Renishaw Plc

Renishaw Metrology Limited

Peter G Lloyd

David R McMurtry

David Wilson

David Jones

Peter Kenneth Hellier

David Sven Wallace

James L Chase

Gillies D Pitt

Geoff McFarland

Stephen James Trull

Stephen I Gregorig

Andrew Daniel Huber

Disclosed is a method of moving an articulating mechanism () for a measuring device, comprising the steps of: releasing two bodies (a,b) which form the articulating mechanism allowing relative movement thereof; moving one of the bodies with respect to the other until a desired position is reached; and re-constraining the two bodies so they are relatively fixed, perhaps as part of a locking process, characterised in that relative movement prior to re-constraining at the desired position occurs under particular conditions. The particular conditions including moving from the same direction; and stopping, slowing down or maintaining the condition at a position adjacent to the desired position. Also disclosed is a method of positioning an articulating mechanism () for a measuring device which is controlled by a potentiometer and a controller () for a measuring device.

Articulating device

Disclosed is a method of moving an articulating mechanism () for a measuring device, comprising the steps of: releasing two bodies () which form the articulating mechanism allowing relative movement thereof; moving one of the bodies with respect to the other until a desired position is reached; and re-constraining the two bodies so they are relatively fixed, perhaps as part of a locking process, characterised in that relative movement prior to re-constraining at the desired position occurs under particular conditions. The particular conditions including moving from the same direction; and stopping, slowing down or maintaining the condition at a position adjacent to the desired position. Also disclosed is a method of positioning an articulating mechanism () for a measuring device which is controlled by a potentiometer and a controller () for a measuring device.

A measurement probe ( ) is disclosed having strain sensing elements ( ) mounted on spokes ( ) of a strain sensing member ( ). The member ( ) is disposed in parallel and spaced from a diaphragm ( ). Inner portions of the member and diaphragm are connected to a stylus holder ( ) and outer portions of the member and diaphragm are connected to probe body ( ). The probe can be used to produce a signal when contact force on the stylus ( ) is within an adjustable upper and lower limit, and is thereby suited to use with a manually manipulatable coordinate measuring device.

Force sensing probe

A touch trigger probe incorporates piezoelectric sensors , whose outputs are processed by an interface circuit. The interface circuit discriminates between signals generated from the piezoelectric sensors as a result of machine vibration and those generated as a result of a genuine measurement event, by the use of a timing circuit . The timing circuit compares the time intervals (t -t );(t -t ) between attainment of first and second , and second and third output signal levels from the sensor , and upon the basis of this comparison validates (or rejects) measurements made with the probe. Additionally, the interface determines whether measurements made with the probe are taken upon the basis of outputs generated by the sensors due to a shock wave in the stylus of the probe, or as a result of strain in the stylus ; as an alternative, measurements may be made only on the basis of strain.

Touch probe and signal processing circuit therefor

A touch trigger probe incorporates piezoelectric sensors 50, whose outputs are processed by an interface circuit. The interface circuit discriminates between signals generated from the piezoelectric sensors 50 as a result of machine vibration and those generated as a result of a genuine measurement event, by the use of a timing circuit 90. The timing circuit 90 compares the time intervals (t.sub.1 -t.sub.2);(t.sub.2 -t.sub.3) between attainment of first 1.sub.1 and second 1.sub.2, and second 1.sub.2 and third 1.sub.3 output signal levels from the sensor 50, and upon the basis of this comparison validates (or rejects) measurements made with the probe. Additionally, the interface determines whether measurements made with the probe are taken upon the basis of outputs generated by the sensors 50 due to a shock wave in the stylus 24 of the probe, or as a result of strain in the stylus 24; as an alternative, measurements may be made only on the basis of strain.

Contact probes

Workpiece inspection

Signal processing for contact-sensing probe

The probe has a piezo-electric sensor (22A) for determining initial contact of a stylus (16) with a workpiece (4). It also has a kinematic support (18) made up of confronting electrical contacts (19, 20) which are connected to indicate displacement of the stylus from a rest position and correct reseating on the kinematic support. The sensor (22A) and the electrical contacts (19, 20) are connected to an electrical circuit (24) within the probe. The circuit (24) has only two terminals connecting it to an external interface (9), which both receives the signals from and supplies power to the sensor (22A) and the contacts (19, 20). This enables the receipt of a signal from the contacts (19, 20) to provide a fail-safe backup to the signal from the sensor (22A) and to indicate correct reseating of the probe, while maintaining the interface (9) compatible with prior art probes having only one workpiece-engagement sensing arrangement with two terminals.

Growing community of inventors

Bristol, United Kingdom

Peter G Lloyd