Abstract: A laser interferometer is disclosed comprising a housing capable of being substantially repeatably mounted to a wall of an environmental chamber, the housing including a laser source, a reflector attached to an object located within the environmental chamber, and a light passage provided through the wall of the environmental chamber enabling passage of a laser beam from the laser source to the reflector. At least one beam steerer may be provided for adjusting direction of passage of a laser beam through the light passage. Also disclosed is a column laser interferometer.

Abstract: A touch-trigger probe is described having a workpiece-contact sensor (15) in the form of a kinematic seating (10) and workpiece contacting stylus (12). A processor ?P in the form of a reprogammable PIC microcontroller is used to monitor the signal from the sensor (15). When the signal is above a threshold for a continual period of time (CT) then the processor issues a trigger signal. The monitoring of the time period (Ct) may be delayed. This delay (Ci) allows triggering initiated by the shock wave produced initially when workpiece contact occurs.

Abstract: A bearing arrangement for an articulatable support includes bearing assemblies. In one embodiment, the assemblies have a ball and aperture having sliding contact at discrete areas during relative rotation. In another embodiment, the sliding contact may be formed at a ball and a plastics (e.g. P.T.F.E. support). Resilient displacement of the bearing contact along a rotational axis is provided by planar spring supports and a rigid support is provided by supports.

Abstract: A laser system is disclosed comprising a laser source for producing a laser beam along a beam path, means to stabilize the frequency of the laser beam, at least one optical component which produces back-scattered light when in use, and a phase modulator for modulating the phase of the back-scattered light. The optical component may be a plane mirror or an optical fibre. The phase modulator may be an oscillating glass block, optionally driven by a motor. Alternatively, the phase modulator is a glass block cyclically compressed by a piezoelectric element.

Abstract: In order to determine movements of two subjects, two or more signals of different phase are obtained which depend on the movement, and processed by locating constellation status of the signals in at least one co-ordinate axis system, it must have at least six separate segments rotationally displaced. Where there are two or more co-ordinate axis systems, each must have an axis radiating from an origin. The change in the constellation states is monitored using at least two processed data samples obtained by sampling the signals at a suitable clock rate. It is possible to derive a prediction of values of the signal and filter the signals in dependence on the prediction. The second co-ordinate axis system may be rotatable relative to the first co-ordinate axis system enabling the provision of a movable region of uncertainty.

Abstract: A storage port (20) for separating a magnetically coupled task module (18) from a modular probe (16) mounted on a machine comprises a housing (22) and arm (24) receivable by the task module (18). A mechanism is provided for separating the task module from the probe body using a mechanical advantage, such that physical movement of the machine actuates the mechanism thereby separating the task module (18) from the modular probe (16). The arm (24) may be rotatable about a pivot (26) such that on moving the probe upwards, the task module (18) is also pulled upwards, causing the arm (24) and hence the task module (18) to rotate about the pivot (26) and thus breaking contact between the task module (18) and the probe (16) with a tilting action. Damping means (38, 48, 60, 62) are provided to ensure smooth and controlled movement of the arm (24).

Abstract: The invention relates to the transmission of power and/or data from/to a stationary part of a machine tool 200 to/from an accessory 100 mounted in the spindle 210 of the machine tool 200. A first electrical link or interface 1a,1b,1c,1d provides electrical communication between the stationary part 200 and the spindle 210, and a second electrical link or interface 3 is provided electrically connected to the first electrical link at the accessory mounting area 230. The second link 3 is in the form of electrical contacts. The invention extends to an accessory shank 360 for mounting to the spindle 210 of the machine tool, and also to an accessory 100 e.g. in the form of a measurement probe, connected to the said shank 360.

Abstract: The present invention teaches a method and apparatus for making measurement of an object on a machine, such as a machine tool, using an optical measuring apparatus which includes a light source for generating a beam of light which is incident on a detector. A detection signal is generated within the detector each time the beam is interrupted. The duration and/or frequency of the detection signals are evaluated and an output signal is emitted from the detection only if a further detection signal is present within the detector in a specified time interval from the generation of an earlier detection signal.

Abstract: Apparatus which can be used to calibrate, or provide measurement data on, a machine. The apparatus comprises two structures each with three spherical supports spaced in a triangular array thereon. The supports may be balls or sockets. The structures are interconnected by six members and each support has the ends of two members connected to it. The members are passive extensible measuring bars and the structures are respectively connected to fixed and movable parts of a machine so that movement of the machine parts causes relative movement between the structures and varies the lengths of the measuring bars. From measurements of the lengths of the measuring bars the actual movement of the machine part can be determined. Calibration of the spherical supports is carried out using a measuring bar which is pre-calibrated in a Zerodur jig.

Abstract: Apparatus for releasably connecting together two members (18, 20) comprises two members (18, 20), each provided with co-operating elements (22a, 24A) to define the location of one member with respect to the other member. A damper (30) is provided on at least one of the members to reduce the impact when the two members are joined together. The two members may comprise two modules of a modular surface sensing probe. The damper may include guide means to assist in guiding the members together.

Abstract: An adjustable device is disclosed comprising two relatively re-orientatable members each having a lockable universal joint; and a connecting member for connecting the two relatively re-orientatable members whereby when the two relatively re-orientatable members are connected the two joints are in mechanical communication via the connecting member. The two lockable joints may be locked and unlocked using an actuator, a lever, which may act on compression means in order to render the lockable joints either mobile or locked. The compression means may cause a change in cross-sectional area of the tube over at least a part of its length. At least one of the lockable universal joints may provide for linear movement between the two relatively re-orientatable members. Also disclosed is an apparatus for the simulation of the orientation of a sample with respect to a cutting tool or scanning probe and method for aligning the adjustable device.

Abstract: A method of calibrating a probe mounted on a machine in which the probe has a probe calibration matrix which relates the probe outputs in three orthogonal axes to the machine's X, Y and Z coordinate system. A datum ball mounted on the machine is bi-directionally scanned by the probe in one or more planes. For each plane, the mean direction of two approximate probe vectors in the plane is rotated about an axis orthogonal to that plane until the apparent material condition from the scan in each direction is the same. This process may be iterative. The mean values of the directions of the probe vectors for each plane are rotated, thus forming a corrected probe calibration matrix. The datum ball is preferably bi-directionally scanned in three orthogonal planes.

Abstract: A probe 8 comprises a housing 10 and a member 20 movable with respect to the housing onto which a stylus 12 may be mounted such that movement of the stylus results in movement of the member and a primary transducer 50, 52 for measuring movement of the member relative to the housing. The member may be located in a precisely defined rest position 22, 24 with respect to the housing, putting the probe in a mechanical datum position. For a combined transducer probe, this enables the primary transducer 52, 54 to be locked whilst enabling use of a secondary transducer 70. The primary transducer outputs can be datumed whilst in this mechanical datum position. Drive 40, 50, 60 or bias 26 means in one axis secure the member in its rest position in all axes.

Abstract: An electron microscope 10 is adapted to enable spectroscopic analysis of a sample 16. A parabolic mirror 18 has a central aperture 20 through which the electron beam can pass. The mirror 18 focuses laser illumination from a transverse optical path 24 onto the sample, and collects Raman and/or other scattered light, passing it back to an optical system 30. The mirror 18 is retractable (within the vacuum of the electron microscope) by a sliding arm assembly 22.

Abstract: A measuring system for calibrating a machine in which a base (10) is attachable to a surface of the machine and a housing (20) is mountable on the base, wherein at least one surface of the base and at least one surface of the housing are each provided with a complementary part of a mounting device, such that when the two parts of the mounting device are connected together, the housing may be aligned in any of a plurality of predetermined directions. The base includes a lifting mechanism (64) which when lowered allows the complementary parts of the mounting device (93, 95) of the housing (20) and the base (10) to be in contact and when raised causes them to at least partly break contact with one another. The level of the base (10) may be adjusted using a system of balls and tapered rollers.

Abstract: The present invention teaches a method and apparatus for making measurement of an object on a machine, such as a machine tool, using an optical measuring apparatus which includes a light source for generating a beam of light which is incident on a detector. A detection signal is generated within the detector each time the beam is interrupted. The duration and/or frequency of the detection signals are evaluated and an output signal is emitted from the detection only if a further detection signal is present within the detector in a specified time interval from the generation of an earlier detection signal.

Abstract: Accelerations of a probe or probe head due to vibrations of a machine during a measuring operation are measured using accelerometers placed in the probe or probe head. The acceleration signals are double integrated to determine the corresponding displacements of the probe or probe head and these are added to the readings of displacement of the machine taken from the machine scales using a data fusion algorithm to correct the scale readings for the vibration of the probe. Both linear and angular accelerations of the probe can be corrected in this way.

Abstract: An optical apparatus e.g. an interferometric displacement determination device: spectroscopic analysis apparatus; polarisation measurement apparatus; or a heterodyne frequency measurement device has a linear HeNe gas laser having an Ne content of an Ne20 isotope and an Ne22 isotope in substantially equal proportions, the apparatus in use having optical feedback toward the laser causing, 0.1% or more of the light output of the laser to be returned toward the laser (1). Use of this type of laser provides good polarisation stability even though excessive backreflection may occur, and hence the laser's frequency can be readily controlled.

Abstract: A probe for position determining apparatus such as a machine tool transmits optical measurement signals to a receiver module. The probe is battery powered and the battery powers light emitting diodes which transmit the optical measurement signals. The optical measurement signals comprise serially transmitted codewords which are generated by a universal synchronous/asynchronous receiver transmitter (USART). The output of the USART is combined with a pulse width modulator which has an output having the same form as the output of the USART but with reduced duration of each pulse, thus enhancing the life of the battery powering the light emitting diodes. The pulse width modulator may also be used to set the timing of the USART.

Abstract: A bearing arrangement for an articulatable support (6) comprises bearing assemblies (20/28, 22/29, 24/30 and 26/32). In one embodiment the assemblies comprise a ball (20, 22, 24, 26) and aperture (40 FIG. 2) having sliding contact at discrete areas (36) during relative rotation. In another embodiment the sliding contact may be formed at a ball (20,22,24,26) and a plastics e.g. P.T.F.E. support (84, 85 FIGS. 10 and 11). Resilient displacement of the bearing contact along a rotational axis (A and B) is provided by planar spring supports (28, 32) and rigid support is provided by supports (29 and 30).