Patents by Inventor Keskiniva MARKKU

Keskiniva MARKKU 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).

  • Valve piloting arrangements for hydraulic percussion devices
    Patent number: 11680446
    Abstract: A hydraulic percussion device comprising a piston mounted for reciprocal motion within a cylinder to impact a percussion bit and a control valve to control reciprocation of the piston. A valve pilot line is arranged to switch the control valve based on the position of the piston within the cylinder, wherein the valve pilot line is alternately connected, by the reciprocal movement of the piston, to high and low pressure lines (P, T) via an undercut in the piston. The undercut is located at a portion of the piston having a diameter less than the maximum sealing diameter of the piston.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: June 20, 2023
    Assignee: MINCON INTERNATIONAL LIMITED
    Inventor: Keskiniva Markku
  • VALVE PILOTING ARRANGEMENTS FOR HYDRAULIC PERCUSSION DEVICES
    Publication number: 20200165871
    Abstract: A hydraulic percussion device comprising a piston mounted for reciprocal motion within a cylinder to impact a percussion bit and a control valve to control reciprocation of the piston. A valve pilot line is arranged to switch the control valve based on the position of the piston within the cylinder, wherein the valve pilot line is alternately connected, by the reciprocal movement of the piston, to high and low pressure lines (P, T) via an undercut in the piston. The undercut is located at a portion of the piston having a diameter less than the maximum sealing diameter of the piston.
    Type: Application
    Filed: July 17, 2018
    Publication date: May 28, 2020
    Applicant: MINCON INTERNATIONAL LIMITED
    Inventor: Keskiniva MARKKU