WO2022259059A1

WO2022259059A1 - Lawnmower

Info

Publication number: WO2022259059A1
Application number: PCT/IB2022/054376
Authority: WO
Inventors: Nicholas Gerald Grey; Christopher Vagges; Leo Smith
Original assignee: Grey Technology Limited
Priority date: 2021-06-08
Filing date: 2022-05-11
Publication date: 2022-12-15
Also published as: GB202108149D0

Abstract

The invention relates to a lawnmower (10), and in particular to a battery-powered lawnmower. The lawnmower has a cutter body (12) and an operating handle (14). The cutter body has an electric motor (16) and a rotary cutter blade (18), the rotary cutter blade being connected to the motor by way of a drive shaft (20) which is substantially perpendicular to the cutter blade. The cutter body has a front end (22), a back end (24) and two side edges (26, 28), the cutter body having a centreline from the front end to the back end which is equally spaced from the side edges. The operating handle is connected to the cutter body at a single location (30) substantially at the centreline.

Description

LAWNMOWER

FIELD OF THE INVENTION

The invention relates to a lawnmower, and in particular to a battery-powered lawnmower.

As defined herein, a lawnmower is a machine for cutting grass (although it will also cut other vegetation if required) with an operating handle which is grasped and manipulated by a user walking behind the lawnmower during use. This definition excludes “ride-on” mowers, tractor mowers and the like to which the invention is not directed. For ease of reference, directional and orientational terms such as “vertical”, “horizontal” etc. refer to the lawnmower is use upon horizontal ground, though it will be understood that the lawnmower of the invention (as with known lawnmowers) will also be used to cut grass on surfaces which are not horizontal.

BACKGROUND TO THE INVENTION

Many different designs of lawnmower are available but all share the same basic structure of a cutter body to which one or more cutter blades are mounted, the cutter blades being driven to move relative to the cutter body as the cutter body is moved across the ground (e.g. across the lawn being mowed). The different designs can be broadly categorised firstly according to the design of the cutter blades and secondly according to how the cutter blades are powered. There are two general categories of lawnmower according to the design of the cutter blades. The first general category has one or more cutter blades which are driven to rotate by a drive shaft which is perpendicular to the blade(s). The drive shaft is vertical and the blade(s) move around a circle which is horizontal. The cutter blades rotate rapidly and slice through the grass as the cutter body is moved across the lawn. Lawnmowers in this class are referred to as “rotary” lawnmowers.

The second general category has a set of helically curved moving cutter blades. The cutting edges of the cutter blades together define a virtual cylinder. The moving cutter blades are driven to rotate about a horizontal axis at the centre of the cylinder. The lawnmower also has a fixed cutter blade which is located close to the ground and the moving cutter blades pass very close to the fixed cutter blade to cut the grass by a “scissor” action. Lawnmowers in this class are referred to as “cylinder” lawnmowers.

Some designs of lawnmower have a roller which follows the cutter blades and flattens the remaining grass. Rollers are more typically (but not exclusively) fitted to cylinder lawnmowers.

The cutter blade(s) of a lawnmower are typically driven to rotate by a motor which is mounted to the cutter body. The motor may be an internal combustion engine or an electric motor. The motor is connected to a control lever on the operating handle so that the user can control the motor as the lawnmower is being pushed or guided across the ground. The electric motor can be powered by mains electricity in which case an electrical cable is connected to the lawnmower; the cable is typically connected to the operating handle where it can be controlled by the user and reduce the likelihood that the cable is cut by the rotating blades.

Alternatively, the electric motor can be battery-powered, the battery also being mounted to the cutter body.

In many designs of lawnmower the cutter body has wheels which determine the height of the blade(s) above the ground and therefore determine the length of the remaining grass, the wheels often being adjustable to allow the cutting height to be adjusted. The lawnmower may have four wheels, one at each corner of the cutter body. Alternatively, the lawnmower may have a roller at the back of the cutter body and two wheels (or another roller) at the front of the cutter body. Some designs of lawnmower have no wheels or rollers and the cutter body hovers above the ground in use. These so-called “hover” mowers have a rotary cutter blade which also acts as a propellor to lift the cutter body.

In another category of lawnmower the cutter blades are connected by way of gearing to one or more of the wheels, the blades being driven to rotate rapidly as the lawnmower is pushed along by the user. The invention is not directed to these (non-motorised) lawnmowers.

The known lawnmowers have a number of drawbacks.

One drawback of hover mowers is that a large proportion of the energy consumed by the mower is used to lift the cutter body off the ground so that only a small proportion of the energy consumed is used to cut grass. Hover mowers are typically electrically-powered and use mains electricity. The weight of the cutter body is thereby reduced firstly because it does not carry batteries and secondly because an electric motor is typically significantly lighter than an internal combustion engine. Even so, the energy required to lift the cutter body off the ground is significant.

One drawback of lawnmowers having a roller is that the roller is necessarily heavy so that it can flatten the remaining grass as desired. The heavy roller significantly increases the weight of the lawnmower and makes it more cumbersome and awkward to use. Larger lawnmowers with a roller will often be self-propelled, i.e. the motor is also used to drive the roller to rotate and move the lawnmower across the ground. With a self-propelled lawnmower the user steers the lawnmower by way of the operating handle, and the operating handle has a control to determine the speed of movement across the ground. Self-propelled lawnmowers are convenient for some users, but are necessary for others since the lawnmower may be too heavy to be pushed along by the user. Again, a proportion of the energy consumed by a self-propelled lawnmower is used to move the lawnmower rather than to cut grass. One drawback of cylinder lawnmowers is that they will only reliably cut grass when moving forwards; when they are moved backwards the fixed cutter blade flattens the grass and significantly reduces the amount of grass which is engaged by the moving cutter blades and therefore cut.

As above stated, an internal combustion engine is typically significantly heavier than an electric motor having an equivalent power output. It is therefore a general drawback of lawnmowers with an internal combustion engine that they are heavier and more cumbersome than an electrically-powered equivalent. Internal combustion engines are also generally more harmful to the environment than an electrically-powered equivalent, and definitely more harmful if the electrical supply for an electric lawnmower is generated from renewable sources.

One drawback of lawnmowers which are powered by mains electricity, however, is that their range is limited by the requirement for a supply of electricity and the length of the mains electrical cable. Whilst extension leads can be utilised they often make the lawn mowing procedure more time consuming. Accordingly, the use of mains electricity powered lawnmowers in many more remote areas is not practical or perhaps not possible.

Typically, lawn mowing is conducted in a forward direction only, with the operator walking forwards behind the lawnmower (and pushing the lawnmower if it is not self-propelled). When the lawnmower reaches the end of the lawn it is moved by way of the operating handle and another strip of grass is cut in a different (often the opposite) direction. As above stated, forwards motion is a necessary feature for cylinder lawnmowers and whilst rotary lawnmowers can cut grass when moving backwards most users will undertake the same forwards motion for lawn mowing with a rotary lawnmower.

Lawnmowers are often not used during Winter months when the grass grows more slowly. Often the grass will begin to grow before it is cut for the first time in Spring, with the result that the lawnmower is required to cut grass which is longer than normal. In such a situation, the procedure of mowing by moving forwards results in the cutter blades continuously engaging and cutting long grass. Significantly more power is usually required to cut long grass than short glass and the power of the motor will often not be sufficient to maintain the rotation of the cutter blades at the desired rate when cutting long grass. In such circumstances the cutter blade(s) can slow down significantly. If the cutter blades of a cylinder mower slow down they will continue to cut grass, albeit at a reduced rate. However, if the cutter blades of a rotary mower slow down they can stop slicing through the grass and instead merely push the grass towards the ground. Most users will seek to avoid this outcome by moving the lawnmower forwards sufficiently slowly that the motor can maintain the required high speed of the cutter blade(s). Alternatively, the user will advance the lawnmower in a series of progressive steps, the lawnmower being moved forwards to cut grass during which the cutter blade(s) slow down, then stopping the lawnmower to allow the cutter blade to accelerate back to full speed before this cycle is repeated.

The operating handle is usually fixed relative to the cutter body. With a lawnmower which is not self-propelled the fixed mounting is required so that the user can apply the required pushing force to the cutter body to move the lawnmower across the ground. With a self-propelled lawnmower the fixed mounting is desirable so that the user can retain full control of the lawnmower during use, especially during changes of direction. Many operating handles are nevertheless foldable so as to reduce the space occupied by the lawnmower during storage.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a lawnmower which overcomes or reduces some or all of the drawbacks of the known lawnmowers. It is another object of the invention to provide a lawnmower which has advantages and benefits over the known lawnmowers. According to the present invention there is provided a lawnmower having a cutter body and an operating handle, the cutter body having an electric motor and a rotary cutter blade, the rotary cutter blade being connected to the motor by way of a drive shaft which is substantially perpendicular to the cutter blade, the cutter body having a front end, a back end and two side edges, the cutter body having a centreline between the front end and the back end and which is equally spaced from the side edges, the operating handle being connected to the cutter body at a single connection located substantially at the centreline.

Providing a single connection for the operating handle has significant benefits. Firstly, a single connection requires less moulding and/or machining of the material of the cutter body than two connections as is typical of most lawnmowers. Secondly, with a single handle connection it is not necessary to design the cutter body to accommodate two (or perhaps more) handle connections. Furthermore, a single handle connection avoids any requirement to align multiple handle connections.

Providing the single connection at (or at least very close to) the centreline ensures that the force applied by the handle can act relatively close to the centre of mass of the cutter body. The force which the user applies to the cutter body by way of the handle therefore has only a very small (or perhaps zero) component which is offset from the centreline. The cutter body can be made less robust because it does not have to accommodate offset forces. The reduction or avoidance of offset forces also reduces the strain upon the handle and therefore the connection between the handle and the cutter body. Furthermore, the user is not required to apply a lateral force to oppose an offset force and can instead apply pushing and pulling forces directly along the longitudinal axis of the handle.

In addition, the motor will be located at (or at least very close to) the centre of the cutter body and the cutter body is therefore necessarily sufficiently robust adjacent to its centre to support the motor. Connecting the handle close to the centre of the cutter body takes advantage of the robustness of the cutter body at that location and minimises the requirement for local reinforcement or support for the handle connection.

Alternatively stated, in a known lawnmower in which the handle is rigidly connected at two spaced locations at either side of the cutter body, the cutter body must be made sufficiently robust at those locations to directly withstand the forces which are applied by the handle. Also, the cutter body must be made sufficiently robust to communicate those forces throughout the cutter body. With the present invention, however, the extent of the cutter body which must be made sufficiently robust to withstand the forces applied by the handle are significantly reduced; the forces are concentrated around the centre of the lawnmower where it is already robust.

Preferably the operating handle is removable. The provision of a removable handle is another benefit of a single handle connection since it is only necessary to provide one releasable connector for the handle. Also, re-attaching the handle requires the alignment of only one connection which is likely to be significantly easier than aligning multiple separate connections. Providing a removable handle is beneficial in terms of the space occupied by the lawnmower during storage (and/or transportation). It is also beneficial in that a single common handle can be used with other garden implements such as a hedge trimmer for example.

Preferably also the lawnmower is battery powered. A battery-powered lawnmower is not restricted by the availability of mains electricity or by the length of the electrical cable. Also, recent advances in battery technology mean that a relatively lightweight battery can power a lawnmower for a significant length of time.

Desirably, the battery is mounted to the handle. Such an arrangement avoids the requirement for the cutter body to accommodate a battery and also reduces the weight of the cutter body. Separating the motor from the battery is also expected to provide ergonomic benefits over an arrangement in which these relatively heavy components are located together. Preferably the operating handle includes a pivoting joint, i.e. the angle of the handle relative to the ground is not fixed and can change as the lawnmower is being used. Preferably also the operating handle includes a rotating joint, i.e. the handle can rotate about its longitudinal axis relative to the cutter body. Desirably, the pivoting joint and the rotating joint together provide a steering joint, i.e. a joint by which the user can manipulate the direction of travel of the cutter body by rotating the handle. The provision of a steering joint is another benefit of a single connection for the operating handle to the cutter body.

In embodiments in which the operating handle is removable, the operating handle preferably has a connecting part and the cutter body has a cooperating connecting part. Desirably the pivoting joint and/or the rotatable joint is carried by the connecting part of the cutter body, whereby the pivoting joint and/or the rotatable joint are not removed with the operating handle. Preferably the cutter body has a socket into which the end of the operating handle can be inserted, the socket being a part of a mounting structure of the cutter body which mounting structure also includes the pivoting joint and/or the rotatable joint.

Desirably the cutter body has four wheels, ideally located at or adjacent to the corners of the cutter body (where the front end and back end meet the respective side edges). Desirably also the wheels are adjustable whereby the cutter height can be adjusted by the user. Preferably, there are two front wheels adjacent to the front end and two back wheels adjacent to the back end. The front wheels are preferably both mounted to a first common axle which spans the cutter body. The back wheels are preferably both mounted to a second common axle which spans the cutter body. The provision of common axles can also result in a relatively low weight and low cost arrangement for mounting the wheels and readily ensures that the front wheels are substantially aligned with each other and the back wheels are substantially aligned with each other, thereby minimising the force required to move the lawnmower.

Preferably the cutter body has a shroud to cover the rotary blade. Preferably also a part of the shroud provides a part of each of the side edges. Desirably the cutter body has a motor housing within which the motor is rigidly mounted. Desirably also the single connection for the operating handle is adjacent to the motor housing. The motor will typically be the heaviest component of the cutter body and so the centre of mass of the cutter body will likely be close to or coincident with the motor.

It will be understood that many of the above-stated features have benefits in terms of reducing the weight of the lawnmower. In particular, the lawnmower can be made sufficiently light that it does not need to be self-propelled. Avoiding the additional componentry necessary to make the lawnmower self-propelled also contributes to avoiding any unnecessary weight. Also, avoiding the requirement for the battery to move the lawnmower enables the use of a smaller and lighter battery.

Notwithstanding the benefits of a battery-powered lawnmower in not being limited by the availability of mains electricity, practical embodiments of the invention are relatively small and light and are particularly suitable for small gardens.

Practical embodiments of the invention are also suitable for cutting grass in difficult locations, for example on steep inclines and the like. Cutting grass on a steep incline typically requires a self-propelled lawnmower since it is not always possible to push a lawnmower up the incline (and it may not be possible to cut all of the grass with the lawnmower moving down the incline). The grass can be damaged if a self-powered lawnmower slides whilst moving up the incline, and the user can be in significant danger if he or she slips and falls to the ground whilst mowing grass on a steep incline. The present invention enables an alternative method of lawn moving than the usual forwards motion described above. In particular, the invention enables a “push and pull” action during which the user adopts a fixed and stable stance (or a substantially fixed and stable stance) and pushes the lawnmower away from him or herself and then pulls the lawnmower back towards him or herself, cutting grass on each forwards and backwards stroke. If the grass is short the user can manipulate the lawnmower so that a fresh strip of grass in cut on each forwards and backwards stroke, whereas if the grass is long the user can manipulate the lawnmower so that only a partial strip is cut on each stroke. Reducing the amount of grass which is cut on each stroke will reduce the likelihood that the cutter blade will slow down significantly. This ’’push and pull” method is expected to be particularly suitable for cutting grass on a steep incline, in that the user can remain at the top or bottom of the incline as desired, with only the lawnmower being moved up and down the incline as the grass is cut. BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which:

Fig.1 shows a perspective view of the lawnmower according to the invention;

Fig.2 shows a cross-sectional view through a part of the cutter body of the lawnmower of Fig.1 ;

Fig.3 shows a plan view of the lawnmower of Fig.1 ;

Fig.4 shows a side view of the lawnmower of Fig.1 ;

Fig.5 shows a perspective view of the lawnmower of fig.1 , with the operating handle separated from the cutter body;

Fig.6-9 show views of the lawnmower in an optional method of use. DETAILED DESCRIPTION

The lawnmower 10 has a cutter body 12 and an operating handle 14. As seen in the sectional view of Fig.2, the cutter body has an electric motor 16 and a rotary cutter blade 18. The rotary cutter blade 18 is connected to the motor 16 by way of a drive shaft 20 which is substantially perpendicular to the cutter blade 18. As with the known rotary lawnmowers, in use the motor 16 drives the drive shaft 20 to rotate about a vertical axis and the cutter blade 18 is driven to move around a horizontal circle.

The cutter body 12 has a front end 22, a back end 24 and two side edges 26, 28. The cutter body 12 has a centreline from the front end 22 to the back end 24 and which is equally spaced from the side edges 26, 28, the centreline being coincident with a part of the line C-C shown in Fig.3. The operating handle 14 is connected to the cutter body 12 at a single connection provided by the mounting structure 30 which is located substantially at the centreline.

In common with known lawnmowers, the cutter body 12 includes a shroud 32 which is provided for the primary purpose of covering the rotating cutter blade 18 and protecting the user from the blade and also from stones and the like which may be impacted by the blade and propelled away from the blade. As seen in Fig.3, the shroud 32 provides at least part of the side edges 26, 28 of the lawnmower 10.

The shroud 32 is connected to formations which provide the front end 22 and the back end 24 of the lawnmower 10. In common with known lawnmowers, the shroud 32 and formations are formed as a single plastic moulding. Also, in common with known lawnmowers the formations have aligned holes (not seen) which accommodate a metal shaft (also not seen) providing a first common axle for the front wheels 34 and metal shaft 38 providing a second common axle for the rear wheels 36 (see Fig.2).

The cutter body 12 has a central motor housing 40 which is sized to accommodate the motor 16. Since the motor 16 is relatively heavy the motor housing 40 is internally reinforced to support the motor, and also to withstand the torque as the motor rotates in use. The mounting structure 30 for the operating handle is located adjacent to the motor housing 40, and in this embodiment includes an extension of the plastic moulding forming the motor housing. The mounting structure 30 therefore takes advantage of the local reinforcement of the cutter body at the motor housing 40.

In addition, no reinforcement of other parts of the cutter body 12 is required for the mounting structure 30. The shroud 32 is therefore not required to support a handle connection and therefore requires no local reinforcement for that function.

The centre of mass of the cutter body is located upon the centreline and at the approximate position CM indicated in Fig.2. Accordingly, when viewed from above as in Fig.3, the longitudinal axis L-L of the handle is coincident with the line C-C and is therefore aligned with the centre of mass CM of the cutter body. As the user pushes and pulls the cutter body 12 by way of the handle 14, the forces act along the longitudinal axis L-L and the line C-C and are therefore aligned with the centre of mass CM. The cutter body 12 therefore requires little if any reinforcement to accommodate horizontally offset forces, i.e. forces applied by the user which are not aligned with the line C-C.

In addition, as seen in Fig.2, the longitudinal axis L-L of the handle 14 passes relatively close to the centre of mass CM in the vertical direction also. As explained below, the handle 14 is pivotable and it will be understood that the handle can be pivoted to a position in which the angle of orientation a (Fig.4) relative to the ground is reduced, in which case the longitudinal axis L-L can be moved closer to (and ideally aligned with) the centre of mass CM. The vertically offset forces which the cutter body must be designed to withstand are therefore also minimised, further reducing the requirement for reinforcement of the cutter body 12.

As best seen in Fig.2, the mounting structure 30 includes a pivoting joint 42, specifically a part-circular body 44 located at one end of a handle sleeve or socket 46 which can rotate about a horizontal axis 48 within a part-circular surround 50 which is fixed to the cutter body 12. The handle sleeve 46, and therefore the handle 14, can thereby pivot about the axis 48 so as to adjust the orientation angle a as desired by the user during use.

In addition, the mounting structure 30 includes a rotating joint 52 whereby the upper part 54 of the handle sleeve 46 can rotate relative to the lower part 56 of the handle sleeve 46. Importantly, the plane P (Fig.4) of the interface between the upper part 54 and the lower part 56 (and which plane defines the plane of relative rotation) is not perpendicular to the longitudinal axis L-L but is at an angle b to that axis.

The rotating joint 52 with its angled plane of rotation P and the pivoting joint 42 together define a steering joint enabling the cutter body 12 to be steered by way of the handle 14. In particular, as the user twists the operating handle 14 clockwise about its longitudinal axis L-L, the angled plane of rotation P causes the cutter body 14 to turn towards the right as viewed by the user behind the lawnmower. Similarly, as the user twists the operating handle 14 anti-clockwise about its longitudinal axis L-L, the angled plane of rotation P causes the cutter body 14 to turn towards the left as viewed by the user behind the lawnmower.

It will be understood that offset forces which are applied by the user as he or she pushes or pulls the cutter body can act to pivot and/or twist the handle 14. However, reducing the offset will reduce those forces. It is a particular benefit of a central handle connection, and in particular of closely aligning the longitudinal axis L-L of the operating handle with the centre of mass CM, that the offset forces are minimised and consequently the forces seeking to pivot or twist the handle are minimised. If the user wishes the lawnmower to move in a straight line he or she must oppose the forces which are seeking to pivot or twist the handle 14 and minimising those forces will therefore directly benefit the user.

Figs. 6-9 show the lawnmower in use with the user 60 employing a “push and pull” method of operation to cut grass on a steep incline 62. In particular, the user adopts a substantially fixed and stable stance (at the top of the incline in Figs. 6 and 7 and at the bottom of the incline in Figs. 8 and 9. The user undertakes a series of push and pull strokes, alternately pushing the lawnmower away and pulling the lawnmower back. The lawnmower 10 can cut grass on each stroke.

As above stated, the lawnmower 10 has a steering joint and the user 60 is thereby able to twist the operating handle 14 as it is being pushed and/or pulled to cause the cutter body 12 to traverse sideways across the incline 62. If the grass is short the user 60 can cause the cutter body to traverse rapidly so that fresh grass is cut on each forwards and backwards stroke. Alternatively, if the grass is long the user 60 can cause the cutter body 12 to traverse slowly so that only a small amount of fresh grass is cut on each forwards and backwards stroke and the speed reduction of the cutter blade 18 is minimised.

It will be observed from Figs. 6-9 that whilst the user 60 can impart steering movements to the cutter body 12 by twisting the operating handle 14, the pushing and pulling forces which the user applies during most of the movement of the cutter body 12 is directed along the line C-C and therefore aligned with the centreline of the cutter body 12 (and ideally closely aligned with the centre of mass CM).

In this embodiment the operating handle 14 is removable from the cutter body 12. It will be seen from Fig.5 that because the pivoting joint 42 and rotating joint 52 are both parts of the mounting structure 30 they are not also removed with the handle 14. The bottom end 64 of the handle comprises a generally cylindrical “plug” which can be slid into (and out of) the sleeve or socket 46. The fitted handle is retained by a resilient latch 66 (Figs.2,5) which projects through an opening in the sleeve 46. The latch 66 and opening prevent relative rotation between the fitted handle 16 and the sleeve 46, and ensure that any twisting of the handle 14 is communicated to the rotating joint 52.

The latch 66 is accessible to the user and can be pressed inwardly to release it from the opening in the sleeve 46 and allow removal of the handle 14.

In this embodiment the operating handle 14 carries the battery 68 (Fig.5) which provides electrical energy for the motor 16. The battery is connected to cables which run along the inside of the handle and connect to electrical contacts at the bottom end 64. The electrical contacts of the handle engage corresponding contacts of the cutter body 12 when the handle 14 is properly inserted into the sleeve 46.

It is another benefit of the central mounting of the handle connection, and in particular the central mounting adjacent to the motor housing 40, that the cabling to connect the electrical contacts to the motor is minimised and is all internal to the cutter body. There are therefore no exposed wires which could be damaged inadvertently. The cabling passes through the pivoting joint 42 and since the articulation of the pivoting joint is closely controlled the bending of the cabling is similarly controlled and the likelihood of damage to the cabling caused by repeated pivoting (and twisting) movements of the operating handle 12 is minimised.

The battery 68 is releasably mounted to the remainder of the handle 14 and can therefore be removed for recharging. The battery can also if desired be recharged in situ but that is not preferred as it is desired to provide two batteries so that the user can replace a depleted battery with a fully charged battery and therefore continue lawnmowing whilst the depleted battery is recharged.

The provision of a removable handle has benefits for the storage and transportation of the lawn mower. In particular, it will be understood that lifting and manipulating the cutter body 12 is made much easier when the operating handle 14 is removed, both in terms of the reduced weight to be moved and also because the projecting handle is cumbersome.

The provision of a removable handle also has the benefit that the same operating handle 14 may be connected to other machinery, for example a hedge trimmer, when it is not in use with the lawnmower.

It will be seen that the operating handle 14 has a secondary handle part 70 whereby the user 60 can grasp the handle 14 with two hands, which can be beneficial for certain actions, for example if it is desired to lift the lawnmower 10 off the ground.

Claims

1 . A lawnmower having a cutter body and an operating handle, the cutter body having an electric motor and a rotary cutter blade, the rotary cutter blade being connected to the motor by way of a drive shaft which is substantially perpendicular to the cutter blade, the cutter body having a front end, a back end and two side edges, the cutter body having a centreline from the front end to the back end which is equally spaced from the side edges, the operating handle being connected to the cutter body at a single location substantially at the centreline.

2. A lawnmower according to claim 1 in which the lawnmower is battery powered.

3. A lawnmower according to claim 2 in which the battery is mounted to the operating handle.

4. A lawnmower according to any one of claims 1 -3 having a pivoting joint for the operating handle.

5. A lawnmower according to any one of claims 1 -4 having a rotating joint for the operating handle.

6. A lawnmower according to claim 4 and claim 5 in which the pivoting joint and the rotating joint together provide a steering joint.

7. A lawnmower according to any one of claims 1 -6 in which the operating handle is removable from the cutter body.

8. A lawnmower according to claim 4 and claim 7 in which the cutter body has a mounting structure to which the operating handle is releasably connectable, in which the pivoting joint is a part of the mounting structure.

9. A lawnmower according to claim 5 and claim 7 in which the cutter body has a mounting structure to which the operating handle is releasably connectable, in which the rotatable joint is a part of the mounting structure.

10. A lawnmower according to claim 8 or claim 9 in which the mounting structure has a sleeve into which a part of the operating handle can be inserted.

11. A lawnmower according to any one of claims 1-10 in which the cutter body has four wheels.

12. A lawnmower according to claim 11 in which the wheels are adjustable relative to the cutter body.

13. A lawnmower according to claim 11 or claim 12 in which there are two wheels adjacent to the front end which are both mounted to a first common axle, and in which there are two wheels adjacent to the back end which are both mounted to a second common axle.

14. A lawnmower according to any one of claims 1-13 in which the cutter body has a shroud to cover the rotary blade.

15. A lawnmower according to claim 14 in which a part of the shroud provides a part of each of the side edges.

16. A lawnmower according to any one of claims 1-15 in which the cutter body has a motor housing within which the motor is rigidly mounted.

17. A lawnmower according to claim 16 in which the operating handle is connected to the cutter body adjacent to the motor housing.