Patents Assigned to Powerscreen International Limited
  • Patent number: 4983280
    Abstract: Screening apparatus comprises a feeder conveyor, an elevator, a screen box, an end boom elevator and two lateral boom elevators all carried on a wheeled trailer. The elevator has an elongated support with an endless belt arranged around two rollers longitudinally spaced apart on the support. A superstructure framework on the trailer carries the support in a plurality of inclined positions, and the screen box is pivotally linked to the end of the support corresponding to the discharge end of the belt and hinged to the structure at the opposite end. The support extends and retracts along its lengths by means of hydraulic rams and thereby pivots the screen. The screen box also has hydraulic rams and cylinders to adjust the angle of inclination of the screen relative to the support and thereby also adjust the inclination of the support.
    Type: Grant
    Filed: April 5, 1989
    Date of Patent: January 8, 1991
    Assignee: Powerscreen International Limited
    Inventor: Jan E. Eriksson
  • Patent number: 4879023
    Abstract: A conveyor assembly comprising a main inclined conveyor with a screen box located at a discharge or off-loading end thereof, the main conveyor and screen box being located on an elongate structure including length adjustable legs intermediate its ends mounted on wheels. The loading end of the screen box is pivoted on an axis transversely of and at the discharge end of the structure with the screen box extending towards the loading end of the structure, the discharge end of the screen box being connected to the structure by length-adjustable legs thereby to alter the inclination of the box. A cradle is suspended below the structure to carry one or more boom conveyors the or each to receive a grade of material, the cradle being horizontally oriented and connected by linkage with the structure and the box whereby pivotal movement of the box causes synchronous movement of the cradle such as to maintain a horizontal orientation of the cradle.
    Type: Grant
    Filed: September 16, 1988
    Date of Patent: November 7, 1989
    Assignee: Powerscreen International Limited
    Inventor: Michael L. Mallaghan
  • Patent number: 4058198
    Abstract: A conveyor assembly comprises a main conveyor and a boom conveyor. A mounting is pivotally connected at the discharge end of said main conveyor for movement about a transverse axis relative to said main conveyor, said mounting having a rotatable support on which the boom conveyor is mounted for pivotal movement laterally. A linkage retains said mounting in a horizontal position extended outwardly beyond said discharge end with said rotatable support upright. The support has an attachment device at its upper end providing for pivotal connection about a transverse axis of said boom conveyor for movement thereof in a vertical plane, the boom conveyor being supported by a length-adjustable tie from said mounting. The linkage comprises a series of interconnected pivotal links between said mounting and said main conveyor to provide for synchronized adjustment of the mounting to maintain the support upright on alteration of the inclination of said main conveyor.
    Type: Grant
    Filed: March 30, 1976
    Date of Patent: November 15, 1977
    Assignee: Powerscreen International Limited
    Inventors: Patrick O'Neill, Patrick Joseph Douglas, Michael Lee Mallaghan
  • Patent number: D244925
    Type: Grant
    Filed: November 11, 1975
    Date of Patent: July 5, 1977
    Assignee: Powerscreen International Limited
    Inventors: Patrick O'Neill, Patrick J. Douglas, Michael L. Mallaghan