Vacuum cleaner attachment for rotary lawnmowers

#This invention relates to a lawnmower attachment for converting a rotary type lawnmower to a vacuum cleaner to remove debris from sidewalks, driveways, and the like.

#Lawn maintenance usually involves mowing the grass, edging the grass along sidewalks and driveways, and cleaning the cut grass and other debris, such as dirt and leaves, from the sidewalks and driveways. This latter operation is commonly done by sweeping this debris into one or more piles where it can be picked up and removed. There are special vacuum cleaners on the market that can be used for this purpose also.

#By far, the majority of lawnmowers in use today are of the rotary type which employ a rotating propeller type blade moving in a horizontal plane to cut grass. The rotating blades of most of these mowers have knife edge cutting surfaces adjacent their outer tips that are flat on bottom and tapered on top so they will act as fan blades and pull air upwardly past the blades. The air so moved is useful in pulling the grass upwardly into the cutting edge of the blade and in pulling the cut grass upwardly into the housing where it can be discharged with the moving air into a receptacle out the side of the mower housing.

#In the drawings:

#FIG. 1 is a vertical sectional view of a rotary type lawnmower with one embodiment of the attachment of this invention mounted thereon to convert the lawnmower into a very effective vacuum cleaner;

#FIG. 2 is a bottom view of the lawnmower of FIG. 1, taken along line 2--2 of FIG. 1;

#FIG. 1 is a vertical cross section through a typical rotary lawnmower. The mower is shown more or less schematic, and as will be the case in the Figures showing other embodiments of this invention, only the essential parts of the mower and attachment will be shown. The mower of FIG. 1 includes motor 10 mounted on housing 11 which is supported for movement over the ground by wheels 12. Housing 11 includes upper plate 11a which supports the motor and downwardly extending generally cylindrical skirt 11b which combines with plate 11a to form chamber 14 in which is located mower blade 15. Output shaft 16 of motor 10 extends through plate 11a and supports through the opening in the bottom of the housing. The downward flow of air or spillage of air from chamber 14 in the conventional rotary type mower is what causes much of the scatter of debris when a running mower is moved across a sidewalk or the like without the attachment of this invention. By providing the baffle member with the portion extending inwardly, such as the portion of plate 21 between the side wall and the opening in plate 21, so that a portion of the outer tips of the blade are more or less enclosed, much of the air compressed between the tips of the blade and the walls of the housing of the mower will be prevented from flowing downwardly out of chamber 14 to scatter the debris away from the mower. There will, of course, continue to be this compression of air, but the inward flow of air through opening 21 will be such that this air will flow into the upwardly moving stream of air and be carried out of the chamber without causing any extraneous air currents that interfere with the proper vacuuming of a surface, such as a sidewalk.

#The size of opening 21 should be such that it is compatible with the opening between plate 20 and the surface being vacuumed through which the air must travel to reach opening 21. This passageway or duct which encircles opening 21 will be referred to herein as the horizontal duct leading to opening 21. It is one that reduces in size as the air moves inwardly toward the opening. In other words, there is less space for the air to flow through adjacent the opening than there is at the outer edge of the plate. Thus, a given volume of air moving through the horizontal duct will increase in velocity as it approaches opening 21, and generally it is desirable that this increase in velocity be maintained as the air moves upwardly through the opening so that the debris entrained in the air will not tend to fall out at this point. Therefore, preferably the size of opening 21 should be such that the velocity of air moving through the horizontal duct is not unduly decreased as it moves through opening 21.

#In accordance with this invention, means are provided to releasably attach the baffle member to the housing of the mower when it is desired to convert the mower into a vacuum cleaner for cleaning a sidewalk and the like. In the embodiment shown in FIGS. 1 and 2, and as best seen in FIG. 3, plate 20 is provided with four equally spaced ears 23 to each of which is attached eye bolt 24 and spring 25. Four eye bolts 26 are attached to upper plate 11a and positioned to be above ears 23 when the plate is installed in place under the housing. Each spring has hook 25a to connect to eye bolt 26 and support plate 20 in position across the bottom of the housing. If desired, each ear can be provided with lug 27 to engage the outer surface of the sidewall of the mower housing to hold the plate centered with respect to the housing.