Product manual

Model #RB3-065/035 15 R20140519
8. Programming and Operation Recommendations
VERSABALL® Grippers utilize a technology known as granular
jamming to grip and release objects through rapid hardness
modulation. You can see this same effect if you buy vacuum-packed
coffee at the grocery store – hard as a brick until you release the seal,
whereupon the particles will flow more like a fluid. It can be useful to
keep this concept in mind when you are working with your gripper –
vacuum-pack the gripper to so that it will become rigid and grip onto
an object, inflate the gripper to release the vacuum seal and soften the
gripper for contact with the next object. This process is shown in
Figure 10.
Figure 10
When gripping a target object, VERSABALL® Grippers may achieve
retention forces by three independent mechanisms, as shown in
Figure 11. Shown on the left, friction forces from pinching are the most
common. These forces develop during the small volume contraction
that occurs when the gripper is vacuum-hardened. In the center,
entrapment or capture of the object can occur if the gripper can wrap
around some geometric feature. This mechanism is less common, but
can increase holding force dramatically when it occurs. Finally on the
right, a vacuum-suction force can develop in the sealed gap that forms
between the gripper and a smooth object. This mechanism is also less
common, but can provide dramatic increases in holding force as well.