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:
Sep. 10, 2002
Filed:
Apr. 18, 2001
Ulrich Becher, Porrentruy, CH;
Ateliers Busch SA, Chevenez, CH;
Abstract
Displacement machines for compressible media having single-threaded, twin screw rotors with continuously decreasing pitch to achieve an inner compression are known. The demand for compact pumps with rotors as short as possible, and the frequent, process-related demand for quick disassembly of the housing, set limits however for the wrapping angle or respectively for the variation of the end profiles, which, in turn, leads to extreme pitch ratios or to insufficient compression rates. The present invention uses screw rotors with an optimized, non-monotone pitch course and alternative end profile variation with constant diameters. Suction capability is improved with the same space requirement, and compression rates of 3.0 and more are achieved easily with only four wraps. Displacement machines equipped with such twin screw rotors provide optimal results with respect to energy requirement, temperature, construction space and servicing with application possibilities in chemistry and in semiconductor technology.