Patent Publication Number: US-2004055768-A1

Title: Aeration machine

Description:
[0001] This invention concerns improvements in or relating to aeration machines.  
       [0002] Aeration machines are used to aerate turf for example on golf greens, cricket squares or other sports pitches or leisure areas. They usually comprise a plurality of tines which are rapidly movable into and out of the ground as the machine moves along. The tines maybe solid, or for instance hollow to remove cores of turf. Problems can be encountered with such machines in avoiding wear on the machine, elongation of round holes, and/or tearing of the ground as the machine moves whilst the tines are entering and leaving the ground. It is desirable that longitudinal movement of the tines relative to the ground, only occurs when the tines are wholly clear of the ground.  
       [0003] According to the present invention there is provided an aeration machine, the machine comprising one or more tines selectively movable into and out of the ground, and a linkage arrangement between the machine and the tines which arrangement is substantially vibration absorbing and permits the tines to move in substantially only a vertical direction when any part of the tines extends into the ground.  
       [0004] The linkage may comprise a vibration absorbing member. The vibration absorbing member may comprise first and second parts, with the first part located at least partially within the second part and held therein by one or more resilient members. The resilient members may comprise one or more pieces of a resilient material. The resilient material is preferably self-damping and may comprise rubber.  
       [0005] The second part may comprise a hollow housing with the first part held therein by a plurality of pieces of resilient material. The first part may be of generally square cross-section, and desirably a piece of material is provided along each side thereof. The second part may be of square cross-section, and in a rest condition the first and second parts may be oriented at substantially 45° relative to each other.  
       [0006] The first part is preferably mountable to the tines and the second part mountable to the remainder of the machine.  
       [0007] The first part is preferably mounted to the tines by a pivotal arrangement, and the arrangement may comprise a first member extending from the vibration absorbing member and which pivotally mounts a linkage member, which linkage member pivotally connects to the tines.  
       [0008] The tines may be vertically drivable by a member pivotally mounted off centre on a drive wheel. The link member preferably pivotally mounts the linkage. 
     
    
    
     [0009] An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:  
     [0010]FIG. 1 is a diagrammatic rear view of an aeration machine according to the present invention;  
     [0011]FIG. 2 is a perspective view from beneath and behind of the machine of FIG. 1;  
     [0012]FIGS. 3A to D show sequential diagrammatic side views of the part of the machine of FIG. 1 in use;  
     [0013]FIG. 4 is a diagrammatic perspective view of part of the apparatus of FIG. 1; and  
     [0014]FIG. 5 is a diagrammatic exploded cross-sectional view of the components of FIG. 4.  
    
    
     [0015] The drawings show an aeration machine  10  suitable for aerating golf greens and the like. The machine comprises a front roller  12  mounted on a body  14  which contains a drive mechanism  16  connected to two sets of four tines  18 . The tines  18  in each set are rigidly connected, and each set is arranged to enter the ground at a different time relative to the other set. The machine  10  is drivable behind a tractor (not shown) in a conventional manner, with the tractor providing the drive for the machine  10 .  
     [0016] Considering the drive mechanism  16  in more detail, this will be described for one set of tines  18  but an identical arrangement is provided for each set. The tines  18  are removably mounted on a bracket  20  which is mounted on the free end of an elongate link member  22 . The other end of the link member  20  is pivotally mounted off centre on a drive wheel  24 . A drive wheel  24  is provided for each set of tines  18  and mounted on an axial  26 . A drive belt  28  extends around a one of the wheels  24  and also around a further drive wheel (not shown) which connects to a towing tractor.  
     [0017] The first end of the link member  22  pivotally mounts a linkage member  30  at one end thereof. The other end of the member  30  pivotally links a relatively short connecting bar  32 . The other end of the bar  32  connects to a vibration absorbing linkage  34  which is mounted to the frame of the machine  10 .  
     [0018] The linkage  34  comprises a length of tube  36  of square section, but with rounded corners. A piece of rubber  38  is located extending along each corner of the tube  36 . A square section block  40  is located within the tube  36  and held in position by the pieces  38 . The block  40  is orientated at substantially 45° to the tube  36 . Threaded holes  42  are provided in the block  40  to permit mounting thereof to a U-shaped bracket  44  mountable on the frame of the machine  10 . Mounted on the free end of the bar  32  is a square section bracket  46 . A gap is provided in the upper side of the bracket  46  and has upturned flanges with aligned holes through which a bolt  48  extends engageable with a nut  50 . The bracket  46  is locatable around the tube  36 , and can be rigidly mounted thereon by tightening the nut  50  on the bolt  48 .  
     [0019]FIGS. 3A to  3 D show operation of the machine  10  and particularly the drive mechanism  16 . In FIG. 3A as the link member  22  reaches its lowest position the tine  18  is driven fully into the ground. As the link member  22  rises (FIG. 3B) the tine  18  rises. At the same time the machine  10  will almost certainly be moving forwards i.e. to the right as shown in FIGS. 3A to D. Rather than the tine  18  being moved sideways, the relative spacing between the tine  18  and the axis of the wheel  24  is taken up by the linkage  34  connecting via the bar  32  and linkage member  30 . The resilience of the rubber pieces  38  permits the bar  32  and hence block  40  to rotate relative to the tube  36 .  
     [0020] When the tine  18  is fully out of the ground (FIG. 3C) the resilience of the rubber pieces  38  allows the block  40  and hence bar  32  to rotate back to a relaxed condition. In FIG. 3D as the tine  18  re-enters the ground, the linkage  34  permits the block  40  and hence the bar  32  to rotate to the right as shown in the drawings which compensates for the upper end of the member  22  being to the right hand side of the axis of the wheel  24 .  
     [0021] There is thus described an aeration machine and particularly a drive mechanism and linkage therefor which provides considerable advantages. The linkage  34  allows the tines  18  to remain vertical during use and therefore avoid ripping the ground or elongating a round hole. The linkage  34  also absorbs vibration. This reduces ware of components and also the noise of operation. The arrangement is of relatively straightforward construction and can thus be inexpensively and robustly manufactured,  
     [0022] Various modifications may be made without departing from the scope of the invention. For example, a different linking arrangement could be provided between the linkage and the tines. A different vertical drive arrangement could also be provided.  
     [0023] Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or nor particular emphasis has been placed thereon.