Magnetostrictive linear position detector with reflection termination

A magnetostrictive linear displacement detector comprising:

• a magnetostrictive wire anchored at opposite head and foot ends and defining a measurement interval therebetween;
• a cylindrical torus disposed proximate said foot end of said magnetostrictive wire having a hole along its axis through which said magnetostrictive wire is passed and attached, said cylindrical torus forming a reflection termination placing a predetermined mechanical impedance to torsional motion on said magnetostrictive wire for inducing reflections of torsional motion;
• a damping termination mechanically coupled to said magnetostrictive wire at said head end for damping reflections of torsional motion;
• a return wire having a foot end electrically coupled to said foot end of said magnetostrictive wire and a head end;
• a magnet disposed for displacement along the said magnetostrictive wire within said measurement interval, the position of said magnet within said measurement interval being the linear displacement detected;
• an electrical excitation means electrically coupled to said head end of said magnetostrictive wire and said head end of said return wire or producing a predetermined electrical excitation through said magnetostrictive wire and said return wire;
• a torsional motion sensor disposed proximate to said head end of said magnetostrictive wire for generating an electrical indication of torsional motion within said magnetostrictive wire;
• and
• a displacement determination means connected to said electrical excitation means and said torsional motion sensor for detecting the position of said magnet within said measurement interval of said magnetostrictive wire from the interval of time between the detection of the torsional motion within said magnetostrictive wire induced by said electrical excitation traveling directly to said torsional motion sensor and the detection of the torsional motion within said magnetostrictive wire induced by said electrical excitation traveling to said reflection termination and then reflected back to said torsional motion sensor following each electrical excitation of said magnetostrictive wire and said return wire.

A magnetostrictive linear displacement detector comprising:

• a magnetostrictive wire anchored at opposite head and foot ends and defining a measurement interval therebetween;
• a reflection termination mechanically coupled to said magnetostrictive wire at said foot end placing a predetermined mechanical impedance to torsional motion on said magnetostrictive wire for inducing reflections of torsional motion;
• a damping termination mechanically coupled to said magnetostrictive wire at said head end for preventing reflections of torsional motion;
• a return wire having a foot end electrically coupled to said foot end of said magnetostrictive wire and a head end;
• a magnet disposed for displacement along the said magnetostrictive wire within said measurement interval, the position of said magnet within said measurement interval being the linear displacement detected;
• a torsional motion excitation means disposed proximate to said head end of said magnetostrictive wire for imparting a predetermined torsional motion within said magnetostrictive wire;
• and
• an electrical excitation detection means electrically coupled to said head end of said magnetostrictive wire and said head end of said return wire for detecting an electrical signal through said magnetostrictive wire induced by the passage of torsional motion within said magnetostrictive wire by the position of said magnet.

A magnetostrictive linear displacement detector comprising:

• a magnetostrictive wire anchored at opposite head and foot ends and defining a measurement interval therebetween;
• a cylindrical torus disposed proximate said foot end of said magnetostrictive wire having a hole along its axis through which said magnetostrictive wire is passed and attached, said cylindrical torus forming a reflection termination placing a predetermined mechanical impedance to torsional motion on said magnetostrictive wire for inducing reflections of torsional motion;
• a damping termination mechanically coupled to said magnetostrictive wire at said head end for damping reflections of torsional motion;
• a return wire having a foot end electrically coupled to said foot end of said magnetostrictive wire and a head end;
• a magnet disposed for displacement along the said magnetostrictive wire within said measurement interval, the position of said magnet within said measurement interval being the linear displacement detected;
• a torsional motion excitation means disposed proximate to said head end of said magnetostrictive wire for imparting a predetermined torsional motion within said magnetostrictive wire;
• an electrical excitation detection means electrically coupled to said head end of said magnetostrictive wire and said head end of said return wire for detecting an electrical signal through said magnetostrictive wire and said return wire induced by the passage of torsional motion within said magnetostrictive wire by the position of said magnet;
• and
• a displacement determination means connected to said torsional motion excitation means and said electrical excitation detection means for determining the position of said magnet within said measurement interval of said magnetostrictive wire from the interval of time between the detection of the induced electrical signal within said magnetostrictive wire and return wire by said torsional motion traveling directly to said magnet and the detection of the induced electrical signal within said magnetostrictive wire and said return wire by said torsional motion traveling to said reflection termination and reflected back to said magnet following each torsional excitation of said magnetostrictive wire.