Bend-tolerant superconductor cable

An electric cable for use in forming a coil, said cable comprising:

• (a) superconductor;
• (b) a tubular housing for said superconductor for locating the netural plane of bending away from said superconductor when the cable is bent to form a coil, said housing having a thin-walled, elongated channel portion for holding said superconductor and a corresponding elongated reinforcing portion of substantial cross section, said channel portion having a pair of opposed sidewalls and a floor on said first side of said housing connecting corresponding ends of said sidewalls, and being located on a first side of said housing placed in compression when the cable is bent laterally in a predetermined direction to form a coil, and said reinforcing portion being located on a second side of said housing opposite from said first side and secured to said channel portion by crimping the free ends of the sidewalls of said channel portion to said reinforcing portion, and bonding said reinforcing portion to said channel portion with solder;
• and
• (c) a flowable filler material for securing said superconductor and said housing in a fixed longitudinal relationship.

An electric cable comprising:

• (a) superconductor means for conducting electricity in a substantially resistance-free manner in a longitudinal direction along said cable;
• (b) channel means for holding said superconductor means;
• and
• (c) elongated reinforcing means disposed adjacent said superconductor means, said reinforcing means being secured to said channel means to hold said superconductor means therein, said reinforcing means having a yield strength sufficiently greater than the yield strength of said channel means for enabling said reinforcing means to resist substantially all tensile stresses imposed on the cable by lateral being thereof in a predetermined direction having a radius of curvature on the side of said cable in which said superconductor means is disposed.

A composite superconductor structure bendable laterally in a predetermined direction, said superconductor structure comprising:

• (a) a U-shaped sheath having an opening thereinto extending the length of said sheath and opposite thereto a floor defining the predetermined direction for lateral bending;
• (b) a superconductor member disposed in said sheath adjacent said floor thereof;
• and
• (c) a reinforcing member secured in said opening to said sheath to seal said superconductor member therein, said reinforcing member having a higher yield strength than said sheath, and so comprised and configured relative to said sheath to bear substantially all tensile stresses imposed on said composite superconductor structure when said structure bends in said predetermined direction.

A method for fabricating an elongated superconductor structure bendable laterally in a predetermined direction, said method comprising the steps of:

• (a) bending an elongated copper strip into a continuous longitudinally extending U-shaped duct;
• (b) disposing in said duct a superconductor member;
• (c) introducing into said duct a flowable filler to surround said superconductor member and stabilize said superconductor member in a fixed longitudinal relationship to said duct;
• (d) closing said duct with an elongated reinforcing member of relatively substantially cross section compared to that of said duct;
• and
• (e) securing said reinforcing member to said duct in a fixed longitudinal relationship by crimping, to fix said reinforcement member to said duct.