WO2011136666A2

WO2011136666A2 - Drive system for lateral deck mowers

Info

Publication number: WO2011136666A2
Application number: PCT/NZ2011/000062
Authority: WO
Inventors: Keith Ross Mabey; James Iain Mcewen; Robert Charles Sievwright; Graeme Young
Original assignee: Trimax Mowing Systems Nz Limited
Priority date: 2010-04-29
Filing date: 2011-04-29
Publication date: 2011-11-03
Also published as: GB2495665B; WO2011136666A3; WO2011136666A4; GB2495665A; GB201301157D0

Abstract

A work implement, including a frame, a drive axle, a central work portion substantially in line with and coupled to the drive axle, at least one additional work portion pivotally mounted to the frame, at least one actuator configured to pivot the at least one additional work portion with respect to the frame, characterised in that each of the at least one work portions is operatively coupled to the drive axle by a drive belt such that pivoting of the at least one additional work portion by the actuator causes the drive belt to slacken thereby disengaging the at least one work portion.

Description

IMPROVEMENTS TO WORK IMPLEMENTS

STATEMENT OF CORRESPONDING APPLICATIONS

This application is based on New Zealand Patent Application Nos. 584986, 584987, and 585030, the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to work implements, and in particular improved tractor powered mowing attachments.

BACKGROUND ART Mowers are known for cutting grass and plant matter. These devices generally comprise a plurality of cutting decks with mowing blades. The mowing blades are operatively coupled to a drive assembly which causes them to rotate and thereby cut grass and plant matter.

It is known to arrange cutting decks laterally of each other with respect to the mower's direction of travel. This provides a wider cut area and may decrease the total time required to mow a large area. In addition, the lateral decks can be raised to a storage position which reduces the mower's width for transport.

The devices can be an independent attachment that has two or more cutting decks. Such attachments are secured to and driven by a tractor. Alternatively, attachments to ride on mowers are known. In that case, an additional mowing deck can be attached to the ride on mower.

A selection of prior art is described below to provide context for the present inventions and to highlight deficiencies in the art which would beneficial to address. United States Patent No. 4,497,160 to Mullet et al discloses a mower with lateral extension wings.

The lawn mower is intended for use in conjunction with a small tractor. It provides a main mower deck disposed forwardly of the tractor, and a pair of laterally extending wing mower decks disposed at opposite sides of the tractor.

A power take off is used to drive the main mowing deck. A complex belt system is used to transfer power from the PTO to the lateral mowing decks.

The lateral mowing decks can be pivotally raised with respect to the tractor. This causes the drive belts to slacken, thereby disengaging the blades. However, the belt system is complex, meaning that it may be difficult to maintain and service.

Further, the orientation of the drive belts to the PTO means that the pivoting of the lateral mowing decks is an inefficient way to disengage these. This also means that a complex assembly is required to ensure the belts are sufficiently tensioned to operate.

Yet a further failing of the mower of the Mullet patent is that it may be cumbersome due to the main mowing deck being forward mounted. For instance, the mower disclosed therein may be difficult to turn or otherwise manoeuvre.

United States Patent No. 7,305,811 to Murawski relates to a side mower deck for a mower tractor.

The invention disclosed in this patent is an attachment to be used with a ride on tractor. This is a comparatively small vehicle and has a small mowing area. The attachment is intended to extend that mowing area.

The side mower deck is pivotally mounted to the body of the ride on. A winch is configured to pivotally raise and lower the lateral mowing deck between in use and storage positions.

A drive belt is used to couple the lateral mowing deck to the central mowing deck.

Raising the lateral mowing deck slackens the drive belt. Accordingly, the lateral mowing deck is disengaged and its mowing blades stop rotating.

However, this device has the cutting decks in line with each other. This means that the respective cutting areas do not overlap. Accordingly, in use, mowing using the device disclosed in the Murawski patent may be inefficient.

In addition, the Murawski patent discloses only an attachment for use with a ride on mower. Therefore, it is not applicable for use with tractors which do not have an integral cutting deck. This limits the application for the Murawski mower. Further, that arrangement would not be easily applied to a tractor powered mowing attachment.

United States Patent No. 4,429,515 to Davis discloses a self propelled lawn mower.

The mower of the Davis patent includes a central cutting deck, and a plurality of side mower wings. The side mower wings are pivotally attached to the main body of the mower. A main drive belt is coupled to a drive system, and used to rotate the central mowing deck. The belt is also routed around a series of double pulleys. The pulleys are located such that they can engage additional drive belts to power the side mower wings.

As the side mower wings are raised, the side mower drive belts are slackened to stop the mowing blades rotating.

Again though, the mower of the Davis patent is intended only for use with a ride on having a central mowing deck. The arrangement of the drive belts, and side mower wings cannot be applied to mowing attachments for use with tractors.

In addition, the arrangement of the drive belts can be inefficient and complex.

Yet a further feature of multi-deck mowers is that they include guards to surround moving parts and assemblies. This is a necessity of health and safety

requirements. These guards ensure that people cannot access the moving components while in use.

However, it is necessary to have a plurality of guards, one for each moving part or assembly. To service the mower it is necessary to remove all of the guards separately of each other. This can be time consuming and fiddly.

In addition, having a series of guards adversely affects the appearance of the mower as it is difficult to provide the mower with a sleek and desirable aesthetic appearance. Previous attempts to provide covers on multi-deck mowers have been hampered by the requirement that the mowers be moved from storage to in use positions and particularly that they are pivotally raised / lowered.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.

Throughout this specification, the word "comprise", or variations thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF THE INVENTION

According to one aspect of the present invention, there is provided a work implement, including a frame, a drive axle, a central work portion coupled to the drive axle, at least one additional work portion pivotally mounted to the frame, at least one actuator configured to pivot the at least one additional work portion with respect to the frame, characterised in that each of the at least one additional work portions is operatively coupled directly to the drive axle by a drive belt such that pivoting of the at least one work portion by the actuator causes the drive belt to sufficiently slacken to disengage the at least one additional work portion.

According to another aspect of the present invention, there is provided an improved work implement as substantially described above, wherein the work implement includes an adjustment mechanism configured to change the distance between the work portion and the drive axle and thereby adjust tension in the drive belt.

According to a further aspect of the present invention, there is provided an adjustment mechanism, including a first component having a first screw thread, the first component having an aperture through the first screw thread, a second component having a second screw thread complementary to and engaged with the first screw thread, the second component having a channel that dissects the second screw thread, wherein the first component and the second component can rotate with respect to each other to cause a change in length, characterised in that the adjustment mechanism includes a locking portion that extends through the aperture and can releasably engage the channel to prevent the first component and second component from rotating with respect to each other. According to yet a further aspect of the present invention, there is provided a mounting arrangement, including an axle, a work portion secured to the axle, wherein the work portion is configured to rotate about the axle, characterised in that the mounting arrangement includes a biasing assembly to urge the work portion to rotate about the axle towards an equilibrium position.

According to yet a further aspect of the present invention, there is provided a cover assembly for use with a work implement, wherein the work implement is attached to a frame such that it can be moved between a raised position and a lowered position, characterised in that the cover is configured such that it accommodates changes in length of the work implement as it is moved between the raised position and the lowered position.

According to yet a further aspect of the present invention, there is provided a cover assembly as substantially described above for use with a work implement, including a first cover section, a second cover section secured to the work implement, wherein the first and second cover sections are configured to slide with respect to each other as the work implement is moved between the raised and lowered positions.

According to yet a further aspect of the present invention, there is provided a work implement, including a frame, a first work portion secured to the frame, wherein the first work portion is movable between an in use position and a storage position, a plurality of additional work portions, wherein the additional work portions are secured to the frame and movable between in use positions and storage positions, characterised in that the work implement includes a locking system that locks the plurality of work portions in the storage position when the first work portion is in the storage position. According to another aspect of the present invention, there is provided a tensioning mechanism, including a first pulley, a second pulley, an endless drive belt around the first and second pulleys so as to transfer rotation of one of the pulleys to the other, an idler pulley, characterised in that the idler pulley is configured to move concentrically to the first pulley and thereby facilitate adjusting tension in the endless drive belt.

The present specification describes a number of inventions having particular application to mowing apparatus. Reference will be made herein to aspects of the present inventions and their application to mowers and mowing attachments.

In the preferred embodiment the work portions are mowing decks and reference will be made as such.

In the particularly preferred embodiments the present inventions are incorporated into tractor powered mowing attachments, and in particular multi-deck mowing attachments. However, the foregoing should not be seen as limiting as the present inventions can find use in other embodiments and applications. For instance, the present invention(s) may be used with swathers or ploughs.

Throughout the present specification, reference to the term "mowing deck" should be understood as meaning a component having a plurality of cutting assemblies. Each cutting assembly includes a plurality of cutting blades rotatably mounted to the mowing deck. Preferably, the cutting assemblies are rotatably mounted cutting blades. Such as fling top cutting blades as should be known to those skilled in the art.

Reference to the term "lateral mowing deck" should be understood as meaning a mowing deck which is laterally staggered to a central mowing deck and offset to each other along the length of the drive axle.

The lateral mowing decks and central mowing decks can provide a wide cut area. In addition the decks provide overlapping cutting areas and help to ensure that there are no sections of ground missed during use of the mower. However the foregoing should not be seen as limiting. It is also possible that the lateral mowing decks are adjacent to the central mowing deck and that these do not overlap.

Throughout the present specification, reference to the term "frame" should be understood as meaning a body to which the components of the mower can be secured. The frame may include wheels and/or rollers to support the mower and facilitate its movement and use.

The frame may include a coupler to secure the mower to a work vehicle. In this embodiment, the mower is a mowing attachment as should be known to those skilled in the art. Throughout the present specification, reference to the term "drive axle" should be understood as meaning an elongate member that can rotate to drive one or more mowing decks.

In a preferred embodiment, the drive axle may engage with a power take off ("PTO") gear box on a work vehicle. The PTO rotates the drive axle to thereby facilitate driving the mowing decks. This should become clearer from the following description.

Preferably, the lateral mowing decks are directly coupled to the drive axle e.g. by a drive belt. This is a direct connection and is in contrast to the prior art where complex belt systems are required. The direct connection is made possible by the configuration and arrangement of the mowing decks and the drive axle. This aspect should become clearer from the following description:

Throughout the present specification, reference to the term "drive belt" should be understood as meaning a closed loop of material that is configured to transfer rotational force from one object to another. The drive belt may be formed from a flexible material.

In a preferred embodiment/ the drive belt may be a rubber drive belt or V drive belt as should be known to those skilled in the art. However this should not be seen as limiting and alternatives are envisaged. These include chains or other assemblies.

In a preferred embodiment, the lateral mowing decks are attached to mounting arms. The mounting arms are pivotally attached to the frame such that pivoting the mounting arms decreases the distance between the mowing deck and the drive axle.

In a preferred embodiment the mowing decks are secured to the mounting arms using a floating assembly.

The term "floating assembly" should be understood as referring to an assembly that allows the mowing decks to rotate about the mounting arm. In effect the mounting arm acts as an axle. This helps the mowing decks adjust to undulation in the ground over which the mowing deck is used. In addition, the floating assembly allows the mowing deck to be retained in an operative position regardless of the orientation / position of the adjustment mechanism. This maybe useful as it compensates for changes in orientation of the mowing deck by the adjustment mechanism (as will be discussed below).

Throughout the present specification, reference to the term "actuator" should be understood as meaning a device to cause a lateral mowing deck to pivot.

In a preferred embodiment, the actuator may be a hydraulic cylinder and ram. This is as should be understood by those skilled in the art.

However, the actuator could be of any known type such as a winch arrangement, pneumatic cylinder, or a helical drive actuator. Accordingly, the foregoing should not be seen as limiting on the scope of the present invention.

In a preferred embodiment, the actuator(s) pivots the mounting arm(s) with respect to the frame. This moves the lateral mowing deck(s) between several positions. Those positions have several functional relevancies according to different aspects of the present inventions. Reference will be made to: • an in use position and a storage position;

• an engaged position and a disengaged position.

These positions may be the same depending on the functional aspect of the inventions being considered. Throughout the present specification, reference to the term "in use position" should be understood as referring to a position in which the mowing deck is used to cut grass or plant matter.

In a preferred embodiment, the in use position is that in which the mowing deck is pivotally lowered as to be able to cut plant material. Throughout the present specification, reference to the term "storage position" should be understood as meaning a position in which the mowing deck does not cut grass or plant matter.

In a preferred embodiment, the storage position is that in which the mowing deck is raised above the in use position. Throughout the present specification, reference to the term "engaged position" should be understood as meaning an orientation and/or position of the lateral mowing deck(s) in which drive belts are sufficiently tensioned such that they transfer rotation of the drive axle to the mowing deck, to thereby drive the cutting assemblies. Throughout the present specification, reference to the term "disengaged position" should be understood as meaning an orientation for the mowing deck(s) in which the drive belt is sufficiently slackened such that it does not transfer the rotational force of the drive axle to the cutting decks.

Slackening of the drive belts through pivotal movement of the mowing decks acts as a self-clutching mechanism. This reduces the need for expensive and heavy clutches. As a result, the mowers according to the present invention may be lighter in weight and more cost effective to manufacture than those of the prior art.

In a preferred embodiment the arrangement of the mower axle is such that the mowing deck(s) are disengaged when the mounting arms pivot through an angle of substantially between 10-30 degrees.

More preferably, a lateral mowing deck is disengaged when mounting arms pivot through an angle of substantially 15 degrees.

However this should not be seen as limiting and other ranges for engagement and disengagement of the mowing decks are envisaged.

It should be appreciated that moving the mowing deck with respect to the frame causes a change in width. That is, the distance between the centre of the frame and the outside edge of the mowing deck is decreased.

The relevance of the change in length should become clearer from the following description.

In a preferred embodiment the adjustment mechanism is configured to change the distance between the work implement and the drive axle when the work implement is in a particular position. Therefore, the adjustment mechanism changes the distance without pivoting of the work implement with respect to the frame. This may be useful as it facilitates adjusting the tension in the drive belt. This compensates for variations in drive belt length, stretching of the drive belt in use, and assists in changing the drive belts.

In a particularly preferred embodiment the adjustment mechanism may be incorporated into a mounting arm for a lateral mowing deck. Throughout the present specification, reference to the term "locking mechanism" should be understood as referring to one or more components that can secure two components with respect to each other.

In a preferred embodiment, the locking mechanism is intended to prevent unwanted rotation of components having complementary and engaged screw threads.

In a preferred embodiment, the locking mechanism may be incorporated into the adjustment mechanism described herein. Therefore, in this embodiment the locking mechanism prevents the distance between the mowing deck and the drive axle changing. Such a change may adversely affect performance of the mower through the drive belt slipping or stretching.

However the foregoing should not be seen as limiting. For instance it is envisaged that the adjustment mechanism and locking mechanism may be incorporated into alternate applications where it is desirable to affect a change in length or secure two or more components with respect to each other.

Throughout the present specification reference to the term "biasing arrangement" should be understood as meaning an assembly configured to ensure that the mowing deck is in the equilibrium position.

Throughout the present specification, reference to the term "equilibrium position" should be understood as meaning the preferred operative position for the mowing deck.

In a preferred embodiment, the equilibrium position is that in which the mowing deck is orientated with respect to the ground such that it can mow grass or plant matter (e.g. substantially parallel to the ground). The floating assembly allows the mowing deck to move away from the equilibrium position. This may be caused by the mowing deck contacting an obstruction or the leading edge of the mower catching the ground. Alternatively, an actuator may move the mowing deck. However, the biasing assembly urges the work implement to return to the equilibrium position. In a preferred embodiment, the biasing assembly is a leaf spring. The leaf spring is mounted on a reference point, and attached to the mowing deck.

This leaf spring is configured such that rotating the mowing deck around the axle loads the leaf spring. The load causes the leaf spring to apply force to the mowing deck to limit continued rotation and urge the mowing deck to rotate in a counter direction towards the equilibrium position.

In a particularly preferred embodiment, the biasing assembly may be incorporated into a mounting arm described herein. In this embodiment, the biasing assembly is connected to the floating assembly at the forward and backward edges of the mowing deck, with regard to the mower's direction of travel in use. The biasing assembly is connected to the mounting arms to provide the reference point.

However, the foregoing should not be seen as limiting and alternatives are envisaged. These include the use of coil springs and/or rubber torsion springs positioned on either side of the axle and connected between the mowing deck and reference points. Throughout the present specification, reference to the term "cover assembly" should be understood as meaning a component which can extend over top of a mowing deck.

In a preferred embodiment, the cover provides a physical barrier to the mowing deck. This is beneficial as it restricts access to moving parts. In addition, the cover may further prevent cut matter or objects being thrown from the mowing deck in use.

Reference to the term "first cover section" and "second cover section" should be understood as meaning components forming part of the cover.

In a preferred embodiment, the first cover section and second cover section are slidingly coupled to each other. This allows the two sections to slide so as to reduce the overall length of the cover section. This is beneficial as it allows the cover to accommodate changes in length of the mowing deck as it is moved between in use and storage positions.

However, the foregoing should not be seen as limiting. For instance, it is envisaged that the first and second cover sections may be pivotally attached to each other. Alternatively, the first and second cover sections may be connected by a compressible gusset. In this embodiment as the mowing deck is moved between in use (engaged) and raised (storage) positions, the gusset compresses and expands to provide a change in length of the cover. In a preferred embodiment, the cover assembly may be releasably attached to the mowing deck. This allows the cover to be separated from the mowing deck to facilitate easy access to the working components and cutting assemblies of the mower and mowing decks.

In a particularly preferred embodiment, the cover assembly may be pivotally attached to the frame. This allows the cover section to easily pivot as the mowing deck is pivotally moved between the raised and lowered positions.

In addition, this allows the cover to be raised independently of the mowing deck thereby facilitating access to the components underneath the cover.

However, the foregoing should not be seen as limiting and alternatives are envisaged. These include that the cover is detachable so as to be able to be lifted away from the mowing deck or slides to allow access underneath.

In a preferred embodiment, the locking system may be a plurality of spring biased detents mounted on the frame.

The detents are connected to the central mowing deck. When the central mowing deck is lowered the detents are moved to a release position. This allows the lateral mowing decks to be raised and lowered as required.

However, when the central mowing deck is in the raised position, the biasing detents are urged into a locking position.

In the locking position, the detents are disposed in the path of the mounting arms. Therefore, the detents provide a physical block to the mounting arms lowering and these being moved to the in use position.

However, the foregoing should not be seen as limiting and alternatives are envisaged. These include a sensor and automatic actuator arrangement. In this embodiment, the sensor determines whether the central mowing deck is in the raised or lowered position. An appropriate signal is sent to the actuator to move the locking portion. Accordingly the locking portions prevent the mounting arms moving and thereby prevent the lateral mowing decks being lowered.

In a preferred embodiment the present invention may include a dampening mechanism. Throughout the present specification, reference to the term "dampening mechanism" should be understood as meaning an assembly configured to allow substantially vertically movement of a mowing deck in use.

In a preferred embodiment, the dampening assembly is configured to reduce or eliminate the actuator interfering with the vertical movement of the mowing deck. In a particularly preferred embodiment the dampening mechanism is configured to provide suspension for the mowing deck in use.

Preferably, the dampening mechanism may be a spring element. The Spring element is configured so as to apply an urging force to the actuator and thereby ensure that the actuator is retracted to a position in which it does not hinder movement of the mowing deck when the mowing deck is in use.

The dampening mechanism is beneficial as it helps to provide a contour following mowing deck. In use, the mowing deck is able to move substantially vertically about the pivot of the mounting arm. Therefore, the mowing deck can respond to variations in contour of undulating ground over which the mowing deck is used.

The spring element is also configured so as to provide resistance to vertical movement of the mowing deck. The spring pressure increases as it is loaded by the mowing deck moving downwards. This helps to provide a smooth action for the deck to follow contours. It may also help to limit bouncing of the mowing deck . Throughout the present specification, reference to the term "move concentrically" should be understood as meaning to move about a circle having a common centre.

In the preferred embodiment, the idler pulley is configured to move about a circle centred at the centre of the first pulley.

This is useful as it provides a compact and efficient way to adjust tension in the drive belt. In addition, the idler pulley and first pulley may be contained in close relationship to each other yet provide considerable variation in adjusting the tension of the drive belt.

In a particularly preferred embodiment, the idler pulley may be secured to an idler mounting plate. The mounting plate is configured to hold the idler pulley at the circumference of a circle concentric to the first pulley. However, the mounting plate may be rotated to move the idler pulley around the circumference of the circle.

However, the foregoing should not be seen as limiting and alternatives are envisaged. For instance, these include track arrangements on housings. In this embodiment the idler pulley can move along the length of the track. However, the track is defined so as to move the idler pulley around the circumference of a circle having its centre at the centre of the first pulley.

It should be appreciated from the foregoing discussion that the present invention may have a number of advantages and benefits over the prior art. These include that the inventions may be:

• Either independently or in combination, cost effective to manufacture;

• Light weight compared to drive arrangements and mounting arrangements disclosed in the art; · Easier to service and maintain thereby improving reliability of mowing apparatus; and

• An elegant way to provide a tractor powered mowing attachment having central and lateral mowing decks.

BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the present invention will become apparent from the following description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1 A is a front perspective view of a mowing attachment according to the present invention connected to a tractor; Figure 1 B is a rear perspective view of Figure 1A.

Figure 2 A is an exploded diagram of the mounting assembly according to the present invention;

Figure 2 B is an assembled view of Figure 2A; Figure 3 is a close up side cross sectional view of Figure 2B;

Figure 4 A is a close up view of a mounting assembly according to the present invention;

Figure 4 B is an alternative angle view of Figure 4A;

Figure 5 A is a rear perspective view of a mower having a first lateral mowing deck in an engaged position and a second lateral mowing deck in a disengaged position;

Figure 5 B is a front close up view of a mower having a first lateral mowing deck in an engaged position and a second lateral mowing deck in a disengaged position; Figure 5 C is a front view of Figure 5B;

Figure 6 A is a side view of a lateral mowing deck in the equilibrium position;

Figure 6 B is a side view of a lateral mowing deck rotating around an axle away from the equilibrium position;

Figure 7 shows a plan view of an idler pulley in a first position; Figure 8 shows a perspective view of an idler pulley in a second position to tension a drive belt;

Figure 9 is a rear perspective view of a mower having the mowing decks in the storage position;

Figure 10 is a rear perspective view of a mower (with the mowing decks hidden) in a configuration corresponding to having a lateral mowing deck in the storage position; Figure 11 is a view of a mower (with the mowing decks hidden) in a configuration corresponding to having the central mowing deck and a lateral mowing in the storage position;

Figure 12 is a close up front perspective view of Figure 10;

Figure 13 is a close up front perspective view of Figure 11 ; Figure 14 A is a rear top perspective exploded view of a cover assembly;

Figure 14 B is a bottom perspective view of Figure 14A;

Figure 15 A is a front perspective view of a mower having lateral mowing decks in an engaged position;

Figure 15 B is a front perspective view of a mower having a lateral mowing deck dropped down below the engaged position;

Figure 15 C is a front perspective view of a lateral mower having a lateral mowing deck partially raised;

Figure 15 D is a front perspective view of a mower having a lateral mowing deck partially raised; and Figure 15 E is a front perspective view of a mower having a lateral mowing deck in the disengaged position. BEST MODES FOR CARRYING OUT THE INVENTION

There is provided an improved mower (1 ) in the form of a rear mounted tractor powered mowing attachment. Throughout the following description like numerals refer to like components. General Description

The mower (1 ) has a frame (2) to which the components of the mower (1 ) are secured.

The frame (2) has wheels (3) that can support the weight of the mower (1 ) and facilitate its movement across the ground. A jockey wheel (3a) is attached to frame (2).

A draw bar (4) extends from frame (2) and provides a hitch (4a) to secure the mower (1 ) to the rear of a tractor (5). The hitch (4a) can be any coupling as should be known to those skilled in the art.

A drive axle (6) has a coupling to engage with a power take off (7) ("PTO") on the tractor. The PTO (7) rotates drive axle (6) about an axis defined by its longitudinal axis. The direction of rotation is indicated by arrow (8).

A central mowing deck (9) is secured to the frame (2). The central mowing deck (9) is substantially in line with the drive axle (6).

An actuator (10) is secured to frame (2) and central mowing deck (9). The actuator (10) is configured to pivotally raise and lower central mowing deck (9) with respect to frame (2).

The central mowing deck (9) is operatively coupled to the drive axle (6). Therefore, the drive axle (6) can drive rotation of cutting assemblies (1 1 ) secured to the central mowing deck (9). The mower (1) includes lateral mowing decks (12, 13). The lateral mowing decks (12, 13), their attachment to mower (1 ), and functionality/operation, are equivalent. Therefore only lateral mowing deck (12) will be discussed herein. It should be appreciated that the description of lateral mowing deck (12) also applies to lateral mowing deck (13).

Rollers (73) are provided at leading edge (74) of mowing deck (12). The rollers may assist in normal operation by improving efficiency of cutting assemblies (27).

Mowing deck (12) is secured to mounting arms (14) as is described below under the heading Mounting Assembly. The mounting arms (14) are secured to mounting axle (40). The mounting axle (40) is rotatably secured to the frame (2) at point (41 ). Point (41 ) is between the drive axle (6) and an edge of the frame (2) on which the lateral mowing deck (12) operates. This can be seen in Figure 5C.

The mounting axle (40) is at the same height as the drive axle (6). This may assist in providing a self clutching mechanism (as should become clearer from the following description).

A housing (42) is secured between mounting arms (14).

The mounting arms (14) support spaced apart mounting plates (15, 16) having a gap therebetween. An actuator (17) is provided in the form of a hydraulic cylinder (18) and spear (19). The hydraulic cylinder (17) is immovably secured to the frame (2).

A control system (not visible) is provided between actuator (17) and a control panel (not visible) in tractor (5). The control system allows an operator to control expansion and contraction of the actuator ( 7). Spear (19) extends into the gap between mounting plates (15, 16). Each mounting plate (15, 16) has a slot aperture (21 , 22).

A cross pin (23) extends through the slot apertures (21 , 22) and is secured to actuator spear (19). Expansion and contraction of the actuator (17) is transferred to mounting arms (14) by the cross pin (23). This allows the actuator (17) to pivot the mounting arms (14) about mounting axle (40) with respect to the frame (2). This moves mowing deck (12) between a raised (disengaged) position for storage and transport, and an in use position (engaged) in which it can cut grass or plant matter.

Driving Mowing Decks

Pulleys (24) are provided about drive axle (6) between the central mowing deck (9) and the PTO (7). The pulleys (24) are configured to rotate with the drive axle (6) and facilitate driving lateral mowing decks (12, 13). A drive pulley (25) is provided on mowing deck (12). Drive belt (36) is secured around drive pulley (25) and pulley (24). Drive pulley (25) is coupled to a right angled gear box (26) on mowing deck (12). Cutting assemblies (27) are formed by cutting blades (28) secured to spindles (29).

Pulleys (30A, 30B and 30C) are secured on spindles (29). One of spindles (29) is coupled to right angled gear box (26). Right angled gear box (26) transfers rotation of drive belt (36) so as to be able to drive fling tip style cutting assemblies (27) on mowing deck (12).

An idler pulley (31 ) is rotatably secured to a mounting plate (32).

The mounting plate (32) has an aperture (33) through which one of spindles (29) extends.

Fasteners (34) can extend through the gap between edge (35) of aperture (33) and spindle (29).

A secondary drive belt (72) is positioned around pulleys (30A, 30B and 30C,). To tension secondary drive belt (72) at least one of fasteners (34) is loosened. The mounting plate (32) is rotated to move idler pulley (31 ) through a circle centred at pulley (30A).

Fasteners (34) are tightened to secure the mounting plate (32) and therefore idler pulley (31 ) with respect to the mowing deck (12).

Mounting Assembly and Adjustment Mechanism

Mowing deck (12) is secured to mounting arms (14) by a mounting assembly which is generally indicated as (37). The mounting assembly (37) is best seen in Figures 2A, 2B, and 3.

The housing (42) provides a cavity (43) having an internal screw thread (44).

The housing (42) has an aperture (45) that extends from outside surface (46) completely through screw thread (44).

A locking portion (47) is disposed in the aperture (45). A spring (48) urges the locking portion (47) through the aperture (45) into a locking position.

An axle (49) is provided. An adjuster boss (50) is secured and fixed relative to the axle (49) by pin (51) which extends through apertures (52, 53) in the adjuster boss (50) and apertures (54, 55) in the axle (49).

The adjuster boss (50) has a screw thread (56) corresponding to the internal screw thread (44). The adjuster boss (50) provides engagement portion (57). The engagement portion (57) can be engaged by a spanner or other tool to rotate adjuster boss (50) and thereby the axle (49).

Rotation of the adjuster boss (50) causes the screw thread (56) to engage with internal screw thread (44). This facilitates moving the axle (49) along its length.

Channels (58, 59) on distal sides of adjuster (50) boss dissect the screw thread (56).

The channels (58, 59) and screw threads (44, 56) are configured such that rotating the adjuster boss (50) through 180 degrees aligns one of the channels (58, 59) with the aperture (45). This allows locking portion (49) to extend into channel (58 or 59) to thereby lock the adjuster boss (50) with respect to the housing (42). This also locks the axle (49) with respect to the housing (42).

The locking portion (47) helps to prevent unwanted rotation of the axle (49) which would cause lateral mowing deck (12) to move towards and away from the drive axle (6).

However, the locking portion (47) can be moved so as to overcome the force of the spring (48). This moves the locking portion (47) out of channel (58 or 59). Accordingly, the adjuster boss (50) can be rotated causing a corresponding movement in the axle (49) with respect to the housing (42). The mounting assembly and adjustable mechanism facilitates changing the distance between the mowing deck (12) and drive axle (6). This may be beneficial in adjusting tension in drive belt (36).

Floating Assembly

The lateral mowing deck (12) is mounted to the axle (40) using a floating assembly.

The floating assembly includes a beam (60) having an aperture (61 ) through which axle (49) can extend. The beam (60) is able to pivot about the axle (49).

Thrust washers (62, 63) are positioned at either side of the beam (60). The thrust washers (62, 63) transfer movement of the adjuster boss (50) caused by interaction of the screw threads (44, 56) to the beam (60). Accordingly, rotation of the adjuster boss (50) and movement of the axle (49) causes a corresponding movement in the beam (60). This changes the distance between the beam (60) and the drive axle (6). A bush (64) is positioned inside cavity (43) in housing (42) to support axle (49) and facilitate it moving with respect to the housing (42).

Bolt (66) extends through thrust washer (62) and into axle (49). This secures the thrust washer (62) to the axle (49).

Beam (60) provides a forward arm (67) and a backwards arm (68). The mowing deck (12) is secured to the forward and backward arms (67, 68). The designations forward and backwards are arbitrary and made only with reference to the mower's normal direction of travel in use.

Movement of the beam (60) caused by rotation of the adjuster boss (50) is transferred to the lateral mowing deck (12). In addition, rotation of the beam (60) about axle (49) causes the mowing deck (12) to also rotate. This may help to compensate for changes in slope of the ground underneath the mower (1 ).

This may also be useful as it changes the distance between mowing deck (12) and drive axle (6), and therefore also pulley (24) and drive pulley (25). This can slacken or tighten drive belt (36) to facilitate optimum operation of mower (1 ).

This may address issues due to drive belt (36) stretching or variations in the length of drivebelts from different manufacturers. It may also facilitate changing of drive belts (36) at servicing. Biasing Assembly

A biasing assembly is formed from a leaf spring (69). The leaf spring (69) is attached to mounting members (38, 39). This provides a reference point that does not move as the mowing deck (12) rotates about the axle (49).

The leaf spring (69) is inserted through slot aperture (70) in forward arm (67) and slot aperture (71 ) in backward arm (68).

The slot apertures (70, 71 ) are wider than leaf spring (69). This may help to ensure that the biasing assembly does not hinder moving lateral mowing deck (12) using the adjustment mechanism. In addition it may help to ensure that the biasing assembly can operate to urge the lateral mowing deck to rotate around the axle (49) towards an equilibrium position.

Cutting Operation

The operation of the mower (1 ) will now be described.

The mower (1 ) is connected to tractor (5) using hitch (4A) on drawbar (4). The drive axle (6) is connected to PTO (7). This is as should be known to those skilled in the art.

The mower (1 ) is positioned with respect to the ground over which it is to be used.

The central mowing deck (9) is lowered to the operative position. Actuators (16) are used to pivot mounting arms (14) and thereby lower lateral mowing deck (12). This tensions drive belt (36).

Control system is used to start drive axle (6) rotating in the direction of arrow (8). As drive belt (36) is sufficiently tensioned it transfers rotation of drive axle (6) to drive pulley (25). Right angled gear box transfers rotational motion of drive pulley (25) to pulley (30). This rotates secondary drive belt (69) and thereby spindles (29) to provide the cutting action for the mower (1 ).

The tractor (5) moves forward to mow the ground in the direction shown by arrow (A). Leading edge (74) of lateral mowing deck (12) may catch and dig into the ground. This causes the lateral mowing deck (12) to rotate around axle (49) in the direction shown by arrow (75) in Figure 6A. This is facilitated by floating assembly. Note that this causes back edge (76) of the lateral mowing deck (12) to rise off the ground. Leaf spring (69) is distorted and loaded. This applies an urging force against leading edge (74) and back ward edge (75). The force causes the lateral mowing deck (12) to rotate around axle (49) in the direction shown by arrow (77) in Figure 6B. This urges the lateral mowing deck (12) towards the equilibrium position shown in Figure 6A. When needed, actuators (16) are engaged to pivotally raise lateral mowing deck (12). When the mounting arms (14) pivot around mounting axle (40) through approximately 15° the drive belt (36) is sufficiently slackened that the spindles (29) stop rotating and the cutting assemblies (37) are disengaged. This acts as a self clutching mechanism. If needed the adjustment mechanism may be used to adjust tension in the drive belt (36). To do so, the locking portion (47) is moved to over come the force of spring (48). This moves the locking portion (47) out of channel (58, 59). A tool engages engagement portion (57) and rotates adjuster boss (50). This causes the adjuster boss (50) and axle (49) to move and thereby also move the beam (60) and lateral mowing deck (12).

The adjuster boss (50) is rotated through 180° so that one of the channels (58, 59) aligns with aperture (45). The locking portion (47) is released and spring (48) urges locking portion (47) into the channel (58 or 59). This secures the adjuster boss (50) and thereby axle (49) with respect to the housing (42). Covers

The mower (1 ) includes a cover assembly generally indicated as (78). The cover assembly (78) has a first sub-assembly (79) to cover lateral mowing deck (12), a second sub-assembly (80) to cover lateral mowing deck (13), and a third subassembly (93) to cover central mowing deck (9). The first and second sub assemblies (79, 80) are equivalent and therefore only one will be described herein.

The first sub-assembly (79) has a first cover section (84) and a second cover section (85).

A double hinge (81 ) is formed in first cover section (84) which secures first cover section (84) to cover mounting plates (82, 83). The cover mounting plates (82, 83) are secured to the frame (2). The double hinge (81 ) allows the first sub assembly (79) and second sub assembly (81 ) to pivot with respect to the frame (2) independently of the other. The first cover section (84) provides a first track (86) and a second track (87) on its forward (88) and backward (89) sides respectively. The first track (86) is a slot aperture in the first cover section (84).

The second track (87) is a rail secured or the inside of the first cover section (84). The second cover section (85) provides protrusions or rollers (90) that sit in tracks (86, 87). This slidingly couples the first cover section (84) and the second cover section (85) together.

Second cover section (85) can be releasably secured to lateral mowing deck (12).

When actuator (17) pivotally raises the lateral mowing deck (12) it also pivots the first sub assembly (79).

This causes outside edge (91 ) of lateral mowing deck (12) to move closer to the double hinge (81). The coupling of the first cover section (84) and second cover section (85) allows the second cover section (85) to slide inside first cover section (84). This is made possible by first cover section (84) providing an internal cavity sufficient to receive an appropriate portion of second cover section (85).

Accordingly, the length of the first and second cover sections (84, 85) between outside edge (91 ) and double hinge (81 ) is reduced. This compensates for the change in length of the lateral mowing deck (12) as this is pivotally moved from the lowered (in use) to the raised (storage) position. The sub assemblies (79, 80) are configured to be pivotally raised about double hinge (81 ) without raising the lateral mowing decks (12). This may be beneficial by allowing easy access under the cover assembly (78).

Gas struts (not visible) may be used to support the first and second cover sections (84, 85) in a raised position. Third sub assembly (93) extends over central mowing deck (9) and is configured to allow central mowing deck (9) to pivot with respect to frame (2).

The cover assembly (78) also includes a fourth cover section (94). The fourth cover section (94) is secured to frame (2) and does not move as lateral mowing deck (12) is raised and lowered. This provides a cover which extends over the mower's (1) components which are not located on mowing deck (12).

Referring now to Figures 11A to 11 E showing the cover assembly (26) allowing the lateral mowing deck (14) to move with respect to the frame (2).

Figure 11A shows that mounting arms (14) can pivot downwards to allow lateral mowing deck (12) to follow contours in the ground. The sliding coupling of the first cover section (84) and the second cover section (85) allows this to occur.

Figure 11 B shows the lateral mowing deck (12) pivotally raised in comparison to the position shown in Figure 11 A. Note that the first cover sub assembly (79) has decreased in length as second cover section (85) has slid with respect to first cover section (84).

Figure 11C shows the lateral mowing deck (12) pivotally raised in comparison to the position shown in Figure 11 B.

The second cover section (85) has slid inside and underneath first cover section (84). This compensates for the decrease in length between outside edge (91 ) and frame (2).

Figure 11 D shows the lateral mowing deck (12) pivotally raised higher than the position shown in Figure 11C.

Note that the second cover section (85) has separated from the lateral mowing deck (12) to create a gap indicated by line (95). This is due to double hinge (81 ) being higher than the mounting axle (40). Therefore the cover sub assembly moves to a different position to lateral mowing deck (12) as this is raised. However the sliding coupling of the first and second cover sections (84, 85) helps to accommodate this. Figure 11 E shows the lateral mowing deck (12) pivotally raised as far as possible through its range of motion. The second cover section (85) is retracted inside cover section (84) as far as made possible by the respective shape and configuration of the cover sections (84, 85).

Locking Mechanism The mower (1 ) includes a locking system configured to secure the lateral mowing deck (12) in a raised position only when the central mowing deck (9) is in a raised position.

Locking detents (96, 97) are moveably secured in housings (98, 99) that are secured to cover mounting plate (82). The locking detents (96, 97) can move through and protrude out of openings (100, 101 ) in the housings (98, 99).

Springs (102, 103) are connected to central mowing deck (9) and locking detents (96, 97). The actuator (10) pivots the central mowing deck (9) between a raised position (storage) and in use position (lowered).

When in the raised position the springs (102, 103) urge locking detents (96, 97) forward and through openings (100). The locking detents (96, 97) sit in the path of mounting arms (14). If the mounting arms (14) are pivoted upwards around axle (40), then the locking detents (96, 97) prevent the mounting arms (14) pivoting downwards to lower lateral mowing deck (12).

However, when the central mowing deck (9) is lowered the springs (102, 103) are pulled tight. This pulls the locking detents (96, 97) into housings (98, 99) and out of the path of mounting arms (14). Accordingly, the locking detents (96, 97) do not prevent pivoting of the mounting arms (14). The mounting arms (14) can therefore lower the lateral mowing deck (12) to the in use position.

Dampening Mechanism A dampening mechanism is provided by a leaf spring (104) secured to mounting arms (14). Leaf spring (104) is curved and sits proximate to cross pin (23).

Spacers (106,107) are positioned around cross pin (23).

To raise lateral mowing deck (12) the actuator (17) is engaged and caused to extend. This causes spear (12) to move cross pin (23) along slots (21 , 22) to contact edge (108). This stops the cross pin (23) moving with respect to the mounting plates (15, 16). Accordingly, the continued extension of the actuator (17) causes the mounting arms (14) to pivot about mounting axle (40). The extension of actuator (17) continues until lateral mowing deck (12) is fully raised. To lower the lateral mowing deck (12) a signal is sent to actuator (17) to contract. Spear (19) slides within cylinder (18). This moves cross pin (23) along slot apertures (21 , 22) to reduce the force against mounting arms (14). This allows mounting arms (14) to pivot downwards around mounting axle (40) and thereby lower the lateral mowing deck (12) to the ground. The leaf spring (104) applies an urging force to spacers (106, 107). This causes the actuator cylinder (17) to contract further.

The leaf spring (104) forces the actuator (17) to contract such that the cross pin (23) is in approximately the middle of the slot aperture (21 , 22).

The actuator (17) is configured to provide resistance to contraction of the actuator (17) past approximately point (109) caused by action of spring (104) on spacers (106, 107).

The leaf spring (104) helps to ensure that the actuator (17) does not affect the mounting arms (14) pivoting around mounting axle (40). This means that when the mowing deck (12) is lowered and being used it may be better able to follow the contours of the ground.

In addition, the actuator's resistance to continued contraction provides a surface against which the leaf spring (104) can press. Therefore, the leaf spring (104) provides a compressible resistance to the mowing deck (12) dropping in use. In effect, the leaf spring (104) is providing suspension for the lateral mowing deck (12) in use.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

WHAT WE CLAIM IS:

1. A work implement, including

2. a frame, a drive axle, a central work portion coupled to the drive axle, at least one additional work portion pivotally mounted to the frame, at least one actuator configured to pivot the at least one additional work portion with respect to the frame, characterised in that each of the at least one work portions is operatively coupled to the drive axle by a drive belt such that pivoting of the at least one additional work portion by the actuator causes the drive belt to slacken sufficiently to disengage the at least one work portion.

3. The work implement as claimed in claim 1 , wherein the work portions are mowing decks.

4. The work implement is claimed in claim 2, wherein the mowing decks include a plurality of cutting assemblies.

5. The work implement as claimed in claim 2, wherein the cutting assemblies are rotatably mounted cutting blades.

6. The work implements as claimed in any one of claims 1 to 4, including a power take off configured to engage with a power take off on a work vehicle.

7. The work implement as claimed in any one of claims 2 to 5, wherein the drive belt directly couples the drive axle to the mowing deck.

8. The work implement as claimed in any one of claims 2 to 6, wherein the at least one additional mowing deck is secured to a mounting arm pivotally secured to the frame.

9. The work implement as claimed in claim 7, wherein pivoting the mounting arm decreases the distance between the mowing deck and the drive axle.

10. The work implement as claimed in any one of claims 1 to 8, wherein the actuator is configured to pivotally move the mowing deck between an in use position and a storage position.

11. The work implement as claimed in any one of claims 7 to 9, wherein pivoting the mounting arm through an angle of between 10-30 degrees sufficiently slackens the drive belt to disengage the cutting assemblies.

12. The work implement as claimed in claim 0, wherein moving the mounting arm through an angle of substantially 15 degrees sufficiently slackens the drive belt so as to disengage the cutting assemblies.

13. The work implement as claimed in any one of claims 2 to 11 , including an adjustment mechanism configured to change the distance between the mowing deck and the drive axle.

14. The work implement as claimed in claim 12, wherein the adjustment

mechanism includes: a first component having an aperture through the first screw thread, a second component having a second screw thread complimentary to and engaged with the first screw thread, the second component having a channel that dissects the second screw thread, wherein the first component and the second component can rotate with respect to each other to cause a change in length and thereby the distance between the mowing deck and the drive axle, and wherein the adjustment mechanism includes a locking portion that extends through the aperture and can releasably engage the channel to prevent the first component and second component from rotating with respect to each other.

15. The work implement as claimed in claim 8, wherein the at least one

additional mowing deck is secured to the mounting arm using a floating assembly configured to retain the mowing deck in an operative position regardless of the orientation / position of the adjustment mechanism.

16. The work implement as claimed in any one of claims 2 to 14, including a biasing arrangement configured to urge the mowing deck towards an equilibrium position.

17. The work implement as claimed in claim 15, wherein the biasing assembly is a leaf spring connected to a reference point and the mowing deck.

18. The work implement as claimed in any one of claims 2 to 16, including a cover assembly is configured to accommodate changes in length between an outside edge of the mowing deck and the frame.

19. The work implement as claimed in claim 17, wherein the cover assembly includes a first cover section and a second cover section slidingly coupled to each other.

20. The work implement as claimed in either one of claims 17 or 18, wherein the cover assembly is releasably attached to the mowing deck.

21. The work implement as claimed in any one of claims 17 to 19, wherein the cover assembly is pivotally attached to the frame.

22. The work implement as claimed in any one of claims 2 to 20, including a locking system that secures the at least one additional mowing deck in a storage position when the central mowing deck is in the storage position.

23. The work implement as claimed in any one of claims 2 to 21 , including a tensioning mechanism that includes a first pulley, a second pulley, an endless drive belt around the first and second pulleys that is configured to transfer rotation of one of the pulleys to the other, an idler pulley, wherein the idler pulley is configured to be moved concentrically to the first pulley to thereby facilitate adjusting tension in the endless drive belt.

24. The work implement as claimed in claim 22, wherein the idler pulley is

secured to an idler mounting plate configured to hold the idler pulley at the circumference of a circle having its centre at the first pulley.

25. The work implement as claimed in claim 23, wherein the mounting plate is configured to be rotated to move the idler pulley around the circumference of the circle.

26. The work implement as claimed in anyone of claims 2 to 24, including a dampening mechanism configured to allow substantially vertical movement of the mowing deck when it is in use.

27. The work implement as claimed in claim 25, wherein the dampening

mechanism is configured to reduce or eliminate the actuator interfering with vertical movement of the mowing deck.

28. The work implement as claimed in either one of claims 25 or 26, wherein the dampening mechanism is a spring configured to bias the actuator towards a retracted position to thereby ensure that the actuator does not hinder vertical movement of the mowing deck when the work implement is in use.

29. A work implement as substantially described herein by reference to the best modes section of the attached specification and accompanying drawings.