Patents by Inventor Harm Jan Grijpstra

Harm Jan Grijpstra 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).

  • Gripper device and hoisting device for a trash rake cleaner, trash rake cleaner and method therefor
    Patent number: 9840821
    Abstract: A gripper device comprises a gripper with a gripper arm rotatable around a rotation axis such that the gripper is movable between an open end position and a closed end position, and a hoisting device connected to the gripper and comprising a first cable and a second cable which are each connected with their one outer end to the gripper and are each connected with their other outer end to respectively a first and second hoisting means for raising and lowering the gripper with the cables, wherein each hoisting means is, driven by a separate drive, wherein a controller transmits the same control signal to both drives for the purpose of raising or lowering the gripper, and each drive comprises a motor with internal slippage or a slippage coupling so that synchronous running of the hoisting means is automatically realized.
    Type: Grant
    Filed: July 22, 2014
    Date of Patent: December 12, 2017
    Assignee: Cerberus Termunterzijl Beheer B.V.
    Inventors: Robert Alexander Haak, Harm Jan Grijpstra
  • GRIPPER DEVICE AND HOISTING DEVICE FOR A TRASH RAKE CLEANER, TRASH RAKE CLEANER AND METHOD THEREFOR
    Publication number: 20160194845
    Abstract: A gripper device comprises a gripper with a gripper arm rotatable around a rotation axis such that the gripper is movable between an open end position and a closed end position, and a hoisting device connected to the gripper and comprising a first cable and a second cable which are each connected with their one outer end to the gripper and are each connected with their other outer end to respectively a first and second hoisting means for raising and lowering the gripper with the cables, wherein each hoisting means is, driven by a separate drive, wherein a controller transmits the same control signal to both drives for the purpose of raising or lowering the gripper, and each drive comprises a motor with internal slippage or a slippage coupling so that synchronous running of the hoisting means is automatically realized.
    Type: Application
    Filed: July 22, 2014
    Publication date: July 7, 2016
    Inventors: Robert Alexander Haak, Harm Jan Grijpstra