GB2503458A

GB2503458A - Lawnmower with vegetation guide

Info

Publication number: GB2503458A
Application number: GB201211338A
Authority: GB
Inventors: Douglas Begg; Ian Zetterstrom Smith
Original assignee: Husqvarna UK Ltd
Current assignee: Husqvarna UK Ltd
Priority date: 2012-06-26
Filing date: 2012-06-26
Publication date: 2014-01-01
Also published as: GB201211338D0; DE102013105410A1

Abstract

A lawnmower comprises a housing 1 defining a cutting chamber 5, the housing having a front side 10, a back side 11 and two lateral sides 12, each of the lateral sides joining the front side to the back side, the sides surrounding the chamber; a cutting element 6 in the cutting chamber; in which the lawnmower further comprises two vegetation guides 13 positioned sequentially along one of the lateral sides of the housing, the vegetation guides being spaced along the lateral side, each vegetation guide comprising a passage running through the housing so as to guide vegetation into the cutting chamber. Each passage may comprise an inlet in the form of an aperture and the inlet may be provided with a comb member. Also disclosed is a lawnmower with wheels in which the wheels each comprise at least one circumferential groove in which grass can lie.

Description

LAWNMOWERS

This invention relates to lawnmowers.

Lawnmowers are well known; they generally comprise a housing on which is mounted a ground-facing cutting element, such a rotary blade. User safety requires that the user not be able to contact the cutting clement in use, which generally means that the housing surrounds the cutting element to form a cutting chamber. However, this means that, when it is desired to cut near an edge of a lawn, particularly if the lawn is bordered by an immovable object such as a wall, it is difficult to manoeuvre the lawnmowcr such that the cutting element passes over in particular the grass closest to the edge. This leads to untidy edges, which have to be separately dealt with, typically by manual cutting or using a nylon line trimmer.

According to a first aspect of the invention, there is provided a lawnmower, comprising: a housing defining a cutting chamber, the housing having a front side, a back side and two lateral sides, cach of the lateral sides joining the front side to the back side, the sides surrounding the chamber; a cutting element in the cutting chamber; in which the lawnmower further comprises two vegetation guides positioned sequentially along one of the lateral sides of the housing, the vegetation guides being spaced along the lateral side, each vegetation guide comprising a passage running through the housing from so as to guide vegetation into the cutting chamber.

As such, the sequential positioning of the guides along the side of the housing provides a second chance for grass or other vegetation that escape the first vegetation guide that it brushes against to pass through one of the vegetation guides.

This is particularly apparent when the lawnmower is arranged so as to be propelled front side first over a lawn (thus defining a forwards direction; backwards and sideways or lateral having the respective meanings); typically, the lawnmower will comprise a handle fixed to the housing and extending backwards from the housing.

Alternatively, the lawnmower may be provided with a propulsion unit arranged to drive the housing over the lawn surface in a generally forwards direction.

Each passage may comprise an inlet of the form of an aperture in the side and an outlet in the cutting chamber; the inlet may be further forwards than the outlet, so as to guide vegetation towards the cutting chamber as the lawnmower is moved forwards.

The inlet may be provided with a comb member extending from the side, and arranged to catch grass or vegetation as the lawnmower is moved forwards. The vegetation guide may be positioned at the furthest lateral extent of the housing.

Where the cutting element is a rotary blade rotatable about an axis and sweeping through a cutting area, each inlet may be radially and laterally outside the cutting area. Each outlet may also be outside, but typically adjacent to the cutting area; however, each outlet may be within the lateral extent of the cutting area.

The lawnmower may be a wheeled lawnmower, although the invention could also be applied to hover mowers.

According to a second aspect of the invention, there is provided a lawnmower, comprising: a housing dcfining a cutting chamber; a cutting element in the cutting chamber; and a plurality of wheels supporting the housing above a surface to be cut; in which a subset of the wheels comprising at least one of the wheels each comprise at least one groove running circumferentially in which grass can lie when the wheel runs over the grass.

The groove therefore will mean that the wheels of the subset will pin less grass to the ground as it passes. Furthermore, because of the circumferential direction of the groove, the grass can be conditioned to lie in the direction of travel, which may make it more likely to spring back up and be cut.

In one embodiment the wheels of the subset comprise plurality of discs with space between the discs, the space defining the groove, such that vegetation can pass through the space between the discs.

By forming a wheel from spaced-apart discs, rather than a solid generally cylindrical mass, less vegetation will be pinned to the ground and subsequently not cut. As such, use of these wheels may improve the amount of grass that is cut.

The discs of each wheel may be parallel to one another and may be mounted on a support rotatably mounted on the housing.

Alternatively, each groove may comprise a recess in the body of the wheel, in that each wheel is unitary. lO

By "running eircumferentially", we include any situation where the direction of the groove has a circumferential element. However, the groove can run purely circuniferentially. The direction of the groove can include an axial element; in one embodiment, the groove can be helical. This is useful where it is desired to move the grass laterally before it is cut.

Preferable, the subset of wheels will comprise at least two of the wheels; the subset may comprise all of the wheels. Generally, the wheels will align so as to define a preferred direction of travel; the subset of wheels may comprise the wheels at a front of the lawnrnower, being the furthest pair of wheels along the direction of travel in a sense that the lawnmower is generally propelled. The front pair of wheels thus define a forwards direction; backwards and sideways or lateral having the respective meanings.

The lawnrnower may comprise a handle fixed to the housing and extending backwards from the housing. Alternatively, the lawnmower may be provided with a propulsion unit arranged to drive the housing over the lawn surface in a generally forwards direction. The subset can not include wheels at the rear of the lawnmower.

The wheels not forming the subset may have a solid tread.

The housing may have at least one vegetation guide comprising a passage running through the housing so as to guide vegetation into the cutting chamber. The vegetation guide may be positioned at the furthest lateral extent of the housing.

The lawnmower may be a lawnmower in accordance with the first aspect of the invention.

There now follows, by way of example only, embodiments of the invention described with reference to the accompanying drawings, in which: Figure 1 shows a schematic plan view of a lawnmower according to a first embodiment of the invcntion; Figure 2 shows a plan view of a lawninower according to a second embodiment of the invention; Figure 3 shows an enlarged view of one of the front wheels of the lawnrnower of Figure 2; Figure 4 shows an underneath view of the lawnmower of Figure 2; Figure 5 shows a schematic plan view of a lawnmower according to a third embodiment of the invention; Figure 6 shows a perspective view of one of the front wheels of the lawnmower of Figure 5; and Figure 7 shows a perspective view of an alternative front wheel for use with the lawnniower of Figure 5.

A lawnmower according to a first embodiment of the invention is shown in Figure 1 of the accompanying drawings. The lawnrnower 1 comprises a housing 2 supported off the ground by front 3 and rear 4 wheels. The housing 2 defines a cutting chamber 5 open on the underside iii which a rotary blade 6 is mounted. A handle 7 is provided to the rear of the housing, so that a user can push the lawnmower 1 generally forwards (that is, to the left in Figure 1).

In this embodiment, the wheels 3, 4 extend less far laterally (that is, perpendicular to the backwards-forwards direction, and so vertically in Figure 1) than the housing 2, and are so within the cutting width of the lawnmower. This means that, if the lawnmower is propelled along a wall 8, the wheels will not flatten the grass 9 immediately adjacent to the wall 8.

The housing 2 has a front 10, back 11 and two lateral sides 12. In each of the lateral sides 12, there are provided two vegetation guides 13, 14. Each vegetation guide 13, 14 is formed as a passage from the outside of the housing into the cutting chamber 5.

The vegetation guides are formed sequentially in each lateral side, with first vegetation guide 13 being further forwards than second vegetation guide 14.

The inlet to each vegetation guide commences with an edge arranged so as to scoop grass 9 into the passage. Accordingly, as the lawnmower I is propelled by a user along wall 8, sonic of the grass 9 adjacent to the wall will be caught by the first vegetation guide 13. Some grass 9a will escape, but the second vegetation guide 14 will catch at least some of that escaped grass 9a. Both of the vegetation guides 13, 14 will deliver the grass passing through them to the cutting chamber 5.

Because the housing 2, and in particular the widest point of the vegetation guides 13, 14 is wider laterally than the cutting chamber, the action of the vegetation guides 13, 14 is to guide the grass 9 (or other similar vegetation) into the cutting chamber that would otherwise escape, leaving an uncut area adjacent to the wall 8. As such, the provision of a second vegetation guide 14 can be seen to improve the cutting efficiency of grass adjacent to a wall 8 or similar obstruction.

A lawnmower according to a second embodiment of the invention is shown in Figures 2 to 4 of the accompanying drawings. In this embodiment, equivalent features to those of the first embodiment are shown with the corresponding reference numeral, raised by 50. Whilst forward is to the left in Figures 2 to 4.

In this embodiment, the lawnmower 51 again comprises a housing 52, with supports 57 for a handle (not shown) at the rear of the housing. A single vegetation guide 63 is provided on the lateral side of the lawnrnower 51.

However, in place of the solid wheels of the first embodiment, the front wheels 53 are each formed of five coaxially mounted parallel discs 66. The discs 66 are supported by a support 67 so that they can rotate about their common horizontal axis 68. A space 69 is defined between each of the discs 66.

Thus, the front wheels 53 still support the housing 52 off the ground, but will tiatten less grass (or other vegetation) onto the ground, as grass can bend into the spaces 69.

As such, the spaces can also act to generally cause the grass to be aligned to lie in the same direction (that is, the direction circumferential to the discs 66 and the wheels 53) and so be more likely to spring back up after passage of the wheel and so be cut.

Combining the effects of alignment and less flattening, the efficiency with which this lawnmower cuts grass is likely to be higher than otherwise would be the case.

Because the lawnmower is generally pushed in the forwards direction (that is, to the right in Figures 2 and 3), the rear wheels 54 do not need to be fonned of the (liseS 66 of the front wheels 53 and so are simple solid wheels as in the first embodiment.

In a third embodiment of the invention, shown in Figures 5 and 6 of the accompanying drawings, a less extreme version of the wheels of the second embodiment is employed.

In this embodiment, equivalent features to those of the first embodiment are shown with the corresponding reference numeral, raised by 100.

In the second embodiment, the front wheels 53 were formed as discs separated by spaces 69. These spaces 69 can be seen as grooves running between the discs. In the third embodiment, the front wheels 103 (forwards being to the left in Figure 5) have circumferential ridges 120 separated by circumferential grooves 119.

The grooves will therefore cause the grass 9 to be deflected, but to a lesser extent than a solid wheel. They will also tend to cause the grass to align along the circumference of the wheels. As before, these effects combine to improve the efficiency with which the grass is cut.

An alternative front wheel 153 for use with this embodiment is shown in Figure 7 of the accompanying drawings. This wheel has a ridge 170 defining a corresponding groove 169, but in this ease both the ridge 170 and the groove 169 are helical. As the wheel rotates, the groove 169 and ridge 170 tend to urge the grass 9 inwards towards the centre line of the lawnmower. This means that grass at an outer lateral edge of the lawnmower is more likely to be cut, as it will be gently urged in sideways.

Claims

SCLAIMS1. A lawnmower, comprising: a housing defining a cutting chamber, the housing having a front side, a back side and two lateral sides, each of the lateral sides joining the front side to the back side, the sides surrounding the chamber; a cutting clement in the cutting chamber; in which the lawnmower further comprises two vegetation guides positioned sequentially along one of the lateral sides of the housing, the vegetation guides being spaced along the lateral side, each vegetation guide comprising a passage running through the housing so as to guide vegetation into the cutting chamber.
2. The lawnmower of claim 1, in which each passage comprises an inlet of the form of an aperture in the side and an outlet in the cutting chamber
3. The lawnmower of claim 2, in which the inlet is further forwards than the outlet.
4. The lawnmower of claim 2 or claim 3, in which the inlet is provided with a comb member extending from the side and arranged to catch grass or vegetation as the lawnmower is moved forwards.
5. The lawnmower of any of claims 2 to 4, in which the cutting element is a rotary blade rotatable about an axis and sweeping through a cutting area, and each inlet is radially and laterally outside the cutting area.
6. The lawnmower of any preceding claim, in which at least one of the vegetation guides is positioned at the furthest lateral extent of the housing.
7. A lawnmower, comprising: a housing defining a cutting chamber; a cutting element in the cutting chamber; and a plurality of wheels supporting the housing above a surface to be cut; in which a subset of the wheels comprising at least one of the wheels each comprise at least one groove running circumferentially in which grass can lie when the wheel runs over the grass.
8. The lawnmower of claim 7, in which the wheels of the subset comprise a plurality of discs with space between the discs, the space defining the groove, such that vegetation can pass through the space between the discs.
9. The lawnmower of claim 8, iii which the discs of each wheel are parallel to one another and are mounted on a support rotatably mounted on the housing.
10. The lawnmower of any of claims 7 to 9, in which the groove runs purely circumferential ly.
11. The lawnmower of any of claims 7 to 9, in which the direction of the groove includes an axial element
12. The lawnmowcr of claim 11, in which the groove is helical.
13. The lawnmower of any of claims 7 to 12, in which the subset of wheels will comprise the front two wheels of the lawnmower, but exclude the rear two wheels.
14. The lawnmower of any of claims 7 to 13, in which the housing has at least one vegetation guide comprising a passage running through the housing so as to guide vegetation into the cutting chamber.
15. The lawnmower of any of claims 7 to 14, which is also a lawnmower in accordance with claims 1 to 6.
16. A lawnrnower of the kind set forth substantially as described herein with reference to and as illustrated in Figure 1, or Figures 2 to 4, or Figures 5 and 6, or Figure 7 of the accompanying drawings.