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:
Jan. 21, 2003
Filed:
Feb. 20, 2001
Robert C. Berfield, Jersey Shore, PA (US);
Shop-Vac Corporation, Williamsport, PA (US);
Abstract
A pump has a housing defining a pump chamber and having a shaft opening. An impeller shaft extends through the shaft opening and is sized to define a gap between the impeller shaft and the shaft opening. An impeller is attached to the shaft inside the pump chamber. The impeller includes a first set of impeller blades for transporting fluid through the pump chamber and a second set of impeller blades for creating a pressure force which pushes fluid away from the shaft opening. The pump with sealless shaft prevents fluid from leaking through the gap, and therefore is particularly suited for use in a tank-type vacuum cleaner capable of collecting both dry material and fluid. The gap is used in such an application to prime the pump, thereby discharging fluid collected in the tank.