GB2024591A - Plastics casing for a lawn mower - Google Patents

Abstract

A plastics casing 2 for a lawn mower is in the form of a one piece double walled hollow body preferably blow moulded and containing sound- absorbing material between the walls. The walls include an upper wall 17 and well wall 3 for together at least partially covering and housing a cutter blade drive motor 7, and a lower wall 18 shaped to provide a cover for a cutter blade 8, a suction volute 14 and a nozzle 18 for ejecting cut grass. <IMAGE>

Description

SPECIFICATION Plastics casing for a lawn mower This invention relates to a plastics casing for a lawn-mower, for covering at least partially, a cutter blade drive mechanism and the components controlled thereby.

In a known lawn-mower the casing comprises side pieces made of insulating plastics, supporting a rotary cylinder which carries cutter blades. An arrangement of this known type increases the safety of a lawn-mower powered by mains electricity, but does not give the casing adequate strength or sound absorption.

There is thus a need for a generally improved plastics casing for a lawn-mower.

Accordingly the present invention provides a plastics casing for a lawn mower, comprising a one piece double walled hollow body capable of containing sound absorbing material between the walls, which walls include an upper wall and a well wall for together at least partially covering and housing drive means for a cutter blade or blades, and a lower wall shaped to provide a cover for the cutter blade or blades, when the latter is or are present, a suction volute for directing cut grass and a nozzle for ejecting cut grass.

A casing produced in this way has the advantage that it can be made simply and economically by processes of blowing a plastics material such as polypropylene, to give a hollow body forming the double walled casing. Preferably the casing provides a skirt for protecting the cutter blade or blades.

The external wall of the casing is continuous and advantageously free from any undulations in which blades of grass might become trapped.

Preferably the casing has injected sound absorbing material between the walls. This constructional measure considerably reduces the noise of the cutting blade however the blade is driven.

Moreover the doublewalled casing thus constructed has good strength and does not suffer from the danger of breakage as a result of stones thrown up by the cutting blade.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of a lawn-mower, having a casing according to the invention.

Figure 2 is a view of the casing, in a longitudinal section taken along the line ll-ll in Figure 1, and Figure 3 is a view of the casing, in a cross-section taken along the line Ill-Ill in Figure 1.

Figure 1 of the accompanying drawings shows a mower of the "hand" type with a casing 2 according to the invention, although the invention can also be applied to self-propelled mowers. The lawn-mower shown in Figure 1 is provided in known manner with a frame 1 with the casing 2 mounted on it.

As shown in Figures 2 and 3, the casing 2 comprises a one piece doublewalled hollow body whose walls include a well wall 3.

This well wall 3 forms an at least partial housing for a drive mechanism 4 for a cutter blade or blades 8 and is closed by a protective cover 5. The drive mechanism may e.g. be an electric motor 7 driving the cutting blade 8 which is arranged below the frame 1. Handles 9 are provided to push and guide the mower. The mower has four support wheels 10, 11,12, 13 which are arranged in pairs and mounted eccentrically relative to the frame 1.

The hollow body forming the casing 2 has integral means for directing and ejecting the cut grass. These means consist of an appropriately shaped suction volute 14 and an ejecting nozzle 15 provided by the lower wall of the casing 2. The top and bottom of the well wall 3 respectively support the cover 5 and a grating 6 for protecting the motor blade 7. The lower wall of the casing 2 also provides a cover for the cutting blade or blades 8. Thus the cutting blades and the drive mechanism are housed in a casing formed by a one piece hollow body of doubewall configuration.

The upper wall 17 has a simple configuration, without any undulations which might retain the blades of cut grass, and is integral with the well wall 3.

The lower wall 18 is integral with the wall 17 (the hollow body being bounded by the internal surfaces of the walls 17 and 18), and a sound absorbing material may be injected into the internal volume of the body.

The special configuration of part 18 of the wall 17 corresponds to that of the suction volute 14 and enjecting nozzle 15. Preferably the casing 2 is made by blowing a plastics material such as polypropylene.

1. A plastics casing for a lawn mower, comprising a one piece double walled hollow body capable of containing sound absorbing material between the walls, which walls include an upper wall and a well wall for together at least partially covering and housing drive means for a cutter blade or blades, and a lower wall shaped to provide a coverforthe cutter blade or blades, when the latter is or are present, a suction volute for directing cut grass and a nozzle for ejecting cut grass.

2. A casing according to claim 1, in which the body is made by blowing plastics.

3. A casing according to claim 1 or claim 2, in which the external wall of the casing is free from any undulations in which blades of grass might become trapped.

4. A casing according to any one of claims 1 to 3, having injected sound absorbing material between the walls.

5. A plastics casing for a lawn mower, substantially as hereinbefore described with reference to the accompanying drawings.

6. A lawn mower having a plastics casing substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Plastics casing for a lawn mower This invention relates to a plastics casing for a lawn-mower, for covering at least partially, a cutter blade drive mechanism and the components controlled thereby. In a known lawn-mower the casing comprises side pieces made of insulating plastics, supporting a rotary cylinder which carries cutter blades. An arrangement of this known type increases the safety of a lawn-mower powered by mains electricity, but does not give the casing adequate strength or sound absorption. There is thus a need for a generally improved plastics casing for a lawn-mower. Accordingly the present invention provides a plastics casing for a lawn mower, comprising a one piece double walled hollow body capable of containing sound absorbing material between the walls, which walls include an upper wall and a well wall for together at least partially covering and housing drive means for a cutter blade or blades, and a lower wall shaped to provide a cover for the cutter blade or blades, when the latter is or are present, a suction volute for directing cut grass and a nozzle for ejecting cut grass. A casing produced in this way has the advantage that it can be made simply and economically by processes of blowing a plastics material such as polypropylene, to give a hollow body forming the double walled casing. Preferably the casing provides a skirt for protecting the cutter blade or blades. The external wall of the casing is continuous and advantageously free from any undulations in which blades of grass might become trapped. Preferably the casing has injected sound absorbing material between the walls. This constructional measure considerably reduces the noise of the cutting blade however the blade is driven. Moreover the doublewalled casing thus constructed has good strength and does not suffer from the danger of breakage as a result of stones thrown up by the cutting blade. For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of a lawn-mower, having a casing according to the invention. Figure 2 is a view of the casing, in a longitudinal section taken along the line ll-ll in Figure 1, and Figure 3 is a view of the casing, in a cross-section taken along the line Ill-Ill in Figure 1. Figure 1 of the accompanying drawings shows a mower of the "hand" type with a casing 2 according to the invention, although the invention can also be applied to self-propelled mowers. The lawn-mower shown in Figure 1 is provided in known manner with a frame 1 with the casing 2 mounted on it. As shown in Figures 2 and 3, the casing 2 comprises a one piece doublewalled hollow body whose walls include a well wall 3. This well wall 3 forms an at least partial housing for a drive mechanism 4 for a cutter blade or blades 8 and is closed by a protective cover 5. The drive mechanism may e.g. be an electric motor 7 driving the cutting blade 8 which is arranged below the frame 1. Handles 9 are provided to push and guide the mower. The mower has four support wheels 10, 11,12, 13 which are arranged in pairs and mounted eccentrically relative to the frame 1. The hollow body forming the casing 2 has integral means for directing and ejecting the cut grass. These means consist of an appropriately shaped suction volute 14 and an ejecting nozzle 15 provided by the lower wall of the casing 2. The top and bottom of the well wall 3 respectively support the cover 5 and a grating 6 for protecting the motor blade 7. The lower wall of the casing 2 also provides a cover for the cutting blade or blades 8. Thus the cutting blades and the drive mechanism are housed in a casing formed by a one piece hollow body of doubewall configuration. The upper wall 17 has a simple configuration, without any undulations which might retain the blades of cut grass, and is integral with the well wall 3. The lower wall 18 is integral with the wall 17 (the hollow body being bounded by the internal surfaces of the walls 17 and 18), and a sound absorbing material may be injected into the internal volume of the body. The special configuration of part 18 of the wall 17 corresponds to that of the suction volute 14 and enjecting nozzle 15. Preferably the casing 2 is made by blowing a plastics material such as polypropylene. CLAIMS

1. A plastics casing for a lawn mower, comprising a one piece double walled hollow body capable of containing sound absorbing material between the walls, which walls include an upper wall and a well wall for together at least partially covering and housing drive means for a cutter blade or blades, and a lower wall shaped to provide a coverforthe cutter blade or blades, when the latter is or are present, a suction volute for directing cut grass and a nozzle for ejecting cut grass.

2. A casing according to claim 1, in which the body is made by blowing plastics.

3. A casing according to claim 1 or claim 2, in which the external wall of the casing is free from any undulations in which blades of grass might become trapped.

4. A casing according to any one of claims 1 to 3, having injected sound absorbing material between the walls.

5. A plastics casing for a lawn mower, substantially as hereinbefore described with reference to the accompanying drawings.

6. A lawn mower having a plastics casing substantially as hereinbefore described with reference to the accompanying drawings.