Quench protection for actively shielded magnets
Patent 5644233 Issued on July 1, 1997. Estimated Expiration Date: 
February 22, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 22, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesActively shielded, superconducting magnet of an NMR tomography apparatus Apparatus for propagating a quench in a superconducting magnet Integrated active shielded magnet system Magnet assembly Magnet device for generating static magnetic field in MRI Magnetic resonance apparatus comprising a superconducting magnet Patent #: 5426366 InventorsAssigneeApplicationNo. 605666 filed on 02/22/1996US Classes:324/318, Spectrometer components324/319Polarizing field magnetExaminersPrimary: Arana, LouisAttorney, Agent or FirmForeign Patent References
International ClassG01V 003/00AbstractThis invention is concerned with actively shielded magnetic resonance (MR) devices and more particularly with protecting such systems in the event of a quench by preventing changes in the stray field outside the magnetic devices. The invention includes dividing the system's coils into groups each comprised of inner and outer coils and arranged so that the net dipole moment, and the contribution to stray field from each group is always close to zero. Each group is connected in parallel to a protective unit, for example a resistor, so that the excess current can flow through the protective unit in the event of a quench; thus avoiding the burnout of the system's coils. | |
