US3646740A

US3646740A - Lawnmower protective guard

Info

Publication number: US3646740A
Application number: US63176A
Authority: US
Inventors: John J Grimes
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-08-12
Filing date: 1970-08-12
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

Lawnmower having a guard extending across lower portion of discharge opening and embodying vertical flange outwardly of and in alignment with tip of rotary cutter blade and horizontal flange extending inwardly from upper edge of vertical flange over and in spaced relation to tip of cutter blade. Rear end of guard extends beyond trailing edge of discharge opening and forward end of guard extends forward from leading edge of discharge opening a distance equal substantially the distance from said leading edge to first tangent of exposure of cutter blade less the height of horizontal flange above cutter blade.

Description

United States Patent Grimes 1 Mar. 7, 1972 [54] LAWNMOWER PROTECTIVE GUARD 2,864,226 12/1958 Bright ..56/l3.4 [72] Inventor: John J. Grimes, Route 4, Box 554A, Sel- Primary Emminer RusseR Kinsey 3670] Attorney-Jennings, Carter & Thompson [22] Filed: Aug. 12, 1970 [57] ABSTRACT [21] Appl. No.: 63,176

Lawnmower having a guard extending across lower portion of discharge opening and embodying vertical flange outwardly of [52] US. Cl. ..56/320.2 and in alignment with tip of rotary cutter blade and horizontal [51] Int. Cl. ..A0ld 35/26 flange extending inwardly from upper edge of vertical flange [58] Field of Search ..56/320.2, 12.2, 13.4 Over and in Spaced relation to p of cutter blade. r end f guard extends beyond trailing edge of discharge opening and [56] References Cited forward end of guard extends forward from leading edge of discharge opening a distance equal substantially the distance UNITED STATES PATENTS from said leading edge to first tangent of exposure of cutter blade less the height of horizontal flange above cutter blade. 3,468,108 9/l969 Mattson ..56/l3.4 2,719,396 10/1 955 Morris et al. ..56/l 2.2 4 Claims, 5 Drawing Figures PATENTEDMAR 7. I972 I NVEN TOR. John I Grimes W MfW Attorneys LAWNMOWER PROTECTIVE GUARD BACKGROUND OF THE INVENTION This invention relates to a lawnmower having a protective guard and more particularly to a guard member which is secured to the housing for a rotary cutter blade and extends transversely across the lower portion of the discharge opening for the housing.

As is well known in the art to which my invention relates, difficulties have been encountered in protecting persons against injury from contact with the rotary blade and from flying debris discharged from rotary lawnmowers, such as bits of metals, rocks and the like. While many safety devices have been proposed for rotary lawnmowers, such devices have not reduced the exposure of the tip of the rotary blade to zero as the blade rotates relative to the discharge opening.

BRIEF SUMMARY OF THE INVENTION In accordance with my invention, I provide a guard member which is secured to and extends transversely across the lower portion of the discharge opening of a rotary lawnmower. The guard member is provided with a vertical flange which extends across the discharge opening with an intermediate portion of the vertical flange being in horizontal alignment with the path of rotation of the cutter blade. An inwardly extending, horizontal flange is carried by the upper edge of the vertical flange and extends over and in spaced relation to the path of rotation of the tip of the cutter blade. The rear end of the horizontal flange extends beyond the trailing edge of the discharge opening while the forward end of the horizontal flange extends forwardly from the leading edge of the discharge opening a distance equal substantially the distance from the leading edge to the first tangent of exposure passing through the upper portion of the leading edge and the path of rotation of the tip of the cutter blade less the height of the horizontal flange above the cutter blade.

Apparatus embodying features of my invention is illustrated in the accompanying drawing, forming a part of this application in which:

FIG. 1 is a side elevational view, partly broken away, showing a lawnmower having my improved guard member mounted thereon;

FIG. 2 is a top plan view of the lawnmower shown in FIG. 1;

FIG. 3 is an enlarged, sectional view taken generally along the line 33 of FIG. 1;

FIG. 4 is a fragmental, sectional view taken generally along the line 4-4 of FIG. 3; and

FIG. 5 is a diagrammatic view taken generally along the line 55 of FIG. 3 showing the relationship of the cutter blade to the elongated guard member.

Referring now to the drawing for a better understanding of my invention, I show a lawnmower having a downwardly opening housing which is mounted on supporting wheels 11. The mower is provided with a conventional-type power unit, such as an internal combustion engine 12. Upwardly and rearwardly extending handle members 13 are mounted at the rear end of the mower, as shown in FIGS. 1 and 2.

As shown in FIGS. 1, 2 and 3, the downwardly opening housing 10 is provided with a tangential discharge opening 14 at one side thereof for discharging grass cuttings outwardly and laterally of the housing 10 in a manner well understood in the art to which my invention relates. The power unit 12 is provided with a vertical drive shaft 16, as shown in FIG. 1. Secured to and adapted for rotation with the shaft 16 is a rotary cutter blade 17 having a cutter edge 18 adjacent each end thereof. The tip of the cutter blade 17 rotates in a circular path indicated by the dot-dash line 19. The rotary cutter blade 17 thus rotates in a horizontal plane with the tip thereof moving in an arcuate path inwardly of the inner surface of the downwardly opening housing 10.

My improved guard member is indicated generally at 21 and comprises a vertical flange 22 which extends transversely across the lower portion of the discharge opening 14. Secured to and extending inwardly of the upper edge of the vertical flange 22 is a horizontal flange 23 having an arcuate, concave inner edge 24. Preferably, the horizontal flange 23 is formed integrally with the vertical flange 22, as shown in FIG. 4. The vertical flange 22 of the guard member 21 is positioned outwardly of the path of rotation of the tip of the cutter blade 17 with an intermediate portion of the flange 22 being in horizontal alignment with the path of rotation 19 of the tip of the cutter blade 17. Also, as shown in FIG. 4, the horizontal flange 23 extends inwardly over and in spaced relation to the path of rotation 19 of the tip of the cutter blade 17.

The rear end of the horizontal flange 23 extends rearwardly beyond the trailing edge 26 of the discharge opening 14, as shown in FIG. 3. The forward end of the horizontal flange 23 extends forwardly from the leading edge 27 of the discharge opening 14 a distance equal substantially to the distance from the leading edge 27 to the first tangent or exposure defined by a line which passes through the upper portion of the leading edge 27 and extends forward tangent to the path of rotation 19 of the tip of the cutter blade less the height of the horizontal flange 23 above the tip of the cutter blade 17 and its path of rotation 19. The first tangent of exposure is thus indicated by the line 28 in FIGS. 3 and 5 and extends from the upper inner surface of the discharge opening 14 adjacent the edge 27 thereof and extends tangent to the path of rotation 19 of the tip of the cutter blade 17. Since the cutter blade 17 is below the horizontal flange 23, as indicated by line 29 in FIG. 5 and as clearly shown in FIG. 4, the horizontal flange 23 does not have to extend the full length from the edge 27 to the point of first tangent of exposure, as indicated at 25. That is, the distance the horizontal flange 23 extends forward is reduced by an amount equal the height that the horizontal flange 23 is above the path of rotation of the tip of the cutter blade 17.

The last tangent of exposure is indicated by the line 31 which passes through the trailing edge 26 of the discharge opening 14 and extends forward tangent to the path of rotation 19 of the tip of the cutter blade 17. As shown in FIG. 3, the rear end of the horizontal flange 23 extends rearwardly past the trailing edge 26. Accordingly, the exposure of the tip of the rotary cutter blade 17 is zero at the first tangent of exposure, indicated at the point line 28 touches the path of rotation 19, and remains so throughout the last tangent of exposure, indicated at the point line 31 touches the path of rotation 19. The guard member 21 thus provides complete protection throughout the critical areas of concern in safety specifications for rotary power mowers.

As shown in FIG. 3, the forward inner portion of the horizontal flange 23 is convexly curved to present a rounded leading edge 32 to thus provide a minimum resistance to the outwardly moving stream of grass cuttings. As shown in FIGS. 3 and 4, depending, vertical flanges 33 are carried by the forward and rear ends of the horizontal flange 23 with each depending flange 33 being secured rigidly to the housing 10 of the lawnmower by suitable means, such as by welding. Accordingly, the elongated guard member 21 not only provides a safety device for the lawnmower but also adds strength thereto.

From the foregoing description, the construction and opera tion of my improved lawnmower protective guard will be readily-understood. The depending flanges 33 are secured rigidly to the inner surface of the housing 10 at opposite sides of the discharge opening 14 with the vertical flange 22 extending transversely of the lower portion of the discharge opening 14. As shown in FIG. 4, an intermediate portion of the vertical flange 22 is in horizontal alignment with the path of rotation of the tip of the cutter blade 17 whereby a foot or hand ofa person cannot move horizontally into contact with the blade 17 and any debris thrown outwardly of the end of the blade 17 strikes the vertical flange 22. The horizontal flange 23 is positionecl at an elevation above and extends over the tip of the cutter blade 17, as shown in FIGS. 3 and 4. With the guard member 21 thus mounted, the rear end of the horizontal flange 23 extends rearwardly of the trailing edge 26 while the forward end of the horizontal flange 23 extends from the leading edge 27 of the discharge opening 14 a distance equal sub stantially the distance from the leading edge 27 to the first tangent of exposure passing through the upper portion of the leading edge 27 and the path of rotation 19 of the tip of the cutter blade 17, less the height of the flange 23 above the cutter blade 17. Accordingly, the horizontal flange 23 extends from the leading edge 27 of the discharge opening 14 to a point 30 on the line 29, as shown in FIG. 5, which represents the distance from the leading edge 27 to the point of the first tangent of exposure 25 less the height of the horizontal flange 23 above the cutter blade 17.

From the foregoing, it will be seen that l have devised an improved lawnmower protective guard. By providing a protective guard which reduces the blade tip exposure at the first tangent to zero and maintains the blade tip exposure at zero through the last tangent, my safety guard member complies with safety specifications for rotary power mowers in the most critical areas of concern. Furthermore, by providing the vertical flange 22 and the horizontal flange 23 which extends to the points mentioned hereinabove, I reduce to a minimum the danger of a hand or foot of a person contacting the rotary tip of the blade.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is:

1. In a lawnmower having a downwardly opening housing with a discharge opening at one side thereof and a cutter blade mounted for rotation in a horizontal plane inwardly of said discharge opening:

a. an elongated guard member having a vertical flange extending transversely across the lower portion of said discharge opening outwardly of the path of rotation of the tip of said cutter blade with an intermediate portion of said vertical flange being in horizontal alignment with said path of rotation of the tip of said cutter blade,

b. a horizontal flange carried by the upper edge of said verti cal flange extending inwardly over and in spaced relation to said path of rotation of the tip of said cutter blade,

. the rear end of said horizontal flange extending inwardly over said path of rotation and rearwardly beyond the trailing edge of said discharge opening, and

d. the forward end of said horizontal flange extending inwardly over said path of rotation and forwardly from the leading edge of the discharge opening a distance equal substantially to the distance from the leading edge of said discharge opening to a first tangent of exposure defined by a line passing through the upper portion of said leading edge and extending forwardly and tangent to said path of rotation of the tip of said cutter blade less the height of said horizontal flange above said path of rotation of the tip of said cutter blade.

2'. A lawnmower as defined in claim 1 in which the central portion of the inner edge of said horizontal flange is concavely curved.

3. A lawnmower as defined in claim I in which the forward inner portion of said horizontal flange is convexly curved to present a rounded leading edge.

4. A lawnmower as defined in claim 1 in which a depending flange is carried by said forward end and rear end of said horizontal flange with each said depending flange being secured rigidly to said housing for the lawnmower.

Claims

1. In a lawnmower having a downwardly opening housing with a discharge opening at one side thereof and a cutter blade mounted for rotation in a horizontal plane inwardly of said discharge opening: a. an elongated guard member having a vertical flange extending transversely across the lower portion of said discharge opening outwardly of the path of rotation of the tip of said cutter blade with an intermediate portion of said vertical flange being in horizontal alignment with said path of rotation of the tip of said cutter blade, b. a horizontal flange carried by the upper edge of said vertical flange extending inwardly over and in spaced relation to said path of rotation of the tip of said cutter blade, c. the rear end of said horizontal flange extending inwardly over said path of rotation and rearwardly beyond the trailing edge of said discharge opening, and d. the forward end of said horizontal flange extending inwardly over said path of rotation and forwardly from the leading edge of the discharge opening a distance equal substantially to the distance from the leadiNg edge of said discharge opening to a first tangent of exposure defined by a line passing through the upper portion of said leading edge and extending forwardly and tangent to said path of rotation of the tip of said cutter blade less the height of said horizontal flange above said path of rotation of the tip of said cutter blade.

2. A lawnmower as defined in claim 1 in which the central portion of the inner edge of said horizontal flange is concavely curved.

3. A lawnmower as defined in claim 1 in which the forward inner portion of said horizontal flange is convexly curved to present a rounded leading edge.