Patent ID: 7124863

Claim:
A brake assembly for releasably coupling two components to one another, the brake assembly comprising: at least one brake housing ( 2 ); a motor shaft ( 3 ) extending axially through the brake housing ( 2 ); an electromagnetic component ( 6 ) supported by the brake housing ( 2 ) and being longitudinally slidable with respect to the brake housing ( 2 ); a frictional cone ( 9 ) supported by the motor shaft ( 3 ) and being axially displaceable therealong; a spindle nut ( 5 ) threadedly mounted on the motor shaft ( 3 ) and is axially displaced along the motor shaft ( 3 ), the spindle nut ( 5 ) having a central position and being axially displaceable to a first end position in which at least the electromagnetic component ( 6 ) is also displaced with the spindle nut ( 5 ), and the spindle nut ( 5 ) being axially displaceable to a second end position in which at least the frictional cone ( 9 ) is also displaced with the spindle nut ( 5 ); a separating distance (d) between the electromagnetic component ( 6 ) and the frictional cone ( 9 ), when the spindle nut ( 5 ) is in one of the first and the second end positions, is greater than the separating distance (d) between the electromagnetic component ( 6 ) and the frictional cone ( 9 ) when the spindle nut ( 5 ) is in the central position; the brake assembly ( 1 ) is disengaged, regardless of whether or not electrical current is applied to the electromagnetic component ( 6 ), when the spindle nut ( 5 ) is in one of the first and the second end positions; and the brake assembly ( 1 ) is engaged, whether or not electrical current is applied to the electromagnetic component ( 6 ), when the spindle nut ( 5 ) is in its central position, and the brake assembly ( 1 ) is disengaged when electrical current is applied to the electromagnetic component ( 6 ).