The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 25, 1987
Filed:
May. 27, 1986
Robert E Schwall, Sudbury, MA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A superconductive magnet has a main coil for creating a primary magnetic field and a plurality of shim coils for correcting aberrations in different gradients in the primary field. The shim coils are also connected in shunt with shim quench heaters and with superconductors which together with the shim coils form a plurality of persistent loops. A plurality of protective heaters are electrically connected to the main coil and are thermally connected to the superconductors. When quenching begins in the main coil, current is diverted through the protective heaters causing them to heat. This increases the temperature of the superconductors in the persistent loops causing them to switch from the superconductive to the resistive state and divert current into the shim quench heaters. These heaters in turn heat the shim coils and drive the shim coils resistive to safety dissipate any energy therein.