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. 08, 2000
Filed:
May. 12, 1999
Thomas Hofmann, San Diego, CA (US);
James K Howey, Vista, CA (US);
Robert A Shannon, El Cajon, CA (US);
Richard C Ujazdowski, San Diego, CA (US);
Cymer, Inc., San Diego, CA (US);
Abstract
A tangential fan with cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential positions of blade members can shift monotonically or reversibly between ends. Blade members can be formed into air foil shapes and are stiffened by one or more transverse annular hub members. Processes for making tangential fans include soldering, casting, and machining from a solid block. Monolithic structures can be joined, typically by soldering or electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Soldering produces substantially silicon-free assemblies. Tangential fans produced in accordance with the invention have improved mechanical rigidity, accurate tolerances, and low contaminant concentrations.