Abstract: This transformer comprises a tank containing insulating liquid and an amorphous alloy core within the liquid comprising 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 and locating the legs within two windows of the coil structure. A box-like enclosure primarily of electrical insulating material encloses the lower yoke and is positioned to capture therein chips of amorphous alloy that might become detached from the core and fall toward the bottom of the tank.A first portion of the box-like enclosure extends between the two windows of the coil structure and is held against the bottom of the coil structure. This first portion includes flaps that are folded upwardly into the two coil windows to form liners for these windows, but still leaving clearance space within the windows around the core legs through which detached chips may fall past the liners into the box portion of the enclosure.

Abstract: This method of making a transformer core from strips of amorphous metal utilizes an arbor that has a longitudinal axis and an external surface surrounding the axis that includes a portion of concave configuration forming a depression in the external surface. A plurality of packets are assembled, each packet comprising a plurality of groups of amorphous metal strips, the groups in each packet (i) comprising many aligned amorphous metal strips and (ii) having transversely-extending edges that are staggered with respect to each other longitudinally of the packet. The packets are sequentially wrapped about the arbor in superposed relationship while the arbor is held against rotation, thereby building up a core form about the arbor. Each packet prior to its being wrapped about the arbor is located so that when wrapped, opposite ends of each group meet in overlapping relationship in a location angularly aligned with said surface portion of concave configuration.

Abstract: This method is practiced by first providing a plurality of spools of amorphous steel strip in each of which the strip is wound in single-layer thickness. Then, in a pre-spooling machine, the single-layer thickness strips are unwound from said plurality of spools and combined to form strip of multiple-layer thickness which is wound onto a plurality of master reels, on each of which the strip is wound in multiple-layer thickness. These master reels are then placed on a plurality of payoffs, and the multiple-layer thickness strip is unwound from these payoffs and combined into a composite strip that has a thickness in strip layers equal to the sum of the strip layers in the combined multiple-layer thickness strips. Then the composite strip is cut into a plurality of sections, or lengths, of composite strip, and with these sections a hollow core form is constructed, which form has a window about which the sections are wrapped.

Abstract: This method of making a transformer core from strips of amorphous metal utilizes an arbor that has a longitudinal axis and an external surface surrounding the axis that includes a portion of concave configuration forming a depression in the external surface. A plurality of packets are assembled, each packet comprising a plurality of groups of amorphous metal strips, the groups in each packet (i) comprising many aligned amorphous metal strips and (ii) having transversely-extending edges that are staggered with respect to each other longitudinally of the packet. The packets are sequentially wrapped about the arbor in superposed relationship while the arbor is held against rotation, thereby building up a core form about the arbor. Each packet prior to its being wrapped about the arbor is located so that when wrapped, opposite ends of each group meet in overlapping relationship in a location angularly aligned with said surface portion of concave configuration.

Abstract: This method is practiced by first providing a plurality of spools of amorphous steel strip in each of which the strip is wound in single-layer thickness. Then, in a pre-spooling machine, the single-layer thickness strips are unwound from said plurality of spools and combined to form strip of multiple-layer thickness which is wound to form strip of multiple-layer thickness which is wound onto a plurality of master reels, on each of which the strip is wound in multiple-layer thickness. These master reels are then placed on a plurality of payoffs, and the multiple-layer thickness strip is unwound from these payoffs and combined into a composite strip that has a thickness in strip layers equal to the sum of the strip layers in the combined multiple-layer thickness strips. Then the composite strip is cut into a plurality of sections, or lengths, of composite strip, and with these sections a hollow core form is constructed, which form has a window about which the sections are wrapped.

Abstract: A method and apparatus for severing a stack of amorphous alloy ribbons in a softened state is disclosed. The method provides a smooth burr-free edge of close dimensional tolerance while preserving the desirable magnetic properties of the alloy. Resistance self-heating is applied to heat a localized portion of the stack to a temperature above the softening temperature of the alloy. Severing occurs adjacent the electrodes in an adjacent stack portion which is heated by diffusion from the directly heated stock portion.

Abstract: This amorphous steel core transformer comprises: (i) a coil subassembly having a coil window of generally rectangular cross-section bounded by two end faces and two side faces, at least one of the side faces being slightly concave, and (ii) a core having a leg that fits within the coil window and comprises superposed aligned strips of amorphous steel stacked in the direction of the leg thickness and between said side faces. Each strip has two edges and, disposed between the two edges, a width that approximates the distance between the end faces of the coil window. The strips are further characterized by a slightly greater thickness in their central region than in the region of their edges. The core leg has a thickness that is substantially less in both edge regions of the strips than in the central region of the strips, thus rendering the leg capable of fitting more tightly within said coil window.

Abstract: A method of constructing a transformer having an amorphous steel core with a coil about a leg of the core wherein the core leg is formed to a cross-section that more closely conforms to the configuration of the coil window of the coil that surrounds the core leg.

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: A laminated amorphous-metal transformer core having four sides joined by corner regions includes (a) joints located in a joint region in one of its sides and (b) side portions between the joint region and two corner regions. After annealing the core and while restraining the core laminations in a core region remote from the joint region, the joints are separated by displacing each of the side portions into a position of approximate alignment with the side of the core interconnected therewith at a corner region. Then a splint is applied to each of the side portions and the aligned interconnected side, thus holding these two parts in approximately aligned relation. The splint is relied upon to facilitate insertion of the aligned parts into the window of a coil, following which the splint is slid off the aligned parts, and core-lacing is completed.

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: 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 method for forming cores for an electrical transformer is disclosed. Also disclosed are the cores made from such a method. In one embodiment an amorphous metal core has relatively thick superimposed laminations comprised of relatively thin amorphous metal sheets. The amorphous metal sheets are heated and bonded together by a metallic bonding agent to form relatively thick amorphous metal packets for the superimposed laminations of the core. The heating and bonding of the amorphous metal sheets reduce the mechanical stresses normally induced into the amorphous metal during the fabrication process. In another embodiment a hybrid core has superimposed laminations certain of which comprise sheets of non-crystalline amorphous metal and one or more sheets of crystalline silicon steel metal.