Lawn mower

Abstract: A lawn mower of the type which collects grass cuttings, comprises a motor driven blade rotatable about a substantially vertical axis, at least one fan rotatable about the same axis, and grass collecting means of the type in which grass collection is aided by suction from an airstream produced by the at least one fan. The said grass collecting means is adjustable between a first position in which it is adapted to collect grass cut by the mower and deposited on the ground, and a second position in which it is adapted to collect garden debris lying on the ground.

Description: This invention relates to a lawn mower, and is particularly concerned with a lawn mower of the type which comprises a motor driven blade and one or more fans rotatable about a substantially vertical axis. Lawn mowers of this type include both mowers which are supported on wheels, known as "wheeled rotary mowers", and those which in operation are supported on a cushion of air, known as "hover" mowers. The first rotary and hover mowers left the cut grass, normally in a finely divided state, on the ground. Users could then either leave the cut grass on the ground, for example as a mulch, or they could pick up the cut grass in a secondary operation. In due course attempts were made to design mowers of the rotary or hover type which picked up the grass as they went along. A number of designs of lawn mower have been proposed in which the cut grass is sucked up by an air stream which is either specifically created for that purpose or alternatively may, in the case of a hover mower, then form or contribute to the formation of the air cushion on which the mower hovers. Garden tools have also been provided which collect leaves and other debris from the lawn, and include motorised rakes and garden vacuum cleaners of various types. It is a disadvantage of these tools that they are used for only a short time during the year, in particular in autumn when leaves are falling, and a potential purchaser may feel that this short period of time does not justify either the expense of purchasing or the need for storing a machine dedicated to this single task, for such occasional use. Mowers which are provided with a suction system for collecting cut grass are designed so that the aperture through which the cut grass is picked up is located in the area of the mower deck where the cut grass is principally deposited during the mowing operation. Such mowers are not suitable for the collection of leaves and other debris from lawns, which is more generally distributed about the lawn. It has been proposed, in GB Patent Application No. 2,127,665, to provide a flexible hose which is a remote pick up for grass and debris, for attachment to a lawn mower which picks up grass by suction, but such a machine would be very inconvenient to handle, as separate control would be required for directing the nozzle mounted on the end of the flexible hose towards the debris to be collected. The respective apertures for debris and grass collection may be variably opened and closed. It is an object of the present invention to provide a lawn mower of the type which collects grass cuttings, which mower comprises a motor driven blade rotatable about a substantially vertical axis, at least one fan rotatable about the same axis, and grass collecting means of the type in which grass collection is aided by suction from an airstream produced by the at least one fan, which grass collecting means is provided with a first aperture for grass collection and a second aperture for debris collection, characterised in that said first and second apertures are positioned adjacent to each other, and are provided either with a closure means which is adapted to be adjusted between a first position in which both the grass collection aperture and the debris collection aperture are open, and a second position in which the grass collection aperture is open and the debris collection aperture is closed or with a closure means which is adapted to be adjusted between a first position in which the grass collection aperture is closed and the debris collection aperture is open and a second position in which the grass collection aperture is open and the debris collection aperture is closed. The invention will now be further described with reference to the accompanying drawings, of which Figure 1 is a general view of a first embodiment of a lawn mower showing the grass collecting means; Figure 2 is a part section view of the embodiment of Figure 1 showing the grass collecting means arranged to collect grass cuttings; Figure 3 is a general view of a second embodiment of a lawn mower showing the grass collecting means; Figure 4 is a part section view of a second embodiment of a lawn mower showing the grass collecting means arranged to collect garden debris; and Figure 5 is a part section view of the embodiment of Figure 4 showing the grass collecting means arranged to collect grass. In a first embodiment of a lawn mower according to the invention, as shown in Figures I and 2, a hover mower (2) comprises a grass box (4) which is provided in conventional manner with a grass collection aperture (6). The aperture (6) is positioned, in known manner, in the base of the grass box in the area where the cut grass is preferentially deposited during mowing. The grass box (4) is further provided with a debris collection aperture (8) at the base of the substantially vertical rear wall (10) of the grass box (4). A flap (12) is pivotally mounted at pivot points (14, 16), on the side walls of the grass box (4). The flap (12) comprises a substantially rectangular portion (18) which corresponds in size and shape to the debris collection aperture (8), and two attachment arms (20) at right angles to the rectangular portion (18). The pivot points (14, 16) are located on the attachment arms (20). A locking mechanism is provided so that the flap (12) can be locked in a first position A, a second position B, or in any discrete position in between to allow partial opening of the debris collection aperture (8). The grass box (4) is provided with a removable lid (22) so that it can be emptied. In operation, the mower can be used in a debris collection mode, as shown in solid lines in Figure 1, or a grass collecting mode as shown in dotted lines in Figure 1 and in Figure 2. For debris collection, the flap (12) is located in a first position (A) in which the grass collection aperture (6) is closed by the flap (12) and the debris collection aperture (8) is open. The mower is pushed in the opposite direction to that used for grass cutting and collection, i.e. with the debris collection aperture to the front. As the mower is operated, the full width of the aperture is available to suck up garden debris and collect it in the grass box. For grass collection, the flap (12) is moved to the second position (B) in which the debris collection aperture (8) is blocked and the grass collection aperture (6) is open. As the mower is operated, the suction is directed to the grass collection aperture (6) so that the cut grass is collected, from the areas where it has been preferentially deposited by the mower (2). In an alternative embodiment, as shown in Figures 3 to 5, the flap (24) is of modified design and deeper than the flap (12) of the first embodiment. It is provided with a slot which extends across substantially the full width of the grass box (4) in the region of the flap adjacent to the mower (12). The depth of the slot is approximately equal to the depth of the debris collection aperture (8). The operation of the mower is similar to that of the mower of the first embodiment, except that in the grass collection mode, the debris collection aperture (8) is closed by the solid portion of the flap (24), and in the debris collection mode both the grass collection aperture (6) and the debris collection aperture (8) are open.

Claims: A lawn mower of the type which collects grass cuttings, which mower (2) comprises a motor driven blade rotatable about a substantially vertical axis, at least one fan rotatable about the same axis, and grass collecting means (4) of the type in which grass collection is aided by suction from an airstream produced by the at least one fan, which grass collecting means (4) is provided with a first aperture (6) for grass collection and a second aperture (8) for debris collection, characterised in that said first and second apertures (6,8) are positioned adjacent to each other, and are provided either with a closure means which is adapted to be adjusted between a first position in which both the grass collection aperture (6) and the debris collection aperture (8) are open, and a second position in which the grass collection aperture (6) is open and the debris collection aperture (8) is closed or with a closure means which is adapted to be adjusted between a first position in which the grass collection aperture (6) is closed and the debris collection aperture (8) is open and a second position in which the grass collection aperture (6) is open and the debris collection aperture (8) is closed. A lawn mower according to claim 1 characterised in that it is a mower of the type which in operation is supported on a cushion of air.

Inventors: THOMAS W ROGER, WEBSTER CRAIG DUNCAN, THOMAS, W. ROGER, WEBSTER, CRAIG DUNCAN
Applicants: BLACK & DECKER INC, BLACK & DECKER INC.
Application year: 1992
Main classification: A01D34
IPC codes: A01D43, A01D34, A47L9, A01G1