Patents by Inventor Steven M. Millett

Steven M. Millett 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: 11897725
    Abstract: A braking system for an elevator includes an electromagnetic brake operably connected to an elevator car, and a control circuit operably connected to the electromagnetic brake. The control circuit includes a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car. The switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement.
    Type: Grant
    Filed: July 10, 2020
    Date of Patent: February 13, 2024
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Steven M. Millett, Ismail Agirman, Amir Lotfi
  • Publication number: 20200339382
    Abstract: A braking system for an elevator includes an electromagnetic brake operably connected to an elevator car, and a control circuit operably connected to the electromagnetic brake. The control circuit includes a switching mechanism configured to selectively modify a rate of engagement of the electromagnetic brake to selectively modify a rate of deceleration of the elevator car. The switching mechanism has a first position, a second position and a third position, to selectively modify the rate of engagement.
    Type: Application
    Filed: July 10, 2020
    Publication date: October 29, 2020
    Inventors: Steven M. Millett, Ismail Agirman, Amir Lotfi
  • Patent number: 10734925
    Abstract: A regenerative drive (30) and method for providing power from such to at least one auxiliary power supply (41, 43) is disclosed. The drive may include a converter (32) and an inverter (34) connected by a DC bus (33), and a controller (54) configured to apply at least one of unipolar modulation and bipolar modulation to the converter (32) and the inverter (34), and to provide about half of the output voltage across the upper portion (130) of the DC bus (33) and about half of the output voltage across the lower portion (136) of the DC bus (33), when the upper and lower portions (130, 136) of the DC bus (33) are unevenly loaded. A first auxiliary power supply (41) may be connected to one of the upper and lower portions (130, 136) of the DC bus (33) and may receive power from the multilevel regenerative drive (30).
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: August 4, 2020
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Steven M. Millett, Ismail Agirman
  • Patent number: 10450162
    Abstract: A brake system for an elevator car includes a multiple of brake segments for deceleration of the elevator car and a brake control circuit operable to control operation of each of the multiple of brake segments to passively sequence activation of each of the multiple of brake segments.
    Type: Grant
    Filed: June 27, 2016
    Date of Patent: October 22, 2019
    Assignee: Otis Elevator Company
    Inventors: Amir Lotfi, YiSug Kwon, Steven M. Millett
  • Patent number: 10246294
    Abstract: A regenerative elevator drive device, a method for buffering energy of a regenerative elevator drive device, and an elevator system are disclosed. The regenerative elevator drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The regenerative drive may further include a direct current (DC) link bridging the inverter and the converter, the DC link including a first capacitor bridging the inverter and the converter and a second capacitor in parallel with the first capacitor. The regenerative elevator drive device may be a multi-level regenerative drive device.
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: April 2, 2019
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Ismail Agirman, Steven M. Millett, HanJong Kim
  • Patent number: 10008917
    Abstract: A regenerative drive device and a method for configuring the DC link of a regenerative drive device are disclosed. The multilevel regenerative drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The multilevel regenerative drive device may also include a direct current (DC) link bridging the inverter and the converter, the DC link including a capacitor, an inverter neutral point, and a converter neutral point independent of the inverter neutral point. Alternatively, the inverter neutral point and the converter neutral point may be connected.
    Type: Grant
    Filed: December 18, 2013
    Date of Patent: June 26, 2018
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Ismail Agirman, Steven M. Millett, Shashank Krishnamurthy, Yang Wang
  • Publication number: 20170317607
    Abstract: A three-level converter includes a first converter leg having first switches connected across a positive DC node and a negative DC node, a second converter leg having second switches connected across the positive DC node and the negative DC node, and a third converter leg having third switches connected across the positive DC node the negative DC node. The converter includes a battery connected between the positive DC node and the negative DC node, and center-connected to a ground node having a ground potential. Each of the first, second, and third converter legs is connected to the ground node.
    Type: Application
    Filed: October 21, 2015
    Publication date: November 2, 2017
    Inventors: Ismail Agirman, Steven M. Millett, Daryl J. Marvin, Shashank Krishnamurthy
  • Patent number: 9804612
    Abstract: An exemplary power supply includes a low side switch and a high side switch. A driver controls operation of the high side switch. A bootstrap capacitor supplies power to the driver. An energy storage portion is in parallel with the bootstrap capacitor to provide control over whether a voltage of the bootstrap capacitor drops below a desired voltage. A voltage regulator is in parallel with the bootstrap capacitor for limiting current provided to the bootstrap capacitor and for regulating a voltage of the bootstrap capacitor.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: October 31, 2017
    Assignee: OTIS ELEVATOR COMPANY
    Inventors: Daryl J. Marvin, Steven M. Millett
  • Publication number: 20170029242
    Abstract: A regenerative elevator drive device, a method for buffering energy of a regenerative elevator drive device, and an elevator system are disclosed. The regenerative elevator drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The regenerative drive may further include a direct current (DC) link bridging the inverter and the converter, the DC link including a first capacitor bridging the inverter and the converter and a second capacitor in parallel with the first capacitor. The regenerative elevator drive device may be a multi-level regenerative drive device.
    Type: Application
    Filed: December 18, 2013
    Publication date: February 2, 2017
    Applicant: OTIS ELEVATOR COMPANY
    Inventors: Ismail Agirman, Steven M. Millett, HanJong Kim
  • Publication number: 20170008731
    Abstract: A brake system for an elevator car includes a multiple of brake segments for deceleration of the elevator car and a brake control circuit operable to control operation of each of the multiple of brake segments to passively sequence activation of each of the multiple of brake segments.
    Type: Application
    Filed: June 27, 2016
    Publication date: January 12, 2017
    Inventors: Amir Lotfi, YiSug Kwon, Steven M. Millett
  • Publication number: 20170005562
    Abstract: A regenerative drive device and a method for configuring the DC link of a regenerative drive device are disclosed. The multilevel regenerative drive device may include an inverter having a plurality of power components and a converter having a plurality of power components. The multilevel regenerative drive device may also include a direct current (DC) link bridging the inverter and the converter, the DC link including a capacitor, an inverter neutral point, and a converter neutral point independent of the inverter neutral point. Alternatively, the inverter neutral point and the converter neutral point may be connected.
    Type: Application
    Filed: December 18, 2013
    Publication date: January 5, 2017
    Inventors: Ismail Agirman, Steven M. Millett, Shashank Krishnamurthy, Yang Wang
  • Publication number: 20160308474
    Abstract: A regenerative drive (30) and method for providing power from such to at least one auxiliary power supply (41, 43) is disclosed. The drive may include a converter (32) and an inverter (34) connected by a DC bus (33), and a controller (54) configured to apply at least one of unipolar modulation and bipolar modulation to the converter (32) and the inverter (34), and to provide about half of the output voltage across the upper portion (130) of the DC bus (33) and about half of the output voltage across the lower portion (136) of the DC bus (33), when the upper and lower portions (130, 136) of the DC bus (33) are unevenly loaded. A first auxiliary power supply (41) may be connected to one of the upper and lower portions (130, 136) of the DC bus (33) and may receive power from the multilevel regenerative drive (30).
    Type: Application
    Filed: December 18, 2013
    Publication date: October 20, 2016
    Inventors: Steven M. Millett, Ismail Agirman
  • Patent number: 8970152
    Abstract: An exemplary power supply assembly includes a drive device having a bus capacitor. A switch associated with an input side of the drive device selectively connects the drive device to a power supply. An inductor has an impedance that limits an amount of current supplied to the bus capacitor during an initial charging of the bus capacitor when the switch connects the input side of the drive device to the power supply. A restrictive circuit portion dampens a resonance effect of the inductor. The restrictive circuit portion has a resistance that allows the bus capacitor to charge quickly. The impedance of the inductor has a more significant effect on how quickly the bus capacitor charges than an effect of the resistance. A dampening factor of the restrictive circuit controls a voltage of the bus capacitor during the charging of the bus capacitor.
    Type: Grant
    Filed: July 30, 2010
    Date of Patent: March 3, 2015
    Assignee: Otis Elevator Company
    Inventors: Daryl J. Marvin, Michael Mann, Steven M. Millett
  • Publication number: 20130119910
    Abstract: An exemplary power supply assembly includes a drive device having a bus capacitor. A switch associated with an input side of the drive device selectively connects the drive device to a power supply. An inductor has an impedance that limits an amount of current supplied to the bus capacitor during an initial charging of the bus capacitor when the switch connects the input side of the drive device to the power supply. A restrictive circuit portion dampens a resonance effect of the inductor. The restrictive circuit portion has a resistance that allows the bus capacitor to charge quickly. The impedance of the inductor has a more significant effect on how quickly the bus capacitor charges than an effect of the resistance. A dampening factor of the restrictive circuit controls a voltage of the bus capacitor during the charging of the bus capacitor.
    Type: Application
    Filed: July 30, 2010
    Publication date: May 16, 2013
    Applicant: OTIS ELEVATOR COMPANY
    Inventors: Daryl J. Marvin, Michael Mann, Steven M. Millett
  • Publication number: 20130119965
    Abstract: An exemplary power supply includes a low side switch and a high side switch. A driver controls operation of the high side switch. A bootstrap capacitor supplies power to the driver. An energy storage portion is in parallel with the bootstrap capacitor to provide control over whether a voltage of the bootstrap capacitor drops below a desired voltage. A voltage regulator is in parallel with the bootstrap capacitor for limiting current provided to the bootstrap capacitor and for regulating a voltage of the bootstrap capacitor.
    Type: Application
    Filed: July 30, 2010
    Publication date: May 16, 2013
    Applicant: OTIS ELEVATOR COMPANY
    Inventors: Daryl J. Marvin, Steven M. Millett