigger signal.

Abstract: A method of using a temperature sensor to determine the temperature of an object is described. The method comprises bringing the temperature sensor into thermal contact with the object to be measured. The temperature sensor is then used to acquire a plurality of temperature readings, the plurality of temperature readings being acquired prior to the temperature sensor reaching thermal equilibrium with the object. At least some of the plurality of temperature readings are then used to determine a pseudo-stable temperature at which the rate of change of temperature readings with time is less than a predetermined rate. The actual temperature of the object may then be predicted from the pseudo-stable temperature.

Abstract: This invention relates to an indexer for providing rotation of a part from a first index position to a second index position. The indexer comprises an indexer frame and a part for rotation. The indexer frame has at least one index feature, and the part has at least one index feature, wherein the at least one index feature on the indexer frame is co-operable with the at least one index feature on the part so as to provide two or more index positions of the part with respect to the indexer frame. In use the part locates with the indexer frame so as to form an axis about which the part is able to rotate relative to the indexer frame, the axis being kinematically located.

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: This invention relates to a method of operating an absolute encoder apparatus comprising a scale having features defining absolute position information in at least one measuring dimension, and a readhead configured to read the features. The method comprises: obtaining at least one representation of at least some of the features defining absolute position information; analyzing the at least one representation to determine at least one parameter indicative of the quality of the representation; and providing an output indicative of the relative setup of the scale and readhead based at least in part on the at least one parameter.

Abstract: A wireless device is described that comprises a spread spectrum radio-frequency (RF) communications portion, such as a Bluetooth module, and an ancillary RF receiver portion. The spread spectrum RF communications portion is activated on receipt of a characteristic RF signal by the ancillary RF receiver portion. The ancillary RF receiver portion may consume substantially less power than the spread spectrum RF communications portion thereby allowing a low power standby mode to be implemented. The wireless device may be a measurement probe, such as a temperature probe, for use with machine tools and the like. An interface for transmitting the characteristic RF signal is also described.

Abstract: A method of forming an optical device comprises applying a laser beam to a target area of the surface so as to selectively heat material of the surface thereby to provide transfer of material due to a surface tension gradient, wherein the surface is such that, when liquid, parts of the surface at higher temperatures have a higher surface tension than adjacent parts of the surface at lower temperatures.

Abstract: Apparatus for a co-ordinate positioning machine is described that comprises an articulating probe head for supporting a measurement probe. The articulating probe head comprises at least one electric motor. Heating means are provided for generating heat in the articulating probe head. The heating means may be the motors or discrete heating elements. Temperature sensing means, such as one or more temperature sensors, is also provided for determining the temperature at the articulating probe head. The apparatus allows the temperature of the articulating probe head to be controlled.

Abstract: A method for orienting a surface sensing device (SSD) uses an apparatus having a support attachable to a moveable arm of a machine, such as a coordinate measuring apparatus. The support includes a first member rotatable about a first axis of rotation and a SSD for sensing the surface of a workpiece; the SSD is releasably connectable to the first member for rotation therewith. The method includes the steps of disconnecting a SSD from a support, the SSD being connected to the support in a first orientation; rotating one of the SSD and the support relative to the other of the SSD and the support and reconnecting the SSD and the support into a second orientation. An apparatus for orienting a surface sensing device is further described.

Abstract: A measurement probe, such as a touch trigger measurement probe, is described that comprises a measurement portion for measuring an object and a data transfer portion for receiving data from and/or transmitting data to an associated unit. The measurement device also comprises an authentication module for verifying the authenticity of the associated unit. The authentication module may include a processor for running a one-way hash algorithm. Authenticity may be established using a challenge and response authentication process.

Abstract: Measurement apparatus is described that comprises a measurement portion for acquiring object measurements and an output portion for outputting measurement data relating to the acquired object measurements. A deactivation portion is provided for inhibiting normal operation of the measurement apparatus such that output of the measurement data is prevented. The deactivation portion, in use, reads apparatus usage information from an apparatus usage module and inhibits normal operation of the measurement apparatus if said apparatus usage information fails to meet one or more predetermined criteria. The apparatus usage module may be provided as an integral part of the measurement apparatus or as a separate activation button. The measurement apparatus may comprise a measurement probe such as a touch trigger measurement probe.

Abstract: A method and apparatus is disclosed for producing precision marks (28) for a metrological scale in the form of a stainless steel ribbon (10). A laser (21) is used to produce ultra-short pulses, which have a fluence at the ribbon such that ablation takes place. The laser light can be scanned via scanner (25) and the pitch of the marks (28) can be controlled. The ablative technique causes little thermal input and improves the accuracy of the scale.

Abstract: A measurement probe, such as a touch trigger measurement probe, is described that comprises a measurement portion for measuring an object and a data transfer portion for receiving data from and/or transmitting data to an associated unit. The measurement device also comprises an authentication module for verifying the authenticity of the associated unit. The authentication module may include a processor for running a one-way hash algorithm. Authenticity may be established using a challenge and response authentication process.

Abstract: Methods are described for calibrating a turning machine having a first rotatable portion or chuck for holding a workpiece. The first rotatable portion has a first feature associated therewith. The method comprises the steps of using a measurement probe to determine the position of the first feature, rotating the first rotatable portion through an angle, and using said measurement probe to determine the new position of the first feature. The extension of the technique to swivel head mill-turn machines is also described.

Abstract: A Raman spectroscopy system has a filter arrangement comprising two filters (16, 26A) in series, to reject light of the illuminating wavenumber from the scattered light of interest. The filters are tilted and have different characteristics for light of first and second different polarisation states. To counter this, the filters are arranged so that their respective effects on the respective polarisation states at least partially cancel each other out. This may for example be done by arranging their tilt axes (32, 34) orthogonally to each other.

Abstract: Metrology apparatus is described that includes a first structure rotatably connected to a second structure by a bearing arrangement. The bearing arrangement includes at least a first friction bearing including parts in sliding contact during rotation of the first structure relative to the second structure. The apparatus includes at least one magnet that relieves the load on the first friction bearing. Multiple magnets, provided in an attracting or repelling arrangement, may be used. The metrology apparatus may include an articulating probe head for a coordinate positioning apparatus.

Abstract: Measurement apparatus is described that comprises a measurement portion for acquiring object measurements and an output portion for outputting measurement data relating to the acquired object measurements. A deactivation portion is provided for inhibiting normal operation of the measurement apparatus such that output of the measurement data is prevented. The deactivation portion, in use, reads apparatus usage information from an apparatus usage module and inhibits normal operation of the measurement apparatus if said apparatus usage information fails to meet one or more predetermined criteria. The apparatus usage module may be provided as an integral part of the measurement apparatus or as a separate activation button. The measurement apparatus may comprise a measurement probe such as a touch trigger measurement probe.