Patent ID: 7714685

Claim:
An electromagnetically operated unit for engaging and disengaging a radial connection between a driving part and a driven part, the unit comprising: a first part ( 2 ) being fixed, in a slip free manner, to one of the driving part and the driven part, and the first part ( 2 ) having one of a contoured surface and a frictional surface; a second part ( 3 ) being fixed, in a slip free manner, to the other of the driving part and the driven part, and the second part ( 3 ) of the unit supporting one of a plurality of magnets and a plurality of electromagnets ( 4 ) each of which has a magnetic pole; the second part ( 3 ) of the unit further having radially displacable switching elements ( 5 ) supported about a circumference thereof, and the switching elements ( 5 ) having the other of the contoured surface and the frictional surface, and one of the contoured surface and the frictional surface having at least one fixed tooth ( 8 ) formed therein and the other of the contoured surface and the frictional surface having a plurality of recesses ( 6 ) formed therein, each sized to matingly receive the at least one fixed tooth ( 8 ) therein and form a positive engagement between the contoured surface and the frictional surface while remaining surfaces of the contoured surface and the frictional surface form a frictional engagement between the contoured surface and the frictional surface; one of the contoured surface and the frictional surface, of the radially displacable switching elements ( 5 ), matingly engages with a corresponding one of the contoured surface and the frictional surface of the first part ( 2 ) to form the positive engagement and the frictional engagement between the first part ( 2 ) and the second part ( 3 ); if the unit is a closed current system, then each of the switching elements ( 5 ) of the second part ( 3 ) are radially displaced toward the first part ( 2 ), when a current is applied to one of the plurality of magnets and the plurality of electromagnets ( 4 ), to release engagement between the first part ( 2 ) and the second part ( 3 ); but if the unit is an open current system, then each of the switching elements ( 5 ) of the second part ( 3 ) are radially displaced, against a force of at least one spring ( 7 ), away from the first pad ( 2 ), when the current is applied to one of the plurality of magnets and the plurality of electromagnets ( 4 ), to induce disengagement between the first part ( 2 ) and the second part ( 3 ).