Permanent magnet assembly

Claim 1

A MAGNETIC CIRCUIT HAVING AT LEAST ONE AIR GAP THEREIN COMPRISING A PERMANENT MAGNET IN THE FORM OF A RECTANGULAR PARALLELEPIPED HAVING A SHORT LENGTH AND LARGE CROSS SECTIONAL AREA, SAID MAGNET BEING MAGNETIZED ALONG AN AXIS PARALLEL TO SAID SHORT LENGTH AND HAVING POLES ON ITS OPPOSITE LARGE CROSS SECTIONAL AREA SURFACES, FIRST AND SECOND FERROMAGNETIC PARTS EACH HAVING AN L-SHAPED CROSS SECTION WIHT ONE LEG OF THE CROSS SECTION ABUTTING A RESPECTIVE POLE SURFACE OF SAID MAGNET, THE OTHER LEG OF THE CROSS SECTION OF SAID FIRST FERROMAGNETIC PART BEING SUBSTANTIALLY SHORTER THAN ITS SAID ONE LEG AND EXTENDING OUTWARDLY FROM AND EDGE OF ITS ASSOCIATED POLE SURFACE, AND THE OTHE LEG OF THE CROSS SECTIN OF SAID SECOND FERROMAGNETIC PART BEING SUBSTANTIALLY SHORTER THAN ITS SAID ONE LEG AND EXTENDING ALONG AN OPPOSITE SIDE OF THE PERMANENT MAGNET WHICH IS PARALLEL TO SAID SHORT LENGTH, SAID OTHER LEG OF THE SECOND FERROMAGNETIC PART BEING SPACED FROM SAID LASTMENTIONED SIDE AND SAID FIRST FERROMAGNETIC PART TO FORM AN AIR GAP THEREBETWEEN AND BEING EQUAL IN LENGTH TO THE OUTWARDLY EXTENDED PERPENDICULAR DISTANCE FROM THE PERMANENT MAGNET SURFACE ABUTTED BY SAID ONE LEG OF THE SECOND FERROMAGNETIC PART TO THE TERMINUS OF SAID OTHER LEG OF THE FIRST FERROMAGNETIC PART, THEREBY DEFINING CONTACTS FOR EFFECTING ADHERENCE TO A METALLIC SURFACE.