Anti-theft fastening device

Claim 1

The combination of a fastening device and a detaching tool for releasing the same comprising: a. a generally cylindrical non-metallic housing closed at one end and formed with a central opening and a relatively enlarged recess at the open end of said housing; b. a ring mounted in said recess in said housing, said ring being formed with a downwardly and inwardly tapered inner surface; c. an insert formed of magnetic material loosely received within said housing and extending upwardly substantially into said central opening, said insert being formed with a conical lower end adapted to mate with said tapered surface of said ring, an axial bore, and at least one transverse opening formed in said conical end of relatively greater dimension than said axial opening; d. a pin extending upwardly through said axial bore of said insert; e. retaining ball means disposed within said transverse opening of said insert; f. spring means for resiliently biasing said insert toward the open end of said housing thereby adapting said retaining ball means to tightly frictionally engage said pin and retain the same in said insert, and g. a detaching tool for releasing said retaining ball means and freeing said pin, said tool including electromagnetic means and circuit means for energizing said electromagnetic means, said detaching tool when positioned adjacent the closed end of said housing and when said electromagnetic means is energized functioning to retract said insert against the bias of said spring means thereby permitting movement of said retaining ball means away from said pin to permit removal of said pin.