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.

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.

The invention relates to a method for operating a conveyor means, in particular a hoist, a crane, a continuous conveyor or the like, and to a control unit, the conveyor means comprising a drive unit (21) and a control unit (20) for controlling the drive unit, the drive unit comprising at least two drives (43, 44), the drives being controlled by means of a control device (22) of the control unit, a rotary encoder (25, 38) of the control unit being connected shafts (29, 42) of the drive unit of the conveyor means each allocated to the drives and registering a rotation of the shafts, a rotation angle signal and/or a rotational speed signal being transmitted to the control device by means of an encoder device (26, 39) of the corresponding rotary encoder in order to control the drives, the control device determining the corresponding rotational speed of the shafts and comparing it to a referential rotational speed, the control device controlling the drives depending on the comparison

The invention relates to a method for operating a conveyor means, in particular a hoist, a crane, a continuous conveyor or the like, and to a control unit, the conveyor means comprising a drive unit (21) and a control unit (20) for controlling the drive unit, the drive unit comprising at least two drives (43, 44), the drives being controlled by means of a control device (22) of the control unit, a rotary encoder (25, 38) of the control unit being connected shafts (29, 42) of the drive unit of the conveyor means each allocated to the drives and registering a rotation of the shafts, a rotation angle signal and/or a rotational speed signal being transmitted to the control device by means of an encoder device (26, 39) of the corresponding rotary encoder in order to control the drives, the control device determining the corresponding rotational speed of the shafts and comparing it to a referential rotational speed, the control device controlling the drives depending on the comparison

A control system for a bucket hoist includes a two-axis master switch configured to generate a first and a second command signal responsive to motion along each axis. Each command signal is provided to one of a pair of motor controllers configured to control one of a pair of motors. The two motors are controlled to raise/lower and open/close the load handling member. When the two-axis master switch is moved to the close position, the closing motor controller is commanded to control its respective motor to begin closing the load handling member. The holding motor controller is configured to generate a current to its respective motor to generate torque at a predefined level. The predefined level of torque is selected such that the load handling member lowers into the material in which it is digging as it is being closed.

A control system for a bucket hoist includes a two-axis master switch configured to generate a first and a second command signal responsive to motion along each axis. Each command signal is provided to one of a pair of motor controllers configured to control one of a pair of motors. The two motors are controlled to raise/lower and open/close the load handling member. When the two-axis master switch is moved to the close position, the closing motor controller is commanded to control its respective motor to begin closing the load handling member. The holding motor controller is configured to generate a current to its respective motor to generate torque at a predefined level. The predefined level of torque is selected such that the load handling member lowers into the material in which it is digging as it is being closed.

The invention relates to a method for operating a conveyor means, in particular a hoist, a crane, a continuous conveyor or the like, and to a control unit, the conveyor means comprising a drive unit (21) and a control unit (20) for controlling the drive unit, the drive unit comprising at least two drives (43, 44), the drives being controlled by means of a control device (22) of the control unit, a rotary encoder (25, 38) of the control unit being connected shafts (29, 42) of the drive unit of the conveyor means each allocated to the drives and registering a rotation of the shafts, a rotation angle signal and/or a rotational speed signal being transmitted to the control device by means of an encoder device (26, 39) of the corresponding rotary encoder in order to control the drives, the control device determining the corresponding rotational speed of the shafts and comparing it to a referential rotational speed, the control device controlling the drives depending on the comparison.

The invention relates to a method for operating a conveyor means, in particular a hoist, a crane, a continuous conveyor or the like, and to a control unit, the conveyor means comprising a drive unit (21) and a control unit (20) for controlling the drive unit, the drive unit comprising at least two drives (43, 44), the drives being controlled by means of a control device (22) of the control unit, a rotary encoder (25, 38) of the control unit being connected shafts (29, 42) of the drive unit of the conveyor means each allocated to the drives and registering a rotation of the shafts, a rotation angle signal and/or a rotational speed signal being transmitted to the control device by means of an encoder device (26, 39) of the corresponding rotary encoder in order to control the drives, the control device determining the corresponding rotational speed of the shafts and comparing it to a referential rotational speed, the control device controlling the drives depending on the comparison.