Lawn mowers

Abstract: This invention relates to grass cutting appliances. In particular a grass cutting appliance in the form of a lawn mower comprises a hood (1), a cutting member (7) mounted for rotation in a substantially horizontal plane within the hood (1), a handle (2) for controlling directional movement of the appliance during a cutting operation, a power source (3) disposed remotely from the cutting member (7) and supported from the handle (2), and a drive line (5) for drivingly connecting the power source (3) and the cutting member (7).

Description: This invention relates to grass cutting appliances. In particular the invention relates to rotary lawn mowers having one or more cutting blades mounted for rotation during operation about a generally vertical axis. Generally speaking, there are two main categories of rotary lawn mower, namely (1) a hover-type rotary lawn mower which, when operative is supported by a cushion of air, and (2) a rotary mower which is supported on wheels and which may include a rear roller for producing a striped effect on a mown lawn. Mowers falling under category (1) are manually propelled by a user whereas mowers falling under category (2) may be either manually propelled by a user or propelled by a drive-line taken from a power unit connectable via a clutch to one or more wheels or a roller system. In the latter case the power unit combines the functions of driving the rotatable cutting blade(s) and the mower per se. Mowers falling within either category may be driven directly or indirectly by either an i/c engine or an electric motor. It is an object of the present invention to improve the manoeuvrability of type (1) and type (2) mowers as defined above. According to the present invention a lawn mower comprises a hood defining a cutting chamber, a cutter member mounted for rotation in a substantially horizontal plane within the cutting chamber, a handle for controlling directional movement of the mower during a cutting operation, a power source disposed remotely from the cutter member and supported from the handle, a drive line for drivingly connecting the power source to the cutter member, a grass collector removably supported on the hood for collecting cut grass, and an inlet aperture disposed adjacent the hood, characterised in that an impeller is mounted within the hood and is drivingly connectable to the power source for producing a stream of pressure air for entraining cut grass and directing the cut grass into the grass collector and in that the stream of pressure air is drawn through the grass collector to the impeller. Preferably the cutter member and the impeller are co-axially mounted on the common shaft and driven via the drive line. Conveniently the handle is pivotally attachable to the hood. The handle could include a tubular member, and the drive line could be housed within the tubular member. The grass collector may include an outlet which overlies an inlet to the impeller through which pressure air is drawn. In order to accommodate the handle, the grass collector is preferably slotted to permit pivotal movement of the handle. Embodiments of lawn mowers in accordance with the present invention are illustrated in the accompanying drawings, in which : Figures 1A, B, C and D are sectional views of a first embodiment of the present invention; Figure 2 is an exploded view showing the grass-box separated from the hood; Figure 3 is a side view of an assembled mower; and Figure 4 is a disassembled view of a mower showing the grid. Referring to figure 1, a hood 1 in the form of an inverted dish is pivotally connected to lower end 2A of a handle 2. The handle 2 supports an electric motor 3 that is powered by an electric current supplied by a cable 4. The electric motor 3 is connected via a drive line 5, within the handle 2, to a drive shaft 6 on which is mounted a rotatable cutting blade 7 and an impeller 8, both contained within a plenum chamber 9 of the hood 1. A grass box 10 is supported on the hood 1 as shown and includes a filter grid 11, an inlet 12, air outlet 13, a lid 14 hingedly supported at 15 from the hood 1 and a removable container 16 (shown in outline) for collecting cut grass. In use, air is drawn through inlet apertures 17 by the impeller 8 to create a cushion of air to support the mower. In addition air is drawn into the grass box 10 by operation of the impeller 8 through inlet 12, grid 11 and air outlet 13. The suction created within the grass box 10 draws grass cuttings and other debris into the box through inlet 12 where it is collected in the disposable container 16. Referring to figure 1A, (where like components are designated with the same reference numbers as figure 1), in addition to drawing debris and grass cutting into the box 10 through inlet 12, debris can be collected while the handle 2 is released by the attachment of a suction hose 18 to an aperture 19 formed on the exterior of the grass box 10 between the air inlet apertures 17 and the grid 11a. When not in use, such an aperture can be sealed with an air-tight cap 20. The grass box 10 can be removed from the hood 1 of the mower by hand by gripping the box along the contour 21, as shown more clearly in figure 1B. Referring to figure 1C, rotational energy from the drive line 5 is transmitted to the drive shaft 6 to a drive the cutting blade and impeller 8 by means of bevel gears 22a, 22b and 22c. Gear 22a is constrained to rotate about the pivotable axis of the handle 2, and gears 22b and 22c are respectively fixed to the drive line 5 and drive shaft 6. The drive shaft 6 is held in substantially vertical alignment by means of washers 24. The height of the cutting blade 7 relative to the ground datum can be varied by inserting or removing spacing discs 23 along the dirve shaft 6 between the blade 7 and the impellers. Refering to figure 1D, the grass box 10 has a slot 25 (also shown in fig. 4) in order to accomodate and permit up and down arcurate movement of the handle 2 when the grass box is mounted on the hood 1 of the mower. Air and debis is sucked into the grass box 10 through the inlet aperture 12 disposed rearwardly of the hood 1. Grass cuttings and debris can either be collected in the box 10 itself or in the removable container 16 supported in spaced relationship within the grass collector box 10 as shown. The container 15 is preferably permeable to air, allowing air to flow (as shown) out of it where it can be sucked back into the impeller, and can be of a disposable kind. Referring to figure 2, the grass collector box 10 is detached from the hood 1 of the mower in a generally upward direction 26. Collected debris and grass cuttings accumulate within the volume of the box indicated by the hatching. Referring to figure 3, the appearance of the mower with the grass collector box 10 mounted on the hood 1 is as shown. Referring to figure 4, the grass box 10 is opened up from the lid 14 enabling cut grass and collected debris and/or removable container to be removed therefrom. The grid 11 is inserted into the grass box 10 by first inserting it into the interior of the lid as shown, and then closing the lid. In a further embodiment of the invention the mower is supported on forward and rearward wheels. To assist manoeuvrability front wheels may be in the form of conventional casters. In particular, the wheels are disposed outside the plenum chamber 9 of the hood 1. In common with our former designs of wheeled or otherwise supported rotary lawn mowers, the plenum chamber 9 of this embodiment is in the form of a semi toroid. The air circulation or suction system operates in substantially the same manner as previously described with reference to Figure 1. In these embodiments, the grass collector 10, may carry a disposable bag for receiving grass cuttings.

Claims: A lawn mower comprising a hood defining a cutting chamber, a cutter member mounted for rotation in a substantially horizontal plane within the cutting chamber, a handle for controlling directional movement of the mower during a cutting operation, a power source disposed remotely from the cutter member and supported from the handle, a drive line for drivingly connecting the power source to the cutter member, a grass collector removably supported on the hood for collecting cut grass, and an inlet aperture disposed adjacent the hood, characterised in that an impeller is mounted within the hood and is drivingly connectable to the power source for producing a stream of pressure air for entraining cut grass and directing the cut grass into the grass collector and in that the stream of pressure air is drawn through the grass collector to the impeller. A mower according to claim 1, characterised in that the cutter member and the impeller are coaxially mounted on the common shaft and driven via the drive line. A mower according to claim 1 or 2, characterised in that the handle is pivotally attachable to the hood. A mower according to any preceding claim, characterised in that the handle includes a tubular member, and the drive line is housed within the tubular member. A mower according to any preceding claim, characterised in that the grass collector includes an outlet which overlies an inlet to the impeller through which pressure air is drawn. A mower according to any preceding claim, characterised in that the grass collector includes a slot to accommodate a pivotal movement of the handle.

Inventors: DUNN KEN, DUNN, KEN
Applicants: ELECTROLUX OUTDOOR PROD LTD, ELECTROLUX OUTDOOR PRODUCTS LIMITED
Application year: 1991
Main classification: A01D34
IPC codes: A01D43, A01D34