Abstract: A band of fabric over the interface between the slot armor and the copper bar of a pole face winding is both resistant to migration of conductive contaminants under the edge of the slot armor and hospitable to the application and retention of an insulating paint layer over such interface. The band of fabric is preferably of woven glass fiber with a tenacious pressure sensitive adhesive on one side and with the other side bare. The adhesive is compatible with the material of the slot armor, sticks readily to the copper bar and to the bare surface of the woven glass fiber fabric band. The bare side of the fabric provides a good mechanical bond to the insulating paint layer and thereby encourages the establishment and retention of an unbroken paint layer over the interface. The combination provides a long electrical leakage current path between the copper bar and the iron of the pole.

Abstract: A dynamoelectric machine commutator structure having a plurality of conductive commutator segments secured in operating position by a commutator banding is characterized by including a flexible, thermally stable dielectric coating material between the outer edges of the commutator banding and the conductor segments in order to effectively seal the junction between those members, thereby preventing the deposit or buildup of electrically conductive contaminants at that junction so that the likelihood of electrically short circuiting the conductive segments of the commutator is effectively eliminated. According to the preferred method of the invention, a banded commutator is formed by applying such a coating to predetermined portions of the banding grooves so that the coating effectively seals the junctions between the banding and the conductive segments of the commutator, thereby preventing the accumulation of conductive contaminants at those junctions.

Abstract: A dynamoelectric machine commutator structure having a plurality of conductive commutator segments secured in operating position by a commutator banding is characterized by including a flexible, thermally stable dielectric coating material between the outer edges of the commutator banding and the conductor segments in order to effectively seal the junction between those members, thereby preventing the deposit or buildup of electrically conductive contaminants at that junction so that the likelihood of electrically short circuiting the conductive segments of the commutator is effectively eliminated. According to the preferred method of the invention, a banded commutator is formed by applying such a coating to predetermined portions of the banding grooves so that the coating effectively seals the junctions between the banding and the conductive segments of the commutator, thereby preventing the accumulation of conductive contaminants at those junctions.

Abstract: A method for making and applying to a dynamoelectric machine an adhesively bonded, irradiation curable, resin treated glass banding that retains a pre-stressed tension therein when the banding is subjected to a variety of mechanical vibration and temperature changes. The banding is applied in pre-stressed layers and is further characterized by having a substantially uniform thickness of cured resin between each layer thereof, in a range between 0.5 and 2 mils, despite any variation in the pre-stressing tensions applied to the respective layers of the banding.

Abstract: A glass banding for a dynamoelectric machine characterized by incorporating an irradiation curable resin impregnated in pre-stressed layers of the banding. The banding is further characterized by having a substantially uniform thickness of cured resin between each layer thereof, in the range between 0.5 and 2 mils, despite a variation in the pre-stressing tensions applied to the respective layers of the banding. A novel method is also encompassed by the invention for making an adhesively bonded, irradiation curable, resin treated glass banding that retains a pre-stress tension therein when the banding is subjected to a variety of mechanical vibrations and variations in temperatures applied to it.