Parallel Gripper Mechanism and Magnetic Grippers in Robotics
Robotic automation has become an important part of modern manufacturing, helping companies handle components, automate repetitive processes and improve production consistency. At the centre of many robotic handling systems is the gripper—the component that physically interacts with the workpiece.
Different applications require different gripping principles. A parallel gripper mechanism is commonly used when a robot needs to grip components securely between opposing jaws, while a magnetic gripper in robotics can provide an alternative for handling suitable ferromagnetic workpieces. Selecting the right technology depends on the material, geometry, weight and handling requirements of the application.
What Is a Parallel Gripper Mechanism?
A parallel gripper mechanism uses two or more gripping fingers that move along parallel paths to hold a workpiece. The fingers generally move towards or away from each other, allowing the gripper to securely grasp components from their sides.
This relatively straightforward mechanism makes parallel grippers versatile for industrial automation. They can be used for machine loading, assembly, pick-and-place operations, inspection and material handling.
How a Parallel Gripper Works
A typical parallel gripper consists of a housing, drive mechanism and gripping fingers. When the gripper receives a command, the internal drive moves the fingers into the required position.
The fingers contact the workpiece and apply sufficient gripping force to hold it while the robot moves. Once the component reaches its destination, the fingers release it.
Depending on the design, parallel grippers may use pneumatic, electric or other drive technologies.
Advantages of Parallel Grippers
Parallel grippers are widely used because they can offer a combination of versatility, repeatability and relatively simple operation.
Secure Mechanical Grip
Unlike non-contact handling methods, a parallel gripper physically holds the workpiece. This can make it suitable for components that are not compatible with magnetic or vacuum gripping.
Handling Different Geometries
Parallel grippers can be equipped with customised fingers or jaws designed around a particular component. This allows manufacturers to adapt the gripping system to different workpiece shapes.
Repeatable Operation
Automated grippers can perform the same gripping movement repeatedly, supporting consistent handling in high-volume production environments.
Suitable for Automation
Parallel grippers can be integrated with industrial robots, collaborative robots and automated machine-loading systems, depending on the application.
Where Are Parallel Grippers Used?
The versatility of a parallel gripper mechanism allows it to support a wide range of manufacturing processes.
Machine Loading and Unloading
Robots can use parallel grippers to load raw components into CNC machines and remove finished parts after machining.
Assembly
A gripper can pick up components from a feeder or conveyor and position them during automated assembly.
Pick-and-Place
Repeated movement of components between stations is a common application for robotic parallel grippers.
Inspection
Grippers can also hold parts while cameras, sensors or other inspection systems evaluate them.
What Is a Magnetic Gripper in Robotics?
A magnetic gripper in robotics uses magnetic force to pick up and move suitable ferromagnetic components. Rather than gripping an object between mechanical fingers, the magnetic gripper holds the component through magnetic attraction.
This approach can be useful when the workpiece is made from an appropriate magnetic material and the application allows access to a suitable surface.
SCHUNK offers magnetic gripping solutions as part of its broader range of gripping and automation technologies. Its portfolio is designed to support automated handling applications involving different workpiece characteristics and industrial requirements. (schunk.com)
How Magnetic Grippers Differ From Mechanical Grippers
The main difference is how the workpiece is secured.
A parallel gripper uses physical contact and gripping force between its fingers. A magnetic gripper uses magnetic attraction to hold a suitable workpiece.
Benefits of Magnetic Gripping
Magnetic grippers can provide fast engagement with compatible metal components. Since there are no conventional jaws that need to close around the part, they can sometimes access workpieces from positions where mechanical gripping would be difficult.
They can also handle certain flat or irregularly shaped ferromagnetic components without requiring customised mechanical fingers.
Limitations of Magnetic Gripping
Magnetic technology is not suitable for all materials. Wood, many plastics, glass and non-ferrous metals generally cannot be handled using conventional magnetic gripping principles.
Surface conditions, material thickness and workpiece geometry can also influence magnetic holding performance.
Parallel Gripper vs. Magnetic Gripper
Choosing between the two technologies should begin with the application.
| Factor | Parallel Gripper | Magnetic Gripper |
| Holding principle | Mechanical | Magnetic |
| Suitable materials | Wide range | Primarily ferromagnetic |
| Customisation | Custom fingers possible | Magnetic contact surface |
| Typical use | Assembly, machining, handling | Metal handling |
| Side access | Often required | Can reduce side-access requirements |
| Delicate parts | Depends on jaw design | Depends on magnetic force and material |
Neither technology is universally better. The correct choice depends on the workpiece and the required process.
Factors to Consider When Selecting a Robotic Gripper
Selecting a gripper requires more than checking its maximum gripping force. Several application-specific factors should be evaluated.
Workpiece Weight
The gripper must safely handle the component under the robot’s planned acceleration and movement. The combined weight of the workpiece and end-of-arm tooling should also remain within the robot’s payload capabilities.
Workpiece Geometry
The shape and available gripping surfaces can determine whether a mechanical or magnetic solution is more practical.
Material
Material is particularly important when considering magnetic gripping. The workpiece must have appropriate magnetic characteristics.
Cycle Time
High-volume applications may require rapid gripping and release. The gripper’s operating speed should therefore match the required production cycle.
Environmental Conditions
Manufacturing environments may contain coolant, oil, dust, chips and temperature variations. The gripper should be appropriate for these operating conditions.
Required Precision
Some applications require highly repeatable positioning. Gripper repeatability, finger design and robot accuracy should be considered together.
Combining Grippers With Other Automation Technologies
A gripper rarely operates independently. It is usually part of a broader automated system that may include robots, sensors, conveyors, machine tools, fixtures and control software.
For example, a robotic machine-loading cell may use a parallel gripper to pick a component from a conveyor, position it inside a workholding system and remove the finished part after machining.
A magnetic gripper could perform a similar role when the components are suitable ferromagnetic parts.
Improving Automated Production
When gripping technology is properly matched to the process, automation can reduce repetitive manual handling and create more predictable production cycles.
Consistent gripping and positioning can also support quality control by reducing variation in how components are presented to machines or assembly stations.
SCHUNK Solutions for Robotic Handling
SCHUNK develops gripping and automation technologies for industrial applications, including parallel grippers, magnetic grippers and other end-of-arm tooling solutions.
Its approach covers different gripping principles so manufacturers can select technology based on workpiece properties and application requirements. This can be particularly valuable for production environments where different components or processes require different handling methods.
Rather than selecting a gripper based solely on size or gripping force, manufacturers should evaluate the complete application, including robot payload, workpiece characteristics, cycle time, environmental conditions and required precision.
Building a Reliable Robotic Handling System
A well-designed robotic handling system begins with choosing a gripping principle that matches the workpiece and process. A parallel gripper mechanism can provide versatile mechanical handling for a wide range of components, while a magnetic gripper in robotics can offer efficient handling of suitable ferromagnetic parts.
Both technologies have an important place in industrial automation. The key is understanding their capabilities and limitations before implementation.
By evaluating material, weight, geometry, cycle time, robot compatibility and environmental conditions, manufacturers can select a gripping solution that supports safe, repeatable and efficient operation.
SCHUNK’s portfolio of gripping and automation technologies provides manufacturers with options for developing application-specific robotic handling systems and improving the efficiency of modern production processes.
