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. 27, 1988
Filed:
Mar. 10, 1987
Minoru Saruwatari, Calgary, CA;
Other;
Abstract
A progressive cavity pump of the type having a stator member and a rotor member disposed within a cavity in the stator member and being rotated while being permitted to orbit about a central axis of the stator in operation, one of the members being formed of resilient material and the other of rigid material. The rotor is of helical formation having a constant circular transverse cross-section and defining a single-start thread of a preselected pitch and direction, and the cavity of the stator is in the form of a two start thread of the same direction as the rotor and twice the pitch, the cavity in transverse cross-section has an outline defined by a pair of spaced semi-circular concave ends and a pair of sides joining the semi-circular ends. The semi-circular ends have a diameter slightly less than the diameter of the cross-section of the rotor for establishing an interference fit between the rigid and resilient members. The pair of sides have an inward curvature so that the distance between the pair of sides is slightly less than the diameter of the circular ends whereby sealing areas of increased interference are provided between the members. Unlike known progressive cavity pumps, a high pressure output is possible without making the pump inefficient or of a prohibitive length.