Gripper device and hoisting device for a trash rake cleaner, trash rake cleaner and method therefor

A gripper device for a trash rake cleaner, comprising:

• 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 the first cable is attached to the gripper arm at the position of a first point of engagement and the second cable is attached to the gripper arm at the position of a second point of engagement, wherein the points of engagement are provided on either side of the rotation axis such that upward movement of the first cable relative to the second cable carries the gripper to the open end position and upward movement of the second cable relative to the first cable carries the gripper to the closed end position, wherein in the open end position the moment arm of the tensioning force in the first cable relative to the rotation axis is greater than the moment arm of the tensioning force in the second cable relative to the rotation axis, and in the closed end position the moment arm of the tensioning force in the first cable relative to the rotation axis is smaller than the moment arm of the tensioning force in the second cable relative to the rotation axis, characterized in that each hoisting means is driven by a separate drive, the gripper device further comprising a controller connected to the drives for controlling the drives by transmitting a control signal with the controller, wherein the controller has a hoisting mode in which the controller is configured to transmit the same control signal to both drives for the purpose of raising or lowering the gripper, each drive comprising a motor with internal slippage or a slippage coupling such that synchronous running of the hoisting means is automatically realized in the hoisting mode.

A gripper device for a trash rake cleaner, comprising

• a gripper with a gripper arm which is rotatable around a rotation axis such that the gripper is movable between an open end position and a closed end position;
• a hoisting device connected to the gripper and comprising a first hoisting means, a second hoisting means and a cable, the cable comprising a first cable part which comprises the one outer end of the cable and a second cable part which comprises the other outer end of the cable, wherein the one outer end is connected to the first hoisting means and the second outer end is connected to the second hoisting means;
• and
• a redirecting means which is connected fixedly to the rotation axis and around which the cable extends for the purpose of raising and lowering the gripper arm by simultaneously respectively hoisting and lowering the first cable part and the second cable part, carrying the gripper arm to the open end position by hoisting the first cable part relative to the second cable part and carrying the gripper arm to the closed end position by hoisting the second cable part relative to the first cable part,
• wherein in the open end position the moment arm of the tensioning force in the first cable part relative to the rotation axis is greater than the moment arm of the tensioning force in the second cable part relative to the rotation axis, and in the closed end position the moment arm of the tensioning force in the first cable part relative to the rotation axis is smaller than the moment arm of the tensioning force in the second cable part relative to the rotation axis.