Patents by Inventor Randall L. Derr

Randall L. Derr 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).

  • Publication number: 20220314728
    Abstract: A hydraulic actuator for a vehicle suspension includes: a pump assembly including an electric motor coupled to first and second pumps to transfer hydraulic fluid to a discharge header; a first isolation valve having an elastomeric seat and configured to selectively block fluid flow from a port in fluid communication with a height-adjustable damper to the discharge header; and a second isolation valve having a metal seat and connected in series with the first isolation valve to selectively block fluid flow from the port to the discharge header. The first pump transfers hydraulic fluid from a supply fluid passage to a first discharge header, and the second pump transfers hydraulic fluid from the supply fluid passage to a second discharge header. A recirculation valve selectively controls fluid flow from the second discharge header to the supply fluid passage.
    Type: Application
    Filed: March 20, 2022
    Publication date: October 6, 2022
    Inventors: Daniel Norbert BORGEMENKE, Adam Michael OSSWALD, David Fredrick REUTER, Michael William LANDIS, Earl Wayne LLOYD, Randall L. DERR
  • Patent number: 6264290
    Abstract: A single-operation valve assembly useful in such braking system applications, as well as others, includes a flow passage and a valve member located within the flow passage at a first position in which the valve member prevents fluid flow from an upstream side of the valve member to a downstream side of the valve member. The valve member and flow passage are configured for movement of the valve member from the first position along the flow passage to a second position along the flow passage when a pressure difference between the upstream side of the valve member and the downstream side of the valve member exceeds a threshold level. The valve member and the flow passage are also configured for free flow of fluid along the flow passage in either direction when the valve member moves to the second position. Thus, in a braking system circuit the subject valve assembly does not interfere with fluid flow in the circuit after the valve member has been blown to the second position.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: July 24, 2001
    Assignee: Delphi Technologies, Inc.
    Inventors: Gary Chris Fulks, Daniel Norbert Borgemenke, Randall L. Derr, James Randolph Bond
  • Patent number: 5577579
    Abstract: A suspension damper and a method of manufacturing a suspension damper so that a common cylinder end assembly is used with dampers having cylinder tubes of varying diameters to accommodate piston assemblies having various desirable performance characteristics resulting from the specific diameter thereof. This provides a way of varying the cylinder tube to suit the specifically selected piston assembly while reducing component part proliferation of the complicated cylinder end assembly part of the damper.
    Type: Grant
    Filed: October 30, 1995
    Date of Patent: November 26, 1996
    Assignee: General Motors Corporation
    Inventor: Randall L. Derr
  • Patent number: 5333708
    Abstract: A twin-tube hydraulic damper includes a fluid-filled cylinder tube closed at its lower end by a cylinder end. A piston is slidably mounted in the cylinder tube and divides an interior volume of the cylinder tube into upper and lower chambers. A plurality of intake slots permit fluid to flow from a reservoir to the lower chamber. A plurality of exit flow openings permit fluid to flow from the lower chamber to the reservoir. A cut-off cap is slidably mounted on the cylinder end and sprung away from the cylinder end by a reaction spring. An annular wall formed on the cylinder end receives the cap as the piston engages an activation spring near the travel limit of a compression stroke. Reduced fluid flow through the exit flow openings increases the damping force to reduce harsh impacts.
    Type: Grant
    Filed: January 11, 1993
    Date of Patent: August 2, 1994
    Assignee: General Motors Corporation
    Inventors: Eric L. Jensen, Rachel J. Belvo, Randall L. Derr
  • Patent number: 5163538
    Abstract: A semi-active hydraulic damper includes a solenoid valve assembly for controlling fluid flow through a bypass channel. A blow-off valve assembly is provided in series with the solenoid valve assembly to provide low-level damping when the bypass channel is open.
    Type: Grant
    Filed: September 3, 1991
    Date of Patent: November 17, 1992
    Assignee: General Motors Company
    Inventors: Randall L. Derr, Stephen E. Dourson, Chris F. Keller, Jr., William S. Morgan