Method and apparatus for spatially orienting movable members using shape memory effect alloy actuator

An apparatus for spatially orienting the pointing direction of the distal end of a flexible borescope comprising:

• (a) at least one helical spring fabricated from a shape memory effect alloy, said spring being attached to both the cable and tip of said borescope, and said spring having memory of at least a first shape previously imprinted upon said spring, and
• (b) means for varying the temperature of at least part of said spring to approach the transition temperature of the said shape memory effect alloy of which said spring is fabricated, whereby said spring shape may approach its memory shape with an accompanying production of external force effective in moving said borescope tip relative to said borescope cable, the closeness of approach of said spring shape to its memory shape being proportional to the closeness of the actual temperature of said spring to said transition temperature of said spring.

In a structure having a body and an end part movable with respect to said body, the method of moving said movable part to point in an arbitrary desired direction with respect to said body comprising:

• (a) connecting an actuating member fabricated of a shape memory effect alloy between said body and movable end part of said structure, and
• (b) varying the temperature of said actuating member to approach a value at which at least part of said actuating member approaches a transition to a memory shape.