Abstract: A magnet wire having differential build insulation for use in transformer coils is disclosed. The wire has a rectangular conductor with an insulation that is thicker on the top and bottom surfaces of the wire than it is on the sides. With the thicker coating on the top and bottom, the wire can be used in layer wound distribution transformer coils, both high voltage wire wound coils and low voltage wound coils, without needing additional insulation between the layers of the winding.

Abstract: A method and apparatus for manufacturing a variable insulated helically wound electrical coil is disclosed. Insulated rectangular wire is fed from a supply reel to a coating zone and within the coating zone liquid resin insulation is selectively applied to the wire so it has additional insulation only in those areas of the coil where the dielectric strength is needed. The insulated wire is fed through a curing station to allow curing of the additional insulation prior to winding the cured insulated wire into a coil. The cured insulated wire is wound into a coil of predetermined shape at a winding station whereby the portions of the wire having the additional insulatin are located in the areas of the coil where the greatest dielectric strength is needed. The timing of the resin application to the wire is coordinated with the winding of the coil so that the proper insulation thicknesses are achieved at the required locations in the coil.

Abstract: An insulated metallic strip suitable for use in the coils of power transformers and method of producing the same. Following the extrusion of a flat metallic strip of conductive material for winding into a magnet coil, the flat strip having a predetermined thickness and first and second sides bounded by a pair of fully rounded edges, the method of insulating the strip of conductive material by supporting the flat strip in a level state at a predetermined temperature in a vacuum chamber and while in the vacuum chamber applying a liquid coating of resin to the entire first side of the strip and the pair of rounded edges and extending onto the second side of the strip from each of the edges a distance at least as great as about 0.25" to prevent turn to turn discharge.

Abstract: An insulated metallic strip suitable for use in the coils of power transformers and method of producing the same. Following the extrusion of a flat metallic strip of conductive material for winding into a magnet coil, the flat strip having a predetermined thickness and first and second sides bounded by a pair of fully rounded edges, the method of insulating the strip of conductive material by supporting the flat strip in a level state at a predetermined temperature in a vacuum chamber and while in the vacuum chamber applying a liquid coating of resin to the entire first side of the strip and the pair of rounded edges and extending onto the second side of the strip from each of the edges a distance at least as great as about 0.25" to prevent turn to turn discharge.

Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width.

Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width. As the tube is advanced over the forming member, an alignment system maintaining the tube in a centered position. The alignment system includes a light source disposed within the tube and two arrays of photo-transistors arranged to receive light from the light source, the amount of light sensed by each array being a function of the position of the slit in the tube relative to a desired position.

Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width. As the tube is advanced over the forming member, an alignment system maintaining the tube in a centered position. The alignment system includes a light source disposed within the tube and two arrays of photo-transistors arranged to receive light from the light source, the amount of light sensed by each array being a function of the position of the slit in the tube relative to a desired position.

Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width.