Device for adjusting the cutting height of a power lawn mower

Abstract

The present disclosure relates to a lawn mower (100) comprising a cutter propulsion unit (165), a drive shaft (166, 166') having a longitudinal extension direction (L, L') and adapted to be rotated by the cutter propulsion unit (165). The lawn mower (100) further comprises a cutting disc (160) having a radial extension direction (R) extending between a center (182) and an outer edge (181), wherein the cutting disc (160) comprises one or more cutting edges (161, 162, 163) adapted to cut grass when the cutting disc (160) is subjected to a rotational movement by means of the drive shaft (166). The cutting disc (160) also includes a connecting portion (164, 164'), which is suitable for receiving a coupling member (173, 173') included in a transmission shaft (166, 166') in at least two different installation positions, which are suitable for positioning the connecting portion (164) in mutually separated positions along the longitudinal extension direction (L, L').

Description

Technical Field

[0001] The present disclosure relates to a powered lawn mower, such as a robotic lawn mower, wherein the height of cut can be easily adjusted by a user. Background Art

[0002] Lawn mowers are used for domestic and commercial applications and may be powered by either an electric motor or an internal combustion engine. So-called rotary cutters employ a cutting member rotatable in a plane substantially parallel to the ground and about an axis perpendicular to the ground, wherein the cutting member comprises an arm or disc rotatably supported at its center and having cutting edges arranged at its ends or at its periphery.

[0003] Automatic or robotic power tools, such as robotic lawn mowers, are becoming increasingly popular. In a typical deployment of a work area, such as a garden, the work area is surrounded by a boundary line, the purpose of which is to keep the robotic lawn mower within the work area. Electrical control signals can be transmitted through the boundary line, thereby generating an (electro) magnetic field emanating from the boundary line. The robotic working tool is usually arranged with one or more sensors suitable for sensing the control signals.

[0004] The robotic lawn mower can then automatically mow the user's lawn, automatically recharge without user intervention, and require no manual management after being set once. The robotic lawn mower typically includes a charging carriage for contacting corresponding contact pads in the charge when docked to a charging station for receiving a charging current therefrom, and possibly also for transmitting information by means of electrical communication between the charging station and the robotic lawn mower.

[0005] Most conventional lawn mowers include some means for adjusting the height of mowing, as different users prefer to have their lawns mowed to different lengths, and different areas of their lawns cut to different lengths. This can depend on the growth rate of the grass and the frequency of mowing a particular area, as well as the general user's desire for mowing height.

[0006] Most lawn mowers include means for providing an adjustable height of cut, such as wheels or rollers that can be connected to the housing in a number of different positions, each position corresponding to a different cutting height, but requiring a large number of parts in order to adjust the height and therefore being expensive to manufacture.

[0007] Height of cut adjustment can also be made by inserting or removing shims between the cutter blade and the drive shaft to which the cutter blade is secured. Adjustment involves loosening the blade from the drive shaft, inserting or removing the shims, and bolting the blade back onto the drive shaft. This operation is relatively tedious and time consuming, and requires storage of shims.

[0008] EP 531071 discloses moving a cutting member against a compression spring in order to vary the height of mowing, and EP 766911 discloses moving the chassis of the lawn mower in order to vary the height of mowing.

[0009] CN 103621244 discloses a lawn mower having a cutter disc and a transmission component, wherein the transmission component is provided with a matching connection surface connected to the cutter disc in a matching mode. The cutter disc is provided with a first mounting surface and a second mounting surface, one on each side of the cutter disc, for abutting against the matching connection surface. By rotating the cutter disc, a user can switch between two different cutting heights.

[0010] Therefore, there is a need to provide an improved and alternative apparatus for simply varying the height of cut of a lawn mower in a more versatile and efficient manner than previously proposed and requiring fewer parts. Summary of the invention

[0011] An object of the present disclosure is to provide an improved and alternative arrangement for simply varying the height of cut of a lawn mower in a more versatile and efficient manner than previously proposed, thereby requiring fewer parts.

[0012] This object is achieved by means of a lawn mower comprising a cutter propulsion unit, a drive shaft having a longitudinal extension and adapted to be rotated by the cutter propulsion unit, and a cutting disc having a radial extension extending between a center and an outer edge. The cutting disc comprises one or more cutting edges adapted to cut grass when the cutting disc is subjected to a rotational movement by means of the drive shaft. The cutting disc further comprises a connecting portion adapted to receive a coupling member comprised in the drive shaft in at least two different mounting positions adapted to position the connecting portion in mutually separated positions along the longitudinal extension.

[0013] This enables the lawn mower's cutting height to be simply changed in a versatile and efficient manner, requiring few parts and without the need to stock any special parts.

[0014] According to some aspects, the connecting portion comprises at least two engagement platform devices separated from each other along a vertical extension direction extending perpendicularly to the radial extension direction. Each engagement platform device is adapted to receive a coupling member included in the transmission shaft, so that the cutting disc obtains a certain vertical position along the vertical extension direction according to the engagement platform device having received the coupling member, thereby imparting an associated certain mowing height.

[0015] In this way, the formation of the cutting disc determines the number of available mowing heights. Different cutting discs can provide different numbers of mowing heights, while the coupling member is simple and universal.

[0016] According to some aspects, at least one engagement platform arrangement comprises two opposing surfaces against which the coupling member is adapted to abut.

[0017] This provides a secure and reliable contact between the coupling member and the cutting disc.

[0018] According to some aspects, the coupling member is adapted to be positioned between two opposing surfaces of the at least one engagement platform arrangement.

[0019] In this way, all mounting locations for the coupling components are easily accessible.

[0020] According to some aspects, each engagement platform device includes at least one fastening aperture, and the coupling member includes at least one corresponding at least partially threaded hole. Each hole is adapted to receive a corresponding screw extending through the corresponding fastening aperture and adapted to secure the coupling member to the cutting disk.

[0021] This enables easy fixing of the coupling member to the cutting disc in a secure and easily releasable manner.

[0022] According to some aspects, the connecting portion comprises a continuous arcuate wall portion surrounding a surface of the engagement platform arrangement against which the coupling member is adapted to abut.

[0023] This provides an efficient and durable design.

[0024] According to some aspects, the transmission shaft includes a coupling member, which in turn includes a first connecting rod and a second connecting rod. The second connecting rod is adapted to be positioned closer to the cutter propulsion unit than the first connecting rod. The connecting portion includes a first slot and a second slot, wherein the first slot is adapted to be positioned closer to the ground in an extended condition than the second slot along a vertical extension direction extending perpendicularly to the radial extension direction. The first slot is adapted to receive the first connecting rod, and the second slot is adapted to receive the first connecting rod and the second connecting rod.

[0025] This makes it possible to easily handle variations in mowing height.

[0026] According to some aspects, the coupling member is secured to the connecting portion by means of a screw extending through a fastening aperture in the connecting portion and secured to a hole of the connecting rod received in the second slot.

[0027] This enables easy fixing of the coupling member to the cutting disc in a secure and easily releasable manner.

[0028] The present disclosure also relates to a cutting disc and a drive shaft associated with the above-mentioned advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present disclosure will now be described in more detail with reference to the accompanying drawings, in which:

[0030] Figure 1A shows a perspective side view of a robotic lawn mower;

[0031] Figure 1B A schematic overview of a robotic lawn mower is shown;

[0032] Figure 2A A perspective top view of a cutting disk is shown;

[0033] Figure 2B A perspective bottom view of the cutting disc is shown;

[0034] Figure 3 shows a perspective side view of a cutter motor with a drive shaft;

[0035] Figure 4A shows a perspective side view of a cutter motor having a drive shaft connected to a cutting disc in a first installed position;

[0036] Figure 4B shows a cross-sectional side view of a cutter motor having a drive shaft connected to a cutting disc in a first installed position;

[0037] Figure 5A shows a perspective side view of a cutter motor having a drive shaft connected to a cutting disc in a second mounting position;

[0038] Figure 5B shows a cross-sectional side view of a cutter motor having a drive shaft connected to a cutting disc in a second mounting position;

[0039] Fig. 6A shows a perspective side view of a cutter motor having a drive shaft connected to a cutting disc in a third mounting position;

[0040] Figure 6B shows a cross-sectional side view of a cutter motor having a drive shaft connected to a cutting disc in a third mounting position;

[0041] Figure 7 shows a schematic perspective side view of a drive shaft according to another example;

[0042] Figure 8 shows a schematic cut-away side view of a cutting disk connection portion according to another example;

[0043] Fig. 9 shows a schematic top view of a cutting disk according to another example;

[0044] Fig. 10A a schematic cut-away side view showing the drive shaft and the connecting portion in a first installed position; and

[0045] Fig. 10B A schematic cut-away side view of the drive shaft and the connecting part is shown in a first installation position. DETAILED DESCRIPTION

[0046] Various aspects of the present disclosure will now be described more fully below with reference to the accompanying drawings. However, the different devices, systems, computer programs and methods disclosed herein can be implemented in many different forms and should not be construed as limited to the aspects set forth herein. The same numbers in the accompanying drawings always refer to the same elements.

[0047] The terms used herein are only used to describe aspects of the present disclosure and are not intended to limit the present invention.As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0048] It should be noted that even though the description presented herein will focus on a robotic lawn mower, the teachings herein may be applied to any type of lawn mower having a rotary cutter.

[0049] Figure 1A A perspective view of the robotic lawn mower 100 is shown, and Figure 1B A schematic overview of a robotic lawn mower 100 is shown. The robotic lawn mower 100 is adapted for a forward direction of travel D, has a body 140 and a plurality of wheels 130; in this example, the robotic lawn mower 100 has four wheels 130, namely two front wheels and two rear wheels. The robotic lawn mower 100 comprises a control unit 110 and at least one electric motor 150 comprised in a motor arrangement, wherein at least some of the wheels 130 are drivably connected to the at least one electric motor 150. It should be noted that even though the description herein focuses on electric motors, an internal combustion engine may alternatively be used in combination with the electric motor arrangement.

[0050] The robotic mower 100 includes a charging skid 156 for contacting contact plates of a charging station (not shown) to receive charging current when docked to the charging station, and possibly for transmitting information via electrical communication between the charging station and the robotic mower 100 .

[0051] The robotic mower 100 further comprises at least one rechargeable power source, such as a battery 155, for providing power to the motor arrangement 150. The battery 155 is arranged to be charged by means of a charging current received from a charging station, received via a charging carriage 156 or other suitable charging connector.

[0052] The robotic lawn mower 100 also includes a mowing device 160 driven by a cutter motor 165 which is also powered by the battery 155 or alternatively by a separate power source.

[0053] In this example, if Figure 2A and Figure 2B As shown in , the mowing device 160 is composed of a cutting disc 160, which includes a circumferentially extending outer edge 181 and a plurality of cutting edges, such as cutting knives 161, 162, 163, arranged to protrude from the outer edge 181. Figure 3 , the cutting disc 160 has a central hub or connecting portion 164, to which a drive shaft 166 is adapted to be connected. According to some aspects, each cutting knife 161, 162, 163 is pivotally arranged so that during normal operation they are maintained in a working position due to centripetal force, extending radially outward from the center 182 of the cutting disc. If an object more resilient than ordinary grass is encountered, the cutting knives 161, 162, 163 are adapted to pivot to avoid damage to the object and the cutting knives 161, 162, 163. Other types of cutting edges and numbers of cutting edges are certainly conceivable. The drive shaft 166 has a longitudinal extension direction L and includes a main shaft portion 166a and a coupling member 173, wherein the main shaft portion 166a is in the form of a rod adapted to be rotated by means of the cutter motor 165.

[0054] According to the present disclosure, the connecting rod 164 includes a plurality of mounting positions for the drive shaft 166; a first mounting position indicated by a double dotted line 167, a second mounting position indicated by a dashed line 168, and a third mounting position indicated by a dotted line 169. The first mounting position 167 corresponds to a first mowing height, the second mounting position 168 corresponds to a second mowing height, and the third mounting position 169 corresponds to a third mowing height, wherein the first mowing height is lower than the second mowing height, and wherein the second mowing height is lower than the third mowing height.

[0055] Each mounting position 167, 168, 169 is associated with a corresponding engagement platform device 170a, 170b; 171a, 171b; 172, which are separated from each other along a vertical extension direction V extending perpendicularly to a radial extension direction R extending between the center 182 and the outer edge 181. The vertical extension direction V also extends along the longitudinal extension direction L of the drive shaft 166 when the drive shaft 166 is mounted to the cutting disc 160.

[0056] Each engagement platform device 170a, 170b; 171a, 171b; 172 is adapted to receive a coupling member 173 included in the transmission shaft 166 and allows the coupling member 173 to approach the other engagement platform devices 170a, 170b; 171a, 171b; 172 so that the coupling member 173 can occupy all mounting positions 167, 168, 169. By engaging the coupling member 163 with the cutting disc 160 using a certain engagement platform device 170a, 170b; 171a, 171b; 172, a certain vertical position along the vertical extension direction V and thus an associated certain mowing height is obtained.

[0057] In order to fix the coupling member 173 to a certain joint platform device 170a, 170b; 171a, 171b; 172, each joint platform device 170a, 170b; 171a, 171b; 172 includes a corresponding fastening aperture 174a, 174b; 175a, 175b; 176a, 176b. Figure 4B As shown in FIG. 1 , each fastening aperture 174a , 174b ; 175a , 175b ; 176a , 176b is adapted to receive a fastening device 177a , 177b , such as a screw that secures the coupling member 173 to the cutting disk 160 at a selected mounting location 167 , 168 , 169 .

[0058] In this example, three mounting locations are described in more detail below.

[0059] refer to Figure 2A , Figure 2B , Figure 3 , Figure 4A and Figure 4B , the coupling member 173 is mounted to the connecting portion 164 in the first mounting position 167 and engages the first engagement platform device 170a, 170b, which is composed of two opposing surfaces, the coupling member 173 abuts against these two opposing surfaces and is fixed by screws 177a, 177b. The screws are fixed in corresponding at least partially threaded holes 178a, 178b in the coupling member 173.

[0060] refer to Figure 2A , Figure 2B , Figure 3 , Figure 5A and Figure 5B, the coupling member 173 is mounted to the connecting portion 164 in the second mounting position 168 and engages the second engagement platform device 171a, 171b, which is composed of two opposing surfaces, the coupling member 173 abuts against these two opposing surfaces and is fixed by screws 177a, 177b, which in turn are fixed in holes 178a, 178b. The coupling member 173 is here positioned between the two opposing surfaces of the first engagement platform device 170a, 170b.

[0061] refer to Figure 2A , Figure 2B , Figure 3 , Fig. 6A and Figure 6B , the coupling member 173 is mounted to the connecting portion 164 in the third mounting position 169 and engages the third engaging platform device 172, which is constituted by the inner bottom surface of the connecting portion 164, and the coupling member 173 abuts against the inner bottom surface of the connecting portion 164 and is fixed by screws 177a, 177b, which are in turn fixed in holes 178a, 178b. The coupling member 173 is here positioned between the opposing surfaces of the first engaging platform device 170a, 170b and the second engaging platform device 171a, 171b.

[0062] Thus, by switching between the above-mentioned mounting positions 167, 168, 169, three different mowing heights can be easily achieved, while the cutter motor 165 can remain fixed to the main body 140 or internal frame, thereby reducing the number and complexity of components.

[0063] The present disclosure is not limited to the above, but may be freely varied within the scope of the appended claims. For example, the connecting portion 164 is shown as comprising a continuous arcuate wall portion 179 (for clarity, in Figure 2A Only one is shown in the figure), where the opposing surfaces of the first two engagement platform devices 170a, 170b, 171a, 171b are shown as circular. These shapes are only one example, and other suitable shapes, such as rectangular or other linear shapes, may of course be used instead. The surrounding wall formed by the wall portion 179 in this example may be omitted, and the necessary guidance for the coupling member 173 may be provided only by screws 177a, 177b or in combination with some other guiding means.

[0064] like Figure 3As shown in the figure, when the relative surfaces of the first two engaging platform devices 170a, 170b, 171a, 171b are circular or elliptical, the coupling member 173 includes two cylindrical members 173a, 173b positioned on opposite sides of the longitudinal extension direction L, each cylindrical member 173a, 173b having an axial extension direction parallel to the longitudinal extension direction L and formed to correspond to the platform devices 170a, 170b, 171a, 171b.

[0065] Examples of other types of guide means are different types of wall portions and / or slots corresponding to the protrusions of the coupling member 173. In this example, four guide pins 180 are provided for each engagement platform device 170a, 170b, 171a, 171b, 172 (for clarity, in Figure 2A Only one is shown), thereby providing a secure attachment of the coupling member 173.

[0066] In the example provided, there are three engagement platform devices 170a, 170b, 171a, 171b, 172, but of course there may be any suitable number of engagement platform devices.There are at least two engagement platform devices.

[0067] Other types of platform arrangements are of course conceivable, for example the coupling member may comprise different platforms. Figure 7 , Figure 8 , Fig. 9 , Fig. 10A and Fig. 10B The discussion illustrates another example of another type of platform device. Figure 7 A schematic perspective side view of an alternative drive shaft 166' is shown, the drive shaft having a longitudinal extension direction L' and comprising a drive shaft rod 166'a and a coupling member 173'. The coupling member 173' comprises a first connecting rod 183 and a second connecting rod 184, wherein the second connecting rod 184 is adapted to be positioned closer to the cutter motor than the first connecting rod 183. According to some aspects, each connecting rod 183, 184 comprises two at least partially threaded holes 185a, 185b; 186a, 186b. According to some further aspects, the connecting rods 183, 184 extend perpendicularly to each other, thereby forming a cross-shaped coupling member 173'.

[0068] Figure 8 shows a schematic cut-away side view of a connecting portion 164' included in a cutting disk, and Fig. 9A top view of a cutting disc 160' is shown with a connecting portion 164'. The connecting portion 164' in turn comprises a first slot 188 and a second slot 189, wherein the first slot 188 is adapted to be positioned closer to the ground in the extended condition than the second slot 189 in the vertical extension direction. The first slot 188 is adapted to receive a first connecting rod 183, and the second slot 189 is adapted to receive the first connecting rod 183 and the second connecting rod 184.

[0069] exist Fig. 10A , a schematic cut-away side view of the drive shaft 166' and the connecting portion 164' is shown, with the coupling member 173' mounted to the connecting portion 164' in a first mounted position, wherein the first connecting rod 183 is positioned in the first slot 188, and the second connecting rod 184 is positioned in the second slot 189. According to some aspects, the coupling member 173' is secured to the connecting portion 164' by means of screws 187a, 187b, which are secured to holes 186a, 186b in the second connecting rod 184.

[0070] In the corresponding Fig. 10A of Fig. 10B , the coupling member 173' is mounted to the connecting portion 164' in a second mounting position, wherein the first slot 188 is empty and the first connecting rod 183 is positioned in the second slot 189. According to some aspects, the coupling member 173' is fixed to the connecting portion 164' by means of screws 187a, 187b, which extend through fastening apertures 190a, 190b in the connecting portion 164' and are fixed to holes 185a, 185b in the first connecting rod 183.

[0071] The first mounting position corresponds to a first mowing height and the second mounting position corresponds to a second mowing height, wherein the first mowing height exceeds the second mowing height.

[0072] In general, the present disclosure relates to a lawn mower 100 comprising a cutter propulsion unit 165, a drive shaft 166, 166' having a longitudinal extension direction L, L' and adapted to be rotated by the cutter propulsion unit 165, and a cutting disc 160 having a radial extension direction R extending between a center 182 and an outer edge 181. The cutting disc 160 comprises one or more cutting edges 161, 162, 163 adapted to cut grass when the cutting disc 160 performs a rotational movement by means of the drive shaft 166. The cutting disc 160 further comprises a connecting portion 164, 164' adapted to receive a coupling member 173, 173' comprised in the drive shaft 166, 166' in at least two different mounting positions adapted to position the connecting portion 164 in mutually separated positions along the longitudinal extension direction L, L'.

[0073] According to some aspects, the connecting portion 164 comprises at least two engagement platform devices 170a, 170b; 171a, 171b; 172, which are separated from each other along a vertical extension direction V extending perpendicularly to the radial extension direction R. Each engagement platform device 170a, 170b; 171a, 171b; 172 is adapted to receive a coupling member 173 included in the transmission shaft 166, so that the cutting disc obtains a certain vertical position along the vertical extension direction V depending on the engagement platform device 170a, 170b; 171a, 171b; 172 that has received the coupling member 173, thereby imparting an associated certain mowing height.

[0074] According to some aspects, at least one engagement platform arrangement 170a, 170b; 171a, 171b comprises two opposing surfaces against which the coupling member 173 is adapted to rest.

[0075] According to some aspects, the coupling member 173 is adapted to be positioned between two opposing surfaces of at least one engagement platform arrangement 170a, 170b; 171a, 171b.

[0076] According to some aspects, each coupling platform device 170a, 170b; 171a, 171b; 172 includes at least one fastening orifice 174a, 174b; 175a, 175b; 176a, 176b, wherein the coupling member 173 includes at least one corresponding at least partially threaded hole 178a, 178b, each hole 178a, 178b being adapted to receive a corresponding screw 177a, 177b extending through the corresponding fastening orifice 174a, 174b; 175a, 175b; 176a, 176b and being adapted to secure the coupling member 173 to the cutting disk 160.

[0077] According to some aspects, the connecting portion 164 includes a continuous arcuate wall portion 179 surrounding the surfaces of the engagement platform arrangements 170a, 170b; 171a, 171b; 172 against which the coupling member 173 is adapted to abut.

[0078] According to some aspects, the drive shaft 166' includes a coupling member 173', which in turn includes a first connecting rod 183 and a second connecting rod 184, wherein the second connecting rod 184 is suitable for being positioned closer to the cutter propulsion unit 165 than the first connecting rod 183, wherein the connecting portion 164 includes a first narrow groove 188 and a second narrow groove 189, wherein the first narrow groove 188 is suitable for being positioned closer to the ground than the second narrow groove 188 in an extended condition along a vertical extension direction V extending perpendicular to the radial extension direction R, wherein the first narrow groove 188 is suitable for receiving the first connecting rod 183, and the second narrow groove 189 is suitable for receiving the first connecting rod 183 and the second connecting rod 184.

[0079] According to some aspects, coupling member 173 ′ is secured to connecting portion 164 ′ by screws 187a , 187b that extend through fastening apertures 190a , 190b in connecting portion 164 ′ and secure to holes 185a , 185b of connecting rods 183 , 184 received in second slot 189 .

[0080] Screws are shown for securing the coupling members 173, 173' to the cutting discs 160, 160', although other arrangements are contemplated. For example, locking pins extending perpendicular to the vertical extension direction may be used.

[0081] In the case of screws, one or more screws may be used for each engagement platform arrangement 170a, 170b; 171a, 171b; 172 or connecting rod 183, 184. Instead of threaded holes, the holes may be unthreaded and the screws secured by means of separate locking nuts.

[0082] The cutter motor is typically comprised of a cutter propulsion unit 165 .

[0083] The present disclosure also relates to a lawn mower cutting disc 160 having a radial extension direction R extending between a center 182 and an outer edge 181 and comprising one or more cutting edges 161, 162, 163 adapted to mow grass when the cutting disc 160 is subjected to a rotational movement by means of a drive shaft 166, 166' having a longitudinal extension direction L, L'. The cutting disc 160 further comprises a connecting portion 164, 164' adapted to receive a coupling member 173, 173' comprised in the drive shaft 166, 166' in at least two different mounting positions adapted to position the connecting portion 164 in mutually separated positions along the longitudinal extension direction L, L'.

[0084] According to some aspects, the connecting portion 164 includes at least two joining platform devices 170a, 170b; 171a, 171b; 172 separated from each other along a vertical extension direction V extending perpendicular to the radial extension direction R, wherein each joining platform device 170a, 170b; 171a, 171b; 172 is suitable for receiving a coupling member 173 included in the transmission shaft 166, so that the cutting disk can obtain a certain vertical position along the vertical extension direction V according to the joining platform device 170a, 170b; 171a, 171b; 172 that has received the coupling member 173.

[0085] According to some aspects, at least one engagement platform arrangement 170a, 170b; 171a, 171b comprises two opposing surfaces against which the coupling member 173 is adapted to rest.

[0086] According to some aspects, the connecting portion 164 is adapted to receive a coupling member 173 between two opposing surfaces of at least one engagement platform arrangement 170a, 170b; 171a, 171b.

[0087] According to some aspects, each engagement platform arrangement 170a, 170b; 171a, 171b; 172 includes at least one fastening aperture 174a, 174b; 175a, 175b; 176a, 176b adapted to allow passage of a screw to secure the coupling member 173 to the mower cutting disc 160.

[0088] According to some aspects, the connecting portion 164 includes a continuous arcuate wall portion 179 that surrounds the surface of the engagement platform arrangement 170a, 170b, 171a, 171b, 172.

[0089] According to some aspects, the connecting portion 164' includes a first slot 188 and a second slot 189, wherein, in an extended condition, the first slot 188 is adapted to be positioned closer to the ground than the second slot 188 along a vertical extension direction V extending perpendicular to the radial extension direction R, wherein the first slot 188 is adapted to receive a first connecting rod 183, and the second slot 189 is adapted to receive a first connecting rod 183 and a second connecting rod 184, the connecting rods 183, 184 being included in the transmission shaft 166'.

[0090] The present disclosure also relates to a lawnmower drive shaft 166, 166' having a longitudinal extension direction L, L' and comprising a drive shaft 116a, 166a' and a coupling member 173, 173'. The drive shaft 116a, 166a' is adapted to be rotated by the cutter propulsion unit 165, and the coupling member 173, 173' is adapted to be received by the lawnmower cutting disc connection part 164, 164' in at least two different mounting positions, which are adapted to position the connection part 164, 164' in mutually separated positions along the longitudinal extension direction L, L'.

[0091] According to some aspects, the coupling member 173 includes two cylindrical members 173a, 173b positioned on opposite sides of the longitudinal extension direction L. Each cylindrical member 173a, 173b has an axial extension direction parallel to the longitudinal extension direction L and is formed to correspond to the platform device 170a, 170b, 171a, 171b included in the connecting portion 164.

[0092] According to some aspects, coupling member 173' includes a first connecting rod 183 and a second connecting rod 184, wherein second connecting rod 184 is adapted to be positioned closer to cutter advancement unit 165 than first connecting rod 183. First connecting rod 183 is adapted to be received in a first slot 188 in connecting portion 164', and second connecting rod 184 is adapted to be received in a second slot 189 in connecting portion 164'.

[0093] Although the above description is directed to a robotic lawn mower, the present disclosure is applicable to any type of lawn mower having at least one powered cutting disc, such as a robotic lawn mower, a manual lawn mower with or without powered wheels, and a riding lawn mower.

Claims

1. A lawn mower (100) comprising a cutter propulsion unit (165), a drive shaft (166, 166') having a longitudinal extension direction (L, L') and adapted to be rotated by the cutter propulsion unit (165), and a cutting disc (160) having a radial extension direction (R) extending between a center (182) and an outer edge (181), in, The cutting disc (160) comprises one or more cutting edges (161, 162, 163) suitable for mowing grass when the cutting disc (160) is subjected to a rotational movement by means of the transmission shaft (166), wherein the cutting disc (160) further comprises a connecting portion (164, 164') located on one side of the cutting disc (160), the connecting portion being suitable for receiving a coupling member (173, 173') included in the transmission shaft (166, 166') on the one side of the cutting disc (160). At least two different installation positions, the installation positions are suitable for positioning the connection part (164) in mutually separated positions along the longitudinal extension direction (L, L'), wherein the connection part (164) comprises at least two engagement platform devices (170a, 170b; 171a, 171b; 172) mutually separated along a vertical extension direction (V) extending perpendicular to the radial extension direction (R), each of the engagement platform devices (170a, 170b; 171a, 171b; 172) being suitable for The invention relates to a method for receiving a coupling member (173) included in the transmission shaft (166), so that the cutting disc obtains a certain vertical position along the vertical extension direction (V) according to the engagement platform device (170a, 170b; 171a, 171b; 172) that has received the coupling member (173), thereby imparting an associated certain mowing height, and wherein each of the engagement platform devices (170a, 170b; 171a, 171b; 172) comprises at least one fastening aperture (174a, 174b); 4b; 175a, 175b; 176a, 176b), wherein the coupling member (173) comprises at least one corresponding at least partially threaded hole (178a, 178b), each of the holes (178a, 178b) being adapted to receive a corresponding screw (177a, 177b), the screw extending through the corresponding fastening orifice (174a, 174b; 175a, 175b; 176a, 176b) and being adapted to secure the coupling member (173) to the cutting disk (160).

2. The lawn mower (100) according to claim 1, in, At least one of the engagement platform devices (170a, 170b; 171a, 171b) comprises two opposing surfaces against which the coupling member (173) is adapted to abut.

3. The lawn mower (100) according to claim 1 or 2, in, The coupling member (173) is adapted to be positioned between two opposing surfaces of at least one of the engagement platform means (170a, 170b; 171a, 171b).

4. The lawn mower (100) according to claim 1 or 2, in, The connecting portion (164) comprises a continuous arcuate wall portion (179) surrounding a surface of the engagement platform arrangement (170a, 170b, 171a, 171b, 172) against which the coupling member (173) is adapted to abut.

5. The lawn mower (100) according to claim 1, in, The transmission shaft (166') includes a coupling member (173'), which in turn includes a first connecting rod (183) and a second connecting rod (184), wherein the second connecting rod (184) is suitable for being positioned closer to the cutter propulsion unit (165) than the first connecting rod (183), wherein the connecting portion (164) includes a first narrow slot (188) and a second narrow slot (189), wherein the first narrow slot (188) is suitable for being positioned closer to the ground in an extended condition than the second narrow slot (189) along a vertical extension direction (V) extending perpendicular to the radial extension direction (R), wherein the first narrow slot (188) is suitable for receiving the first connecting rod (183), and the second narrow slot (189) is suitable for receiving the first connecting rod (183) and the second connecting rod (184).

6. The lawn mower (100) according to claim 5, in, The coupling member (173') is fixed to the connecting portion (164') by means of screws (187a, 187b) extending through fastening apertures (190a, 190b) in the connecting portion (164') and fixed to holes (185a, 185b) of the connecting rods (183, 184) received in the second slots (189).

7. A lawn mower cutting disc (160) having a radial extension direction (R) extending between a center (182) and an outer edge (181) and comprising one or more cutting edges (161, 162, 163) suitable for mowing grass when the lawn mower cutting disc (160) is subjected to a rotational movement by means of a drive shaft (166, 166') having a longitudinal extension direction (L, L'), in, The lawn mower cutting disc (160) further comprises a connecting portion (164, 164') located on one side of the cutting disc (160), the connecting portion being suitable for receiving a coupling member (173, 173') included in the transmission shaft (166, 166') on the one side of the cutting disc (160) in at least two different installation positions, the installation positions being suitable for positioning the connecting portion (164) in mutually separated positions along the longitudinal extension direction (L, L'), wherein the connecting portion (164) comprises at least two engaging platform devices (170a, 170b; 171a, 171b; 172) mutually separated along a vertical extension direction (V) extending perpendicular to the radial extension direction (R), wherein each of the connecting portions (164) is connected to a coupling member (173, 173') on the one side of the cutting disc (160), wherein the coupling member (173, 173') is connected to the transmission shaft (166, 166' ... The engaging platform device (170a, 170b; 171a, 171b; 172) is suitable for receiving a coupling member (173) included in the transmission shaft (166), so that the cutting disc can obtain a certain vertical position along the vertical extension direction (V) according to the engaging platform device (170a, 170b; 171a, 171b; 172) having received the coupling member (173), and wherein each of the engaging platform devices (170a, 170b; 171a, 171b; 172) comprises at least one fastening hole (174a, 174b; 175a, 175b; 176a, 176b) suitable for allowing a screw to pass through, so that the coupling member (173) can be fixed to the lawn mower cutting disc (160).

8. The lawn mower cutting disc (160) according to claim 7, in, At least one of the engagement platform devices (170a, 170b; 171a, 171b; 172) comprises two opposing surfaces against which the coupling member (173) is adapted to abut.

9. A lawn mower cutting disc (160) according to claim 7 or 8, in, The connecting portion (164) is adapted to receive the coupling member (173) between two opposing surfaces of at least one of the engagement platform means (170a, 170b; 171a, 171b).

10. A lawn mower cutting disc (160) according to claim 7 or 8, in, The connecting portion (164) includes a continuous arcuate wall portion (179) surrounding the surface of the engagement platform means (170a, 170b, 171a, 171b, 172).

11. The lawn mower cutting disc (160) according to claim 7, in, The connecting portion (164') includes a first narrow slot (188) and a second narrow slot (189), wherein, in an extended condition, the first narrow slot (188) is suitable for being positioned closer to the ground than the second narrow slot (189) along a vertical extension direction (V) extending perpendicular to the radial extension direction (R), wherein the first narrow slot (188) is suitable for receiving a first connecting rod (183), and the second narrow slot (189) is suitable for receiving the first connecting rod (183) and the second connecting rod (184), and the first connecting rod (183) and the second connecting rod (184) are included in the transmission shaft (166').

12. A lawn mower drive shaft (166, 166') having a longitudinal extension direction (L, L') and comprising a drive shaft (116a, 116a') and a coupling member (173, 173'), in, The drive shaft (116a, 116a') is adapted to be rotated by a cutter propulsion unit (165), and wherein the coupling member (173, 173') is adapted to be received on one side of a lawn mower cutting disc having a radial extension direction (R) extending between a center (182) and an outer edge (181) by a connecting portion (164, 164') located on the one side of the lawn mower cutting disc in at least two different mounting positions, the mounting positions being adapted to position the connecting portion (164, 164') 4') are positioned in mutually separated positions along the longitudinal extension direction (L, L'), wherein the connecting portion (164) includes at least two engagement platform devices (170a, 170b; 171a, 171b; 172) separated from each other along a vertical extension direction (V) extending perpendicular to the radial extension direction (R), each of the engagement platform devices (170a, 170b; 171a, 171b; 172) being suitable for receiving a coupling member ( 173), so that the mower cutting disc obtains a certain vertical position along the vertical extension direction (V) according to the engagement platform device (170a, 170b; 171a, 171b; 172) that has received the coupling member (173), thereby giving an associated certain mowing height, and wherein each of the engagement platform devices (170a, 170b; 171a, 171b; 172) comprises at least one fastening aperture (174a, 174b; 175a, 175b) b; 176a, 176b), wherein the coupling member (173) includes at least one corresponding at least partially threaded hole (178a, 178b), each of the holes (178a, 178b) being adapted to receive a corresponding screw (177a, 177b) extending through the corresponding fastening aperture (174a, 174b; 175a, 175b; 176a, 176b) and being adapted to secure the coupling member (173) to the lawn mower cutting disc (160).

13. The lawn mower drive shaft (166, 166') according to claim 12, in, The coupling member (173) includes two columnar members (173a, 173b) positioned on opposite sides of the longitudinal extension direction (L), each of the columnar members (173a, 173b) having an axial extension direction parallel to the longitudinal extension direction (L) and formed to correspond to the engaging platform device (170a, 170b, 171a, 171b) included in the connecting portion (164).

14. The lawn mower drive shaft (166, 166') according to claim 12, in, The coupling member (173') includes a first connecting rod (183) and a second connecting rod (184), wherein the second connecting rod (184) is adapted to be positioned closer to the cutter advancement unit (165) than the first connecting rod (183), the first connecting rod (183) is adapted to be received in a first narrow groove (188) in the connecting portion (164'), and the second connecting rod (184) is adapted to be received in a second narrow groove (189) in the connecting portion (164').

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