Turf handling machine

Abstract: An apparatus for laying turf is provided. The apparatus comprises a self propelling chassis which carries a roll of turf (1), means (15) for rotating said roll (1) of turf thereby to unwind said turf onto a surface on which said turf is to be laid and means for synchronising automatically the laying of said turf with the speed of travel of said chassis. The apparatus may be adapted for cutting turf.

Description: This invention relates to an apparatus for laying turf and more particularly to such an apparatus comprising a chassis; carrying and conveying means mounted on the chassis for carrying a roll of turf; propelling means to which said chassis is mounted for driving the chassis in a forward direction over a ground surface at a driving speed at which the turf is to be laid; synchronising means for synchronising the conveying means and the propelling means, thereby to synchronise the laying of the turf substantially with the driving speed. Turf is typically harvested and rolled in small rolls (approx. 1 m²) by a harvesting machine (an example of which is disclosed in EP-A-0221745) and is transported to the site where the turf is to be laid. The turf is then laid manually. This laying process is time consuming and labour intensive, and hence turf laying machines for laying large rolls of turf have been proposed. One example of such a machine is disclosed in AU-B-537118. This document describes a turf cutting and laying machine which, when laying turf, is in the form of a frame which is attached to a suitably modified tractor, and which frame is towed therebehind. Turf is laid behind the tractor by unrolling a roll of turf contained in the frame. This is not desirable as the tracks created by the tractor are substantial, and compress the earth. This causes the laid turf to be uneven and disrupts the previously prepared ground on which the turf is to be laid. Another example of a large roll turf laying machine is disclosed in EP-A-0178081. This document discloses a machine which carries a roll of turf on a frame at its front and which is unwound by means of a control roller. This roller rotates against the exterior of a turf roll to cause it to rotate and hence unwind. This approach is flawed, as the control roller is too small to be able to propel the heavy turf and may instead cut through the turf. Also the fact that the machine drives over the turf as it is laid creates the possibility that any weaknesses in the turf, which are commonplace, will be subjected to unnecessary stress and may cause the turf strip to break. US-A-4084763 discloses a machine for handling artificial turf in which machine a friction drive roller contacts the circumferential surface of the roll of artificial turf to feed out the same. This arrangement is satisfacotry for artificial turf but would suffer from similar problems to those discussed hereinabove in relation to EP-A-0178081 in the unlikely event that it was used for laying natural turf. The present invention aims to provide a machine which will lay adjoining, or at least adjacent, pre-cut strips of natural turf (sods) to form a substantially even covering of turf on a predetermined prepared area of ground. According to one aspect of the present invention therefore there is provided an apparatus of the above mentioned type as known from EP-A-0178081, the apparatus being characterised by the carrying and conveying means being arranged to contact in use a substantial portion of the circumferential surface of the roll of turf at the underside thereof in order to rotate the roll so as to cause the roll to be unwound, and to convey the turf toward the ground surface behind the propelling means, which substantial portion extends from both sides of a notional plane that is substantially perpendicular to the chassis and includes the axis of the roll of turf. A presently preferred embodiment of the invention is a self-propelled vehicle comprising a chassis that generally is run on tracks or rollers and can be steered. The machine will lay a rolled strip of grass or other turf which is mounted to, and carried by, the machine. The rolled strip of grass or other turf may be carried by a bobbin or spindle in the form of a shaft or drum. As will become clearer from the detailed description hereinafter, a preferred machine has a mounting or supporting frame that is located at the top thereof and upon which a roll of turf that is to be laid is rotatably supported by a bobbin or spindle. Means are provided by which a supported roll of turf can be driven independently of the speed of movement of the machine over the ground so that one end of the roll of turf can be fed to an output mechanism of the machine whilst that machine is stationary relative to its surroundings. A mechanism may be provided by which both full rolls of turf, and empty spindles or bobbins, can be loaded onto, and removed from, the machine. This mechanism may be a winch, lifting frame or other means. A motor, that is preferably but not essentially an internal combustion engine, is provided together with gearing that will provide at least one reverse, transit, and one forward, laying, speed of drive to ground-engaging tracks. A roller may be provided which will press the turf strip into engagement with the ground as the turf is fed outwardly from a guide mechanism of the machine. An oscillating rake, rotating cultivator or other mechanism may be mounted on the vehicle to remove and/or repair any marks, footprints or the like that either the vehicle itself or its operator may make during a turf laying operation. A pivotally mounted plate, lever or the like may be provided to measure continuously the amount of turf remaining on any roll and to supply this information in a form in which it can be read mechanically or electronically by a drive synchronisation unit of the machine, so that the speed at which turf is supplied for laying on the ground at any instant will always substantially match the speed of travel of the machine itself over the ground at the same instant. Means may be provided by which the laying mechanism can be lowered into operative engagement with the ground or be moved upwardly entirely out of engagement with the ground. Indicating means may be provided to enable an operator manually to follow a string or like guide, or the edge of a previously laid strip of turf. Such indicating mechanism may be constructed for linking to the steering mechanism of the machine so as substantially automatically to control that steering mechanism whereby the machine will automatically, or semi-automatically, follow a guide or the edge of a previously laid strip of turf. By supplying the strip of turf down a flat or convex chute, conveyor or ramp, abutting parallel strips of turf are laid which when contacted by a pressure roller flatten out and make intimate edge-to-edge contact. The invention also extends to a method of laying turf as claimed in claim 17. The above and further features and advantages of the invention are set forth particularity in the appended claims. In order that the invention may be better understood preferred embodiments will be described by way of example only with reference to the accompanying drawings, in which:- Figure 1 shows a view of one side of a first proposal of a turf laying machine which does not embody the invention; Figure 2 shows a view of the other side of the machine of Figure 1; Figure 3 shows a view of the rear end of the machine of Figure 1; Figure 4 shows a view of the front of the machine of Figure 1; Figure 5 shows a view of one side of a second machine, which machine embodies the invention as claimed; Figure 6 shows a similar view to Figure 5, to a somewhat enlarged scale, omitting some features but illustrating a laying operation in more detail; Figure 7 shows a view of the front of the machine of Figure 5; Figure 8 shows a view of the rear of the machine of Figure 5; Figure 9 shows a view of the side of a third machine, which machine also embodies the invention as claimed; and Figure 10 shows a view of a preferred form of output discharge device. Referring now to the accompanying drawings, it is first noted that the expressions "rear" and "front" as applied to Figures 3, 4, 7 and 8 of the drawings assume that the machines will, in operation, be moved from right to left as seen in Figure 1 with the pedestrian operator thereof at the front of the machine so that he/she does not walk on turf that has just been laid and the machine itself does not travel over such turf. The turf that is to be laid may be pre-cut into strips by any of several machines that are suitable for this purpose and is formed into a roll 1. Such a roll may be formed around a spindle or bobbin 2. The roll of turf may be typically between 750 and 1000 millimetres in width (to enable an overall machine width convenient for taking through side gates of homes to be constructed - see hereinafter), about 12.7 millimetres in thickness and between about 27.4 metres and 45.7 metres in length, depending upon whether the turf is heavy or light, a longer length of strip being satisfactory in the latter case. An example of heavy turf would be turf grown on clay in wet conditions, and light turf may be grown on peat in dry conditions. The turf is rolled soil-side outside. Referring first to Figures 1 to 4 of the accompanying drawings, which show a first proposal for a turf laying machine, a sub-frame assembly 3 is driven on steerable tracks 4 via a drive axle 6 from a motor, track gearbox and track drive assembly 5. The gearbox typically has two reverse transit positions and one forward laying position and is operated by means of a lever 5a. The machine has a steering frame assembly 7 on which are mounted a turf roll drive lever 8, a throttle 9, a track drive engagement lever 10 and steering levers 11. As mentioned, the roll of turf 1 is wound on a spindle 2. This spindle is mounted on the machine on cradle bearings 12 on a support frame 12a mounted on the frame assembly 7. Mounted on the support frame 12a is a pivoted handle 13, and also a drive hub 14 which is connected to a turf roll drive unit 15 via a drive belt 16. The drive hub 14 is engaged with a splined end of the spindle 2 and thus causes the roll 1 to rotate when drive belt 16 is driven by the turf roll drive unit 15. The turf roll drive unit 15 is connected to the motor gearbox assembly 5 via a belt 17 extending between drive axle 6 and an input drive hub 18. Rotation of the turf roll is synchronised to the speed of travel of the machine over the ground by the turf roll drive unit 15 through a system of mechanical, hydraulic or electrical gears. For mechanical operation, the unit 15 may comprise oppositely directed conical input and output members drivably interconnected by a belt or the like, the position of the latter being continuously governed axially of the two cones by the diameter of the turf roll at any instant. Provided that the cone angles are correct, the speed of movement of the strip 1a will change accurately to match the substantially constant speed of "laying" travel of the machine as the turf roll being dispensed progressively reduces in diameter. The speed of transit travel might typically be about 3.5 kilometres per hour, whereas the operative or laying speed might be about 1280 metres per hour. It is preferable that the synchronisation of turf laying with movement of the machine has a manually, or otherwise, set tolerance which allows adjustment of the laying speed according to turf and ground conditions. For example, it may be desirable to compress the turf as it is laid, and this may be achieved by increasing the speed at which the turf is rolled off the machine (as described hereinafter) relative to the speed of travel of the machine. The turf roll rests on a spring-loaded turf roll follower plate 19 which is connected by a lever mechanism to transmit the turf roll diameter at any instant to the turf roll drive unit 15. The leading end of the turf strip 1a is fed around a toothed or knurled output drum 20 (Figure 3), which drum is driven from a rear track wheel assembly by a belt connected to an output drive belt hub 21. The output drive belt hub 21 is connected by a further belt 22 to an output feeder drive hub 23. The output drive belt hub 21 also drives an output roller 24. The output roller 24 is carried on a pivotally mounted frame 25, which is connected to a control lever 26 through the intermediary of a link 27. The machine also has an output chute 28 and an oscillating rake 29 both of which are attached to the sub-frame 3 at the rear of the machine. At the front of the machine are mounted guideline indicators 30. In use, the required number of turf strips 1, rolled onto spindles or bobbins 2, is transported to the laying site and may be off-loaded onto frames or stands that will hold the complete rolls at a slightly greater height above the ground than cradle bearings 12 (Figure 4) of the actual machine. If the rolls are loaded on frames, they are loaded onto the machine by driving the machine under one of the frames or stands holding a turf roll until its cradle bearings 12 are directly under the projecting ends of the spindle or bobbin 2 corresponding to that turf roll. The cradle bearings 12 are then lifted by operation of the pivoted handle 13 so that they raise the roll upwardly out of the frame or stand upon which it was resting. The machine is then backed out of the frame or stand. Alternatively, the rolls 2 may be loaded onto the cradle bearings 12 by means of lifting apparatus such as, for example, a crane or forklift. In any case, the handle 13 is lowered to move the cradle bearings 12 and the supported roll downwardly into an operating position resting on the support frame 12a. The machine is then placed in gear using a lever 5a. The machine then is positioned so that output roller 24 thereof is immediately above the point at which one end of the turf strip 1 is to lie, the machine being aligned in a forward direction relative to the intended line along which the turf is to be laid. The leading end of the turf strip 1a is fed around the output drum 20 (Figure 3), down the output guide chute 28 and thence under the output roller 24 whilst all of these parts 20, 28 and 24 are in a raised position. The frame 25 supporting the drum 20 and the chute 28 is then lowered to bring these parts into their operating position, i.e. when they are almost in contact with the ground. This is effected by operation of the control lever 26. Guide line indicators 30 are lowered to the positions shown in Figure 4 of the drawings and the synchronised turf roll drive 15 is engaged by operation of lever 8. Operation of the gear selector 5a, throttle 9, track drive engagement lever 10 and steering levers 11 then enables the machine to be driven in a forward direction (from right to left as seen in Figure 1 and as discussed above), the indicators 30 being used by the operator to follow a previously laid string line if a first strip is being laid, or the edges of previously laid strips when later strips are subsequently being laid. The turf strip 1a is assisted down the output guide chute 28 by the output feeder drum 20. The output guide chute 28 is preferably convex in section, as shown in Figure 10. This causes the turf to be laid with its centre portion slightly raised which, after laying, causes the turf to flatten thus pushing the edges of the turf outwards. This causes the turf to push against its neighbouring strip, thus creating a better abutment between turf strips. The turf strip is further assisted, and pressed onto the ground, by the output roller 24. The important function of the ground speed synchronisation drive unit 15, the output roller 24 and the output feeder drive hub 23 is to remove the turf strip 1a progressively from the roll 1 at the correct speed at any given instant of operation and to place that strip 1a onto the ground without tearing, stretching, splitting or otherwise damaging the strip 1a which is, of course, a delicate naturally produced article that will vary in consistency along its length due to features such as soil make up, dampness and the quality and nature of the particular grass which is growing on the strip. It is to be noted that the tracks 4 are broad and thus spread the weight of the machine over an increased area. This minimises the amount of compression of the prepared ground and assists the turf to grow once it is laid. Marks and depressions on the ground caused by the feet of the operator, and the machine tracks, are removed or repaired by the oscillating rake 29. On completion of laying a strip or when a roll 1 of turf has been used up, the machine is stopped and the synchronisation drive 15 is disengaged. The output roller 24 is raised by the operation of the control lever 26 via the link 27 and frame 25 (Figure 2). When the roll is not used up, the turf strip is then cut to match the required end of the area that has been turfed. The machine itself is then either turned round and the next strip laid in the same manner as has been described above alongside the first strip, or the machine may be driven back to a point adjacent to the original starting point and the second or next strip may be laid in the same direction alongside the first or previous strip. When a first roll 1 is exhausted and the machine is therefore empty, the lever 26 is operated to raise the output roller 29 clear of the ground and the indicators 30 are also raised. The machine is then driven back to the point where the next turf roll and its spindle or bobbin 2 are waiting either on a lifting means or upon another frame or stand. The operation that has been briefly described is then repeated and this repetition may be effected as many times as is required to cover the complete area that is to be turfed. For operation of the above described machine in the opposite direction, as briefly discussed earlier in this specification, a turf strip from the roll 1 carried by the machine is directed to the right from said roll, as seen in Figure 1, to move around the output roller 24 which, under these circumstances, will be at the leading end of the machine. The output chute 28 may be raised, or be temporarily removed, for such operation. Figures 5 to 8 illustrate a second embodiment of the invention (in which like reference numerals to those used in Figures 1 to 4 indicate like parts), which utilises the cut turf arranged in a roll and wrapped around a spindle or bobbin as in the above described embodiment but in which the spindle or bobbin is not involved in driving the roll, but merely in loading of the roll onto the machine (as described above). When loaded, the roll 2 lies on top of a main roll conveyor 32 between a front roll conveyor 33 and a rear roll conveyor 34. The main conveyor 32 is driven by a pinion, driven in turn by a power take-off shaft 36 from the turf roll drive assembly 15. In contrast to the first embodiment, in which the roll 2 is driven from the centre thereof and hence, in order to synchronise the speed of issue of turf with the speed of travel of the machine, the speed of driving the roll must be altered as the diameter of the roll decreases, in the second embodiment the roll is driven from its periphery by means of the above-mentioned conveyors 32 to 34. Because the periphery is driven, the speed of travel of the machine need only be synchronised to the speed of the conveyors. This is effected by means of gearbox 39. Numeral 35 indicates a pinion which holds the main conveyor 32 in place. Laying is effected by means of the conveyors and after laying, the turf is rolled by output roller 24 (Figure 5) which is, in this case, driven in clockwise rotation by belt 22 supported by a pivotally mounted frame. The belt 22 is driven by rotation of the main conveyor 32. The turf 1a that is to be laid passes over a turf guide conveyor 38 which may have a convex cross section (as shown in Figure 10) to ensure accurate abutment of adjacent turf strips as described above with reference to output chute 18, and which is driven by rotation of the main conveyor 32. Lift cradle 31 is lowered by means of lift frame 37 (which parts are similar in function to handle 26 and cranks 25 of the first embodiment) to enable the turf 1a from the roll 1 to be pressed onto the ground by the roller 24 as that turf 1a is laid. Cog wheels and chains 40 (Figures 7 and 8) extend between the previously mentioned power take-off shaft 36 and the also previously mentioned front roll conveyor 33 to transmit drive to the latter. Operation of the gear lever or selector 5a, the throttle 9, and the clutch controls 10 enable the machine to be driven in a forward direction (as discussed above), the roll 1 being rotated at a synchronised speed by the main conveyor 32, the front roll conveyor 33 and the rear roll conveyor 34. Since these conveyors constantly contact the exterior surface of the roll 1, the speed of issue of the turf 1a being laid from the roll 1 will match the substantially constant speed of "laying" travel of the machine as the roll 1 being dispensed progressively reduces in diameter, provided that the speed of the conveyors is synchronised with the speed of the tracks. The speed of non-laying transit travel might typically be about 6 kilometres per hour whereas the operative or laying speed might be between about 0.6 and 1.37 kilometres per hour. As before, when laying has been completed, the roll 1 is cut to match the required location of that end. It will be noted that the embodiment which has been described and which is illustrated in Figures 5 to 7 of the accompanying drawings, avoids the rolls 1 of turf being driven by the central spindle or the like. The drive to each roll 1 is effected on the external surface of that roll and no central spindle or the like is employed for driving. As mentioned, this simplifies the way in which the speed of laying of the turf is automatically synchronised to the speed of travel of the machine. A third embodiment of the invention, illustrated in Figure 9 utilises the peripheral drive of the second embodiment, but includes a system for loading the roll onto the machine. In this embodiment, there is no output roller 24 and the output conveyor 38 is replaced by an output guide chute 28, which chute may be convex in cross section as described with reference to the first and second embodiments (see Fig. 10). The roll is pulled up the chute 28 by means of a winch system, the operation of which is described below. To load the turf roll 1 onto the machine, winch-cradle arms 41 are unclipped from pivot bearings 42 located on winch-frame 43 enabling them to be pulled out from the machine and attached by means of a latch 44 to spigots at either end of the spindle 2. The roll 1 is then pulled on to the machine by selecting a suitable gear in the winch and conveyor gearbox 45 by means of the winch/conveyor gear lever 46. The winch and conveyor gearbox 45 is located between the power take-off shaft 36 and main roll conveyor 32 and has three operating positions. These are "conveyor" (C) - this synchronises the engine output to the track speed of the vehicle so that the main conveyor 32 drives turf off the machine at substantially the same speed as the vehicle is moving along the ground; "neutral" (N) - which disconnects the laying mechanism from the engine; and "winch" (W) - which connects the engine to the winch. The roll 1 is pulled or rolled up the guide chute 28 and onto the roll conveyor 32 by the winch winding the winch cable 47 onto the drum 48. Once in place, winch cradle arms 41 are refixed to pivot bearings 42 and act to hold the roll 1 on the machine. Cradle arms 41 are able to move radially by means of the pivot bearings and hence will move downwards as the turf is laid and the diameter of the roll 1 decreases. Side guide plates and rear slide plate 49 further act to maintain the position of the roll on the machine and allow the turf to slide off the machine as required. A rotating cultivator 50 driven via drive chains 51 is provided to repair marks or depressions in the prepared soil upon which the turf 1 is to be laid. In transit, the rear guide chute 28 is lifted off the ground by means of the lever 52 and cable 56. As laying work commences, the machine is aligned in a forward direction relative to the intended line along which that turf is to lie, the winch and conveyor gearbox is set to the "conveyor" position and the engine is put in forward gear. The engine now drives the tracks 4 and the roll conveyor 32 thereby rotating the roll 1 as the machine moves forwards as with the above described second embodiment. This is controlled by means of a track brake and steering control levers 11 as well as a throttle. The tension of the roll conveyor 32 is maintained by means of roll conveyor sliders 54 which are held by springs. These sliders allow the roll conveyor 32 to sag by a predetermined amount and to take on substantially the shape of the bottom of the roll 1 when it is loaded. This ensures that a maximum area of conveyor 32 is in contact with the roll 1, thereby providing maximum traction to drive the turf off the machine. It is noted that the machine which have been described preferably have a width of substantially 1.2 metres, a length of substantially 2.2 metres and, when loaded, a height of substantially 1.2 metres. Such a width allows the machine to be driven through a garden gate or the like, which is desirable if the area to be turfed is only accessible through for example a narrow passage or garage doorway. A turf roll has a weight of substantially 500 kilograms and the machine itself has a weight of substantially 250 kilograms so that, when loaded at the beginning of an operation, the machine will have a weight of substantially 750 kilograms. Its ground loading, or pressure upon the ground, is approximately 197 grams per square centimetre and it is noted that this is more or less equivalent to the walking ground loading of an average man. It is also noted that the machine illustrated in the drawings and have been described will be fitted with safety guards and shields but that these are completely omitted from said drawings for the sake of clarity.

Claims: An apparatus for laying turf, the apparatus comprising: a chassis (3); carrying and conveying means (32 to 34,, 19 2, 41) mounted on the chassis for carrying a roll of turf; propelling means (5, 6) to which said chassis is mounted for driving the chassis in a forward direction over a ground surface at a driving speed at which the turf is to be laid; synchronising means (15, 39) for synchronising the conveying means and the propelling means, thereby to synchronise the laying of the turf substantially with the driving speed; characterised by: the carrying and conveying means (32 to 34, 19) being arranged to contact in use a substantial portion of the circumferential surface of the roll of turf at the underside thereof in order to rotate the roll so as to cause the roll to be unwound, and to convey the turf toward the ground surface behind the propelling means, which substantial portion extends from both sides of a notional plane that is substantially perpendicular to the chassis and includes the axis of the roll of turf. An apparatus as claimed in claim 1, wherein the turf carrying means comprises a shaft (2) around which said roll of turf is wound. An apparatus as claimed in claim 1 or 2, wherein the turf conveying means comprises at least one conveyor (32) positioned to engage the circumferential surface portion of said roll. An apparatus as claimed in any preceding claim, further characterised by turf guiding means (28, 38) for guiding said turf from said conveying means to said ground surface behind said propelling means. An apparatus as claimed in claim 4, wherein the guiding means comprises a chute (28, 38) of a width at least equal to that of said roll of turf, the guiding means having a substantially convex profile across the width of the chute. An apparatus as claimed in claim 5, wherein the chute is pivotally mounted to said chassis. An apparatus as claimed in any preceding claim, wherein the propelling means comprises at least two continuous driving tracks. An apparatus as claimed in claim 7 wherein the propelling means further comprises an internal combustion engine and driving gears (39) between said engine and said driving tracks providing at least one reverse and one forward gear to enable said tracks (6) to be driven at least one reverse, transit, and one forward, laying, speed. An apparatus as claimed in claim 7 or 8, wherein the driving tracks are positioned to lie within the width of the roll of turf. An apparatus as claimed in any preceding claim, wherein the synchronising means (39) comprises user operable adjusting means to enable a user of the apparatus to adjust said speed of conveying said turf according to said driving speed. An apparatus as claimed in any preceding claim, wherein the synchronising means comprises automatic adjusting means for automatically adjusting said speed of conveying said turf according to said driving speed. An apparatus as claimed in claim 11, wherein the automatic adjusting means is arranged to alter continually the speed of conveying the turf. An apparatus as claimed in any preceding claim, further characterised by a roller (24) connected to the rear of the chassis for rolling said laid turf. An apparatus as claimed in any preceding claim, further characterised by repairing means (29, 50) connected to the rear of the chassis for repairing said ground surface immediately prior to the laying of said turf. An apparatus as claimed in claim 14, wherein the repairing means comprises an oscillating rake (29). An apparatus as claimed in claim 14, wherein the repairing means comprises a rotating cultivator (50). A method of laying turf, the method comprising the steps of: carrying a roll of turf on a turf laying apparatus comprising a chassis; driving said chassis, by way of propelling means to which said chassis is mounted, in a forward direction over a ground surface at a driving speed at which said turf is to be laid; conveying said turf toward said ground surface behind said propelling means; and synchronising said laying of said turf with said driving speed so that said turf is laid substantially at said driving speed; characterised by: contacting a substantial portion of the circumferential surface of said roll of turf at the underside thereof in order to rotate the roll so as to unwind said roll, which substantial portion extends from both sides of a notional plane that is substantially perpendicular to the ground surface and includes the axis of the roll of turf.

Inventors: MAIL STUART PAUL, MAIL, STUART PAUL
Applicants: TURFGRASS SERVICES INT, TURFGRASS SERVICES INTERNATIONAL LTD
Application year: 1990
Main classification: A01B45
IPC codes: A01B45