Schmalz Finger Grippers Mimic Human Hands

The fingers are gentle enough to grip delicate food products.

(Image courtesy of Schmalz.)

(Image courtesy of Schmalz.)

Schmalz, a leader in vacuum and ergonomic handling systems, recently released an innovative line of finger grippers. The four-fingered grippers are designed around a human hand to give them a precise touch. The grippers are well-suited for delicate, difficult-to-grip foods such as pastries and produce.

The tapered fingers enable the grippers to transfer products onto trays and allow for precise placement of small objects. For example, the grippers can handle a task such as creating a sushi bento box with delicacy. In fact, Schmalz designed the grippers with the food industry in mind. The line includes a hygienic design specifically for direct food handling.

Direct food handling requires accounting for the possibility of contamination and cross-contamination of food products. To address this, Schmalz included several design features to make the grippers easy to clean. The internal vacuum and pneumatic controls are encased in a housing that has a cleanable design. The pneumatic connection has a hygienic design to reduce contamination. Finally, the connection between the gripper fingers and the base unit was designed to avoid contamination by reducing direct contact with food products.

The body of the grippers is made of aluminum or PET-P in the hygienic designs with flange for connection to common robots. The grippers are covered with silicone and curved to mimic a human hand. The articulation of the fingers is controlled pneumatically, and the system uses pressure and vacuum to open and close the fingers.

The Basic control unit opens and closes via the pneumatic system, whereas the Controlled control unit offers variable grip patterns. Users can change the position of the fingers, adjust the opening angle, modify the gripping force, and select between inward and outward gripping. The system is configured via UBS or a serial interface.

The new product line also includes a model with an additional pneumatic connection that features a vacuum grip in the “palm” of the device in the form of a bellow. The bellow can act as a suction cup or blow-off. The additional vacuum grip increases the gripping force and better stabilizes objects while they are being transported.

The finger grippers operate in a pressure range between −0.8 to a maximum of 1.6 bar. The load capacity of the grippers is up to 1.8 kilograms. The gripper speed can reach 0.05 seconds with a repeatability of ±0.06 millimeters. The fingers are heat-resistant up to 200°C, and are resistant to water and dust (class IP68).

Schmalz recommends the grippers for the picking and packaging of small objects. The aluminum versions are best suited to industrial applications, including warehouse logistics and assembly aid, while the hygienic model is ideal for the food industry. The hygienic units are FDA-compliant and easy to clean.

Schmalz may have initially become known for the manufacturing of razor blades, but it has now become a leader in vacuum technology. An important development that Schmalz made has been the IO-link vacuum generator. The company is aiming to create a new wave of Industry 4.0 products, with the finger grippers being the latest innovation to grow out of its product line.