Advantages of Using Flexible Electric Grippers for Industrial Robotic Applications
The following is a publication from our valued supplier-partner Robotiq
Robotiq’s 2-Finger Adaptive Gripper
Part 1 – Introduction and The Easy Gripping Intelligence
Today’s manufacturers are under relentless pressure to reduce costs, increase agility and automate more processes, including the high-mix, labor intensive ones. However, existing technologies such as tool changers provide only limited and expensive solutions when it comes to handling different parts. Changeover costs, custom gripper designs and tooling costs often represent issues which can stop investment in the automation of a process. The return on investment is crucial when automating high-mix part types of applications and it is often hard to achieve. That is why 90% of US manufacturers still don’t use robots in their production processes.
This is why Robotiq has designed the Adaptive Robot Gripper to provide manufacturers with maximum flexibility in robotic parts handling.
2-Finger Gripper Main Features
In keeping with the idea of giving manufacturers the flexibility needed to automate high-mix processes, Robotiq designed the 2-Finger Adaptive Gripper to provide unmatched versatility in handling a broad range of parts.
Fully programmable, the robotic gripper provides:
- Three distinct gripping modes – parallel, encompassing and inside – enable handling of different part geometries including flat, square, cylindrical and irregular
- High payload to weight ratio coupled with long stroke enable handling of a variety of sizes in a compact form factor
- Precise speed and force controls enable handling of parts of different rigidities, ranging from brittle, to deformable, to stiff
- Accurate finger control enables fast cycle times through partial open/closing
Taken together, these capabilities make the 2-Finger Adaptive Gripper a perfect fit for high-mix processes such as light assembly, sorting and kitting, packaging, machine tending, bin picking and parts transfer.
The Easy Gripping Intelligence
How can this Gripper can be so versatile while using only one actuator? The secret lies in its unique mechanical architecture.
Encompassing Grip vs Pinch Grip
The mechanism driving the fingers of this Gripper is optimized to obtain two distinct contact regions. The first one, called the “encompassing grip region”, is located at the base of the fingers, while the second one, called the “pinch grip region”, is located at the end/tip of the finger. The boundary between these two adjacent regions is called the “equilibrium point”.
When the contact of the finger with the object to be grasped occurs in the encompassing grip region, the finger automatically adapts to the shape of the object and curls around it. On the other hand, when the contact is made in the pinch grip region, the finger maintains its parallel motion and the object is pinched.
The finger keeps its parallel motion when a contact is made above the equilibrium point during a pinch grip, the same is true for a contact made below the equilibrium point during an inside grip, i.e. for a force applied at the back of the finger. This unique feature allows the Gripper to pick up objects from the inside, which proves to be very useful in many situations.
Coupling Between the Fingers
In addition to the mechanism used inside each of its fingers, the Gripper also relies on a special coupling architecture between the fingers. In fact, it is mechanically designed to ensure that the two fingers move in conjunction with each other in order to center the object grasped in the middle of the Gripper. This self-centering avoids the need to use expensive sensors and is above all safer.
In the same vein to make this Robot Gripper as reliable as possible, a self-locking feature has been incorporated into it between the actuator and the fingers. By doing so, we are sure that the Gripper will never release the object and let it fall if the power is shut down. It is also economically interesting, as the actuator doesn’t need to apply torque continually when an object is grasped, thus in addition to the power saved, the lifespan of the Gripper is thereby maximized.
Finally, it is important to note that the Gripper may be manually opened when the power is shut down, even if the Gripper is rigidly grasping an object.
Coming Soon: Gripper Communication Basics