Hinged edger housing having improved internal debris guard and labyrinth perimeter seal

#The present invention generally relates to power edgers and more particularly to a housing assembly for housing the blade member of a power edger.

#Powered edgers having a rotary blade for performing an edging operation require routine maintenance in that the rotating blade is subject to wear and must be periodically sharpened or replaced. Furthermore, debris, such as grass and dirt, tend to accumulate on the guard around the blade and must be removed in order to maintain the efficiency and effectiveness of the edger device.

#Typical housing assemblies for rotary edgers include a screw-attached guard plate that must be removed from a housing in order to gain access to the blade or to remove accumulated debris. In addition to being inconvenient, these conventional housing assemblies frequently do not thoroughly seal against the housing such that dirt and debris have been known to infiltrate in an undesired manner around the guard plate.

#Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a perspective view of a power edger having a housing assembly that is constructed in accordance with the teachings of the present invention;

#FIG. 2 is a perspective view of the power edger of FIG. 1 illustrating the door in an open condition;

#With reference to FIGS. 1 and 2 of the drawings, an edger 8 is illustrated to include a housing assembly 10, which has been constructed in accordance with the teachings of the present invention. The edger 8 is also shown to include a shroud 20, a rotary power source 22, front and rear wheels 24 and 26, respectively, a blade 28 and a handle 30. The shroud 20 conventionally houses the rotary power source 22 and serves as the means by which the front and rear wheels 24 and 26 and the handle 30 are coupled to the rotary power source 22. In the particular embodiment illustrated, the shroud 20 is an integrally formed portion of the housing assembly 10, but those skilled in the art will understand that the housing assembly 10 may be discrete and separate from other portions of the edger 8, including those that house a rotary power source. The rotary power source 22 is illustrated to be an electric motor in the example provided and includes an output shaft 34 that is rotatable about a rotary axis 36. The blade 28 is fixedly but removably coupled to the output shaft 34 such that it is rotatable about the rotary axis 36. At least one of the front and rear wheels 24 and 26 is preferably movably coupled to the shroud 20 of the housing assembly 10 to permit the height of the blade 28 to be adjusted relative to the ground. The handle 30 is coupled to the shroud 20 via an attachment socket 38 that is integrally formed into the shroud 20.

#The housing assembly 10 is also illustrated to include a housing 40, a door 42, a hinge pin 44 and a latch mechanism 46. With reference to FIGS. 2 and 3, the housing 40 includes a first wall member 50, a guard 52, a latch securing structure 54, a first labyrinth member 56 and a first hinge structure 58. The housing 40 defines a blade cavity 60 in which the blade 28 is rotatably disposed and a generally vertical portion 62 that is oriented generally perpendicular the rotary axis 36 of the output shaft 34.

#The guard 52 extends generally perpendicularly from the first wall member 50 in a direction that is generally parallel the rotary axis 36 such that the guard 52 bounds the outer perimeter of the blade cavity 60. The guard 52 is illustrated to include a confronting portion 68 having a leading end 70 at the forward end of the housing 40 and a trailing end 72 that is located rearwardly of the leading end 70. The confronting portion 68 is defined by an angle of at least 90° and preferably by an angle of at least 120°. The confronting portion 68 is also characterized by a radius 74 that is centered at a point along the rotary axis 36. The radius 74 is not constant, but rather increases in a smooth manner in the direction in which the blade 28 rotates between a leading end 70 and a trailing end 72. The increasing sweep of the radius 74 therefore provides an increasing amount of clearance between the tip 28a of the blade 28 and the inner surface 68a of the guard 52 between the leading end 70 of the confronting portion 68 and the trailing end 72 of the confronting portion 68. Preferably, the amount of clearance between the leading end 70 and the trailing end 72 increases by a factor of between about 2 to about 10. Those skilled in the art will understand that while the rate by which the radius 74 increases may correspond to any mathematical model, the rate by which the radius 74 increases is dependent upon numerous considerations, including the maximum overall size of the housing assembly 10 and the capability of the blade 28 to circumferentially shed the dirt and debris encountered by the blade 28 during the operation of the edger 8.