Patents by Inventor Nigel Paul Schofield

Nigel Paul Schofield 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: 9279426
    Abstract: A multi-stage, clam shell, vacuum pump comprises two housing components (12) which are to be sealingly connected to one another such that an array of chambers extending longitudinally from an inlet region of the pump to an outlet region of the pump is defined thereby. Sealing means (30) are provided within the vacuum pump, between the two housing components, to prevent transfer of fluid in to and out of the vacuum pump where said components are connected. An array of discrete, elongate channels (33, 34, 36, 38) is provided, located between the sealing means (30) and the array of chambers (14, 16, 18, 20, 22). The channels serve to protect the sealing means (30) from fluid that passes through the chambers during operation of the vacuum pump. Each channel is configured to receive a barrier fluid having a different pressure than a barrier fluid to be received by an adjacent channel.
    Type: Grant
    Filed: October 1, 2008
    Date of Patent: March 8, 2016
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, Stephen Dowdeswell
  • Patent number: 9249805
    Abstract: A vacuum pump comprises a molecular drag pumping mechanism and a regenerative pumping mechanism. A rotor element of the molecular drag pumping mechanism surrounds rotor elements of the regenerative pumping mechanism.
    Type: Grant
    Filed: August 28, 2014
    Date of Patent: February 2, 2016
    Assignee: Edwards Limited
    Inventors: Ian David Stones, Nigel Paul Schofield, Martin Nicholas Stuart
  • Publication number: 20150377239
    Abstract: A vacuum pump may include a regenerative pumping mechanism and a drag pumping mechanism. The regenerative pumping mechanism may include a generally disc-shaped member mounted on an axial shaft for rotation relative to a stator of the regenerative pumping mechanism. The drag pumping mechanism may include a generally cylindrical-shaped member mounted at an outer circumferential portion of the disc-shaped member for rotation about the axial shaft relative to a stator of the drag pumping mechanism.
    Type: Application
    Filed: February 15, 2013
    Publication date: December 31, 2015
    Inventors: Nigel Paul Schofield, Stephen Dowdeswell
  • Patent number: 9127685
    Abstract: A vacuum pump rotor suitable for use in a vacuum pump is described for a vacuum pump that comprises a regenerative pumping mechanism. The rotor has a generally disc-shaped configuration and is mounted on an axial shaft for rotation relative to a stator of a vacuum pump. The rotor has a first and second opposing surface on which a rotor formations are disposed, each rotor formation defining a portion of a pump stage formed between the pump rotor and a stator for pumping gas from an inlet to an outlet in the same radial direction along the first and second opposing surface. A conduit is provided to interconnect the portions of the pump stage and assist with pressure imbalance that might occur on opposing sides of the rotor.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: September 8, 2015
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, Michael Chung Kau Liu
  • Patent number: 9127682
    Abstract: A vacuum pumping arrangement for evacuating an enclosure is provided. The arrangement comprises a turbomolecular vacuum pump having an inlet which is connectable using fixing members to an outlet of an enclosure to be evacuated. Each of the fixing members passes through a first aperture in the inlet and through a second aperture in the outlet. An elongate, circumferentially extending cavity is provided extending from or adjacent to one of these apertures to accommodate a crushable insert. Energy transmitted to the fixing members by the turbomolecular vacuum pump during a failure thereof is thus absorbed by the deformation of the inserts. By absorbing a proportion of the energy in this way separation of the inlet from the outlet is thus inhibited.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: September 8, 2015
    Assignee: Edwards Limited
    Inventor: Nigel Paul Schofield
  • Patent number: 9097252
    Abstract: A scroll pump includes a pump housing, a drive shaft having a concentric shaft portion and an eccentric shaft portion connected to an orbiting scroll. The shaft is driven by a motor so that rotation of the shaft imparts an orbiting motion to the orbiting scroll relative to a fixed scroll for pumping fluid between a pump inlet and a pump outlet of the compressor. The fixed scroll has an opening through which the shaft extends and is connected to the orbiting scroll on an opposing side of the fixed scroll to the motor. An anti-rotation device is located in the high vacuum region for resisting rotation of the orbiting scroll and allowing said orbiting motion, and a bearing arrangement for supporting rotation of the concentric shaft portion and eccentric shaft portion is located in tile low vacuum region.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: August 4, 2015
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, Michael Chung Kau Liu
  • Patent number: 9086071
    Abstract: A pump comprises a regenerative pumping mechanism. A rotor of the pump has a generally disc-shaped pump rotor mounted on an axial driveshaft for rotation relative to a stator, the pump rotor having rotor formations disposed in a surface and defining at least a portion of a flow path for pumping gas from an inlet to an outlet. The rotor formations are formed between the pump rotor and the stator of the pumping mechanism. The pump rotor and the stator comprise an axial gas bearing arrangement for controlling axial clearance between the rotor and the stator during pump operation. The gas bearing is located at a radially outward position on the rotor.
    Type: Grant
    Filed: May 18, 2010
    Date of Patent: July 21, 2015
    Assignee: Edwards Limited
    Inventor: Nigel Paul Schofield
  • Publication number: 20150176584
    Abstract: The present invention provides a scroll pump comprising: a scroll mechanism having an orbiting scroll and a fixed scroll; a drive shaft having a concentric shaft portion and an eccentric shaft portion connected to the orbiting scroll. The shaft is arranged to be driven by a motor so that rotation of the shaft imparts an orbiting motion to the orbiting scroll relative to the fixed scroll for pumping fluid along a flow path from an inlet to an outlet of the scroll mechanism. An axial lip seal is located between the orbiting scroll and the fixed scroll for resisting leakage of fluid from outside the scroll mechanism into the flow path.
    Type: Application
    Filed: June 10, 2013
    Publication date: June 25, 2015
    Inventor: Nigel Paul Schofield
  • Publication number: 20150037137
    Abstract: An improved vacuum pump mechanism is described in which an intersecting solid or perforated element is arranged to intersect a channel member. Relative movement of the intersecting solid or perforated element and channel member causes gas molecules to be urged from inlet to an outlet of the pump. Gas molecules are constrained within the channel member and interaction of the gas molecules with the flat and smooth surfaces of the intersecting solid or perforated member influence momentum of the gas molecules so that they are directed towards the outlet. In one embodiment, the channel member is formed as a helix and the intersecting solid or perforated elements are disk-shaped. An alternative embodiment is provided having the channel member configured as a spiral and the perforated elements as cylindrical skirts. The pump provides significant improvements in pump capacity, reduced power consumption and size of pump.
    Type: Application
    Filed: January 24, 2013
    Publication date: February 5, 2015
    Inventors: Nigel Paul Schofield, Ian David Stones, Stephen Dowdeswell
  • Publication number: 20140369807
    Abstract: A vacuum pump comprises a molecular drag pumping mechanism and a regenerative pumping mechanism. A rotor element of the molecular drag pumping mechanism surrounds rotor elements of the regenerative pumping mechanism.
    Type: Application
    Filed: August 28, 2014
    Publication date: December 18, 2014
    Inventors: Ian David Stones, Nigel Paul Schofield, Martin Nicholas Stuart
  • Patent number: 8851865
    Abstract: A vacuum pump comprises a molecular drag pumping mechanism and a regenerative pumping mechanism. A rotor element of the molecular drag pumping mechanism surrounds rotor elements of the regenerative pumping mechanism.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: October 7, 2014
    Assignee: Edwards Limited
    Inventors: Ian David Stones, Nigel Paul Schofield, Martin Nicholas Stuart
  • Patent number: 8727751
    Abstract: A vacuum pumping arrangement comprises a turbomolecular pumping mechanism and a molecular drag pumping mechanism connected in series. A rotor of the molecular drag pumping mechanism is supported by the rotor blades of the turbomolecular pumping mechanism.
    Type: Grant
    Filed: December 9, 2003
    Date of Patent: May 20, 2014
    Assignee: Edwards Limited
    Inventor: Nigel Paul Schofield
  • Patent number: 8702407
    Abstract: A multistage vacuum pump includes a stator housing a multistage rotor assembly, each stage having intermeshing Roots rotor components, wherein the tip radius of the rotor components at an inlet stage of the pump is larger than the tip radius of the rotor components at an exhaust stage of the pump, wherein a meshing clearance between the rotor components at the inlet stage of the pump is greater than a meshing clearance between the rotor components at the exhaust stage of the pump.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: April 22, 2014
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, Peter Hugh Birch
  • Publication number: 20140079581
    Abstract: The present invention relates to a rotor for a vacuum pump having a roots pumping mechanism, the rotor comprising at least two hollow lobes, each lobe having an outer wall which defines a lobe profile, a hollow cavity generally inward of the outer wall, and at least one strengthening rib located in the cavity to resist stress on the lobes generated during rotation.
    Type: Application
    Filed: April 23, 2012
    Publication date: March 20, 2014
    Applicant: EDWARDS LIMITED
    Inventors: Nigel Paul Schofield, Stephen Dowdeswell
  • Patent number: 8672607
    Abstract: A differentially pumped vacuum system including apparatus having at least first and second chambers; and a vacuum pump for differentially pumping fluid from the chambers to generate a first pressure above 0.1 mbar in the first chamber and a second pressure lower than the first pressure in the second chamber, the pump having at least first and second pump inlets each for receiving fluid from a respective pressure chamber and a plurality of pumping stages positioned relative to the inlets so that fluid received from the first chamber passes through fewer pumping stages than fluid from the second chamber, the inlets being attached to the apparatus such that at least 99% of the fluid mass pumped from the apparatus passes through at least one of the pumping stages of the pump.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: March 18, 2014
    Assignee: Edwards Limited
    Inventors: Ian David Stones, Nigel Paul Schofield, Martin Nicholas Stuart
  • Patent number: 8500425
    Abstract: A Roots vacuum pump stator is arranged to house a pair of intermeshing rotors, said stator being characterized in that it comprises a director or deflector arranged to direct solid material entrained in a gas pumped through the pump towards the outlet. In other words, the stator according to the present invention has a means for directing or deflecting powder or solid material entrained in a gas being pumped directly towards an outlet of the pump or out of the pump. The directing means can comprise a channel disposed between the arcuate surface and the outlet, said channel comprising a portion that engages the arcuate surface prior to the bottom-dead-centre position and which extends away from the rotor's axis of rotation towards the pump outlet.
    Type: Grant
    Filed: October 9, 2009
    Date of Patent: August 6, 2013
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, Stephen Dowdeswell
  • Patent number: 8500422
    Abstract: A vacuum pump housing comprises first (12) and second half-shell stator components (14) defining a plurality of pumping chambers separated by partition members (26, 28, 30, 32). Each pumping chamber comprises an inlet port (42, 44, 46, 48, 50) for receiving fluid and an outlet port (54, 56, 58, 60, 62) through which pumped fluid is exhausted from the chamber. The inlet ports are open on an external surface of the first stator component, and the outlet ports are open on an opposing external surface of the second stator component. The stator components further define transfer channels (66, 68, 70, 72) for conveying fluid between the pumping chambers. Each transfer channel preferably comprises first and second portions located on opposite sides of the housing.
    Type: Grant
    Filed: October 1, 2007
    Date of Patent: August 6, 2013
    Assignee: Edwards Limited
    Inventors: Stephen Dowdeswell, Nigel Paul Schofield, Peter Hugh Birch
  • Publication number: 20130039791
    Abstract: The present invention relates to a scroll pump (10) comprising a pump housing (12), a drive shaft having a concentric shaft portion (14) and an eccentric shaft portion (16) connected to an orbiting scroll (20). The shaft is arranged to be driven by a motor (18) so that during use rotation of the shaft imparts an orbiting motion to the orbiting scroll relative to a fixed scroll (22) for pumping fluid between a pump inlet (24) and pump outlet (26) of the compressor. The fixed scroll has an opening through which the shaft extends and is connected to the orbiting scroll on an opposing side of the fixed scroll to the motor. A high vacuum region is located on an orbiting scroll side of the scroll arrangement and a low vacuum region is located generally on a fixed scroll side of the scroll arrangement.
    Type: Application
    Filed: April 7, 2011
    Publication date: February 14, 2013
    Applicant: EDWARDS LIMITED
    Inventors: Nigel Paul Schofield, Michael Chung Kau Liu
  • Patent number: 8323006
    Abstract: Scroll-type pumping apparatus comprises a stator (104) comprising a fixed scroll member (106) having an end plate with a first spiral wrap (110) extending therefrom; an orbital scroll member (108) having an end plate with a second spiral wrap (112) extending therefrom to intermesh with the first spiral wrap; a plurality of flexible supports (118) each having one end connected to the orbital scroll member and another end connected to the stator to support the orbital scroll member relative to the stator, and a linear drive system (120) for driving the orbital scroll member to orbit relative to the fixed scroll member. The use of a linear drive system in combination with the flexible supports can provide apparatus having no rotational or rubbing parts.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: December 4, 2012
    Assignee: Edwards Limited
    Inventors: Nigel Paul Schofield, James Alexander Haylock
  • Publication number: 20120057995
    Abstract: The present invention provides a pump comprising a regenerative pumping mechanism having a generally disc-shaped rotor mounted on an axial shaft for rotation relative to a stator. The rotor has first and second surfaces each having a series of shaped recesses formed in concentric circles thereon, and a stator channel formed in a surface of the stator which faces one of the rotor's first or second surfaces. Each of the concentric circles is aligned with a portion of a stator channel so as to form a section of a gas flow path extending between an inlet and an outlet of the pump, and the rotor divides the section of flow path into sub-sections such that gas can flow towards the outlet simultaneously along any sub-section, channel or rotor side. As a result, the gas being pumped flows in a parallel fashion along both surfaces of the rotor. Thus, this configuration can provide a pumping mechanism where gas pressures on either side of the rotor can be substantially equal or balanced.
    Type: Application
    Filed: May 18, 2010
    Publication date: March 8, 2012
    Applicant: EDWARDS LIMITED
    Inventor: Nigel Paul Schofield