The gripper is the last and central link in the kinematic chain of a handling device. The efficiency and safety of the entire process depend on the functionality and performance of the end effector. More than 90 % of grippers are pneumatic - they have proven themselves in automation technology for decades thanks to their durability, maintenance-free operation and robustness in all industrial sectors.

Extended functions for pneumatic grippers

Pneumatic grippers have long since made their way into the future. The integration of sensor technology, as offered by the new Schunk PGL-plus-P, opens up new possibilities in terms of process monitoring, safety and individualization. Thanks to the direct connection to the controller, the gripper module can be diagnosed at any time; process and status parameters that can be called up in real time form the basis for various data analyses. An integrated IO-Link sensor system, for example, transmits the finger position over the entire stroke range and can precisely differentiate between workpieces. This eliminates the need for external sensors, which simplifies procurement, commissioning and repair.

Schunk is constantly working on the further development of pneumatic actuators and is paving the way for modern handling scenarios in which pneumatic grippers will continue to be indispensable in the future. The user benefits from high efficiency and easy commissioning, as pneumatic systems are simple in design. Applications with pneumatic grippers achieve very high working speeds. In high-speed pick-and-place applications, for example, fast cycles are realized with the highest possible reliability and short downtimes. Other high-speed applications for pneumatic grippers and modules include highly dynamic handling cells in assembly automation.

Speed, process safety, reliability and durability make pneumatic grippers indispensable for many industrial applications. These properties result in productivity and fail-safe processes. Pneumatic modules have a relatively low dead weight, which means that the robot's payload can be used efficiently for the actual handling process. The combination of dead weight, power density and price-performance ratio is a unique selling point for pneumatic gripper modules. Thanks to their mechanical robustness, they can often withstand individual force and torque overloads without being damaged. They are also suitable for use in dirty environments. They work without problems in harsh and demanding operating environments with moisture and dust and, in suitable designs, also in potentially explosive atmospheres. Pneumatic grippers also score particularly well in medical technology applications and in the laboratory and pharmaceutical sectors. Thanks to their temperature robustness, they are suitable for forges and foundries, where they can handle large and heavy red-hot workpieces with suitable protective measures.

Safety thanks to integrated gripping force maintenance

The pneumatic small parts gripper shows its strengths in low-contamination environments, such as in assembly, laboratories or the pharmaceutical industry. © Schunk

The reliability of the entire gripping and handling process depends largely on the gripping force that is applied to the object during the gripping process. It must counteract all forces that occur - in addition to the weight of the workpiece, this also includes process forces and inertial forces caused by translation and rotation during the handling process. The gripping force must securely pick up and hold the workpiece. The component must not fall under any circumstances, as this can have serious consequences - from mechanical destruction of the component or the entire system to worker injuries and chemical or biological contamination. A gripping force safety device is often required to maintain the gripping force in the event of a power failure. Users of industrial grippers receive this functional safety fully integrated in the universal gripper PGL-plus-P with the certified safe gripping force maintenance GripGuard. At least 80 % of the nominal force is retained. Uncontrolled jaw movement in the event of a sudden drop in pressure is ruled out, and no workpieces are lost in the event of an emergency stop.

Schunk has developed the PGL-plus-P for the premium segment - for more safety in the process with a wider range of applications. With a gripping force of 220 N in size 10 with a total stroke of 20 mm and up to 1,300 N in size 25 with a total stroke of 50 mm, it closes the gap between universal grippers and large stroke grippers. In addition to the certified gripping force maintenance, it is equipped with integrated IO-Link sensors. Users can switch between IO-Link and SIO mode. With the "Gripping Point Mode" and "Gripping Range Mode", Schunk also offers two sensor profiles for easy programming of the workpiece positions or ranges. The gripper has a flat and compact design and is equipped with robust multi-tooth guidance and IP64 sealing. In combination with an integrated sealing air connection, the protection class can be increased to IP67. Thanks to H1-compliant lubrication as standard, the gripper can also be used in medical, pharmaceutical and food applications.

Reliable gripping - from very small to very large

The MPG-plus small parts gripper handles small components and offers short cycle times and compact external dimensions. A whole series of these compact modules are active in many automation cells. The MPG-plus is the gripper of choice, particularly in the electronics industry, where small parts need to be handled in large quantities and in the shortest possible time. It can optionally be fitted with a protective cover and is therefore suitable for use in life science applications.

With the "Gripping" design tool, the right Schunk gripper can be selected easily and specifically for every application. © Schunk

The new PLG large stroke gripper is suitable for really large objects. The pneumatic two-finger parallel gripper has a large jaw stroke, high gripping force and profile rail guidance. Schunk offers the gripping module in a wide range of variants and options with individual configuration. Using a browser-based web tool, customers can configure their large-stroke gripper without having to use their own CAD program. The CAD data and a configuration-specific data sheet are available at the touch of a button. The tool reduces the design effort and provides immediate information on price and delivery time. The gripper is available in two finger versions. In addition to the basic version for short finger lengths, a version for finger lengths up to 800 mm can also be configured. The stroke per jaw can be selected between 100 and 400 mm per jaw.

Schunk offers the PLG with a pre-assembled pressure maintenance valve including tubing for temporary force and position maintenance in the event of a pressure failure. By externally mounting up to ten inductive proximity switches on up to four gripper sides, a correspondingly large number of positions can be queried. Alternatively, the stroke of the base jaw can be queried via an integrated IO-Link query.

In handling processes, pneumatic gripper modules combine high productivity with process reliability and a long service life, even under demanding conditions. Schunk has more than 30 series of different pneumatic grippers in its portfolio - a variety in all sizes for the complete range of industrial applications. With solid planning and requirements analysis, every user can find the right gripper for their task and thus design their application economically and sustainably. With the "Gripping" design tool, the right gripper can be selected for every application.