Abstract: A stator core is formed from a continuous strip of wound sheet stock material, in which the sheet stock material is converted from the sheet stock to a formed material including winding slot cutouts. This strip of formed material is then wound into the stator core, with the winding slot cutouts in the formed material maintained at a substantially constant width throughout most of the radial extent of the resulting winding slots in the finished article. However, one or more of the radially innermost and radially outermost layers may define winding slot cutouts that are wider than the other winding slot cutouts. Where several radial layers are altered in this way, the cutout widths are progressively expanded such that the resulting winding slot has terminal ends with edges that are effectively “radiused” or rounded, thereby protecting windings near the edge of such slots.

Abstract: A method for securing the end sections of an annular laminated article, such as a stator core, which includes a plurality of serially joined sections, each section formed of a plurality of stacked, planar laminas. The article is initially manufactured in a liner form, and is then formed into an annular form with the end sections disposed adjacent one another. At least one tab associated with one of the end sections is displaced by a forming tool into a corresponding cavity of the other of the end sections to secure the end sections together. In another embodiment, a pair of tabs each associated with one of the end sections are respectively displaced toward one another and into corresponding respective cavities each associated with the other of the end sections to secure the end sections together.

Abstract: A stator core is formed from a continuous strip of wound sheet stock material, in which the sheet stock material is converted from the sheet stock to a formed material including winding slot cutouts. This strip of formed material is then wound into the stator core, with the winding slot cutouts in the formed material maintained at a substantially constant width throughout most of the radial extent of the resulting winding slots in the finished article. However, one or more of the radially innermost and radially outermost layers may define winding slot cutouts that are wider than the other winding slot cutouts. Where several radial layers are altered in this way, the cutout widths are progressively expanded such that the resulting winding slot has terminal ends with edges that are effectively “radiused” or rounded, thereby protecting windings near the edge of such slots.

Abstract: An apparatus and method for the production of relatively large diameter annular components, such as stator cores for electric motors, without excessive waste of material. In one embodiment, a first progressive die assembly forms a plurality of identical pole pieces each made of a plurality of individual stacked and interlocked laminations. The pole pieces, having protruding end portions, are loaded into a rotary carousel. A second progressive die assembly forms a continuous strip including a plurality of body segments connected via hinge portions disposed adjacent recesses between the body segments that are dimensioned to receive the protruding ends of the pole pieces.

Abstract: A metal article, such as a stator core, is formed from a continuous strip of wound sheet stock material including winding slot cutouts. The winding slot cutouts are maintained at a substantially constant width throughout most of the radial extent of the winding slots in the finished article, except that one or more of the first and/or last wound layers (i.e., the radially innermost and radially outermost layers) may define winding slot cutouts that are wider than the other winding slot cutouts. Several radial layers may define cutout widths that are progressively expanded such that the resulting winding slot has terminal ends with edges that defining a stair-step profile that approximates a “radiused” or rounded edge. This rounded edge profile protects windings projecting radially into or outwardly from the winding slots near the edge of such slots.

Abstract: A method for securing the end sections of an annular laminated article, such as a stator core, which includes a plurality of serially joined sections, each section formed of a plurality of stacked, planar laminas. The article is initially manufactured in a liner form, and is then formed into an annular form with the end sections disposed adjacent one another. At least one tab associated with one of the end sections is displaced by a forming tool into a corresponding cavity of the other of the end sections to secure the end sections together. In another embodiment, a pair of tabs each associated with one of the end sections are respectively displaced toward one another and into corresponding respective cavities each associated with the other of the end sections to secure the end sections together.

Abstract: An apparatus and method for the production of relatively large diameter annular components, such as stator cores for electric motors, without excessive waste of material. In one embodiment, a first progressive die assembly forms a plurality of identical pole pieces each made of a plurality of individual stacked and interlocked laminations. The pole pieces, having protruding end portions, are loaded into a rotary carousel. A second progressive die assembly forms a continuous strip including a plurality of body segments connected via hinge portions disposed adjacent recesses between the body segments that are dimensioned to receive the protruding ends of the pole pieces.

Abstract: A progressive die assembly and a method for manufacturing lamina stacks from a plurality of separate strips of stock material. The die assembly includes a plurality of feed pathways for the material strips, each feed pathway having an associated punch set. Each punch set includes one or more punches for stamping lamina features in the strip, as well as at least one blanking punch for blanking individual laminas from the strips. The die assembly additionally includes a choke assembly which is adapted to receive laminas which are blanked from each of the material strips by the blanking punches.

Abstract: A progressive die assembly and method for manufacturing lamina stacks from a strip of substantially planar material, in which at least some of the individual laminas are formed with portions which extend from, or are otherwise not within, the plane of the material strip. The die assembly includes die stations having punches for punching features substantially within the plane of the strip corresponding to individual laminas, such as lamina profiles and lamina interlock features. Additionally, the die assembly also includes at least one forming station which includes a selectively actuable forming tool which is configured to form a lamina portion in the strip which is disposed outwardly of the strip plane, such as by bending a portion of the strip.

Abstract: A progressive die assembly and a method for manufacturing lamina stacks from a plurality of separate strips of stock material. The die assembly includes a plurality of feed pathways for the material strips, each feed pathway having an associated punch set. Each punch set includes one or more punches for stamping lamina features in the strip, as well as at least one blanking punch for blanking individual laminas from the strips. The die assembly additionally includes a choke assembly which is adapted to receive laminas which are blanked from each of the material strips by the blanking punches.

Abstract: A method of manufacturing a stack of interlocked laminations in a progressive die assembly having a choke. A strip of sheet stock material is provided and a plurality of laminations are stamped therein. Each of the laminations include at least one interlock feature and include first and second regions and a connecting section extending between the first and second regions. The laminations are separated from the sheet stock material and stacked in the choke with the first and second regions in a first orientation. The laminations are also interlocked substantially concurrently with the separation and stacking of the laminations. The interlocked stack of laminations is removed from the choke with the first and second regions in their first orientation. The stack is then formed into a second shape wherein the first and second regions have a second orientation and the connecting section therebetween has been deformed.

Abstract: An interlocked stack of laminations for rotors wherein each lamination includes a centrally located, circular indentation. The indentation provides corresponding projections and depressions in the laminas which may be interlocked by engagement of a projection in one lamina with an adjacent depression in an adjacent lamina.

Abstract: A method of manufacturing a stack of interlock laminations and thereby shaping the stack of laminations into a desired shape. Each of the individual laminations is formed by a series of punching operations from sheet stock material. The laminations are blanked from the stock material, are stacked atop one another, and are interlocked in a choke. The laminations are thereafter repositioned to form the stack into a second shape. The stacking axis and the core axis may be either parallel or perpendicular to one another. The second shape of the core may be variable in that the second shape may be changed from time to time or may be continuously changed.

Abstract: A method of manufacturing an elongate stack of interlocked laminae in a die assembly. The method includes the steps of stamping a first lamina having generally opposed first and second edges in the strip stock material, stamping at least one first interlock means for engaging another lamina in the first lamina, separating the first lamina from the strip stock material, placing the first lamina into the choke passageway, the first and second edges of the first lamina frictionally engaging the choke passageway, stamping a second lamina having first and second elongate edges in the strip stock material, stamping at least one second interlock means for engaging another lamina in the second lamina, at least partially engaging the first and second interlocking means, separating the second lamina from the strip stock material, placing the second lamina into the choke passageway, and frictionally engaging the choke passageway along the first and second elongate edges of only one of the first and second laminae.

Abstract: A shapeable lamination stack and method of manufacture. The lamination stack includes a plurality of interlocked laminations which may be stamped using a conventional progressive die. The laminations are stacked in a first stack shape wherein each of the laminations are mutually parallel and positioned perpendicular to linear axis. The laminations are relatively repositionable wherein the laminations form a second stack shape wherein at least one of the laminations is oriented non-parallel to another one of the laminations. The stack may also include spacing elements to separate a pair of laminations by a spacing volume. The spacing volume has a substantially uniform thickness when the stack is in the first stack shape and at least one of the spacing volumes has a non-uniform thickness when the stack is in the second stack shape. The spacing element may be lamination or a integral projection located on one of the laminations.

Abstract: A method of manufacturing a stack of interlocked laminations in a progressive die assembly having a choke. A strip of sheet stock material is provided and a plurality of laminations are stamped therein. Each of the laminations include at least one interlock feature and include first and second regions and a connecting section extending between the first and second regions. The laminations are separated from the sheet stock material and stacked in the choke with the first and second regions in a first orientation. The laminations are also interlocked substantially concurrently with the separation and stacking of the laminations. The interlocked stack of laminations is removed from the choke with the first and second regions in their first orientation. The stack is then formed into a second shape wherein the first and second regions have a second orientation and the connecting section therebetween has been deformed.

Abstract: An ignition coil assembly having an inner core element formed from an interlocked stack of elongate laminae plates. Each of the laminae plates has a substantially common length and a substantially uniform width along the length thereof, with the length of each laminae plates being greater than a width thereof. A first one of the plurality of laminae plates being the widest laminae plate in the stack is located substantially in a center thereof with others of the laminae plates located above and below the first laminae plate and having progressively decreasing widths. Each of the laminae plates in the stack being interlocked to an adjacent laminae plate and the stack having substantially planar end surfaces that are provided with guide elements that are aligned substantially perpendicular to the widths of the plurality of laminae plates. The guide elements include notches and/or projections that can have various geometric shapes.

Abstract: An indexing system for a die assembly for manufacturing a stack of laminae from sheet stock material in a punch press, the stack having a desired stack height and a skew angle, the stock material having a nominal thickness. The indexing system includes indexing means for producing a first indexing input movement in response to movement of the punch press, a motor for producing a second indexing input movement in response to a control signal, and differential means for combining the first and second indexing input movements into an indexing output movement and having first and second input means for respectively receiving the first and second indexing input movements. The first input means is coupled to the indexing means, and the second input means is coupled to the motor. The differential means also has output means for transmitting the indexing output movement; a rotatable choke barrel in which laminae are received and stacked.

Abstract: A method of manufacturing an elongate stack of interlocked lamninae in a die assembly. The method includes the steps of stamping a first lamina having generally opposed first and second edges in the strip stock material, stamping at least one first interlock means for engaging another lamina in the first lamina, separating the first lamina from the strip stock material, placing the first lamina into the choke passageway, the first and second edges of the first lamina frictionally engaging the choke passageway, stamping a second lamina having first and second elongate edges in the strip stock material, stamping at least one second interlock means for engaging another lamina in the second lamina, at least partially engaging the first and second interlocking means, separating the second lamina from the strip stock material, placing the second lamina into the choke passageway, and frictionally engaging the choke passageway along the first and second elongate edges of only one of the first and second laminae.

Abstract: A method of manufacturing an elongate stack of interlocked laminae in a die assembly. The method includes the steps of stamping a first lamina having generally opposed first and second edges in the strip stock material, stamping at least one first interlock means for engaging another lamina in the first lamina, separating the first lamina from the strip stock material, placing the first lamina into the choke passageway, the first and second edges of the first lamina frictionally engaging the choke passageway, stamping a second lamina having first and second elongate edges in the strip stock material, stamping at least one second interlock means for engaging another lamina in the second lamina, at least partially engaging the first and second interlocking means, separating the second lamina from the strip stock material, placing the second lamina into the choke passageway, and frictionally engaging the choke passageway along the first and second elongate edges of only one of the first and second laminae.