Method of Manufacturing a Nickel Titanium Coil Actuator

Abstract

A method for pre-loading a shape memory alloy coil spring wound in a first direction after a shape-setting treatment, the method comprising inverting the coil spring by attaching one end of the coil spring to a core and unwinding it while winding it around the core in a second direction opposite to the first direction.

1 . A method for pre-loading a shape memory alloy coil spring wound in a first direction after a shape-setting treatment, the method comprising inverting the coil spring by attaching one end of the coil spring to a core and unwinding it while winding it around the core in a second direction opposite to the first direction. 
     
     
         2 . The method of  claim 1 , wherein the shape memory alloy comprises NiTi. 
     
     
         3 . A method for pre-loading a shape memory alloy coil spring after a shape-setting treatment, the method comprising inverting the coil spring by pulling the spring through its own center. 
     
     
         4 . The method of  claim 3 , wherein the shape memory alloy comprises NiTi. 
     
     
         5 . The method of  claim 3 , further comprising inserting a plastic tube through the center of the coil spring and pulling the coil spring through the plastic tube to invert the coil spring. 
     
     
         6 . The method of  claim 5 , wherein the coil spring is initially wound around a core wire and a length of its own winding wire, and further comprising pulling the length of its own winding wire through the plastic tube to pull the spring through the plastic tube. 
     
     
         7 - 14 . (canceled)