Motor Powered Grabs
Motor Powered Grabs are designed for applications ranging from lifting large batches of heavy timbers to shifting earth, sand and cement. The drives are driven by cylinders powered by an electric motor and hydraulic pump. A cable from the crane provides power to the grab, and also carries its commands. These grabs are designed for exceptional reliability, ensuring that they remain the ideal, cost-effective option for long term operation.
Design
- Crossbeam with compact electro-hydraulic drive unit
- Working cylinders drive jaws directly
- Pair of jaws with synchronization lever
- Optimum usage of lift height thanks to low construction height
- Shell construction relieved of large cylinder forces by force guides
- At the same time, the force guides form protected mounting space for the cylinders
- Grab cutting edges with welded-on, service-friendly, wear-resistant profiles
Parts and Principles
Drive unit
Driven by three-phase AC or DC motor. The electric motor is switched via a reversing contactor and opens and closes the jaws electro-hydraulically depending on the direction of rotation. Reliable switching processes; control is carried out without solenoid valves. Overload protection through self-regulating hydraulics. Low overall height, compact construction. Secure retention of loads even in the case of a power failure, thanks to check valves.
Working cylinders
High clamping force and high opening speed thanks to differential cylinders driving the jaws directly. Thanks to a special installation position, the cylinder is protected from damage on all sides. Corrosion-resistant piston rod thanks to special chrome-plating.
Jaws
The jaws are interchangeable. Various shapes and sizes allow tailoring to the respective load. High degree of filling thanks to favorable top ratio. Robust design for low unladen weight. Long service life thanks to use of fine-grain structural steel and wear-resistant cutting edge sections.
Pivots
All pivots are designed to be low-maintenance. Jaw synchronization with synchronization lever for clamshell grab. For the orange-peel grab, the jaws close independently of one another.