Abstract: Magnetic flux trapping clamps are provided that trap or pin the magnetic flux of ring shaped superconductive magnets in a high permeability metallic core located in the bore of the ring. Preferably, the superconductive magnets comprise a single crystal cut into a ring shape. Multiples of the flux-pinned magnets, having high magnetic strength, can be arranged in a variety of arrays for a range of applications. The devices offer several advantages over permanent or electromagnets. The devices easily activated by charging with a cryogenic fluid, to induce the superconductive effect, and deactivated by draining the fluid.

Abstract: Sesceptor sheets are selected so that their magnetic permeability decreases to unity at approximately the desired operating temperature thereby limiting heating to this "Curie temperature" and providing substantial uniformity of temperature in the panel Preferably, the susceptor includes multiple layers, such as a first metal having a relatively lower Curie temperature, a thin foil of copper in contact with the surface of the first sheet, and a second metal having a relatively higher Curie temperature. Such a susceptor allows thermal control at two spaced set points defined by the Curie temperatures.

Abstract: Quality welds are highly dependent upon achieving appropriate temperatures everywhere along the bond line. The present invention uses multinode thermocouples to measure the bond line temperature in real time and to provide control signals for the moving coil (welding head).

Abstract: A method of upsetting a headed rivet in a countersunk hole using an electromagnetic riveting machine having two opposed drivers which are impelled against each end of the rivet to upset the rivet with a single stroke of the machine. The movement of the driver at the headed end of the rivet in initiated slightly after movement of the driver at the shank end of the rivet to lift the headed end of the rivet slightly out of the countersink so, when the headed end driver operates, the rivet shank is deformed to fill the rivet hole as the head is driven back into the countersink for good shank interference in the hole adjacent the rivet head.

Abstract: For forming or consolidating organic matrix composites, for example, an organic matrix composite panel is sealed between sheets of a susceptor material that is susceptible to induction heating. The susceptor sheets are heated inductively. The sheets in turn conduct heat to the organic matrix composite panel. When heated to the desired temperature, the composite panel is consolidated and/or formed. In the present invention, the susceptor sheets are selected so that their magnetic permeability decreases to unity at approximately the desired operating temperature thereby limiting heating to this "Curie temperature" and providing substantial uniformity of temperature in the panel. Of course, the concept applies to other induction heating operations for metals including SPF, brazing, annealing, heat treating, bonding, hot pressing, and the like.

Abstract: A fiber reinforcement fabric contains a metal susceptor strip paired with each warp thread and woven with the weave thread to produce a thermoplastic welding susceptor of separated and electrically isolated, longitudinal metal strips and fiber reinforcement in the weld.

Abstract: Fluid tooling for use in an inductive welding system for creating a fusion bond along a bond line between two thermoplastic parts includes an elongated vessel made of fluid impervious flexible material and having an elongated axis and an open end at each axial end of the vessel, closed and sealed by end closures. A coil is received in the vessel for generating an alternating magnetic field transverse to the longitudinal axis. A linear guide in the vessel extends axially for substantially the full length of the vessel and guides the coil for movement axially through the vessel. Power leads are connected to the coil and extend through a pass-through in one end closure to connect the coil to a source of high frequency electrical power of about 35 KHz to energize the coil to produce an alternating magnetic field.

Abstract: We form welded reinforced composites by heating a susceptor along the bond line with a time-varying magnetic field produced with a moving induction coil. To obtain more uniform heating across the susceptor when welding composite parts using induction heating, edge regions of lower absolute impedance or a lower longitudinal impedance than the transverse impedance counterbalance the higher current density and current that occurs near the edges. The susceptor has lower impedance at the edges by altering the aspect ratio (length/width) of openings in the susceptor, by folding the susceptor over onto itself, or both. Uniform heating is important to obtaining a uniform, consistent weld on which aerospace designers can rely.

Abstract: For forming or consolidating organic matrix composites, for example, an organic matrix composite panel is sealed in a "retort" between sheets of a susceptor material that is susceptible to induction heating. The susceptor sheets are heated inductively. The sheets in turn conduct heat to the organic matrix composite panel. When heated to the desired temperature, the composite panel is consolidated and/or formed. In the present invention, the susceptor sheets are selected so that their magnetic permeability decreases to unity at approximately the desired operating temperature thereby limiting heating to this "Curie temperature" and providing substantial uniformity of temperature in the panel. Of course, the concept applies to other induction heating operations for metals including SPF, brazing, annealing, heat treating, bonding, hot pressing, and the like.

Abstract: Quality thermoplastic fusion welds are formed in prefabricated resin composite parts by aligning a susceptor along a bondline between parts with the induction coil segments of a solenoid induction coil along the centerline of the coil. Energizing the coil heats the susceptor to form the weld at the bondline. For this operation, our induction heating workcell users complementary dies that define a central cavity with an oval pattern of induction cool segments surrounding all faces of the cavity where the preform composite parts and susceptor are positioned.

Abstract: A conformal skate for use in an inductive welding system for creating a fusion bond along a bond line between two thermoplastic parts includes a wheel having a circumferential casing made of fluid impervious flexible material. The wheel is rotatably mounted on a fixed axle by fluid tight bearings. The axle has an axial passage for admission of pressurizing and cooling fluid, and for power leads for the coil and for leads for sensors inside the wheel. A vertical mount on the axle supports the coil for vertical motion and biases the coil downwardly so that it remains in contact with the inside surface of the casing despite unevenness or contour changes in the upper surface of the top part or changes in the wheel shape when the fluid pressure in the wheel or downward force on the axel is changed.

Abstract: A fixed coil induction heater produces quality thermoplastic fusion welds in prefabricated resin composite parts. A susceptor along a bondline between parts aligns with the induction coil segments of a solenoid induction coil along the centerline of the coil. Energizing the coil heats the susceptor to form the weld at the bondline. For this operation, our induction heating workcell uses complementary dies that define a central cavity with an oval pattern of induction coil segments roughly conforming to the shape of the cavity and surrounding all faces of the cavity where we position the preform composite parts and susceptor.