Dynamoelectric machines with protection for squirrel cage expansion

Claim 1

IN A DYNAMOELECTRIC MACHINE OF THE TYPE HAVING A ROTATABLE CORE MEMBER WITH AN ELECTRICAL WINDING CARRIED THEREBY, SAID WINDING COMPRISING A PLURALITY OF ROTOR BARS OF ELECTRICALLY CONDUCTIVE MATERIAL POSITIONED IN A CORRESPONDING PLURALITY OF AXIAL SLOTS OF UNIFORM CROSS-SECTIONAL SHAPE IN SAID CORE MEMBER, SAID BARS PROJECTING FROM AN END OF SAID CORE AND BEING ELECTRICALLY JOINED TO EACH OTHER BY AN END RING, THE IMPROVEMENT COMPRISING SAID BARS BEING RELIEVED ABOUT THEIR END PORTIONS TO DEFINE A CLEARANCE SPACE BETWEEN SAID BARS AND THE WALLS OF SAID SLOTS, SAID CLEARANCE SPACE EXTENDING COMPLETELY ABOUT THE PERIMETER OF SAID BARS FROM A REGION ADJACENT THE END OF SAID CORE MEMBER TO A REGION INWARDLY OF THE END OF SAID CORE MEMBER, SAID CLEARANCE SPACE BEING OF SUFFICIENT SIZE AND SHAPE SO THAT SAID BARS ARE ENABLED TO FLEX IN SAID SLOTS IN ALL DIRECTIONS UNDER THE INFLUENCE OF FORCES AND MOMENTS IMPOSED ON SAID BARS DURING ACCELERATION AND OPERATION OF SAID DYNAMOELECTRIC MACHINE.