AU5886599A - Ground cultivation apparatus - Google Patents

Description

WO 00/13477 PCT/NZ99/00153 GROUND CULTIVATION APPARATUS FIELD OF THE INVENTION The present invention is directed to apparatus for the aeration of turf and pasture. It is envisaged that the primary uses of the present invention are for the maintenance of 5 sports fields, golf greens, and parks. BACKGROUND ART The present invention is directed towards the maintenance of turf. While it is envisaged that there may be other applications of the present invention, the main use of the present invention will be the aeration of turf (i.e. grassed) areas. These may 10 include sports fields, golf greens, golf fairways, parks, and other recreational areas. The health of the turf depends upon a number of factors though it is recognised that aeration of the soil is desirable in the establishment and maintenance of a healthy turf of good quality. Soil aeration is desirable for a number of reasons, including the improving of drainage and as part of natural nutrient processes. A number of micro 15 organisms associated with soil vitality either require, or are enhanced by, adequate soil aeration. A number of natural organisms, such as earthworms, provide this function though this does not represent a reliable nor predictable method of aeration in all circumstances. Worm casts can also be undesirable in some situations, with turf keepers preferring a mechanical alternative so that they can control the extent and 20 timing of aeration. Ground compaction is another reason for aeration. This not only impedes the ability of soil micro-organisms to work effectively, but can also adversely affect plant root growth, and drainage. Compaction is prevalent where there is vehicle traffic, foot traffic, or where machine based mowing apparatus (e.g. tractors and ride-on mowers) 25 are used. However, these also tend to represent areas where a healthy turf is most desirable. The art has addressed these problems through the use of mechanical aerators. A simple manual method is to insert the tines of a fork into the ground, and move it backwards and forwards slightly before withdrawal. However, a problem associated with the use 30 of tines in such a manner is that they can actually glaze and compress the soil upon entry. This is also a problem associated with known coring type aeration techniques. The consequence may be aeration holes formed into the soil, but their effectiveness are reduced due to the soil compression which acts as a temporary barrier to the passage of water and air. 1 WO 00/13477 PCT/NZ99/00153 The applicant has developed a bladed roller marketed as a GROUNDHOGTM, the subject of US patent specification No. 4,383,580 which is drawn behind a tractor. The blades are oriented in such a manner that they shatter the ground, creating a hole which is substantially V shaped in cross-section, with ground fracture lines extending outwardly 5 from the sides. However, while this is useful in promoting aeration, there are a number of disadvantages associated with its use. For instance, the shattering action of the GROUNDHOGTM device has a tendency to mound the ground slightly along the edges of each crevasse that it forms. In addition, it also throws a small but significant amount of soil onto the surface after a pass. 10 While this is useful for ground aeration, it produces an unpresentable surface which is unacceptable to many turf owners. While this problem is only temporary, and is usually remedied after the first mowing, it may still be a week after ground has been aerated by prior art machines before it is once again presentable or ready for use. While it is noted that the presentation of the surface can be improved after the first 15 mowing (which tends to break up and finely distribute any surface material), compaction of the ground by mowing apparatus tends to negate any aeration which has been performed. Accordingly, if mechanical aeration is to have any effect, it is desirable that at least a week passes before the aerated ground is subjected to any significant traffic, such as vehicular traffic or mowing apparatus. 20 As a consequence, there is a need for apparatus which is able to be used in a manner in which it can effectively mechanically aerate soil, yet which leave a presentable surface substantially immediately after aeration. It is also desirable that this can be achieved without negating the effects of the aeration. Accordingly, it is one object of the present invention to address these needs and provide apparatus useful for achieving same. 25 Another objective of the present invention is to provide the public with a useful alternative to the prior art. DISCLOSURE OF INVENTION According to one aspect of the present invention there is provided an aeration assembly for ground aeration, said assembly including: 30 - a body portion including first coupling means for attachment to a tractor in a manner allowing the aeration assembly to be raised and lowered above the ground; the body also including second coupling means for the attachment of a trailing mowing assembly to be drawn behind the aeration assembly; 2 WO 00/13477 PCT/NZ99/00153 and wherein the first and second coupling means are characterised so as to_ allow, for an arrangement comprising both the aeration assembly and trailing mowing assembly coupled to a tractor, raising of the aeration assembly above the ground initially results only in the raising of the aeration assembly with the 5 mowing assembly remaining in ground contact; - said aeration assembly also including an aerating assemblage consisting of a plurality of ground penetrating members for piercing the ground. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the ground penetrating members 10 include any one or more of: spikes, tines, and blades. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which said ground penetrating members include one or more substantially planar blades with an angled end portion, when viewed perpendicular to the plane, said angle being such so that in use substantially the 15 entire flat of the angled portion encounters the ground at the moment of ground contact. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the aerating assemblage resembles a central drum portion with ground penetrating means extending substantially radially, tangentially, or in a manner therebetween, from the drum. 20 According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the aerating assemblage consists of one or more ground penetrating units, each unit including a cylindrical body portion with ground penetrating members extending outwardly. According to another aspect of the present invention there is provided an aeration 25 assembly, substantially as described above, in which the ground penetrating members of a ground penetrating unit are replaceable. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the ground penetrating units are distributed along a substantially latitudinally oriented, with respect to the direction of 30 travel of the aeration assembly in use, shaft. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the position of one or more ground penetrating units along the shaft are adjustable. 3 WO 00/13477 PCT/NZ99/00153 According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which cylindrical sleeves are present between ground penetrating units on the shaft. According to another aspect of the present invention there is provided an aeration 5 assembly, substantially as described above, in which the first coupling means comprises a three point linkage to the tractor. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the second coupling means comprises mounting points for a three point linkage to the trailing mowing assembly, 10 the mowing assembly including a three point linkage arrangement of a type allowing it to also be coupled to the three point linkage of the tractor when not used in conjunction with the aeration assembly. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which the second coupling means 15 includes two lower couplings, said lower couplings comprising arms pivotable within a substantially vertical plane, further characterised in allowing a trailing mowing assembly attached at these points to travel up and down with respect to the height of the aeration assembly. According to another aspect of the present invention there is provided an aeration 20 assembly, substantially as described above, in which the lower couplings include stop means limiting the extent of pivoting of said arms. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, in which a lower coupling includes adjustable stop means. 25 According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, which includes transmission means for harnessing drive or power-take-off means from the tractor and transferring it to effect driven rotation of the aerating assemblage. According to another aspect of the present invention there is provided an aeration 30 assembly, substantially as described above, in which the transmission means also allows an attached mowing assembly to be driven. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, including a gearbox arrangement to allow 4 WO 00/13477 PCT/NZ99/00153 the ratio of driven speed between the aeration assembly and mowing assembly to be varied. According to another aspect of the present invention there is provided an aeration assembly, substantially as described above, which includes a hydraulic motor, 5 connectable to a hydraulic pump outlet on said tractor. According to a further aspect of the present invention there is provided an aeration assembly for the aeration of ground, said aeration assembly including a body portion in the form a frame supporting an aerating assemblage; said aerating assemblage comprising a plurality of ground penetrating units distributed 10 along a supporting shaft, and wherein optionally at least some of said ground penetrating units are adjustable in position along the length of said shaft; each ground penetrating unit including a cylindrical central sleeve portion which rides along the ground during use of the aeration assembly, and including also at least three outwardly extending blade portions; 15 the supporting shaft of the aerating assemblage oriented substantially transversely with respect to the direction of travel of the aerating assembly during use; said body portion including first coupling means including two fixed lower coupling points on the front of the frame, and a third upper coupling point; there also being present second coupling means, including two lower coupling points 20 at the rear of the frame and which include pivoting links or arms which are pivotable within a substantially vertical plane, and in which the extent of travel is limited, and wherein the second coupling means also includes a third upper rearwardly facing coupling point which need not be pivotable; said aeration assembly also include means for driving the aerating assemblage from 25 power provided from the tractor, and for also allowing the concurrent transfer of power to a trailing mowing unit coupled to the second coupling means. According to a further aspect of the present invention there is provided the combination of an aerating assembly, substantially as described above, with a tractor, and trailing mowing assembly, and wherein the units are coupled such that in use the aerating 30 assembly can be raised above the ground while the mowing assembly remains in contact. According to another aspect of the present invention there is provided the combination, substantially as described above, in which the mowing assembly is a rotary, flail, drum reel or blade type mower. 5 WO 00/13477 PCT/NZ99/00153 According to another aspect of the present invention there is provided a method for the aeration of turf comprising the use of an aeration assembly, substantially as described above. According to another aspect of the present invention there is provided a method for the 5 aeration of turf comprising the use of the combination substantially as described above, in which the aeration assembly creates aerating cavities in the ground, followed immediately thereafter by mowing which also serves to scatter any loose material deposited on the surface as a consequence of aeration. According to another aspect of the present invention there is provided an aeration 10 assembly, substantially as described herein with reference to the accompanying drawings. The present invention has a number of different aspects though common to these varying aspects is ground cultivation apparatus in the form of an aeration assembly. This aeration assembly is characterised in not only being attachable to a tractor, but also 15 allowing for a trailing assembly to be connected in turn to the aeration assembly. Typically the trailing assembly will comprise a mowing assembly. Another characterising feature is the coupling arrangement. A coupling arrangement provided between the tractor, the aeration assembly, and a trailing assembly should be such to allow the aeration assembly to be raised above the ground by at least a limited 20 amount, before the trailing assembly will also follow and be raised. There are a number of mechanisms which can allow for this, some of which will now be described by way of example and for the purpose of illustration only. A typical aeration assembly according to the present invention will comprise a body portion. This may be an open (e.g. frame) or closed type assembly, or variations 25 thereof. The adopted body structure is not important though should be able to provide adequate support for the various components, and not interfere with the operation of the device. Among the various components that the body will support will be the coupling means which for simplicity shall be referred to as a first coupling means - for attachment of 30 the aeration assembly to a tractor - and a second coupling means - to allow the coupling of a trailing assembly such as a mower. The first coupling means may merely comprise suitable connection points to allow the aeration assembly to be attached to the tractor. An almost universal connection arrangement for tractors are 3-point linkages comprising a triangular arrangement of 6 WO 00/13477 PCT/NZ99/00153 two lower couplings, and a single upper coupling. These couplings generally represent fixed points on the connected assembly, and in preferred embodiments of an aeration assembly the three coupling points of the first coupling means are fixed as per normal practice. If desirable, adjustment means may be provided for some forward or 5 rearward adjustment of the top coupling means (so as to alter the inclination of the aeration assembly) though typically these types of adjustment can be made by controlling the 3-point linkage at the tractor. The second coupling means will be accessible from the rear of the aeration assembly, and will allow attachment of a trailing assembly such as a mower. In some respects 10 these will mimic the connection points provided on the tractor, as typically the trailing assembly will represent a standard assembly connectable to the 3-point linkage of the tractor. However, unlike the hydraulically powered linkage arms provided on the tractor, the second coupling means will not be powered so as to allow independent raising of the trailing assembly with respect to the aeration assembly. Instead, in 15 preferred embodiments, the second coupling means merely serves to transfer any up and down movement of the tractor 3-point linkage to the trailing assembly, but in a particular manner ( such as described above). This preferred manner is to allow the 3 point linkage of the tractor to initially raise the aeration assembly above the ground, but without immediately effecting any raising of the trailing assembly. It is only when the 20 aeration assembly has reached a particular height that the trailing assembly will then be raised as well. The net effect is a sequential staggered raising of first the aeration assembly followed by the trailing assembly, and is best illustrated in Figure 3. The second coupling means can achieve this by providing as part of the two lower coupling points, a pivotable arm or link arrangement. The pivoting is limited to within 25 a particular arc within a substantially vertical plane. When this arm is at the lowermost portion of the arc then the aeration assembly is raised with respect to the trailing assembly. If the aeration assembly is raised further in height, then the outermost end of the pivoting arm will also rise in height as it is unable to pivot any further downwardly. Accordingly, any trailing assembly will also be raised which is 30 connected at this point. However, if instead of raising the aeration assembly (when the arm is at the bottom of its permitted arc), then the result is that the aeration assembly will decrease in height until it rests upon the ground. As the trailing assembly is already resting on the ground, the pivotable coupling arm will pivot upwardly within its permitted arc. This 35 will be more clearly seen with respect to the drawings provided later herein. 7 WO 00/13477 PCT/NZ99/00153 Means may be provided to alter the lowest permitted downward inclination of the pivotable arm at its lowermost point. This will in turn affect the maximum height to which the aeration assembly can be raised above the ground before the trailing assembly follows. This adjustment may be provided by an adjustable, or re 5 positionable, stop member though many other known mechanical arrangements can be employed. The upper coupling point (of the second coupling means) may represent a fixed point to which the top mounting point on the trailing assembly can be coupled. A pivotable (within a substantially vertical plane) arm may be used to link the two. 10 The aeration assembly will also include means for aeration of the ground. Typically this will comprise an aerating assemblage which in turn is made up of a plurality of ground penetrating members which can pierce into the ground. Various embodiments may rely on differing types of ground penetrating members, including various arrangements of spikes, tines, studs, and blades, or varying combinations thereof. 15 Preferably these will extend outwardly from a drum arrangement so that ground penetrating members are continually entering and leaving the ground as the aeration assembly travels along the ground. The aeration assemblage may also be driven (this will be discussed in more detail later herein) though may also rely upon the travel of the aeration assembly along the ground to effect rotation of any aeration assemblage (based 20 on a drum with outwardly extending ground penetrating members type arrangement). In preferred embodiments the aerating assemblage will comprise a series of outwardly extending blade arrangements distributed along the length of a rotating axis. This can be accomplished in a number of manners. For instance, there may be provided a substantially transverse shaft upon which there are distributed a plurality of ground 25 penetrating units. Each unit will typically comprise a plurality of outwardly directed ground penetrating members coupled to a central body portion. This central body portion may represent a cylindrical sleeve through which the central shaft passes. The ground penetrating unit may be keyed to the shaft so that it cannot rotate with respect to the central shaft. This allows the central shaft to be driven (i.e. rotated) and for each 30 ground penetrating unit to follow. It is also possible that not all ground penetrating members are keyed to the shaft so that some such units are able to free wheel and will achieve rotational motion purely as a consequence of travel of the aeration assembly along the ground. However it is perhaps best if each set of blades or ground penetrating unit, even in non-driven embodiments, are not capable of rotation 35 independent of all others so as to address situations of a blade sliding across the ground instead of penetrating into it - perhaps as a consequence of the build up of a 8 WO 00/13477 PCT/NZ99/00153 clump of grass or other foreign matter under a ground penetrating member. Forcing blades (etc.) into the ground can help clear them of foreign matter they may encounter, and assist in preventing skidding across hard ground. It is also possible in some embodiments that the position of each ground penetrating 5 unit along the shaft can be altered, or at least the position of some altered. This may be achieved by inserting sleeve-like spacers between each unit, or by being able to slide and fix units at appropriate positions along the shaft. In practice, a preferred arrangement is for the ground penetrating units to be substantially evenly spaced, and the total width matched to the width of a trailing mower assembly. If mowing 10 assemblies of different widths are substituted, then the total width between the outermost ground penetrating units can be adjusted to be commensurate to the width of the mowing assembly. This also allows such an aeration assembly to be set up for use in conjunction with mowing assemblies by different manufacturers, or different models within a manufacturer's range. 15 Other arrangements are also possible. For instance, there may be no central shaft, with an aerating assemblage instead consisting of a plurality of ground penetrating units coupled end to end with each other. Another possibility is to have a substantially single piece aerating assemblage, rather than being made up of a number of smaller units. However, it is envisaged that this arrangement will be more difficult to 20 manufacture. However, as will be appreciated, the examples given above represent just some possible arrangements envisaged by the inventor, and that other arrangements are also possible. Modifications to the various arrangements may also be made. For instance, while a ground penetrating unit, or aerating assemblage, may include fixed blades, it is also 25 possible that individual blades or blade groups may be replaceable. This would allow blades which have become damaged or worn to be quickly replaced. One particular embodiment is shown later herein, in the drawings. This would also allow substitution of different blade designs for varying ground characteristics. The aeration assembly may also include more than one aerating assemblage. The 30 various assemblages may be placed side by side, and/or one behind the other. They may also be angled slightly from being perfectly transverse with respect to the direction of travel, so as to open up a slightly wider crevasse in the ground (depending on the type of ground penetrating member). This angle may also be adjustable. This can be achieved by allowing for the adjustment or substitution (with differently profiled or 35 angled ground penetrating members) or individual ground penetrating members or units. This can also be achieved by varying the angle of the entire aerating assemblage 9 WO 00/13477 PCT/NZ99/00153 to the transverse. For instance a perfectly transverse assemblage may create slots of constant width matching the width of a ground penetrating blade. Varying the angle of the entire assemblage will cause the blades to enter the ground partially side on so a wider crevasse is formed. Accordingly, means for adjusting the angle of the aerating 5 assemblage (within a horizontal plane) may be provided. Another option is to alter the angle of the entire aeration assembly. Adjusting the length of one of the links from the tractor to one lower coupling (based on a 3-point linkage) of the aeration assembly can achieve this. Providing different connection points on the coupling is an alternative to adjusting the length of the link. 10 As mentioned previously, different configurations may be adopted for the ground penetrating member. Preferred embodiments of the present invention comprise blades, which are substantially planar. As will be seen in the drawings later, in preferred embodiments of the blade has an angled tip portion, and is mounted in a ground penetrating unit such that in use, substantially the entire flat of the angled portion 15 encounters the ground at the moment of ground contact. The use of substantially cylindrical drum like body portions, from which the ground penetrating members extend, have been mentioned. In preferred embodiments it is desirable that these drum like portions travel along the ground either side of the ground penetrating member. To a certain extent these help prevent the ground either side of the 20 formed crevasse from mounding up into furrows as the aeration assembly progresses. The trailing assembly will typically comprise a mowing assembly. This may comprise any conventional type of mowing assembly, though mowers which can break up and/or distribute the surface debris resulting from the aeration process is preferred. Most available tractor drawn mowing apparatus is suitable in this regard (though some 25 trial and experimentation may be required to determine which commercial model may be best suited - for embodiments in which the mowing assembly represents a separable component). As most mowing units also attach to the rear 3-point linkage of a tractor, the preferred coupling arrangement (second coupling means) of the aeration assembly will allow 30 connection to the 3-point coupling of the trailing assembly. It has been previously indicated that the aerating assemblage can be driven, or allowed to freely rotate as a consequence of advance over the ground. Driven embodiments will typically include transmission means (as will be discussed later) harnessing the PTO that may be provided on a tractor. However, use may be made of individual 10 WO 00/13477 PCT/NZ99/00153 motors on either or both of the aeration and mowing assemblies. As many tractors allow for coupling to a hydraulic pump for driving hydraulically powered accessories, these individual motors may comprise hydraulic motors coupled to the tractor. Other possibilities such as electric motors, and motors with their own independent fuel or 5 power source, are also envisaged. The arrangement will be more clearly seen from the description relating to the drawings which follows. BRIEF DESCRIPTION OF DRAWINGS Figure 1 illustrates one preferred embodiment of the present invention in side 10 view, focussing on an aerating assembly and showing a trailing mowing assembly in partial view; Figure 2 illustrates, from the front, a slightly different variation of the embodiment of Figure 1, and omitting the trailing mowing assembly; Figure 3a-c schematically illustrate the preferred raising and lowering arrangement 15 allowed for by the couplings of the embodiment of Figures 1 and 2, and Figure 4 is a closer diagrammatic view of a preferred embodiment of the pivoting lower linkage of the second coupling means in the embodiment of Figure 1. BEST MODES FOR CARRYING OUT THE INVENTION 20 With reference to the drawings and by way of example only there is provided an aeration assembly (generally indicated by arrow 1) for ground (2) aeration, said assembly (1) including: - a body portion (generally indicated by arrow 3) including first coupling means (4, 11) for attachment to a tractor in a manner allowing the aeration assembly 25 (1) to be raised and lowered above the ground; the body also including second coupling means (5, 6) for the attachment of a trailing mowing assembly (generally indicated by arrow 7) to be drawn behind the aeration assembly (1); and wherein the first (4, 11) and second (5, 6) coupling means are characterised 30 so as to allow (for an arrangement comprising both the aeration assembly and trailing assembly (as per Figure 1) coupled to a tractor) that raising of the aeration assembly above the ground initially results only in the raising of the 11 WO 00/13477 PCT/NZ99/00153 aeration assembly with the mowing assembly remaining in ground contact (see also Figures 3a-c); - said aeration assembly also including an aerating assemblage (8) consisting of a plurality of ground penetrating members (9) for piercing the ground (2). 5 Figure 1 shows from the side an aeration assembly (1) coupled to a trailing mowing assembly (7) which has been partially cut away. For clarity the tractor has been excluded, though would be positioned, if shown, at the left of the drawing. The preferred direction of travel is from right to left in the figure. The aeration assembly comprises a body portion (3) which comprises a supporting 10 frame structure. Adjustable legs (10) can be used to support the device when not in use and for also holding the aerating assemblage (8) above the ground for adjustment or blade replacement. While the body could be constructed so that the aerating assemblage is shrouded or enclosed, Figures 1 and 2 illustrate embodiments where an open frame structure has been adopted. 15 The first coupling means (4, 11) represent the standard mounting points for connection to a tractor's 3-point linkage. This comprises a single upper coupling (4, 11) and two lower couplings (11). The triangular placement of these couplings can be more clearly seen in Figure 2. At least one of the couplings (11) also includes a number of possible attachment points (36) for the attachment of a linkage from the tractor. Selecting one of 20 these connections points (36) allows the angle of the assembly (1) to be altered (within a horizontal plane) from being purely transverse so the width of formed crevasses in the ground can be altered. The second coupling means comprises a single rearwardly facing upper coupling (5) and two lower couplings (6). These are also distributed in the same triangular 25 arrangement as the first coupling means (4, 11). In Figure 2 the bottom portion of the lower coupling means (6) are just visible while the upper coupling (5) is obscured by coupling (4). The upper coupling (5) of the second coupling means emulates to some degree the upper 3-point linkage connection provided on the tractor. The pivoting arm (12) will 30 typically be used to connect coupling (5) to a suitable coupling (14) provided on a trailing mowing assembly. If the mowing assembly (7) was to be coupled directly to the tractor, then coupling (14) would connect to the upper 3-point linkage of the tractor. The lower couplings (6) of the second coupling means include a pivoting arm portion 35 (15) which can pivot in a substantially vertical plane about pivot point (16) and from 12 WO 00/13477 PCT/NZ99/00153 which it extends rearwardly. A lower stop (17) limits the amount of downward travel of the arm (15). Additional apertures (18) may be provided to allow the position of the stop (17) to be adjusted, so that the furthermost downward position of the arm (15) can be adjusted. Other methods of providing this adjustment may be employed. 5 Towards the rear of the arm (15), provision (19) is made for connection to the couplings (20) of the trailing assembly (7). These couplings (20) represent the lower couplings of the trailing assembly (7) which would be connected (if connected directly to a tractor) to the lower mounting points of a tractor's 3-point linkage. The aerating assemblage (8) can be more clearly seen in the view of Figure 2. Here a 10 number of individual ground penetrating units (22) can be seen positioned on a shaft (23) to which they are keyed. Provision may be made (e.g. a tightening bolt (24) which bears against the bottom face of a keyed slot (25)) to allow the position of each ground penetrating unit (22) along the shaft (23) to be altered. In the arrangement of Figures 1 and 2, ground penetrating units (22) with replaceable 15 blades (9) have been provided. Assembly bolts (27) help secure each blade (9) to this cylindrical body portion (28) which fits about shaft (23). Removing the assembly bolts (27) allows individual blades (9) to be removed and replaced as desired. Further, in the embodiments of Figures 1 and 2, each set of blades (a) is advanced (in rotation) from ground penetrating unit (22) to the next, as one travels along the shaft 20 (23) or assemblage (8). For preferred non-driven embodiments, or driven embodiments operating in a non-driven mode, this arrangement facilitates rotation of the aerating assemblage (8) as the aerating assemblage as the aerating assembly (1) travels with respect to the ground (2). The aerating assemblage (8) may be driven (provision for this is shown in Figure 1) or 25 non-driven, as shown in the embodiment of Figure 2. For an aerating effect it is preferred that the aerating assemblage is not driven. Driving the blades can result in a cultivating rather than aerating effect, which can be too aggressive or pronounced for many applications. However, as drive will need to be transmitted to the trailing mower assembly (7), interrupting this drive to allow the option of driving the blades can 30 increase the flexibility and uses of the aerating assembly (1). Preferably such embodiments of the aeration assembly will include the option of engaging or disengaging drive to the aerating assemblage. One particular arrangement is discussed as follows. Referring to Figure 1, there is provided transmission means which includes a first take 35 off shaft (30) connected to the power-take-off (PTO) of a tractor. As per normal 13 WO 00/13477 PCT/NZ99/00153 practice, universal joints will be employed. This first drive shaft (30) is coupled to a drive splitter (31) which allows drive to be transmitted through second drive shaft (32) to the trailing assembly (7), while also transmitting drive to the aerating assemblage. The drive splitting arrangement (31) may also include gears to allow the ratio of 5 rotational output speed between the trailing assembly (7) and the aerating assemblage (8) to be varied - i.e. there may be included a gear arrangement allowing different gear ratios to be selected. Provision may also be provided for disengaging one or both of the drive outputs. In practice, it is envisaged that an aerating assembly (1) will be coupled directed to a 10 tractor (40), as shown schematically in Figures 3. Coupled to the aeration assembly (1) will be a trailing mowing assembly (7). In use, the arrangement will adopt the configuration schematically shown in Figure 3a, where both the aeration assembly (1) and trailing mowing assembly (3) are substantially in contact with the ground and will provide both ground penetration for aeration, followed by a mowing action to scatter 15 and clear the surface of any debris resulting from the aeration process. However, while the arrangement illustrated schematically in Figure 3a may be adopted for straight line travel, the blade arrangement (9) of the aerating assemblage does not permit any turns to be made by the tractor. Accordingly, when the tractor (40) wishes to change direction, it is necessary to raise the linkage so that the aeration assembly (1) 20 is raised above the ground as shown in Figure 3b. This link (15) coupling the aeration (1) and mowing (7) assemblies may adopt the configuration of (35b) in Figure 4, or a position intermediate positions (35b) and (35c). However, the second coupling means of the aeration assembly (1), allows the trailing mowing assembly (7) to remain in contact with the ground. This in turn allows the mowing action to continue so that the 25 appearance of the grounds can be maintained. As soon as the turn has been made, the aeration assembly (1) is again lowered to adopt the arrangement of Figure 3a. When aeration and mowing have been completed, the aerating assembly (1) is raised to a greater height to the extent that the arm (15) of coupling (6) bears against the lower stop (17) and prevents further downward relative travel of the mowing assembly (7) 30 with respect to the aeration assembly (1). This represents the link (15) in position (35c) of Figure 4. The consequence is that both the mowing assembly (7) and aeration assembly (1) are raised above the ground. It should be noted that Figures 3 illustrate the concept of the invention in a very simplified form. The upper couplings which are also associated with the ability to raise and lower each assembly (1, 7) have been 35 omitted from this view for clarity. 14 WO 00/13477 PCT/NZ99/00153 It is also noted that the present invention has the ability to provide several advantages over the prior art. Firstly, the novel combination of aerator and mower allows for aerated ground to be used immediately afterwards for its normally intended purpose. Furthermore, the tidy appearance of the ground or turf can be maintained, as opposed 5 to the use of an aerating assembly alone in which scattered debris remains on the surface until such time as a mowing pass is subsequently made, perhaps up to a week later. For golf courses, and public gardens, maintaining a tidy appearance at all times is often important. While the present invention also includes a combined aerating and mowing attachment 10 for a tractor (and in such an embodiment the second coupling unit may be simplified further), the illustrated preferred embodiment allows for separation of the aeration assembly (1) and trailing mowing assembly (7). Furthermore, this allows for either unit to be connected directly to a tractor and used alone, as well as allowing for their use in combination. 15 The arrangement of Figures 1 and 2 also can allow for different types or models of mowing assemblies to be connected. This may be of particular advantage if a user already owns a mowing attachment, and wishes to add an aerating assembly as well. While the common 3-point linkage commonly provided on tractors has been described in greatest detail, couplings appropriate to other types of connection systems and 20 schemes are also within the scope of the invention. As can be appreciated, the preferred embodiment provides some flexibility in how the units can be used, and which allow them to extend beyond sole use as a dedicated aerating and mowing unit (though as indicated above, such dedicated units are still within the scope of the present invention). 25 The combination also allows for the potential realisation of a number of advantages. Apart from time and fuel savings in completing the operation in a single pass, and the avoidance of subsequent compaction by having a mower pass over previously aerated ground, there is the benefit of being able to achieve a presentable and re-usable surface immediately after aeration. Other advantages may also be realised. 30 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. 15

Claims (24)

1. An aeration assembly for ground aeration, said assembly including: - a body portion including first coupling means for attachment to a tractor in a manner allowing the aeration assembly to be raised and lowered above the ground; the body also including second coupling means for the attachment of a trailing mowing assembly to be drawn behind the aeration assembly; and wherein the first and second coupling means are characterised so as to allow, for an arrangement comprising both the aeration assembly and trailing mowing assembly coupled to a tractor, raising of the aeration assembly above the ground initially results only in the raising of the aeration assembly with the mowing assembly remaining in ground contact; - said aeration assembly also including an aerating assemblage consisting of a plurality of ground penetrating members for piercing the ground.

2. An aeration assembly as claimed in claim 1, in which the ground penetrating members include any one or more of: spikes, tines, and blades.

3. An aeration assembly as claimed in claim 1 in which said ground penetrating members include one or more substantially planar blades with an angled end portion, when viewed perpendicular to the plane, said angle being such so that in use substantially the entire flat of the angled portion encounters the ground at the moment of ground contact.

4. An aeration assembly as claimed in any one of the preceding claims in which the aerating assemblage resembles a central drum portion with ground penetrating means extending substantially radially, tangentially, or in a manner therebetween, from the drum.

5. An aeration assembly as claimed in either claim 3 or claim 4 in which the aerating assemblage consists of one or more ground penetrating units, each unit including a cylindrical body portion with ground penetrating members extending outwardly.

6. An aeration assembly as claimed in claim 5 in which the ground penetrating members of a ground penetrating unit are replaceable.

7. An aeration assembly as claimed in claim 5 in which the ground penetrating units are distributed along a substantially latitudinally oriented, with respect to the direction of travel of the aeration assembly in use, shaft. 16 WO 00/13477 PCT/NZ99/00153

8. An aeration assembly as claimed in claim 7 in which the position of one or more ground penetrating units along the shaft are adjustable.

9. An aeration assembly as claimed in either claim 7 or claim 8 in which cylindrical sleeves are present between ground penetrating units on the shaft.

10. An aeration assembly as claimed in any one of the preceding claims in which the first coupling means comprises a three point linkage to the tractor.

11. An aeration assembly as claimed in any one of the preceding claims in which the second coupling means comprises mounting points for a three point linkage to the trailing mowing assembly, the mowing assembly including a three point linkage arrangement of a type allowing it to also be coupled to the three point linkage of the tractor when not used in conjunction with the aeration assembly.

12. An aeration assembly as claimed in claim 11 in which the second coupling means includes two lower couplings, said lower couplings comprising arms pivotable within a substantially vertical plane, further characterised in allowing a trailing mowing assembly attached at these points to travel up and down with respect to the height of the aeration assembly.

13. An aeration assembly as claimed in claim 12 in which the lower couplings include stop means limiting the extent of pivoting of said arms.

14. An aeration assembly as claimed in claim 12 in which a lower coupling includes adjustable stop means.

15. An aeration assembly as claimed in any one of the preceding claims which includes transmission means for harnessing drive or power-take-off means from the tractor and transferring it to effect driven rotation of the aerating assemblage.

16. An aeration assembly as claimed in claim 15 in which the transmission means also allows an attached mowing assembly to be driven.

17. An aeration assembly as claimed in claim 16 including a gearbox arrangement to allow the ratio of driven speed between the aeration assembly and mowing assembly to be varied.

18. An aeration assembly as claimed in any one of claims 1 through 14 which includes a hydraulic motor, connectable to a hydraulic pump outlet on said tractor. 17 WO 00/13477 PCT/NZ99/00153

19. An aeration assembly for the aeration of ground, said aeration assembly including a body portion in the form a frame supporting an aerating assemblage; said aerating assemblage comprising a plurality of ground penetrating units distributed along a supporting shaft, and wherein optionally at least some of said ground penetrating units are adjustable in position along the length of said shaft; each ground penetrating unit including a cylindrical central sleeve portion which rides along the ground during use of the aeration assembly, and including also at least three outwardly extending blade portions; the supporting shaft of the aerating assemblage oriented substantially transversely with respect to the direction of travel of the aerating assembly during use; said body portion including first coupling means including two fixed lower coupling points on the front of the frame, and a third upper coupling point; there also being present second coupling means, including two lower coupling points at the rear of the frame and which include pivoting links or arms which are pivotable within a substantially vertical plane, and in which the extent of travel is limited, and wherein the second coupling means also includes a third upper rearwardly facing coupling point which need not be pivotable; said aeration assembly also include means for driving the aerating assemblage from power provided from the tractor, and for also allowing the concurrent transfer of power to a trailing mowing unit coupled to the second coupling means.

20. The combination of an aerating assembly as claimed in any one of the preceding claims with a tractor, and trailing mowing assembly, and wherein the units are coupled such that in use the aerating assembly can be raised above the ground while the mowing assembly remains in contact.

21. The combination of claim 20 in which the mowing assembly is a rotary, flail, drum reel or blade type mower.

22. A method for the aeration of turf comprising the use of an aeration assembly as claimed in any one of claims 1 through 19.

23. A method for the aeration of turf comprising the use of the combination of either claim 20 or claim 21, in which the aeration assembly creates aerating cavities in the ground, followed immediately thereafter by mowing which also serves to scatter any loose material deposited on the surface as a consequence of aeration.

24. An aeration assembly, substantially as described herein with reference to the accompanying drawings. 18