Patents by Inventor Kenneth Cheng-Hoe Nai

Kenneth Cheng-Hoe Nai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8978261
    Abstract: A measurement system has a surface sensing device mounted on an articulating probe head, which in turn is mounted on a coordinate positioning apparatus. The surface sensing device is moved relative to a surface by driving at least one of the coordinate positioning apparatus and probe head in at least one axis to scan the surface. The surface sensing device measures its distance from the surface and the probe head is driven to rotate the surface sensing device about at least one axis in order to control the relative position of the surface sensing device from the surface to within a predetermined range in real time.
    Type: Grant
    Filed: July 21, 2011
    Date of Patent: March 17, 2015
    Assignee: Renishaw PLC
    Inventors: Geoffrey McFarland, Kenneth Cheng Hoe Nai, Nicholas John Weston, Ian William McLean
  • Patent number: 8939008
    Abstract: A method of calibrating an articulating probe head comprising the steps of measuring an artifact of known dimensions with the workpiece sensing probe mounted on the articulating probe head, in which the articulating probe head is unlocked. An error functional map is generated corresponding to the difference between the measured and known dimensions of the artifact. Subsequent workpieces are measured with the articulating probe head unlocked and the corresponding correction applied. The true dimensions of the artifact may be determined by measuring it with a probe mounted on an articulating probe head in which the axes of the articulating probe head are locked. A mechanical lock is provided to lock the axes of the articulating probe head.
    Type: Grant
    Filed: July 20, 2011
    Date of Patent: January 27, 2015
    Assignee: Renishaw PLC
    Inventors: David Roberts McMurtry, Geoff McFarland, Kenneth Cheng-Hoe Nai, Stephen James Trull, Nicholas John Weston
  • Publication number: 20110283553
    Abstract: A measurement system has a surface sensing device mounted on an articulating probe head, which in turn is mounted on a coordinate positioning apparatus. The surface sensing device is moved relative to a surface by driving at least one of the coordinate positioning apparatus and probe head in at least one axis to scan the surface. The surface sensing device measures its distance from the surface and the probe head is driven to rotate the surface sensing device about at least one axis in order to control the relative position of the surface sensing device from the surface to within a predetermined range in real time.
    Type: Application
    Filed: July 21, 2011
    Publication date: November 24, 2011
    Applicant: RENISHAW PLC
    Inventors: Geoffrey McFarland, Kenneth Cheng Hoe Nai, Nicholas John Weston, Ian William McLean
  • Publication number: 20110277534
    Abstract: A method of calibrating an articulating probe head comprising the steps of measuring an artefact of known dimensions with the workpiece sensing probe mounted on the articulating probe head, in which the articulating probe head is unlocked. An error functional map is generated corresponding to the difference between the measured and known dimensions of the artefact. Subsequent workpieces are measured with the articulating probe head unlocked and the corresponding correction applied. The true dimensions of the artefact may be determined by measuring it with a probe mounted on an articulating probe head in which the axes of the articulating probe head are locked. A mechanical lock is provided to lock the axes of the articulating probe head.
    Type: Application
    Filed: July 20, 2011
    Publication date: November 17, 2011
    Applicant: Renishaw plc
    Inventors: David Roberts McMurtry, Geoff McFarland, Kenneth Cheng-Hoe Nai, Stephen James Trull, Nicholas John Weston
  • Patent number: 8006398
    Abstract: A measurement system has a surface sensing device mounted on an articulating probe head, which in turn is mounted on a coordinate positioning apparatus. The surface sensing device is moved relative to a surface by driving at least one of the coordinate positioning apparatus and probe head in at least one axis to scan the surface. The surface sensing device measures its distance from the surface and the probe head is driven to rotate the surface sensing device about at least one axis in order to control the relative position of the surface sensing device from the surface to within a predetermined range in real time.
    Type: Grant
    Filed: April 10, 2006
    Date of Patent: August 30, 2011
    Assignee: Renishaw PLC
    Inventors: Geoffrey McFarland, Kenneth Cheng Hoe Nai, Nicholas John Weston, Ian William McLean
  • Patent number: 8001859
    Abstract: A method of calibrating an articulating probe head comprising the steps of measuring an artefact of known dimensions with the workpiece sensing probe mounted on the articulating probe head, in which the articulating probe head is unlocked. An error functional map is generated corresponding to the difference between the measured and known dimensions of the artefact. Subsequent workpieces are measured with the articulating probe head unlocked and the corresponding correction applied. The true dimensions of the artefact may be determined by measuring it with a probe mounted on an articulating probe head in which the axes of the articulating probe head are locked. A mechanical lock is provided to lock the axes of the articulating probe head.
    Type: Grant
    Filed: June 26, 2009
    Date of Patent: August 23, 2011
    Assignee: Renishaw PLC
    Inventors: David Roberts McMurtry, Geoff McFarland, Kenneth Cheng-Hoe Nai, Stephen James Trull, Nicholas John Weston
  • Publication number: 20100005852
    Abstract: A method of calibrating an articulating probe head comprising the steps of measuring an artefact of known dimensions with the workpiece sensing probe mounted on the articulating probe head, in which the articulating probe head is unlocked. An error functional map is generated corresponding to the difference between the measured and known dimensions of the artefact. Subsequent workpieces are measured with the articulating probe head unlocked and the corresponding correction applied. The true dimensions of the artefact may be determined by measuring it with a probe mounted on an articulating probe head in which the axes of the articulating probe head are locked. A mechanical lock is provided to lock the axes of the articulating probe head.
    Type: Application
    Filed: June 26, 2009
    Publication date: January 14, 2010
    Applicant: Renishaw plc
    Inventors: David Roberts McMurtry, Geoff McFarland, Kenneth Cheng-Hoe Nai, Stephen James Trull, Nicholas John Weston
  • Patent number: 7568373
    Abstract: A method of calibrating an articulating probe head comprising the steps of measuring an artefact of known dimensions with the workpiece sensing probe mounted on the articulating probe head, in which the articulating probe head is unlocked. An error functional map is generated corresponding to the difference between the measured and known dimensions of the artefact. Subsequent workpieces are measured with the articulating probe head unlocked and the corresponding correction applied. The true dimensions of the artefact may be determined by measuring it with a probe mounted on an articulating probe head in which the axes of the articulating probe head are locked. A mechanical lock is provided to lock the axes of the articulating probe head.
    Type: Grant
    Filed: September 22, 2004
    Date of Patent: August 4, 2009
    Assignee: Renishaw PLC
    Inventors: David Roberts McMurtry, Geoff McFarland, Kenneth Cheng-Hoe Nai, Stephen James Trull, Nicholas John Weston
  • Publication number: 20090025463
    Abstract: A measurement system has a surface sensing device mounted on an articulating probe head, which in turn is mounted on a coordinate positioning apparatus. The surface sensing device is moved relative to a surface by driving at least one of the coordinate positioning apparatus and probe head in at least one axis to scan the surface. The surface sensing device measures its distance from the surface and the probe head is driven to rotate the surface sensing device about at least one axis in order to control the relative position of the surface sensing device from the surface to within a predetermined range in real time.
    Type: Application
    Filed: April 10, 2006
    Publication date: January 29, 2009
    Applicant: RENISHAW PLC
    Inventors: Geoffrey McFarland, Kenneth Cheng Hoe Nai, Nicholas John Weston, Ian William McLean
  • Patent number: 7456538
    Abstract: A rotary drive mechanism is disclosed comprising a housing (10), a first motor (12) having a first rotor (38) and a first stator (32) connected to the housing and a second motor (50) having a second rotor (52) and a second stator (54) connected to the housing characterised in that the second motor is mechanically independent of the first motor whereby acceleration torques of the first motor are at least partially inertia balanced by the second motor. The balancing may be effected by equal and opposite rotation of the second motor. Control means may be provided to provide the second motor with a current which is proportional to that supplied to the first motor. Also disclosed is a positioning device and a probe having the rotary drive mechanism.
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: November 25, 2008
    Assignee: Renishaw PLC
    Inventors: Kenneth Cheng-Hoe Nai, Nicholas John Weston, Geoffrey McFarland, David Roberts McMurtry
  • Patent number: 6868356
    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.
    Type: Grant
    Filed: July 4, 2001
    Date of Patent: March 15, 2005
    Assignee: Renishaw PLC
    Inventors: Kenneth Cheng-Hoe Nai, David Allan Wright
  • Publication number: 20030079358
    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.
    Type: Application
    Filed: February 28, 2002
    Publication date: May 1, 2003
    Inventors: Kenneth Cheng-Hoe Nai, David Allan Wright
  • Publication number: 20020095975
    Abstract: A coordinate measuring machine (CMM) carries a probe and is controlled by a controller to drive the probe to take measurements on a workpiece. In order to reduce the effects of acceleration-induced deflections of the probe on the measurements made by the machine, accelerometers are provided to measure the accelerations of the probe and to produce signals indicative thereof. The acceleration signals (45) are passed to the controller (FIG. 2) where they are integrated (46) and filtered (48) before being passed as velocity signals (49) to a summing junction (50) from which they are fed to a velocity feedback control loop[ (34, 35, 36, 37) which reduces any changes in the velocity (and hence deflection) of the probe due to the accelerations.
    Type: Application
    Filed: March 8, 2002
    Publication date: July 25, 2002
    Applicant: Renishaw PLC
    Inventor: Kenneth Cheng-Hoe Nai