WO2023096545A1 - Lawnmower cutting arrangement and lawnmower - Google Patents

Abstract

A lawnmower cutting arrangement (1) is disclosed comprising a cutting unit (3), a driveshaft unit (4) configured to be attached to a driveshaft (20) of a lawnmower (2), a keyed interface (60) for rotationally locking the cutting unit (3) to the driveshaft unit (4), and a skid plate assembly (5) comprising an attachment unit (6) for attaching the skid plate assembly (5) to the driveshaft unit (4). The cutting arrangement (1) comprises a locking mechanism (9) configured to be transferred between a locked state and an unlocked state upon a relative rotation between the attachment unit (6) and the driveshaft unit (4). The present disclosure further relates to a lawnmower (2).

Description

Lawnmower Cutting Arrangement and Lawnmower

TECHNICAL FIELD

The present disclosure relates to a lawnmower cutting arrangement comprising a cutting unit configured to be rotated around a rotation axis by a driveshaft of a lawnmower to cut grass. The present disclosure further relates to a lawnmower comprising a driveshaft and a lawnmower cutting arrangement.

BACKGROUND

A lawnmower is an apparatus capable of cutting grass of a lawn. Various types of lawnmowers exist on today’s market. Examples are walk-behind mowers and self-propelled robotic lawnmowers. A walk-behind mower is a lawnmower usually comprising an elongated handle allowing a user to push, and/or to guide, the lawnmower. Some walk-behind mowers comprise a propulsion arrangement configured to drive one or more wheels of the lawnmower. Walk-behind mowers lacking a propulsion arrangement are sometimes referred to as “push mowers”. Some lawnmowers comprise a power unit in the form of an electric motor configured to rotate the cutting unit and some lawnmowers comprise a power unit in the form of a combustion engine configured to rotate the cutting unit.

A self-propelled robotic lawnmower is a mower capable of cutting grass in areas in an autonomous manner. Some robotic lawnmowers require a user to set up a border wire around a lawn that defines the area to be mowed. Such robotic lawnmowers use a sensor to locate the wire and thereby the boundary of the area to be trimmed. In addition to the wire, robotic lawnmowers may also comprise other types of positioning units and sensors, for example sensors for detecting an event, such as a collision with an object within the area. The robotic lawnmower may move in a systematic and/or random pattern to ensure that the area is completely cut. A robotic lawnmower usually comprises one or more batteries and one or more electrically driven cutting units being powered by the one or more batteries. In some cases, the robotic lawnmower uses the wire to locate a recharging dock used to recharge the one or more batteries. Generally, robotic lawnmowers operate unattended within the area in which they operate. Examples of such areas are lawns, gardens, parks, sports fields, golf courts and the like.

A skid plate is a plate-like device attached below a cutting unit of a lawnmower and having a surface facing a ground surface during operation of the lawnmower. The skid plate is arranged so that it can rotate independently from the cutting unit. A skid plate reduces friction losses which otherwise arise in an engagement between the cutting unit and vegetation being cut. In this manner, a skid plate can reduce the energy required for cutting vegetation. Moreover, a skid plate can prevent damage of the cutting unit caused by collisions between the cutting unit and harder types of objects.

Cutting members of a cutting unit become blunt during use. Therefore, after a certain operational time, the cutting unit, or the cutting members thereof, is preferably replaced or resharpened. Consequently, on some occasions, it may be wanted to remove the cutting unit from the driveshaft and then reinstall the cutting unit, or another cutting unit, to the driveshaft. Moreover, some lawnmowers come with different types of cutting units, such as one cutting unit intended for cutting and another cutting unit intended for mulching vegetation, also referred to as a mulching unit. Thus, also for such reasons, it may be wanted to remove and reinstall a cutting unit to/from a driveshaft of a lawnmower.

A standard cutting disc is normally attached to a driveshaft of a lawnmower using a number of screws, such as seven screws, arranged on a centre hub of the cutting unit or on a centre hub of a skid plate unit. Therefore, the process of removing and reinstalling a cutting unit to and from the driveshaft normally requires technical skills and tools suited for the task. However, even when having technical skills and such tools, the process of removing and reinstalling a cutting unit to and from the driveshaft is usually difficult, time consuming, and burdensome.

Furthermore, generally, on today’s consumer market, it is an advantage if products, such as lawnmowers and associated components, systems, and arrangements, have conditions and/or characteristics suitable for being manufactured and assembled in a cost-efficient manner.

SUMMARY

It is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a lawnmower cutting arrangement comprising a cutting unit configured to be rotated around a rotation axis by a driveshaft of a lawnmower to cut grass, a driveshaft unit configured to be attached to the driveshaft of the lawnmower, and a keyed interface for rotationally locking the cutting unit to the driveshaft unit, and a skid plate assembly. The skid plate assembly comprises an attachment unit for attaching the skid plate assembly to the driveshaft unit and a skid plate rotatably connected to the attachment unit. The cutting arrangement comprises a locking mechanism comprising a first mechanism member arranged on the driveshaft unit and a second mechanism member arranged on the attachment unit of the skid plate assembly. The locking mechanism comprises a locked state, in which the skid plate assembly is axially locked to the driveshaft unit, and an unlocked state, in which the skid plate assembly is axially unlocked from the driveshaft unit. The locking mechanism is configured to be transferred between the locked and unlocked states upon a relative rotation between the attachment unit and the driveshaft unit.

In this manner, a lawnmower cutting arrangement is provided having conditions for a quick and simple replacement of the cutting unit. This is because the locking mechanism can be transferred between the locked and unlocked states simply by causing a relative rotation between the attachment unit of the skid plate assembly and the driveshaft unit.

Moreover, since the lawnmower cutting arrangement comprises the keyed interface between the cutting unit to the driveshaft unit and since the first and second mechanism members are arranged on the driveshaft unit and on the attachment unit of the skid plate assembly, no further arrangements or elements are needed for attaching the cutting unit to the driveshaft unit. Thus, in order words, because the first and second mechanism members are arranged on the driveshaft unit and on the attachment unit of the skid plate assembly, conditions are provided for a quick and simple replacement of the cutting unit. In addition, due to these features, standardized and low-cost cutting units can be used because the cutting unit does not form part of the locking mechanism of the lawnmower cutting arrangement.

Furthermore, since the cutting unit does not form part of the locking mechanism of the lawnmower cutting arrangement and is instead rotationally locked to the driveshaft unit via the keyed interface, the locking mechanism is not subjected to high forces or torques upon sudden high acceleration rates of the cutting unit, for example when the cutting unit is hitting a harder type of object or when the cutting unit is accelerating at start up. Likewise, since the second mechanism member of the locking mechanism is arranged on the attachment unit of the skid plate assembly and since the skid plate is rotatably connected to the attachment unit, the locking mechanism is not subjected to high forces or torques upon sudden high acceleration rates of the skid plate, for example when the skid plate is hitting a harder type of object. Thus, due to these features, a robust and failsafe locking mechanism is provided for axially locking and unlocking the skid plate assembly and thus also the cutting unit to/from the driveshaft unit. Accordingly, a lawnmower cutting arrangement is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the skid plate assembly comprises a first side configured to face a ground surface during operation of the cutting arrangement, and a second side configured to face the cutting unit and the driveshaft unit when the cutting arrangement is assembled to the driveshaft. Thereby, an energy efficient lawnmower cutting arrangement is provided having conditions reducing frictional losses and preventing damage of the cutting unit caused by collisions between the cutting unit and harder types of objects.

Optionally, the second mechanism member is arranged on the second side of the skid plate assembly. Thereby, conditions are provided for a quick and simple replacement of the cutting unit. Moreover, a locking mechanism is provided in which the first and second mechanism members are protected from the outside environment when the skid plate arrangement is attached to the driveshaft unit.

Optionally, the skid plate assembly comprises an arrangement for providing a temporary rotational lock between the skid plate and the attachment unit. Thereby, conditions are provided for a quicker, simpler, and more convenient replacement of the cutting unit. This is because a user may use the arrangement to perform a rotational lock between the skid plate and the attachment unit. Then, the user may rotate the skid plate and the cutting unit relative to each other. Because of the rotational lock between the skid plate and the attachment unit of the skid plate, the relative rotation between the skid plate and the cutting unit is transferred to a relative rotation between the attachment unit and the driveshaft unit. Thus, in this manner, the user can transfer the locking mechanism between the locked and unlocked state in a quick, simple, and convenient manner.

Optionally, the skid plate assembly comprises a first side configured to face a ground surface during operation of the cutting arrangement, and wherein the arrangement is configured to allow the temporary rotational lock to be provided from the first side of the skid plate assembly. Thereby, a more user-friendly lawnmower cutting arrangement is provided allowing a user to transfer the locking mechanism between the locked and unlocked state from the first side of the skid plate assembly.

Optionally, the arrangement comprises a number of through holes defined by surfaces of the skid plate and a number of apertures defined by surfaces of the attachment unit, and wherein the attachment unit is rotationally locked to the skid plate when an object is inserted through a through hole of the number of through holes into an aperture of the number of apertures. Thereby, a lawnmower cutting arrangement is provided allowing a user to transfer the locking mechanism between the locked and unlocked state by inserting an object through a through hole of the number of through holes into an aperture of the number of apertures and then rotate the skid plate and the cutting unit relative to each other. Thus, due to these features, an even more user-friendly lawnmower cutting arrangement is provided allowing a user to transfer the locking mechanism between the locked and unlocked state in a quick, simple, and convenient manner.

Moreover, due to these features, a lawnmower cutting arrangement is provided in which the cutting unit and the skid plate assembly can be removed and attached to/from the driveshaft unit without the need for specialized tools. Instead, the user may insert almost any type of elongated object, such as a screwdriver, a nail, or the like, through a through hole of the number of through holes into an aperture of the number of apertures and then rotate the skid plate and the cutting unit relative to each other. Furthermore, due to these features, a lawnmower cutting arrangement is provided having a low probability of unintended transfers to the unlocked state.

In addition, due to these features, a lawnmower cutting arrangement is provided having conditions and characteristics suitable for being manufactured and assembled in a costefficient manner.

Optionally, the skid plate assembly comprises a skid plate cover centrally arranged on the skid plate, and wherein the arrangement comprises a number of through holes defined by surfaces of skid plate cover and a number of apertures defined by surfaces of the attachment unit, and wherein the attachment unit is rotationally locked to the skid plate when an object is inserted through a through hole of the number of through holes into an aperture of the number of apertures. Thereby, a lawnmower cutting arrangement is provided allowing a user to transfer the locking mechanism between the locked and unlocked state by inserting an object through a through hole of the number of through holes into an aperture of the number of apertures and then rotate the skid plate and the cutting unit relative to each other. Thus, due to these features, an even more user-friendly lawnmower cutting arrangement is provided allowing a user to transfer the locking mechanism between the locked and unlocked state in a quick, simple, and convenient manner. Moreover, due to these features, a lawnmower cutting arrangement is provided in which the cutting unit and the skid plate assembly can be removed and attached to/from the driveshaft unit without the need for specialized tools. Instead, the user may insert almost any type of elongated object, such as a screwdriver, a nail, or the like, through a through hole of the number of through holes into an aperture of the number of apertures and then rotate the skid plate and the cutting unit relative to each other. Furthermore, due to these features, a lawnmower cutting arrangement is provided having a low probability of unintended transfers to the unlocked state.

In addition, due to the skid plate cover centrally arranged on the skid plate, a skid plate assembly is provided in which components of the skid plate assembly, such as components of the attachment unit including the second mechanism member, are more protected from the environment outside of the skid plate assembly.

In addition, due to these features, a lawnmower cutting arrangement is provided having conditions and characteristics suitable for being manufactured and assembled in a costefficient manner.

Optionally, one of the first and second mechanism members comprises a cam surface and the other of the first and second mechanism members comprises a protrusion configured to abut against the cam surface when the locking mechanism is in the locked state. Thereby, a locking mechanism is provided having conditions for being reliable while being simple to use.

Optionally, the first mechanism member comprises the cam surface. Thereby, the skid plate assembly can be provided with a simple and low cost second mechanism member in the form of a protrusion.

Optionally, the locking mechanism comprises a spring element configured to bias the first and second mechanism members against each other when the locking mechanism is in the locked state. Thereby, a play between the first and second mechanism members can be avoided and a lawnmower cutting arrangement is provided having conditions for being reliable while being simple to use.

Optionally, the driveshaft unit comprises a hub member, the first mechanism member being axially movably arranged relative to the hub member, and wherein the driveshaft unit comprises a spring element arranged to bias the first mechanism member in an axial direction towards the hub member. Thereby, a play between the first and second mechanism members can be avoided and a lawnmower cutting arrangement is provided having conditions for being reliable while being simple to use.

Optionally, the second mechanism member is positioned between the first mechanism member and the hub member when the locking mechanism is in the locked state. Thereby, a lawnmower cutting arrangement is provided having conditions for being reliable. Moreover, a further user-friendly lawnmower cutting arrangement is provided. This is because a user may simply position the second mechanism member adjacent to the first mechanism and cause a relative rotation between the attachment unit and the driveshaft unit to transfer the locking mechanism to the locked state.

Optionally, the skid plate assembly comprises a number of bearings rotatably connecting the skid plate to the attachment unit. Thereby, a durable and reliable skid plate assembly is provided.

Optionally, the skid plate assembly comprises a bearing support member, wherein each bearing comprises an outer race rotationally fixed to the bearing support member and an inner race rotationally fixed to a portion of the attachment unit. Thereby, a durable and reliable skid plate assembly is provided having conditions and characteristics suitable for being manufactured and assembled in a cost-efficient manner.

Optionally, the skid plate is attached to the bearing support member via a number of fastening elements. Thereby, a durable and reliable skid plate assembly is provided having conditions and characteristics suitable for being manufactured and assembled in a costefficient manner.

Optionally, the skid plate assembly comprises a skid plate cover centrally arranged on the skid plate, and wherein the number of fastening elements protrudes through holes in the skid plate cover and through holes in the skid plate into holes of the bearing support member. Thereby, a durable and reliable skid plate assembly is provided having conditions and characteristics suitable for being manufactured and assembled in a cost-efficient manner. In addition, due to the skid plate cover centrally arranged on the skid plate, a skid plate assembly is provided in which components of the skid plate assembly, such as components of the attachment unit including the second mechanism member, are more protected from the environment outside of the skid plate assembly. Optionally, the skid plate assembly comprises a skid plate cover centrally arranged on the skid plate, and wherein the number of bearings is/are arranged between the skid plate cover and the second mechanism member. Thereby, a durable and reliable skid plate assembly is provided. In addition, due to the skid plate cover centrally arranged on the skid plate, a skid plate assembly is provided in which the bearings as well as other components of the skid plate assembly, such as components of the attachment unit including the second mechanism member, are more protected from the environment outside of the skid plate assembly.

Optionally, the cutting unit comprises a cutting disc and a number of cutting members pivotally arranged at a periphery of the cutting disc. Thereby, a safer cutting unit is provided having conditions for operating in an energy-efficient manner.

According to a second aspect of the invention, the object is achieved by a lawnmower comprising a driveshaft and a lawnmower cutting arrangement according to some embodiments of the present disclosure.

Since the lawnmower comprises a lawnmower cutting arrangement according to some embodiments, a lawnmower is provided having conditions for a quick and simple replacement of the cutting unit thereof. In addition, a lawnmower is provided having conditions for using standardized and low-cost cutting units. Moreover, a lawnmower is provided comprising a robust and failsafe locking mechanism for axially locking and unlocking the skid plate assembly and thus also the cutting unit to/from the driveshaft unit.

Accordingly, a lawnmower is provided overcoming, or at least alleviating, at least some of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the lawnmower is a self-propelled autonomous robotic lawnmower. Thereby, self- propelled autonomous robotic lawnmower is provided having the above-mentioned advantages.

Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS Various aspects of the invention, including its particular features and advantages, will be readily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which:

Fig. 1 schematically illustrates a lawnmower according to some embodiments of the present disclosure,

Fig. 2 illustrates an enlarged view of a cutting arrangement of the lawnmower illustrated in Fig. 1,

Fig. 3 illustrates the cutting arrangement of the lawnmower illustrated in Fig. 1 in a dissembled state,

Fig. 4 illustrates the cutting arrangement illustrated in Fig. 3 in which the components of the cutting arrangement are illustrated in an exploded view,

Fig. 5 illustrates a second exploded view of components of a skid plate assembly of the cutting arrangement illustrated in Fig. 4,

Fig. 6 illustrates a cross section of the cutting arrangement in an assembled state, Fig. 7 illustrates a second exploded view of the components of a driveshaft unit of the cutting arrangement,

Fig. 8 illustrates a perspective view of an attachment unit of the cutting arrangement, and Fig. 9 illustrates a second cross section of the cutting arrangement in an assembled state.

DETAILED DESCRIPTION

Aspects of the present invention will now be described more fully. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Fig. 1 schematically illustrates a lawnmower 2 according to some embodiments of the present disclosure. According to the illustrated embodiments, the lawnmower 2 is a self- propelled autonomous robotic lawnmower 2 capable of navigating and cutting grass in an autonomous manner in an area without the intervention or the control of a user. For reasons of brevity and clarity, the self-propelled autonomous robotic lawnmower 2 is in some places herein referred to as “the robotic lawnmower 2” or simply the “lawnmower 2”. According to further embodiments, the lawnmower 2 may be another type of lawnmower, such as a walk- behind mower or a push mower. According to the embodiments herein, the lawnmower 2 is a small or mid-sized lawnmower 2 configured to be used to cut grass in areas used for aesthetic and recreational purposes, such as gardens, parks, city parks, sports fields, lawns around houses, apartments, commercial buildings, offices, and the like. The lawnmower 2 comprises a lawnmower body 2’ and a number of lawnmower support members 41, 4T each configured to abut against a ground surface 8 in a first plane P1 during operation of the lawnmower 2 to support the lawnmower body 2’. The lawnmower body 2’, as referred to herein, may also be referred to as a lawnmower chassis. Accordingly, the first plane P1 will extend along a ground surface 11 when the lawnmower 2 is positioned on a flat ground surface 11. According to the illustrated embodiments, the lawnmower support members 41 , 4T is wheels 41 , 4T of the lawnmower 2. According to the illustrated embodiments, the lawnmower 2 comprises four wheels 41 , 4T, namely two drive wheels 41 and two support wheels 4T. The drive wheels 41 of the lawnmower 2 may each be powered by an electrical motor of the lawnmower 2 to provide motive power and/or steering of the lawnmower 2.

In Fig. 1, a longitudinal direction Id of the lawnmower 2 is indicated. The longitudinal direction Id of the lawnmower 2 extends in a longitudinal plane LP of the lawnmower 2. The longitudinal plane LP is parallel to the first plane P1. The longitudinal direction Id of the lawnmower 2 is thus parallel to the first plane P1 and thus also to a ground surface 11 when the lawnmower 2 is positioned onto a flat ground surface 11 . Moreover, the longitudinal direction Id of the lawnmower 2 is parallel to a forward direction fd of travel of the lawnmower 2 as well as a reverse direction rd of travel of the lawnmower 2.

According to the illustrated embodiments, the drive wheels 41 of the lawnmower 2 are nonsteered wheels having a fix rolling direction in relation to the lawnmower body 2’. The respective rolling direction of the drive wheels 41 of the lawnmower 2 is substantially parallel to the longitudinal direction Id of the lawnmower 2. According to the illustrated embodiments, the support wheels 4T are non-driven wheels. Moreover, according to the illustrated embodiments, the support wheels 4T can pivot around a respective pivot axis such that the rolling direction of the respective support wheel 4T can follow a travel direction of the lawnmower 2.

As understood from the above, when the drive wheels 41 , 4T of the lawnmower 2 are rotated at the same rotational velocity in a forward rotational direction, and no wheel slip is occurring, the lawnmower 2 will move in the forward direction fd indicated in Fig. 1. Likewise, when the drive wheels 41 , 4T of the lawnmower 2 are rotated at the same rotational velocity in a reverse rotational direction, and no wheel slip is occurring, the lawnmower 2 will move in the reverse direction rd indicated in Fig. 1. The reverse direction rd is opposite to the forward direction fd. According to the illustrated embodiments, the lawnmower 2 may be referred to as a four- wheeled rear wheel driven lawnmower 2. According to further embodiments, the lawnmower 2 may be provided with another number of wheels 41 , 4T, such as three wheels. Moreover, according to further embodiments, the lawnmower 2 may be provided with another configuration of driven and non-driven wheels, such as a front wheel drive or an all-wheel drive.

According to the illustrated embodiments, the lawnmower 2 comprises a control arrangement 98. The control arrangement 98 may be configured to control propulsion of the lawnmower 2, and steer the lawnmower 2, by controlling electrical motors of the lawnmower 2 arranged to drive the drive wheels 41 of the lawnmower 2. According to further embodiments, the control arrangement 98 may be configured to steer the lawnmower 2 by controlling the angle of steered wheels of the lawnmower 2. According to still further embodiments, the robotic lawnmower may be an articulated robotic lawnmower, wherein the control arrangement 98 may be configured to steer the robotic lawnmower by controlling the angle between frame portions of the articulated robotic lawnmower.

The control arrangement 98 may be configured to control propulsion of the lawnmower 2, and steer the lawnmower 2, so as to navigate the lawnmower 2 in an area to be operated. The lawnmower 2 may further comprise one or more sensors arranged to sense a magnetic field of a wire, and/or one or more positioning units, and/or one or more sensors arranged to detect an impending or ongoing collision event with an object. In addition, the lawnmower 2 may comprise a communication unit connected to the control arrangement 98. The communication unit may be configured to communicate with a remote communication unit to receive instructions therefrom and/or to send information thereto. The communication may be performed wirelessly over a wireless connection such as the internet, or a wireless local area network (WLAN), or a wireless connection for exchanging data over short distances using short-wavelength, i.e. ultra-high frequency (UHF) radio waves in the industrial, scientific, and medical (ISM) band from 2.4 to 2.486 GHz.

The control arrangement 98 may be configured to control propulsion of the lawnmower 2, and steer the lawnmower 2, so as to navigate the lawnmower 2 in a systematic and/or random pattern to ensure that an area is completely covered, using input from one or more of the above described sensors and/or units. Furthermore, the lawnmower 2 may comprise one or more batteries arranged to supply electricity to components of the lawnmower 2. As an example, the one or more batteries may be arranged to supply electricity to electrical motors of the lawnmower 2 by an amount controlled by the control arrangement 98. The lawnmower 2 comprises a lawnmower cutting arrangement 1. For reasons of brevity and clarity, the lawnmower cutting arrangement 1 is in some places herein referred to as “the cutting arrangement 1”. The lawnmower cutting arrangement 1 comprises a cutting unit 3 configured to be rotated around a rotation axis Ax by a driveshaft 20 of a lawnmower 2 to cut vegetation such as grass. According to the illustrated embodiments, the cutting unit 3 comprises a cutting disc and a number of cutting members 30 pivotally arranged at a periphery of the cutting disc. The cutting unit 3 is configured to rotate in a cutting plane PC around the rotation axis Ax. The rotation axis Ax is perpendicular to the cutting plane PC. According to the illustrated embodiments, the cutting plane PC is substantially parallel to the first plane P1. According to embodiments herein, an angle between the cutting plane PC and the first plane P1 may be less than 10 degrees or less than 7 degrees.

The lawnmower 2 further comprises a motor 45 configured to rotate the cutting unit 3 by rotating the driveshaft 20. The motor 45 and the cutting assembly 1 may together be referred to as a cutting arrangement. According to the illustrated embodiments, the motor 45 is an electric motor 45. However, according to further embodiments, the lawnmower 2 may comprise another type of motor, such as an internal combustion engine. According to the illustrated embodiments, the driveshaft 20 is an output shaft of the motor 45. However, according to further embodiments, the lawnmower 2 may comprise a transmission between an output shaft of the motor 45 and the driveshaft 20 as referred to herein.

Fig. 2 illustrates an enlarged view of the cutting arrangement 1 of the lawnmower 2 illustrated in Fig. 1. Moreover, in Fig. 2, the motor 45 of the lawnmower 2 can be seen. As indicated in Fig. 2, the cutting arrangement 1 comprises a skid plate assembly 5. The skid plate assembly 5 comprises a skid plate 15. The skid plate 15 is also seen and indicated in Fig. 1. The skid plate 15 is arranged below the cutting unit 3 when the lawnmower 2 is positioned in an upright use position as is illustrated in Fig. 1. In other words, the skid plate 15 is located between the cutting unit 3 and a ground surface 11 when the lawnmower 2 is positioned in an upright use position on the ground surface 11 as is illustrated in Fig. 1.

According to the illustrated embodiments, the skid plate 15 is disc shaped, is arranged parallel to the cutting unit 3, and has a diameter slightly smaller than the cutting disc 3’ of the cutting unit 3. According to further embodiments, the skid plate 15 may have approximately the same diameter as the cutting disc 3’ of the cutting unit 3. As seen in Fig. 1 , the cutting members 30 of the cutting unit 3 protrudes further out from the rotation axis Ax than the skid plate 15. In this manner, the cutting members 30 can cut vegetation in an efficient manner upon rotation of the cutting unit 3.

As is further explained herein, the skid plate 15 is arranged so that it can rotate independently from the cutting unit 3. Thereby, the skid plate 15 can reduce frictional losses which otherwise arise in an engagement between the cutting unit 3 and vegetation being cut. In this manner, the skid plate 15 can reduce the energy required for cutting vegetation. Moreover, the skid plate 15 can prevent damage of the cutting unit caused by collisions between the cutting unit 3 and harder types of objects. In Fig. 1 and Fig. 2, the cutting arrangement 1 is illustrated in an assembled state.

Fig. 3 illustrates the cutting arrangement 1 of the lawnmower 2 illustrated in Fig. 1 in a dissembled state. Moreover, in Fig. 3, the motor 45 of the lawnmower 2 can be seen. Below, simultaneous reference is made to Fig. 1 - Fig. 3, if not indicated otherwise. The lawnmower cutting arrangement 1 comprises a driveshaft unit 4 configured to be attached and rotationally locked to the driveshaft 20 of the lawnmower 2. The driveshaft unit 4 may comprise internal splines configured to engage with external splines of the driveshaft 20 to ensure a rotational lock between the driveshaft 2 and the driveshaft unit 4. Such internal/external splines are not illustrated in Fig. 3 for reasons of brevity.

The cutting arrangement 1 further comprises a keyed interface 60 for rotationally locking the cutting unit 3 to the driveshaft unit 4 when the cutting unit 3 is positioned against the driveshaft unit 4. According to the illustrated embodiments, the keyed interface 60 is formed by a number of protrusions 47 arranged on the driveshaft unit 4 and a number of recesses arranged on an attachment portion 48 of the cutting unit 3, wherein each protrusion 47 is arranged to be positioned inside a recess of the attachment portion 48 of the cutting unit 3 when the cutting arrangement 1 is in an assembled state. In Fig. 3, the recesses of the keyed interface 60 are not visible. According to further embodiments, the cutting arrangement 1 may comprise another type of keyed interface 60 for rotationally locking the cutting unit 3 to the driveshaft unit 4 when the cutting unit 3 is positioned against the driveshaft unit 4

The skid plate assembly 5 comprises an attachment unit 6 for attaching the skid plate assembly 5 to the driveshaft unit 4. As is further explained herein, the skid plate 15 is rotatably connected to the attachment unit 6. The cutting arrangement 1 comprises a locking mechanism 9 comprising a first mechanism member 9’ arranged on the driveshaft unit 4 and a second mechanism member 9” arranged on the attachment unit 6 of the skid plate assembly 5. As is further explained herein, the locking mechanism 9 comprises a locked state, in which the skid plate assembly 5 is axially locked to the driveshaft unit 4, and an unlocked state, in which the skid plate assembly 5 is axially unlocked from the driveshaft unit 4. Moreover, as is further explained herein, the locking mechanism 9 is configured to be transferred between the locked and unlocked states upon a relative rotation between the attachment unit 6 and the driveshaft unit 4.

Fig. 4 illustrates the cutting arrangement 1 illustrated in Fig. 3 in which the components of the cutting arrangement 1 are illustrated in an exploded view. Moreover, in Fig. 4, the motor 45 of the lawnmower 2 can be seen. In Fig. 4, the components of the cutting arrangement 1 are illustrated slightly from above and in the order in which they are intended to be assembled. Moreover, in Fig. 4, at least some of the recesses 49 of the attachment portion 48 of the cutting unit 3 are seen and are indicated.

In Fig. 4, the components of the driveshaft unit 4 are illustrated inside an area marked with a dotted line provided with reference sign “4”. Likewise, in Fig. 4, the components of the skid plate assembly 5 are illustrated inside an area marked with a dotted line provided with reference sign “5”.

In Fig. 4, the first mechanism member 9’ and the second mechanism member 9” of the locking mechanism 9 are more clearly seen. According to the illustrated embodiments, the driveshaft unit 4 comprises a hub member 14. The first mechanism member 9’ is axially movably arranged relative to the hub member 14, i.e. , movably arranged relative to the hub member 14 in axial direction ad being parallel to the rotation axis of the cutting unit 3. Moreover, according to the illustrated embodiments, the driveshaft unit 4 comprises a spring element 23 arranged to bias the first mechanism member 9’ in the axial direction ad towards the hub member 14.

The driveshaft unit 4 comprises a fastener 51 configured to be attached to the driveshaft 20. The spring element 23 according to the illustrated embodiments is configured to bias the first mechanism member 9’ in the axial direction ad towards the hub member 14 by applying a separating force between the first mechanism member 9’ and the fastener 51 when the driveshaft unit 4 is assembled to the driveshaft 20. According to the illustrated embodiments, the fastener 51 is a nut. However, according to further embodiments, the driveshaft unit 4 may comprise another type of fastener.

According to the illustrated embodiments, the skid plate assembly 5 comprises two bearings 31 , 32. The bearings 31 , 32 rotatably connects the skid plate 15 to the attachment unit 6 when the skid plate assembly 5 is in an assembled state as is illustrated in Fig. 3. According to further embodiments, the skid plate assembly 5 may comprise another number of bearings 31 , 32 than two. The skid plate assembly 5 further comprises a spacer 53 arranged between the bearings 31 , 32 and a screw 55 configured to retain the bearings 31 , 32 against a portion 6’ of the attachment unit 6.

Fig. 5 illustrates a second exploded view of the components of the skid plate assembly 5 according to the illustrated embodiments. In Fig. 5, the components of the skid plate assembly 5 are illustrated slightly from below and in the order in which they are intended to be assembled. As can be seen in Fig. 4 and Fig. 5, the skid plate assembly 5 comprises a bearing support member 35. Moreover, as is indicated in Fig. 5, each bearing 31 , 32 comprises an outer race 3T, 32’ and an inner race 31”, 32”. The outer races 3T, 32’ are rotationally fixed to the bearing support member 35 and the inner races 31”, 32” are rotationally fixed to a portion 6’ of the attachment unit 6 when the skid plate assembly 5 is in an assembled state.

The skid plate assembly 5 comprises a skid plate cover 13 centrally arranged on the skid plate 15, i.e. arranged in a region of a rotation axis of the skid plate 15. According to the illustrated embodiments, the skid plate assembly 5 comprises a number of fastening elements 37, wherein the number of fastening elements 37 protrudes through holes 13’ in the skid plate cover 13 and through holes 15’ in the skid plate 15 into holes 35’ of the bearing support member 35 when the skid plate assembly 5 is in an assembled state as is illustrated in Fig. 3.

The fastening elements 37, the skid plate cover 13, the skid plate 15, the bearing support member 35, and the outer races 3T, 32’ of the bearings 31, 32 thus together form one unit being free to rotate relative to the attachment unit 6 of the skid plate assembly 5 when the skid plate assembly 5 is in an assembled state. In other words, this one unit of components is rotationally arranged relative to the attachment unit 6 of the skid plate assembly 5. Since the attachment unit 6 of the skid plate assembly 5 is configured to be attached to the drive shaft unit, this one unit is also free to rotate relative to the cutting unit 3 around a rotation axis coinciding which the rotation axis of the cutting unit 3 when the skid plate assembly 5 is in an assembled state as is illustrated in Fig. 3.

As explained above, the skid plate 15 is attached to the bearing support member 35 via a number of fastening elements 37. According to the illustrated embodiments, the fastening elements 37 are screws. However, according to further embodiments, the skid plate 15 may be attached to the bearing support member 35 via a number of other types of fastening elements.

The following is explained with simultaneous reference to Fig. 4 and Fig. 5. The skid plate assembly 5 comprises an arrangement 8 for providing a temporary rotational lock between the skid plate 15 and the attachment unit 6. According to the illustrated embodiments, the arrangement 8 comprises a number of through holes 28 defined by surfaces of the skid plate 15 and a number of apertures 8” defined by surfaces of the attachment unit 6. According to these embodiments, the attachment unit 6 becomes rotationally locked to the skid plate 15 when an object is inserted through a through hole 28 of the number of through holes 28 into an aperture 8” of the number of apertures 8” as is further explained herein.

Fig. 6 illustrates a cross section of the cutting arrangement 1 in an assembled state. In Fig. 6, the cross section is made in a plane comprising the rotation axis Ax of the cutting unit 3. As mentioned, the rotation axis Ax of the cutting unit 3 coincides with a rotation axis of the skid plate 15. In Fig. 6, an object 80, schematically illustrated in dotted lines, has been inserted through a through hole 8’ defined by surfaces of skid plate cover 13, through a through hole 28 defined by surfaces of the skid plate 28 and through a through hole 35’ defined by surfaces of the bearing support member 35 into an aperture 8” defined by surfaces of the attachment unit 6. In this manner, the attachment unit 6 is rotationally locked to the skid plate 15 by the abutting contact between the object 80 and surfaces of the respective through hole 8’, 28, 35” and the surfaces of the aperture 8” of the attachment unit 6. The through holes 8’, 28, 35” and the apertures 8” of the attachment unit 6 are also indicated in Fig. 5.

Thus, the arrangement 8 allows a user to perform a temporary rotational lock between the attachment unit 6 and the skid plate 15 in a quick and simple manner by inserting an object 80, such as a screwdriver, nail, or the like, into a hole 8’ of the skid plate cover 13 and push the object 80 into the hole 8’. In this process, the user may have to perform a slight rotation of the skid plate 15 relative to the cutting unit 3 in order to align the apertures 8” of the attachment unit 6 with the holes 8’, 28, 35’ of the skid plate assembly 5 such that the object 80 can reach into an aperture 8” of the attachment unit 6. However, due to the size and shape of the cutting unit 3 and the skid plate 15, this process is simple and intuitive.

As is indicated in Fig. 2, the skid plate assembly 5 comprises a first side s1 . The first side s1 is configured to face a ground surface during operation of the cutting arrangement 1 . Since the hole 8’ of the skid plate cover 13 is arranged on the first side s1 of the skid plate assembly 5, the arrangement 8 allow the temporary rotational lock to be provided from the first side s1 of the skid plate assembly 5.

The skid plate assembly 5 also comprises a second side s2. The second side s2 is configured to face the cutting unit 3 when the skid plate assembly 5 is in an attached state, as is illustrated in Fig. 2. Moreover, as is indicated in Fig. 3, the second side s2 of the skid plate assembly 5 is configured to face the driveshaft unit 4 when the cutting arrangement 1 is assembled to the driveshaft 20. Moreover, as is indicated in Fig. 3, the second mechanism member 9” is arranged on the second side s2 of the skid plate assembly 5.

Fig. 7 illustrates a second exploded view of the components of the driveshaft unit 4 of the cutting arrangement according to the illustrated embodiments. In Fig. 7, the components of the driveshaft unit 4 are illustrated slightly from above and in the order in which they are intended to be assembled. As is best seen in Fig. 7, according to the illustrated embodiments, the first mechanism member 9’ comprises two cam surfaces 19, 19’ and two recesses 59, 59’ each arranged adjacent to one of the two cam surfaces 19, 19’. The two recesses 59, 59’ are arranged at a radially outer periphery of the first mechanism member 9’ and extend in a radially inward direction into the first mechanism member 9’. Therefore, according to the illustrated embodiments, the recesses 59, 59’ of the first mechanism member 9’ may also be referred to as circumferential notches.

Fig. 8 illustrates a perspective view of the attachment unit 6 of the cutting arrangement according to the illustrated embodiments. In Fig. 8, the attachment unit 6 is illustrated slightly from above. As is best seen in Fig. 8, the second mechanism member 9” comprises two protrusions 21 , 2T. According to the illustrated embodiments, each of the two protrusions 21 , 2T protrudes in a radially inward direction of the attachment unit 6.

The following is explained with simultaneous reference to Fig. 2 - Fig. 8. The recesses 59, 59’ of the first mechanism member 9’ have a greater radial extension than the protrusions 21 , 2T of the first mechanism member 9’ and allows an insertion of the protrusions 21 , 2T of the second mechanism member 9” into the recesses 59, 59’ of the first mechanism member 9’ in an assembling procedure of the cutting arrangement 1. As explained in the following, the protrusions 21 , 2T are configured to abut against a respective cam surface 19, 19’ when the locking mechanism 9 is in the locked state.

An assembler/user may first attach the cutting unit 3 to the driveshaft unit 4 and then hold the skid plate assembly 5 and align the protrusions 21, 2T of the second mechanism member 9” with the recesses 59, 59’ of the first mechanism member 9’ and gently press the skid plate assembly 5 in an axial direction ad towards the cutting unit 3. The assembler may, before or after this step, provide a temporary rotational lock between the skid plate 15 and the attachment unit 6 by inserting an object 80 into a hole 8’ of the skid plate cover 13 and push the object 80 into the hole 8’ as explained above.

Then, the assembler can cause a relative rotation between the skid plate 15 and the cutting unit 3 for example by grabbing the skid plate 15 and the cutting unit 3 and turn these relative to each other. Due to the size and shape of the cutting unit 3 and the skid plate 15, this process is simple and intuitive. Since the skid plate 15 and the attachment unit 6 are rotationally locked to each other and since the cutting unit 3 is rotationally locked to the driveshaft unit 4 via the keyed interface 60, this relative rotation causes a relative rotation between the attachment unit 6 and the drive shaft unit 4.

In other words, the relative rotation between the skid plate 15 and the cutting unit 3 also causes a relative rotation between the protrusions 21, 2T of the second mechanism member 9” and the cam surfaces 19, 19’ of the first mechanism member 9’. In this manner, the locking mechanism 9 is transferred from the unlocked state to the locked state and the skid plate assembly 5 becomes axially locked to the driveshaft unit 4. Due to the keyed interface 60 and the fact that the cutting unit 3 is arranged inside the skid plate assembly 5, the cutting unit 3 also becomes axially locked to the driveshaft unit 4. The assembler may then remove the object 80 and the cutting arrangement 1 is ready for operation.

Fig. 9 illustrates a second cross section of the cutting arrangement 1 in an assembled state. In Fig. 9, the locking mechanism 9 is illustrated in the locked state. As is best seen in Fig. 9, the second mechanism member 9” is positioned between the first mechanism member 9’ and the hub member 14 when the locking mechanism 9 is in the locked state. Moreover, as is clearly seen in Fig. 9, the spring element 23 of the locking mechanism 9 is configured bias the first mechanism member 9’ in the axial direction ad towards the hub member 14.

The following is explained with simultaneous reference to Fig. 8 and Fig. 9. As can be seen in Fig. 8, each cam surface 19, 19’ is provided with a ridge 39, 39’ protruding in an axial direction ad from the cam surface 19, 19’. Due to the ridges 39, 39’ and the biasing force between the first and second mechanism members 9, 9’, a predetermined torque is required for transferring the locking mechanism 9 from the locked state to the unlocked state. As explained, due to design of the cutting arrangement in which the attachment unit 6 is attached to the driveshaft unit 4 and the skid plate 15 is rotatably connected to the attachment unit 6, low torques are obtained between the first and second mechanism members 9, 9’ during operation of the cutting arrangement 1 .

The predetermined torque required for transferring the locking mechanism 9 from the locked state to the unlocked state may be designed to be higher than torques obtained between the first and second mechanism members 9, 9’ during operation of the cutting arrangement 1. The predetermined torque required for transferring the locking mechanism 9 from the locked state to the unlocked state is determined by the biasing force provided by the spring element 23 and the shape/inclination of the ridges 39, 39’ of the cam surfaces 19, 19’. Thus, due to these features, the locking mechanism 9 can be securely retained in the locked state during operation of the cutting arrangement 1 .

Moreover, as is best seen in Fig. 9, the skid plate cover 13 is centrally arranged on the skid plate 15, and the bearings 31 , 32 are arranged between the skid plate cover 13 and the second mechanism member 9”.

The following is explained with simultaneous reference to Fig. 2 - Fig. 8. When a user wants to remove the skid plate assembly 5 and/or the cutting unit 3 from the driveshaft unit 4, the user may provide a temporary rotational lock between the skid plate 15 and the attachment unit 6 by inserting an object 80 into a hole 8’ of the skid plate cover 13 and gently push the object 80 into the hole 8’ as explained above. Again, the user may have to perform a slight rotation of the skid plate 15 relative to the cutting unit 3 in order to align the apertures 8” of the attachment unit 6 with the holes 8’, 28, 35’ of the skid plate assembly 5 such that the object 80 can reach into an aperture 8” of the attachment unit 6. However, due to the size and shape of the cutting unit 3 and the skid plate 15, this process is simple and intuitive. Moreover, since the hole 8’ of the skid plate assembly 5 is arranged at the first side s1 of the skid plate assembly 5, the object 80 can be inserted into the hole 8’ in a simple and intuitive manner from the first side s1 for rotationally locking the skid plate 15 to the attachment unit 6.

Then the user can cause a relative rotation between the skid plate 15 and the cutting unit 3 for example by grabbing the skid plate 15 and the cutting unit 3 and turn these relative to each other in relative rotational directions opposite to when attaching the skid plate assembly 5 to the driveshaft unit 4. Due to the size and shape of the cutting unit 3 and the skid plate 15, this process is simple and intuitive. In this process, the user may apply a torque between the skid plate 15 and the cutting unit 3 exceeding the predetermined threshold torque referred to above to transfer the locking mechanism 9 from the locked state to the unlocked state. As explained above, since the skid plate 15 and the attachment unit 6 are rotationally locked to each other and since the cutting unit 3 is rotationally locked to the driveshaft unit 4 via the keyed interface 60, this relative rotation causes a relative rotation between the attachment unit 6 and the drive shaft unit 4. In other words, the relative rotation between the skid plate 15 and the cutting unit 3 also causes a relative rotation between the protrusions 21 , 2T of the second mechanism member 9” and the cam surfaces 19, 19’ of the first mechanism member 9’ in an unlocking direction in which the protrusions 21, 2T are moved over the ridges 39, 39’ of the cam surfaces 19, 19’. The protrusions 21, 2T can be moved over the ridges 39, 39’ of the cam surfaces 19, 19’ because the first mechanism member 9’ can move in a direction opposite to the axial direction ad indicated in Fig. 4, which compresses the spring element 23. In this manner, the locking mechanism 9 is transferred from the locked state to the unlocked state.

As a result, the skid plate assembly 5 becomes axially unlocked from the driveshaft unit 4 and the user can remove the skid plate assembly 5 from the driveshaft unit 4. Since the cutting unit 3 is attached to the driveshaft unit 4 via the keyed interface 60, the user can also remove the cutting unit 3 from the driveshaft unit 4 and can for example perform maintenance of the cutting unit 3 or replace the cutting unit 3.

As explained above, according to the illustrated embodiments, the locking mechanism 9 comprises to protrusions 21 , 2T and two cam surfaces 19, 19’. However, according to further embodiments, the locking mechanism 9 may comprise another number of protrusions 21, 2T and another number of cam surfaces 19, 19’, such as one, three, four, or the like. Likewise, as explained above, according to the illustrated embodiments, the first mechanism member 9’ comprises the cam surfaces 19, 19’ and the second mechanism member 9” comprises the protrusions 21 , 2T. However, according to further embodiments, the second mechanism member 9” may comprise a number of cam surfaces 19, 19’ and the first mechanism member 9’ may comprise a number of protrusions 21, 2T.

Moreover, as explained above, according to the illustrated embodiments, the skid plate 15 has a diameter slightly smaller than the diameter of the cutting unit 3. However, according to further embodiments, the skid plate 15 may have a diameter significantly smaller than the diameter of the cutting unit 3, such as a diameter corresponding to the diameter of the skid plate cover 13 according to the illustrated embodiments. Moreover, the skid plate 15 may have a diameter between the diameter of the cutting unit 3 and the diameter of the skid plate cover 13 according to the illustrated embodiments. Furthermore, as can be seen in Fig. 2 - Fig. 6, and in Fig. 9, according to the illustrated embodiments, the skid plate cover 13 is dome-shaped and the skid plate 15 is disc-shaped. However, according to some embodiments of the present disclosure, the skid plate 15, as referred to herein, may have a shape differing from a disc-shape. As an example, the skid plate 15 may have a dome-shape, for example a dome-shape corresponding to the domeshape of the skid plate cover 13 according to the illustrated embodiments.

It is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only by the appended independent claims. A person skilled in the art will realize that the example embodiments may be modified, and that different features of the example embodiments may be combined to create embodiments other than those described herein, without departing from the scope of the present invention, as defined by the appended independent claims.

As used herein, the term "comprising" or "comprises" is open-ended, and includes one or more stated features, elements, steps, components, or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof.

Claims

1 . A lawnmower cutting arrangement (1) comprising: a cutting unit (3) configured to be rotated around a rotation axis (Ax) by a driveshaft (20) of a lawnmower (2) to cut grass, a driveshaft unit (4) configured to be attached to the driveshaft (20) of the lawnmower (2), a keyed interface (60) for rotationally locking the cutting unit (3) to the driveshaft unit (4), and a skid plate assembly (5) comprising an attachment unit (6) for attaching the skid plate assembly (5) to the driveshaft unit (4) and a skid plate (15) rotatably connected to the attachment unit (6), wherein the cutting arrangement (1) comprises a locking mechanism (9) comprising a first mechanism member (9’) arranged on the driveshaft unit (4) and a second mechanism member (9”) arranged on the attachment unit (6) of the skid plate assembly (5), and wherein the locking mechanism (9) comprises a locked state, in which the skid plate assembly (5) is axially locked to the driveshaft unit (4), and an unlocked state, in which the skid plate assembly (5) is axially unlocked from the driveshaft unit (4), and wherein the locking mechanism (9) is configured to be transferred between the locked and unlocked states upon a relative rotation between the attachment unit (6) and the driveshaft unit (4).

2. The cutting arrangement (1) according to claim 1 , wherein the skid plate assembly (5) comprises a first side (s1) configured to face a ground surface (11) during operation of the cutting arrangement (1), and a second side (s2) configured to face the cutting unit (3) and the driveshaft unit (4) when the cutting arrangement (1) is assembled to the driveshaft (20).

3. The cutting arrangement (1) according to claim 2, wherein the second mechanism member (9”) is arranged on the second side (s2) of the skid plate assembly (5).

4. The cutting arrangement (1) according to any one of the preceding claims, wherein the skid plate assembly (5) comprises an arrangement (8) for providing a temporary rotational lock between the skid plate (15) and the attachment unit (6).

5. The cutting arrangement (1) according to claim 4, wherein the skid plate assembly (5) comprises a first side (s1) configured to face a ground surface (11) during operation of the cutting arrangement (1), and wherein the arrangement (8) is configured to allow the temporary rotational lock to be provided from the first side (s1) of the skid plate assembly (5).

6. The cutting arrangement (1) according to claim 4 or 5, wherein the arrangement (8) comprises a number of through holes (28) defined by surfaces of the skid plate (15) and a number of apertures (8”) defined by surfaces of the attachment unit (6), and wherein the attachment unit (6) is rotationally locked to the skid plate (15) when an object (80) is inserted through a through hole (28) of the number of through holes (28) into an aperture (8”) of the number of apertures (8”).

7. The cutting arrangement (1) according to any one of the claims 4 - 6, wherein the skid plate assembly (5) comprises a skid plate cover (13) centrally arranged on the skid plate (15), and wherein the arrangement (8) comprises a number of through holes (8’) defined by surfaces of skid plate cover (13) and a number of apertures (8”) defined by surfaces of the attachment unit (6), and wherein the attachment unit (6) is rotationally locked to the skid plate (15) when an object (80) is inserted through a through hole (8’) of the number of through holes (8’) into an aperture (8”) of the number of apertures (8”).

8. The cutting arrangement (1) according to any one of the preceding claims, wherein one of the first and second mechanism members (9’, 9”) comprises a cam surface (19, 19’) and the other of the first and second mechanism members (9’, 9”) comprises a protrusion (21 , 2T) configured to abut against the cam surface (19, 19’) when the locking mechanism (9) is in the locked state.

9. The cutting arrangement (1) according to claim 8, wherein the first mechanism member (9’) comprises the cam surface (19, 19’).

10. The cutting arrangement (1) according to any one of the preceding claims, wherein the locking mechanism (9) comprises a spring element (23) configured to bias the first and second mechanism members (9’, 9”) against each other when the locking mechanism (9) is in the locked state.

11 . The cutting arrangement (1) according to any one of the preceding claims, wherein the driveshaft unit (4) comprises a hub member (14), the first mechanism member (9’) being axially movably arranged relative to the hub member (14), and wherein the driveshaft unit (4) comprises a spring element (23) arranged to bias the first mechanism member (9’) in an axial direction (ad) towards the hub member (14).

12. The cutting arrangement (1) according to claim 11, wherein the second mechanism member (9”) is positioned between the first mechanism member (9’) and the hub member (14) when the locking mechanism (9) is in the locked state.

13. The cutting arrangement (1) according to any one of the preceding claims, wherein the skid plate assembly (5) comprises a number of bearings (31 , 32) rotatably connecting the skid plate (15) to the attachment unit (6).

14. The cutting arrangement (1) according to claim 13, wherein the skid plate assembly (5) comprises a bearing support member (35), wherein each bearing (31 , 32) comprises an outer race (3T, 32’) rotationally fixed to the bearing support member (35) and an inner race (31”, 32”) rotationally fixed to a portion (6’) of the attachment unit (6).

15. The cutting arrangement (1) according to claim 14, wherein the skid plate (15) is attached to the bearing support member (35) via a number of fastening elements (37).

16. The cutting arrangement (1) according to claim 15, wherein the skid plate assembly (5) comprises a skid plate cover (13) centrally arranged on the skid plate (15), and wherein the number of fastening elements (37) protrudes through holes (13’) in the skid plate cover (13) and through holes (15’) in the skid plate (15) into holes (35’) of the bearing support member (35).

17. The cutting arrangement (1) according to any one of the claims 13 - 16, wherein the skid plate assembly (5) comprises a skid plate cover (13) centrally arranged on the skid plate (15), and wherein the number of bearings (31, 32) is/are arranged between the skid plate cover (13) and the second mechanism member (9”).

18. The cutting arrangement (1) according to any one of the preceding claims, wherein the cutting unit (3) comprises a cutting disc (3’) and a number of cutting members (30) pivotally arranged at a periphery of the cutting disc (3’).

19. A lawnmower (2) comprising a driveshaft (20) and a lawnmower cutting arrangement (1) according to any one of the preceding claims.

20. The lawnmower (2) according to claim 19, wherein the lawnmower (2) is a self-propelled autonomous robotic lawnmower (2).