Portable blower/vacuum and impeller for use with same

Abstract

A blower/vacuum and an impeller for use with generating air flow in a blower/vacuum. The impeller may include a hub for mounting the impeller on a rotatable output shaft of a motor of the blower/vacuum. The impeller may further include a plurality of air-flow generating blades that define a particular range of inlet and outlet angles. Additional features of the impeller may include a plurality of shortened member that facilitate mulching of air-entrained debris.

1 . An impeller for a portable blower/vacuum comprising:
 a base comprising a first side and a peripheral edge;   a hub located centrally on the first side of the base and defining a rotational axis of the impeller, wherein the hub comprises a face surface offset from the first side of the base; and   a plurality of impeller blades disposed upon the first side of the base and extending generally from the hub to the peripheral edge, each of the impeller blades being arc-shaped when viewed parallel to the rotational axis of the impeller, wherein each impeller blade comprises:
 a first edge surface extending outwardly from the hub and away from the first side of the base, the first edge surface terminating at or near the face surface; 
 a second edge surface extending inwardly from the peripheral edge and away from the first side of the base; and 
 an intermediate, third edge surface connecting the first edge surface to the second edge surface, 
 wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, defines an inlet angle of about 26 degrees to about 34 degrees, the inlet angle measured between: a first line that extends orthogonally from the rotational axis of the impeller to a first point located on the third edge surface; and a second line that is tangent to the impeller blade at the first point. 
   
   
   
       2 . The impeller of  claim 1 , wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, further defines an outlet angle of about 46 degrees to about 54 degrees, the outlet angle measured between: a third line that extends orthogonally from the rotational axis of the impeller to a second point defined by an intersection of a centerline of the impeller blade with the peripheral edge; and a fourth line that is tangent to the impeller blade at the second point. 
   
   
       3 . The impeller of  claim 2 , wherein the outlet angle is about 48 degrees to about 52 degrees. 
   
   
       4 . The impeller of  claim 2 , wherein the outlet angle is about 50 degrees. 
   
   
       5 . The impeller of  claim 1 , wherein the inlet angle is about 28 degrees to about 32 degrees. 
   
   
       6 . The impeller of  claim 1 , wherein the inlet angle is about 30 degrees. 
   
   
       7 . The impeller of  claim 1 , wherein the first point is located along a centerline of the impeller blade at or near an intersection of the second edge surface with the third edge surface. 
   
   
       8 . The impeller of  claim 1 , wherein the plurality of impeller blades comprises three groups of impeller blades, each group of impeller blades comprising two impeller blades, and further wherein each of the three groups is symmetrically spaced about the rotational axis. 
   
   
       9 . The impeller of  claim 8 , further comprising a shortened member disposed between two of more of the three groups of impeller blades. 
   
   
       10 . The impeller of  claim 1 , wherein a centerline of the third edge surface is contained within a plane that is parallel to the first side of the base. 
   
   
       11 . The impeller of  claim 1 , wherein a centerline of the third edge surface is contained within a plane that is parallel to the face surface of the hub. 
   
   
       12 . The impeller of  claim 1 , wherein the first point is radially offset from the rotational axis of the impeller a distance of about 1.35 to about 1.65 inches. 
   
   
       13 . The impeller of  claim 1 , wherein the peripheral edge defines a cylinder having a diameter of about 4.5 inches to about 5 inches. 
   
   
       14 . The impeller of  claim 1 , wherein the base further comprises a second side opposite the first side, the second side comprising a plurality of cooling blades. 
   
   
       15 . The impeller of  claim 1 , wherein each of the impeller blades, when viewed parallel to the rotational axis, defines an arc having a radius of about 1.3 inches to about 1.7 inches. 
   
   
       16 . The impeller of  claim 15 , wherein the radius is about 1.5 inches to about 1.6 inches. 
   
   
       17 . An impeller for a portable blower/vacuum comprising:
 a base comprising a first side and a peripheral edge;   a hub protruding from the first side of the base, the hub comprising a face surface and an outer surface that intersect at an outer hub edge, wherein an opening formed in the hub defines a rotational axis of the impeller; and   a plurality of impeller blades each disposed upon the first side of the base and extending generally between the hub and the peripheral edge, wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, is substantially arc-shaped, each of the impeller blades comprising:
 a first edge surface extending outwardly from a first location that is at or near the outer hub edge, to a second location intermediate the hub and the peripheral edge, wherein the second location is at an elevation below an elevation of the face surface; 
 a second edge surface extending inwardly from the peripheral edge to a third location intermediate the hub and the peripheral edge, the third location at substantially the same elevation as that of the second location; and 
 a third edge surface connecting the first edge surface to the second edge surface, 
 wherein each of the impeller blades defines an inlet angle of about 28 degrees to about 32 degrees, the inlet angle being measured between: a first line that extends orthogonally from the rotational axis of the impeller to a first point located on the third edge surface and along a centerline of the impeller blade; and a second line, coplanar with the first line, that is tangent to the impeller blade at the first point. 
   
   
   
       18 . The impeller of  claim 17 , wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, further defines an outlet angle of about 48 degrees to about 52 degrees, the outlet angle measured between: a third line that extends orthogonally from the rotational axis of the impeller to a second point defined by an intersection of the centerline of the impeller blade with the peripheral edge; and a fourth line that is tangent to the impeller blade at the second point. 
   
   
       19 . The impeller of  claim 17 , wherein the plurality of impeller blades comprises six impeller blades. 
   
   
       20 . The impeller of  claim 18 , further comprising a shortened member disposed upon the first side of the base between at least two of the impeller blades. 
   
   
       21 . A portable blower/vacuum comprising:
 a housing;   an electric motor secured to the housing; and   an impeller attached to a first end of an output shaft of the electric motor, the impeller comprising:
 a base comprising a first side and a peripheral edge; 
 a hub protruding from the first side of the base, the hub comprising a face surface offset from the base, wherein an opening formed in the hub defines a rotational axis of the impeller; and 
 a plurality of impeller blades each disposed upon the first side of the base and extending generally between the hub and the peripheral edge, wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, is substantially arc-shaped, and wherein each of the impeller blades comprises:
 a first edge surface extending outwardly from the hub and away from the first side of the base, the first edge surface terminating at or near the face surface; 
 a second edge surface extending inwardly from the peripheral edge and away from the first side of the base; and 
 an intermediate, third edge surface connecting the first edge surface to the second edge surface, 
 
 wherein each of the impeller blades, when viewed parallel to the rotational axis of the impeller, defines an inlet angle of about 26 degrees to about 34 degrees, the inlet angle measured between: a first line that extends orthogonally from the rotational axis of the impeller to a first point located on the third edge surface; and a second line, coplanar with the first line, that is tangent to the impeller blade at the first point. 
   
   
   
       22 . The blower/vacuum of  claim 21 , wherein each of the impeller blades, when viewed parallel to the rotational axis of impeller, further defines an outlet angle of about 48 degrees to about 52 degrees, the outlet angle measured between: a third line that extends orthogonally from the axis of the impeller to a second point defined by an intersection of a centerline of the impeller blade and the peripheral edge; and a fourth line tangent to the impeller blade at the second point. 
   
   
       23 . The blower/vacuum of  claim 21 , wherein the motor comprises a brush-commutator assembly, the brush-commutator assembly located proximate the first end of the output shaft.