Gripping and Clamping Applications Using Kinitics Bundled Wire Technology
Dynamic Clamping Force and Precise Control of Gripper Fingers
Kinitics’ Bundled Wire technology uses shape memory alloy (SMA) materials to deliver dynamic force and high precision in a compact package. In a gripping or clamping application, the Kinitics wire bundle can provide many unique advantages over other actuation technologies. Kinitics Bundled Wire technology is suitable for a wide range of gripper applications; with sub-newton force control and 5 µm precision, it can be applied to low force cobot grippers, while industrial end-users can take advantage of high gripping strengths of up to 2000 N, and the grippers’ ability to operate in harsh environments.
Kinitics’ wire bundles can be configured to work with industry standard AC or DC power sources, thus eliminating the need for pneumatic or hydraulic infrastructure. Holding current requirements are a small fraction of the wire bundle’s full-rated current. Additionally, rated force can be maintained over long hold periods and is not subject to duty-based derating. A unique aspect of Kinitics’ Bundled Wire technology is that return stroke follows a natural decay curve. Because of this behavior the wire bundle can tolerate brief power interruptions in addition to high levels of electrical noise and still maintain clamping force on the work piece.
From an electrical perspective the SMA wire bundle behaves as a purely resistive device, simplifying control in a gripping application. When combined with force-sensitive gripper fingers, extremely fine force control is possible and clamping forces can be dynamically adjusted from zero to full rated force.
The Kinitics wire bundle can be easily configured with a rod that provides a pushing or pulling force, enabling outside and inside gripping and clamping applications. A through-rod can even be supplied for special arrangements. The wire bundle develops motion and generates force in a purely linear way, permitting its use in rigid assemblies that can effectively minimize mechanical backlash and slop. With no rotary elements present, wear surfaces can typically be reduced down to one linear rod bearing, or bushing, to handle side loading. By maintaining forces and strokes within their rated limits the actuator can provide millions of maintenance-free cycles.
Kinitics wire bundles can be easily integrated into standard gripper designs, including parallel sliding, linkage, and parallel wedge grippers. Contact us for more information on using Kinitics Bundled Wire technology for gripping or clamping applications.
Shape memory alloys in wire form respond to electricity by contracting. Kinitics’ Bundled Wire technology connects several SMA wires between fixed and moving ends, producing direct linear motion.
A commercially available Kinitics linear actuator using shape memory alloy materials. The behaviour of the SMA wires makes Kinitics technology ideal for gripping applications.
Kinitics wire bundle arranged inside a parallel wedge style gripper.
Contact us to receive a more detailed application note describing the use of Kinitics wire bundles in grippers.