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:
Feb. 10, 1976
Filed:
Aug. 30, 1974
Wade L Fite, Pittsburgh, PA (US);
Extranuclear Laboratories, Inc., Pittsburgh, PA (US);
Abstract
Methods and apparatus for spatially separating AC and DC electric fringe fields near the ends of quadrupole mass filters which involve use of materials with electric properties that function as dielectrics to the AC fields and as conductors to the DC fields. Devices constructed of such materials shield against DC fringe fields, but not against AC fringe fields. Such devices include a small shield in the form of a tube or other appropriate configuration disposed coaxially with the axis of the mass filter at either or both ends thereof. A good dielectric is used as the supporting structure and a thin conductive or semi-conductive layer is applied thereto which functions as the shield.