Abstract: A process is provided for assembling a laminated iron core on a support structure about an electric coil from a plurality of laminations to form a shell-type transformer core. According to the process, the plurality of lamination sections are stacked in a staggered relationship to form a first core section which has joint ends to form overlapping joints between an adjacent core section. The first core section is stacked by placing a slider sheet of a low coefficient of friction on a first support member and stacking the lamination sections on the slider sheet. The first core section is then conveyed onto the support structure at which the iron core is to be assembled, and the slider sheet is pulled out to cause the first core section to directly sit on the support structure. The plurality of lamination sections are inserted between the joints on site to form a second core section which connects the joint ends of the first core section to define a magnetic circuit around the coil.

Abstract: A method and apparatus for manufacturing a transformer having an amorphous metal core. The face of the joint portion of the amorphous metal core is covered with an oil compatible porous pads. Pressure plates are disposed over the pads. A frame positioned generally around the plates secures the pads and plates to the amorphous metal core. Banding straps may be threaded about the core assembly to further secure the core assembly.

Abstract: There is disclosed a metal plate laminated body. When a portion encircled by inner and outer closed curves is embossed, a projection is protruded from a lower surface of a metal plate. Since a width of protrusion is slightly larger than that of a recess, when press-fitting the projection into the recess of the contiguous metal plate, an outer peripheral surface of the projection which is formed along the outer closed curve is brought into press-contact with an outer peripheral surface of the recess; and an inner peripheral surface of the projection which is formed along the inner closed curve similarly comes in press-contact with an inner peripheral surface of the recess. These inner and outer peripheral surfaces cooperate to become effective contactual surfaces, and the contiguous metal plates are joined to each other.

Abstract: The transformer core assembly comprises a first stack of laminations having an "E" shape and including at least three legs comprising first and second, outer legs and a third, middle leg, and a second stack of laminations interlocked with the first stack by mechanical engagement of said second stack with the distal ends of the legs of said first stack. Each first and second outer leg has an identical distal end formation adapted to engage a mating formation on the second stack. The middle leg has a third distal end formation which includes an outer end surface and inner end surface offset inwardly from said outer end surface and an inclined surface between the outer and inner end surfaces.

Abstract: A method of making a repairable transformer having an amorphous metal core 1 wherein three uncut legs of an annealed wound amorphous metal core are covered with an adhesive impregnated material 10 while leaving the cut leg, 6 and 7, and both adjoining radii uncovered. The adhesive is cured, causing the adhesive to bond to the core. The core joint is opened and coils 11 and 12 are placed over the legs that adjoin the cut leg. The core joint is closed and the edges of the joint and both adjoining radii are covered with a porous material. No adhesive bonds to the edges of the cut leg or to the edges of adjoining radii. The resulting transformer can be repaired by cutting away the porous material that covers the cut leg and the adjoining radii, opening the core joint, replacing a defective coil, reclosing the core joint, and resealing the cut leg as before.

Abstract: An iron core of a stationary induction apparatus such as a transformer has a plurality of steel sheets stacked in layers. Each corner of the core has a yoke member and a leg member abutting and jointed to each other at their obliquely cut ends in such a manner that the two members of alternating layers partially overlap each other over a predetermined overlapping region at each corner of the core. The surfaces of the members in the overlapping region are roughened by, for example, being provided with fine linear indentations and ridges.

Abstract: A transformer core is made by winding a strip of ferromagnetic material, such as amorphous metal or silicon iron, on a winding mandrel to form a first annulus and cutting once through this annulus to create a plurality of individual laminations which are then assembled in packets about a nesting mandrel of a smaller diameter than the winding mandrel to form a second annulus. Each packet consist of a predetermined number of groups of laminations, with the ends of each lamination group lapping each other to form a lap joint. The lap joints of each packet are arranged in staggered positions to create a repeating step-lap joint pattern confined within a predetermined joint region. By decreasing the lap joint dimension and increasing the number of groups in successively assembled packets, the increase in build of the joint region over that of the remainder of the second annulus is minimized. The complete transformer core is uniquely characterized by its variable lap joint dimension and the absence of short sheets.

Abstract: This transformer comprises preformed coil structure and a wound core of closed-loop configuration extending about a window and having joints in a localized region thereof that allow the core to be opened at the joints to permit insertion into the window of the preformed coil structure. The core comprises superposed laminations of thin amorphous ferromagnetic strip material which extend around the core from the localized joint region. The laminations include predetermined portions adjacent the joints that are displaced to provide a wide opening into the core window for insertion of the coil structure. A coating of adhesive bonding agent applied before said displacement is present on the lateral edges of the laminations in regions of the core not including said predetermined portions, thereby holding the laminations in correct assembled relationship when the core is opened, yet without interfering with displacement of said predetermined portions.

Abstract: An improved transformer core joint for use in connection with amorphous metal transformers which includes a plurality of spirally wound laminations that are divided into a plurality of groups of laminations. The laminations within a group of laminations essentially provide a butt joint within the group while adjacent groups of laminations form a lap joint with each other. The groups of laminations are divided into sets of groups and a step either in the direction of the spiral or against the direction of the spiral occurs between each of the sets of groups. The joint of the invention provides a compact, easily disassembled and reassembled core joint for accommodating the manufacture of amorphous metal transformer cores.

Abstract: A transformer core is made by winding a strip of ferromagnetic material, such as amorphous metal or silicon iron, on a winding mandrel to form a first annulus and cutting once through this annulus to create a plurality of individual laminations which are then assembled in packets about a nesting mandrel of a smaller diameter than the winding mandrel to form a second annulus. Each packet consist of a predetermined number of groups of laminations, with the ends of each lamination group lapping each other to form a lap joint. The lap joints of each packet are arranged in staggered positions to create a repeating step-lap joint pattern confined within a predetermined joint region. By decreasing the lap joint dimension and increasing the number of groups in successively assembled packets, the increase in build of the joint region over that of the remainder of the second annulus is minimized. The completed transformer core uniquely characterized by its variable lap joint dimension and the absence of short sheets.

Abstract: A first annular form used for making a transformer core is wound from a strip of amorphous ferromagnetic material and is thereafter cut. The resulting laminations are then arranged in a second annular form with distributed gap joints, each joint involving a plurality of superposed laminations. The second annular form is then formed into a rectangular shape core and is then annealed. Then a bonding agent is applied to the transverse edges of the laminations over a region of the core removed from the joints. The joints are then separated to open the core, allowing displacement of unbonded regions of the core. Thereafter, preformed coil structure is inserted into the window of said opened core to surround a portion of the core. Then the unbonded regions of the core are returned to their original positions to remake the joints.

Abstract: A fixture for defining the window of a jointed magnetic core, which core is constructed of amorphous metal alloy, and methods of constructing such a fixture. The fixture includes first and second substantially U-shaped metallic frame members which are easily and quickly assembled with interlocking joints which positively maintain the desired geometric configuration of the core window, as well as the peripheral dimension thereof. Notwithstanding the high mechanical strength of the fixture, the interlocking joints are easily unlocked, which feature is necessary as the fixture will be required to be assembled, disassembled, and reassembled a part of the normal processing of the magnetic core. New and improved methods of constructing the fixture enable the same tooling to be used for different sizes of fixtures, which are required to cover the range of transformer ratings the magnetic cores will be an integral part of.

Abstract: A transformer comprises a tank containing insulating liquid, and within the liquid there is an amorphous-alloy laminated core that comprises spaced-apart upper and lower yokes and two spaced-apart legs at opposite ends of the yokes. Coil structure surrounds the legs, locating the yokes outside the coil structure. Box-like enclosures primarily of electrical insulating material respectively enclose the yokes in positions outside the coil structure. The enclosure about the lower yoke is positioned to capture therein chips of amorphous alloy which might become detached from said core and fall toward the bottom of the tank.

Abstract: A transformer core is disclosed having one or more winding legs built up from a plurality of silicon steel laminations and a pair of yokes built up from a plurality of amorphous steel laminations. The yokes and legs are serially joined by silicon steel-amorphous steel lamination joints to create a magnetic loop circuit and thus provide a transformer core having significantly improved core loss characteristics as compared to a power transformer core formed exclusively of silicon steel laminations.

Abstract: This transformer comprises a generally rectangular core having two yokes and two legs connecting the yokes, with joints located in one of the yokes. Coil structures surround the two legs. Flexible banding under tension applies clamping forces to two clamping plates spaced outwardly from the yokes, and these clamping forces are transmitted to the coil structures by paths bypassing the core. The banding extends alongside the legs and is oriented so as to engage the core at opposite ends of said one yoke but so as to be spaced from the core at opposite ends of the other yoke.

Abstract: A core shunt packet for reducing the telephone influence factor in a transformer of the type having a core formed from strips of magnetic material arranged in end-to-end relation forming a series of staggered gaps at one end of the core, the core shunt packets including one or more steel laminations mounted in an envelope, the envelope being mounted on the side of the core in a position to bridge the gap area on the core with a sheet of insulation located between the envelope and the side of the core.

Abstract: A core for an inductor or transformer includes a number of concentric turns of a ferromagnetic strip material. An inner core portion (13) consists of a non-amorphous material and an outer core portion (27) consists of an amorphous material. The transition between the two core portions (13, 27) is formed by a welded joint between the overlapping outer (17) and inner (15) end portions of the outer turn of the inner core portion (13), and with the inner end portion (19) of the inner turn (33) of the outer core portion (27) disposed therebetween.

Abstract: Plural leg laminations of equal length are stacked in two groups having concealed stepped-lap joint halves at one ends and visible stepped-lap joint halves at the other ends. Plural yoke laminations of incrementally varying lengths are stacked in a first group having visible stepped-lap joint halves at each end and a second group having concealed stepped-lap joint halves at each end. A rectangular magnetic core is assembled by mating the visible joint halves of the first yoke group and the concealed joint halves of the two leg groups, and then mating the visible joint halves of the leg groups with the concealed joint halves of the second yoke group.

Abstract: Power Transformer cores are assembled by inserting a plurality of lamination inserts between the upper yoke laminations and the leg laminations in the transformer core assembly process. The arrangement allows the upper yoke to be readily removed for inserting the transformer windings over the core legs. The upper yoke is then reassembled with the inserts reinserted to complete the transformer core.

Abstract: An iron core including two outer legs and a central leg connected at each end to a different one of the outer legs through a yoke. Each of the outer legs includes a stack of trapezoid laminations connected to a stack of trapezoid laminations of the yoke alternating its trapezium laminations through angle butt joints arranged stepwise with equal incremental intervals, the yoke laminations being longer than one another by equal increments equal to that intervals. The central leg includes a stack of parallelogramic laminations alternating those inverted widthwise from the same and connected in lapped relationships to the yoke laminations.

Abstract: A magnetic core including a plurality of layers of laminations formed from a magnetic strip material wherein at least two side leg and two yoke laminations are assembled around a core window to form four outer corners. Each of the side leg and yoke laminations have had one end thereof sheared diagonally with respect to the longitudinal dimension of the strip material. The other half of this one end is sheared substantially perpendicular to the strip material's longitudinal dimension. In each layer, the ends of the side leg and yoke laminations form two joints that are half straight and half diagonal. The ends of the side leg and yoke laminations in each layer form a step pattern about the outer corners of the core with the joints between the side leg and yoke laminations in one layer overlapping the joints between the side leg and yoke laminations in the next adjacent layer. A series of lap joints is thus formed in step relation.

Abstract: A three-phase and three-leg core of a core-type transformer comprising three main legs formed of a plurality of steel sheets stacked in the form similar to a circle in cross section and spaced each other, and upper and lower yokes formed of a plurality of steel sheets stacked in the form similar to a circle in cross section for magnetically connecting the main legs. The steel sheets for forming each main leg are cut diagonally at opposite longitudinal ends thereof, and each yoke is formed of two types of steel sheets, one type being of diagonal cuts disposed at opposite longitudinal ends thereof to provide steel sheets of the trapezoidal shape and the other type being of a diagonal cut disposed at one of opposite longitudinal ends thereof and a right angle cut disposed at the other longitudinal end thereof to provide steel sheets of the trapezoidal shape. The steel sheets for forming the upper and lower yokes have a width greater than the width of the steel sheets for forming the main legs.

Abstract: The invention concerns a transformer lamination of the EI type, having a center leg, two outer legs and two yokes connecting these legs and having joints between one side of the center leg and between one side of the outer legs and the adjacent yoke for interleaving with a winding. The characteristic feature is that the width of the jointlessly connecting yoke is greater than that of the parted yoke, and that the width of the parted yoke and/or the width of the two outer legs is greater than half the center leg width.

Abstract: The invention concerns EI-type core laminations, especially for transformers. The E-piece has a center leg of width f, two outer legs of width b, a yoke of width c.sub.1 and two windows of width h and length e. The I-piece has the width c.sub.2. The laminations have the following ratios:e is greater than 3 f/2 and less than 3.5 f/2;c.sub.1 and b are both at least 1.1 f/2;c.sub.1 -c.sub.2 is at least 0.1 f/2;c.sub.1 +c.sub.2 is at least 2.1 f/2 and at most 2.5 f/2.A preferred embodiment of the invention has the ratios:e=3.25 f/2; c.sub.1 =b=1.25 f/2; c.sub.2 =h=f/2.

Abstract: Core laminations of the UI or EI type for iron cores, particularly for transformers, having two or three legs of equal length e and equal width f, spaced mutually apart by the same distance h, wherein the width c.sub.1 of the jointlessly connecting yoke is greater than the width c.sub.2 of the parted yoke, using the following dimensions: 1.1f.ltoreq.c.sub.1 .ltoreq.2.1f and 1.0f.ltoreq.c.sub.2 .ltoreq.1.5f and 0.1f.ltoreq.c.sub.1 -c.sub.2 .ltoreq.0.6f. Preferred dimensions for a waste-free UI shape and a suitable EI shape are: c.sub.1 =1.4f; c.sub.2 =h=1.2f; e=3.2f. Preferred dimensions for a waste-free EI shape are: c.sub.1 =1.5f; c.sub.2 =h=1.2f; e=2.7f.

Abstract: A transformer for measuring current flowing through a conductor includes a U-shaped housing which is adapted to be received about the conductor. A closure member is secured by a sliding hinge assembly to one distal end of the housing, and is adapted to be latched between the distal ends. Within the housing a plurality a U-shaped core laminations are disposed in adjacent laminated groups. The closure member includes a plurality of laminated groups which are disposed to interleave with the distal ends of the U-shaped laminations to form a continuous magnetic circuit about the conductor. Equal secondary windings about the legs of the U-shaped laminations are connected in series to counteract any proximity effect of the conductor within the transformer.

Abstract: A unique core for an electrical transformer and method of construction thereof is disclosed which is applicable to either shell-form or core-form transformers of either single-phase or multi-phase application. The cross sectional area of the outside core leg and a portion of the yoke outside the electrical coil of the transformer is increased thereby decreasing the magnetic induction of that portion of the core with a concomitant reduction in electrical losses and noise. The structure comprises leg and yoke stacks formed of lamina of grain-oriented steel that are stacked in a laminar relationship such that adjoining edges of the leg and yoke members are periodically overlapped to enhance flux transfer. The core is stacked in such a fashion such that the outside leg members (outside the electrical coil) have additional laminar members periodically interspersed so that there are more outside leg lamina than inside leg lamina thereby increasing the cross-sectional area of the outside legs.

Abstract: Magnetic core structure of the stacked type having outer legs, an inner leg, and top and bottom yokes formed of a plurality of stacked groups of layers of metallic laminations. The length dimensions of the leg and yoke laminations are varied in opposite directions from layer to layer within each group of layers, while maintaining the midpoints of the laminations in each leg and yoke portion in alignment. This arrangement offsets the ends of the leg and yoke laminations from layer to layer and provides a stepped lap joint between adjoining ends of the leg and yoke laminations. The relative locations of the leg and yoke laminations are selected to uniformly divide the voids formed at the inner corners of the magnetic core between the leg and yoke laminations within each group of layers of laminations.

Abstract: New and improved magnetic cores for electrical inductive apparatus, and new and improved methods of constructing electrical apparatus, which facilitate the manufacture of such apparatus. The new and improved magnetic cores are of the stacked type, and they utilize different step-lap joints between selected yoke and leg members of the magnetic core. The new and improved methods include the steps of prestacking the leg members, stacking the bottom yoke member while the legs are substantially horizontally oriented, starting at one side of the leg members and progressing to the other side, and stacking the upper yoke member while the legs are substantially vertically oriented, starting from substantially the midpoints of the leg members and progressing outwardly in opposite directions.

Abstract: An adjustable transformer core and the method of manufacturing an adjustable transformer core, the transformer including a core and coils, the core being formed from a plurality of lamination sets, each lamination set including a number of legs and a pair of yoke members, the lamination sets being stacked in face-to-face relation so that the legs can be moved relative to each other. The coils may be wound directly on the legs and are moved toward each other to obtain predetermined characteristics. The coils are enclosed within a pair of core clamps to retain the relative position of the coils. Such adjustment can be employed to obtain different impedance or insulation levels. It is also within the contemplation of this invention to use the core as a common core for a variety of transformer designs.

Abstract: The invention concerns a transformer lamination having a center leg, two outer legs and two yokes connecting these legs and having at least one joint between one side of the center leg and the adjacent yoke. The characteristic feature is that the width of the jointlessly connecting yoke is greater than that of the parted yoke. In a preferred embodiment the sum of both yoke widths is roughly 1.35 times the center leg width.

Abstract: The invention concerns a transformer lamination having a center leg, two outer legs and two yokes connecting these legs and having at least one joint between one side of the center leg and the adjacent yoke. Characteristic features are that the length of the joint at each side of the center axis is at least 0.75 times the center leg width and that the joint has at least one concave part and at least one convex part on at least one side of the center axis. A preferred embodiment contains two symmetrical joints, each of them comprising two sections which are parallel to the center axis and one section which is perpendicular to the center axis.

Abstract: In a three-phase and three-leg core structure of a core-type transformer comprising three main legs of a substantially circular cross-sectional shape and a yoke of a non-circular cross-sectional shape for magnetically connecting the three main legs, each of the three main legs having a cross-sectional area substantially equal to the cross-sectional area of the yoke, wherein at least joints between the steel plate laminations of a center main leg and the adjoining steel plate laminations of the yoke are in a mitered oblique joint without requiring the shearing of the ends of the steel plate laminations, and the edges of the leg and yoke laminations at which edges the oblique miter joints are formed approach each other in length.

Abstract: A single-phase three-legged core for a core type transformer in which a plurality of steel sheets constituting each layer of laminations of a main leg are jointed at their diagonally cut sides to corresponding sides of a plurality of steel sheets constituting each layer of laminations of yokes to form a plurality of joints. At the inner corner portion of each joint, a recess is provided along the main leg or yoke steel sheet having a greater width than the other, so that a plurality of main leg laminations having stepwise varying width can be jointed to a plurality of yoke laminations at the same joint angle in the area of the recesses thereby simplifying the step of sheet cutting. At the outer corner portion of some of the joints, the vertex of the diagonally cut side of the corresponding main leg steel sheet mates with that of the associated yoke steel sheet to provide an outer corner joint, so that magnetic flux can uniformly pass through the joints to minimize the core loss.

Abstract: A split core current transformer for coupling monitoring apparatus to a current carrying conductor includes a two-piece annular core structure formed by first and second arcuate core assemblies having windings, connectable to the monitoring apparatus, wound on laminated core sections, the laminated core sections each including a plurality of flat lamination elements arranged in a stacked configuration with alternate elements having generally circular end portions which project beyond the main body portion of the arcuate core section at each end thereof defining generally circular gaps, permitting interleaving of the projecting end portions of the core sections of the two core assemblies providing an annular core structure having two interleaved joints which are held together by way of removable hinge pins which permit separation of the interleaved projecting end portions at either one of the joints to facilitate coupling to the current carrying conductor.

Abstract: A high voltage current transformer, and method of constructing same, including a primary winding having concentric leads, and a secondary winding on a magnetic core which is inductively linked with the primary winding. The magnetic core is a wound, two part core, with the two core parts being joined by stepped-lap joints. The secondary winding is a distributed winding having turns which are uniformly distributed about the complete magnetic circuit of the magnetic core. The conductor of the secondary winding is severed and the associated ends electrically re-connected, each time the conductor passes a stepped-lap joint.