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. 13, 2005
Filed:
Oct. 07, 2002
Jonathan E. Mccallum, Edmonton, CA;
Terry D. Nelson, Edmonton, CA;
Murray C. Gerwing, Edmonton, CA;
Flexxaire Manufacturing Inc., Edmonton, CA;
Abstract
An improved variable pitch fan comprising a fan hub, with fan blades extending radially outward from the fan hub and mounted for rotation about respective radially extending axes corresponding to each fan blade. Each fan blade has a blade surface extending perpendicularly to the radially extending axis of the fan blade, each blade surface lying between respective outer edges of the corresponding fan blade and facing rearward. A pitch shifting mechanism is mounted in the hub and interconnects with the fan blades to control the rotational position of each fan blade about the corresponding radially extending axis of the fan blade. The respective outer edges of each fan blade diverge as the fan blade extends further radially outward; and the blade surface of each fan blade has an angle of attack that decreases as the fan blade extends radially outward. Each blade surface has a constant or increasing radius of curvature as the respective fan blade extends further radially outward. The respective outer edges of each fan blade are straight. Each fan blade has integral moulded counterweight supports and counterweights mounted on the counterweight supports.