Patents by Inventor Randall L. Hofmann

Randall L. Hofmann 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: 6874603
    Abstract: The invention provides a magnetorheological piston and damper assembly. The piston includes a piston body including at least one bypass port and an annular gap formed therein. The bypass port is in fluid communication with the annular gap. The bypass port includes a longitudinal portion extending substantially parallel to a piston longitudinal axis, and a bend portion extending substantially away from the longitudinal axis. The annular gap is spaced apart from the longitudinal portion and extends substantially parallel to the piston longitudinal axis. During operation, fluid flows through the bypass port and annular gap. The damper assembly includes a rod and a housing including the fluid carried therein. The piston is slidably carried in the housing and operably attached to the rod.
    Type: Grant
    Filed: January 9, 2003
    Date of Patent: April 5, 2005
    Assignee: Delphi Technologies, Inc.
    Inventors: Ilya Lisenker, Randall L. Hofmann, Michael W. Hurtt
  • Patent number: 6786311
    Abstract: A magnetorheological piston includes a body having a substantially magnetically energizable passageway and a substantially magnetically non-energizable passageway. The substantially magnetically non-energizable passageway has a valveless passageway throat and has a flow cross-sectional area which has a minimum at the passageway throat and which is larger away from the passageway throat. A magnetorheological damper includes a cylinder and the above-described magnetorheological piston, wherein the piston is positioned in, and slideably engages, the cylinder.
    Type: Grant
    Filed: April 23, 2003
    Date of Patent: September 7, 2004
    Assignee: Delphi Technologies, Inc.
    Inventors: Saiman Lun, Randall L. Hofmann, Ilya Lisenker
  • Publication number: 20040134728
    Abstract: The invention provides a magnetorheological piston and damper assembly. The piston includes a piston body including at least one bypass port and an annular gap formed therein. The bypass port is in fluid communication with the annular gap. The bypass port includes a longitudinal portion extending substantially parallel to a piston longitudinal axis, and a bend portion extending substantially away from the longitudinal axis. The annular gap is spaced apart from the longitudinal portion and extends substantially parallel to the piston longitudinal axis. During operation, fluid flows through the bypass port and annular gap. The damper assembly includes a rod and a housing including the fluid carried therein. The piston is slidably carried in the housing and operably attached to the rod.
    Type: Application
    Filed: January 9, 2003
    Publication date: July 15, 2004
    Applicant: DELPHI TECHNOLOGIES INC.
    Inventors: Ilya Lisenker, Randall L. Hofmann, Michael W. Hurtt
  • Publication number: 20030192752
    Abstract: A magnetorheological piston includes a body having a substantially magnetically energizable passageway and a substantially magnetically non-energizable passageway. The substantially magnetically non-energizable passageway has a valveless passageway throat and has a flow cross-sectional area which has a minimum at the passageway throat and which is larger away from the passageway throat. A magnetorheological damper includes a cylinder and the above-described magnetorheological piston, wherein the piston is positioned in, and slideably engages, the cylinder.
    Type: Application
    Filed: April 23, 2003
    Publication date: October 16, 2003
    Inventors: Saiman Lun, Randall L. Hofmann, Ilya Lisenker
  • Patent number: 6612409
    Abstract: A magnetorheological piston includes a body having a substantially magnetically energizable passageway and a substantially magnetically non-energizable passageway. The substantially magnetically non-energizable passageway has a valveless passageway throat and has a flow cross-sectional area which has a minimum at the passageway throat and which is larger away from the passageway throat. A magnetorheological damper includes a cylinder and the above-described magnetorheological piston, wherein the piston is positioned in, and slideably engages, the cylinder.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: September 2, 2003
    Assignee: Delphi Technologies, Inc.
    Inventors: Saiman Lun, Randall L. Hofmann, Ilya Lisenker
  • Publication number: 20030121738
    Abstract: A magnetorheological piston includes a body having a substantially magnetically energizable passageway and a substantially magnetically non-energizable passageway. The substantially magnetically non-energizable passageway has a valveless passageway throat and has a flow cross-sectional area which has a minimum at the passageway throat and which is larger away from the passageway throat. A magnetorheological damper includes a cylinder and the above-described magnetorheological piston, wherein the piston is positioned in, and slideably engages, the cylinder.
    Type: Application
    Filed: December 27, 2001
    Publication date: July 3, 2003
    Inventors: Saiman Lun, Randall L. Hofmann, Ilya Lisrnker
  • Patent number: 6390258
    Abstract: A guide assembly for a rod of a motor vehicle strut comprises a rod guide, a seal cover, and a retainer. The seal cover engages the rod guide, and defames an area therebetween. The retainer is engaged with the seal cover. A first O-ring is disposed between the seal cover and the rod guide, and a second O-ring is disposed between the rod guide and the retainer.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: May 21, 2002
    Assignee: Delphi Technologies, Inc.
    Inventors: Randall L. Hofmann, Steven R. Robinson, Michael W. Hurtt