Patents by Inventor David Kenneth Thomas

David Kenneth Thomas 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: 8890546
    Abstract: An apparatus for digitizing an impedance is provided that comprises a first impedance element having a first impedance that varies with a property to be measured and a second impedance element having a second impedance. The apparatus also includes a drive signal generator for applying a first alternating drive signal to the first impedance element and a second alternating drive signal to the second impedance element. An analog-to-digital converter, ADC, receives a resultant signal comprising the combination of the signals produced by the application of the first and second alternating drive signals to the first and second impedance elements. The first alternating drive signal is phase shifted relative to the second alternating drive signal such that the resultant signal received and sampled by the ADC sequentially relates to the sum of, and the difference between, the first and second impedances.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: November 18, 2014
    Assignee: Renishaw PLC
    Inventor: David Kenneth Thomas
  • Publication number: 20110316566
    Abstract: An apparatus for digitising an impedance is provided that comprises a first impedance element having a first impedance that varies with a property to be measured and a second impedance element having a second impedance. The apparatus also includes a drive signal generator for applying a first alternating drive signal to the first impedance element and a second alternating drive signal to the second impedance element. An analogue-to-digital converter, ADC, receives a resultant signal comprising the combination of the signals produced by the application of the first and second alternating drive signals to the first and second impedance elements. The first alternating drive signal is phase shifted relative to the second alternating drive signal such that the resultant signal received and sampled by the ADC sequentially relates to the sum of, and the difference between, the first and second impedances.
    Type: Application
    Filed: March 1, 2010
    Publication date: December 29, 2011
    Applicant: RENISHAW PLC
    Inventor: David Kenneth Thomas
  • Patent number: 8029217
    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.
    Type: Grant
    Filed: February 24, 2010
    Date of Patent: October 4, 2011
    Assignee: Renishaw PLC
    Inventors: David Collingwood, Graham Richard Ferguson, Timothy Donald Hayter, Tim Prestidge, Clive Esmond Harwood Renton, Edward Stott, David Kenneth Thomas
  • Patent number: 7970488
    Abstract: A workpiece inspection system is disclosed for determining measurements of a workpiece on a machine tool. The system utilizes a measurement device which outputs data relating to the workpiece (e.g. in place of a conventional cutter). The problem of obtaining real time data relating to the position of the machine tool is overcome by recording a machine tool position data set and a measurement device data set at selected instants which are defined by a synchronization signal. The data sets are combined later in the correct relative position because the synchronization signal was used. The synchronization signal can issue from the machine tool controller, an interface, measurement device or another part of the system.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: June 28, 2011
    Assignee: Renishaw PLC
    Inventors: Tim Prestidge, John Charles Ould, David Kenneth Thomas, Andrew James Harding
  • Publication number: 20100156056
    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.
    Type: Application
    Filed: February 24, 2010
    Publication date: June 24, 2010
    Applicant: RENISHAW PLC
    Inventors: David Collingwood, Graham Richard Ferguson, Timothy Donald Hayter, Tim Prestidge, Clive Esmond Harwood Renton, Edward Stott, David Kenneth Thomas
  • Patent number: 7695223
    Abstract: The transmission of power and/or data from/to a stationary part of a machine tool to/from an accessory mounted in the spindle of the machine tool. A first electrical link or interface provides electrical communication between the stationary part and the spindle, and a second electrical link or interface is provided electrically connected to the first electrical link at the accessory mounting area. The second link is in the form of electrical contacts. An accessory shank for mounting to the spindle of the machine tool, and also to an accessory e.g. in the form of a measurement probe, connected to the said shank.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: April 13, 2010
    Assignee: Renishaw PLC
    Inventors: David Collingwood, Graham Richard Ferguson, Timothy Donald Hayter, Tim Prestidge, Clive Esmond Harwood Renton, Edward Stott, David Kenneth Thomas
  • Patent number: 7594337
    Abstract: A tool shank (18;38;138) is described that comprises a spindle attachment portion (20) that is removably attachable to the rotatable spindle (12) of a machine tool (10), a shank body portion (21;121) which extends beyond the end of the spindle when the tool shank (18;38;138) is attached to the spindle (12) of a machine tool (10) and the first part (26;38;148) of a separable electrical coupling (22;132). The shank body portion comprises a feature (28;128) suitable for engagement with a tool change device (29) and the first part (26;38;148) of the separable electrical coupling (22;132) is located on the shank body portion (21;121) between the feature (28;128) and the spindle attachment portion (20). A machine tool (10), and a kit for retrofitting a machine tool (10), that comprise the second part (24;148) of the separable electrical coupling (22;132) are also described.
    Type: Grant
    Filed: March 20, 2006
    Date of Patent: September 29, 2009
    Assignee: Renishaw PLC
    Inventors: David Roberts McMurtry, Geoffrey McFarland, David Kenneth Thomas
  • Publication number: 20090080990
    Abstract: A tool shank (18;38;138) is described that comprises a spindle attachment portion (20) that is removably attachable to the rotatable spindle (12) of a machine tool (10), a shank body portion (21;121) which extends beyond the end of the spindle when the tool shank (18;38;138) is attached to the spindle (12) of a machine tool (10) and the first part (26;38;148) of a separable electrical coupling (22;132). The shank body portion comprises a feature (28;128) suitable for engagement with a tool change device (29) and the first part (26;38;148) of the separable electrical coupling (22;132) is located on the shank body portion (21;121) between the feature (28;128) and the spindle attachment portion (20). A machine tool (10), and a kit for retrofitting a machine tool (10), that comprise the second part (24;148) of the separable electrical coupling (22;132) are also described.
    Type: Application
    Filed: March 20, 2006
    Publication date: March 26, 2009
    Applicant: Renishaw PLC
    Inventors: David Roberts McMurtry, Geoffrey McFarland, David Kenneth Thomas
  • Publication number: 20080164045
    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.
    Type: Application
    Filed: March 17, 2008
    Publication date: July 10, 2008
    Applicant: RENISHAW PLC
    Inventors: David Collingwood, Graham Richard Ferguson, Timothy Donald Hayter, Tim Prestidge, Clive Esmond Harwood Renton, Edward Stott, David Kenneth Thomas
  • Patent number: 7364393
    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.
    Type: Grant
    Filed: April 17, 2003
    Date of Patent: April 29, 2008
    Assignee: Renishaw PLC
    Inventors: David Collingwood, Graham Richard Ferguson, Timothy Donald Hayter, Tim Prestidge, Clive Esmond Harwood Renton, Edward Stott, David Kenneth Thomas
  • Publication number: 20080051927
    Abstract: A workpiece inspection system is disclosed for determining measurements of a workpiece on a machine tool. The system utilises a measurement device which outputs data relating to the workpiece (e.g. in place of a conventional cutter). The problem of obtaining real time data relating to the position of the machine tool is overcome by recording a machine tool position data set and a measurement device data set at selected instants which are defined by a synchronisation signal. The data sets are combined later in the correct relative position because the synchronisation signal was used. The synchronisation signal can issue from the machine tool controller, an interface, measurement device or another part of the system.
    Type: Application
    Filed: January 6, 2005
    Publication date: February 28, 2008
    Applicant: Renishaw PLC
    Inventors: Tim Prestidge, John Charles Ould, David Kenneth Thomas, Andrew James Harding
  • Patent number: 7328519
    Abstract: Transmission of power and/or signal across a machine tool spindle shank is disclosed. Contacts (340) on the shank are connectable to tracks (24/22) on the spindle (210). A circuit (e.g. FIG. 15) is used to determine the orientation of the contacts relative to the tracks when the shank is inserted in an unknown orientation into the spindle.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: February 12, 2008
    Assignee: Renishaw PLC
    Inventors: Andrew James Harding, David Kenneth Thomas, Timothy Donald Hayter
  • Patent number: 6683780
    Abstract: A displacement responsive device e.g. a measurement probe (110) is disclosed. Displacement of a stylus (130) causes resilient movement of a carriage (134) supported by planar springs (112) and (114). This movement is detected by a capacitance sensor (160), formed from two cylinders (164) and (166). The cylinders move in at least three degrees of freedom and changes in their capacitance during the said movement can be determined by a circuit (e.g. FIG. 5). Movement in x, y and z directions can be sensed.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: January 27, 2004
    Assignee: Renishaw PLC
    Inventors: David Kenneth Thomas, Andrew Loach, Graham Richard Ferguson
  • Publication number: 20030048592
    Abstract: A displacement responsive device e.g. a measurement probe (110) is disclosed. Displacement of a stylus (130) causes resilient movement of a carriage (134) supported by planar springs (112) and (114). This movement is detected by a capacitance sensor (160), formed from two cylinders (164) and (166). The cylinders move in at least three degrees of freedom and changes in their capacitance during the said movement can be determined by a circuit (e.g. FIG. 5). Movement in x, y and z directions can be sensed.
    Type: Application
    Filed: September 20, 2002
    Publication date: March 13, 2003
    Inventors: David Kenneth Thomas, Andrew Loach, Graham Richard Ferguson