Patent ID: 7999645
Filing Date: 2011-08-16
Classification: B23Q,B25B

Abstract:
1. A magnetic holding apparatus for holding workpieces comprising: a base plate made of a ferroelectric material; a working face made of a monolithic block of ferroelectric material, being arranged above said base plate and having an outer surface configured for supporting workpieces; a plurality of recesses provided within said working face; a pocket provided within said base plate; a plurality of reversible permanent magnets received within said pocket; a plurality of electrical windings received within said pocket together with said reversible permanent magnets configured for reversing said reversible permanent magnets upon application of an electrical current flowing through said electrical windings; a plurality of magnetic poles formed within said working face demarked by slots extending from said outer surface of said working face toward said base plate; a plurality of non-reversible permanent magnets received below said slots within said recesses; wherein said non-reversible permanent magnets are configured for magnetically clamping workpieces by magnetic flux extending through said magnetic poles and through said workpieces; wherein said recesses are separated from said slots by solid material of said working face; and wherein said reversible permanent magnets are configured for either substantially neutralizing said magnetic flux of said non-reversible permanent magnets upon activating said electrical windings with a first electrical current, thereby allowing removal of a workpiece, or for transferring said magnetic flow of said non-reversible permanent magnets through said magnetic poles to said workpiece for magnetic clamping thereof.