Patents by Inventor Michael Alexander Duff

Michael Alexander Duff 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).

  • Hydraulic system, manifold and volumetric compensator
    Patent number: 6519939
    Abstract: A hydraulic system manifold having a body, a counterbalancer in the body and a flow controller in the body is disclosed. The body has first and second pump ports, first and second cylinder ports, first and second compensator ports and first and second supply conduits in communication with the first and second pump ports, the counterbalancer and the flow controller. The counterbalancer is in communication with the first and second supply conduits and the cylinder ports, to communicate hydraulic fluid between the first and second supply conduits and the first and second cylinder ports while counterbalancing hydraulic fluid pressure in the first and second supply conduits. The flow controller is in communication with the first and second supply conduits and the compensator ports, to control the flow of hydraulic fluid between the compensator ports and the first and second supply conduits to supply and store hydraulic fluid in a volumetric compensator in communication with the compensator ports.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: February 18, 2003
    Assignee: M-Mac Actuators, Inc.
    Inventor: Michael Alexander Duff
  • Hydraulic system, manifold and volumetric compensator
    Patent number: RE39158
    Abstract: A hydraulic system manifold having a body, a counterbalancer in the body and a flow controller in the body is disclosed. The body has first and second pump ports, first and second cylinder ports, first and second compensator ports and first and second supply conduits in communication with the first and second pump ports, the counterbalancer and the flow controller. The counterbalancer is in communication with the first and second supply conduits and the cylinder ports, to communicate hydraulic fluid between the first and second supply conduits and the first and second cylinder ports while counterbalancing hydraulic fluid pressure in the first and second supply conduits. The flow controller is in communication with the first and second supply conduits and the compensator ports, to control the flow of hydraulic fluid between the compensator ports and the first and second supply conduits to supply and store hydraulic fluid in a volumetric compensator in communication with the compensator ports.
    Type: Grant
    Filed: June 4, 2003
    Date of Patent: July 11, 2006
    Assignee: M-Mac Actuators, Inc.
    Inventor: Michael Alexander Duff