FIELD OF THE INVENTION

The present invention relates to a mower, particularly remotely controlled, that is capable of driving on sloping areas.

BACKGROUND OF THE INVENTION

Lawns on sloping areas with varying inclination are difficult to mow with known tractor driven lawn mowers. Sloping areas are therefore typically mowed by handheld lawn mowers, which are not convenient from a work environmental point of view. For instance, the users need protective clothing which minimizes the ability to move with, and control securely, the handheld lawn mower. In an attempt to remedy these deficiencies lawn movers which can be remotely controlled have been introduced. Typically, such lawn mowers are powered by combustion engines. The use of combustion engines, however, set a number of requirements to the construction of such lawn mowers. Firstly, the combustion engine constitutes a considerable part of the total weight of the lawn mower. Since the lawn mower is intended to mow lawns on sloping areas without tipping over, the engine must be placed such that the centre of gravity is as close to the ground as possible. Secondly, the nature of such engines is such that they must be lubricated at all times. When mowing sloping areas, problems with internal lubrication of the sloping engine may occur. This problem has been solved by providing suspension of the engine keeping it in an approximately horizontal position at all times. However, since the suspended engine requires space to move, the width of the lawn mowers is correspondingly wide. Furthermore, such a lawn mower is more expensive to manufacture.

A further problem with prior art lawn mowers with combustion engines as described above is that in order to reduce requirements to the power of the engine, the cutting means are not as broad as the lawn mower and typically placed between tracks of the lawn mower, and this results in areas which cannot be reached by the cutting means of the lawn mower such as edges of a lawn.

A further problem with the broad lawn mowers which typically has a width being larger than the length is that there is a risk that the mower might tip forward or backwards when driving up or down a sloped surface.

OBJECT AND SUMMARY OF THE INVENTION The object of the present invention is to provide a mower that remedy or eliminates all or some of the above-mentioned problems

In a first embodiment of a mower for mowing sloped surfaces comprising at least two tracks, cutting means are positioned in front of the tracks and the width of the cutting means overlaps at least partly the tracks, and the mower is driven by at least one engine being mounted between said tracks and having an active lubrication system.

This results in a narrow mower where the cutting means can get closer to edges of e.g. a lawn. Further, since the mower is narrow, the cutting means are also narrow, whereby the power requirements of the engine are reduced.

Further, the length of the mower is larger than the width, whereby the risk of forward or backward tipping is reduced. Further, the mower is able to tilt e.g. when mowing on sloped surfaces, and the engine will not deliver a too low power output or risk being damaged due to an insufficient lubrication. The engine does not need to be specially suspended, whereby the width of the mower is reduced.

In an embodiment the width of the cutting means completely overlaps the tracks, whereby the width of the cutting means at least corresponds to the width of the mower. Thereby the cutting means can access edges. In another embodiment of the mower, the lubrication system is configured to provide lubrication of the engine at a spatial tilt of the engine of at least 30 degrees. Here the advantages are as listed above.

In yet another embodiment the mower comprises at least two tracks, at least two frames and a carriage, where the tracks are connected to the frames, and where a first end of the frames are pivotably connected to a first end of the carriage, and where a second end of the frames is interconnected by a lever arm which is pivotably connected to the carriage. The advantage of this suspension system is that the tracks are in contact with the ground at all times, even when driving on sloping areas that are uneven. Further, the rear end of the mower does not slide downhill, when the mower is driven along inclining areas.

In a further embodiment the mower comprises means for being remotely controlled. This is an advantage as the person in control of the mower can operate the mower at a secure distance of both the mower and other elements nearby the mower. The latter could e.g. be when the mower mows lawns near roads.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, preferred embodiments of the invention will be described referring to the figures, where

figure 1 illustrates an end view of a prior art mower comprising a suspended combustion engine;

figure 2 illustrates a perspective of a mower 200 of the present invention comprising suspended tracks. DESCRIPTION OF EMBODIMENTS

Figure 1 illustrates a mower 100 of the prior art comprising a suspended engine 112 fastened to the carriage (not shown) of the mower 100. The mower 100 is depicted on a sloping surface 101. Due to the suspension (not shown) of the engine 112, the engine 112 is in an approximately horizontal position. If this was not the case, the engine will be lubricated insufficiently.

This can lead to a breakdown of the engine 112. The suspension of the engine 112 is, however, very space consuming, which is undesirable.

Further, the centre of gravity is relatively high, whereby the mower 100 cannot be driven along steep inclinations.

Figure 2 illustrates a perspective of a mower 200 of the present invention designed especially for mowing slopes and uneven ground. The mower 200 comprises two tracks 116, 117 driven by the wheel 107, respectively. The track 116 is stretched between the wheel 107 and wheel 130, and is towards the ground further supported by the wheels 131 , 132, 133. The axles of the wheels 130, 131 , 132, 133 are all mounted in a frame 104. Further, the frame 104 is pivotably mounted to the carriage 102, thus enabling the whole track

116 to pivot. The track 117 is stretched in a similar way between the wheels and supported by a number of supporting wheels. The wheels for stretching and supporting track 117 are mounted in a frame 105, which is also pivotably mounted to the carriage 102. The allowed movement 124 of the rear end of the tracks 116, 117 is defined by a transversal link 118 which ends are fastened to the frame 104, 105 in rubber bushings 120, 121. The transversal link is further mounted pivotably to the carriage 102. By establishing a connection between the frames 104 and 105 it is ensured that the tracks 116,

117 of the mower 200 will always be in contact with the ground, also on e.g. uneven sloping areas. Thus, there is no risk that the rear end of the mower 200 will slide downhill and thereby undesirably change the direction of the mower 200. The mower 200 comprises a combustion engine 112 mounted to the carriage 102. The combustion engine 112 has a substantially horizontal crank shaft (not shown) and is configured with an active lubrication system (not shown) that supports for the lubrication of the combustion engine 112, also during the tilting condition experienced by the mower 200. The active lubrication could in an embodiment be a splash type lubrication. This ensures that the combustion engine 112 is always lubricated even when mowing on slopes and areas with an inclination of at least 30 degrees. Since the combustion engine 112 with the active lubrication system is mounted non-pivotably to the carriage 102, little space between the tracks 116, 117 is needed. This also gives the mower 200 a very low centre of gravity, which is desirable when driving on sloping areas. The combustion engine could in one embodiment drive an electrical generator or hydraulic system (not shown). The electricity from the generator could be used to actuate two electrical motors or hydraulic actuators for propelling the tracks 116, 117 independently. In addition the electricity from the generator could be used to charge a battery (not shown) on the mower 200. Using the battery the mower 200 could be driven over smaller distances without using the combustion engine. This could e.g. be on or off a transporting trailer, from or to it was or is to be used. This hybrid of an embodiment would further comprise a control unit (not shown). The mower 200 can preferably be remotely controlled due to environmental and security reasons. The remote controller (not shown) and control unit would, for instance, use a 2.4 GHz Spread Spectrum wireless technology. Limiting the service range to, for instance, 100 meters will ensure that the mower 200 stops if it comes outside that range. The remote controller can also be equipped with starting functionality of the engines and an emergency stop button. The mower 200 is further embodied with a cutting device 114 mounted in the front of the carriage 102. The cutting device could e.g. have a breadth of 750mm. The cutting device could also be replaced by other tools. The cutting device is preferably driven by the combustion engine 112. In another embodiment the engine could be driven by an electrical motor (not shown).

In general the mower 200 of the present invention is advantageous by having a small width and having the cutting device 114 placed in front of the mower 200. The small width of the mower 200 is obtainable by having an unsuspended engine with an active lubrication system. This ensures a low centre of gravity, which again enable the mower 200 to drive along steeply inclined surfaces without a breakdown of the engine 112.

REFERENCES

100 mower of the prior art

101 sloping surface

102 carriage

104 frame

105 frame

106 axle

107 propelling wheel

112 internal combustion engine

114 cutting means

116 track

117 track

118 transversal link or lever arm

120 rubber bushing

121 rubber bushing

124 vertical movement

130 wheel

131 wheel

132 wheel

133 wheel

135 wheel

200 mower of the present invention