Abstract:
A roller assembly adapted to follow ground contours during operation which includes a pair of roller components each having respective inner ends connected to each other by a flexible and movable primary coupling and having their respective outer ends connected to a support shaft which extends through a hollow interior of each roller component by a secondary coupling.

Description:
CROSS REFERENCE 
     This is a continuation-in-part of International Application PCT/AU2007/001669, with an international filing date of Nov. 1, 2007, which claimed the priority of Australian Patent Application 2006906096, filed Nov. 1, 2006. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to an improved roller assembly which may be used as a drive roller or idler roller in machines or vehicles incorporating rolling apparatus for rolling of turf or grass surfaces inclusive of golf greens and bowling greens. However this is not the only application of the roller assembly of the invention which could be employed in relation to rolling of snowfields, road surfaces during preparation of roads and rolling of other uneven surfaces such as sand. 
     BACKGROUND OF THE INVENTION 
     One conventional rolling apparatus is described in U.S. Pat. No. 6,457,903 which has a mobile main frame and at least a pair of undercarriages attached to the main frame in side by side relationship wherein each undercarriage has one or more smoothing rollers and there is further provided a control arm or plate pivotally attached to the main frame about a horizontal axis wherein each undercarriage is pivotally attached to the control arm or plate. There was further provided a transmission interconnecting each undercarriage to an operating lever or joystick wherein actuation of the operating lever or joystick causes reciprocatable pivotal movement of each undercarriage such that in use the or each smoothing roller closely follows ground contours. 
     It is important in rolling of golf greens or bowling greens that smoothing or idler rollers as described in U.S. Pat. No. 6,457,903 closely follow ground contours. If such is not the case the smoothing rollers may leave indentation lines or unsightly marks on the greens and this was detrimental to achievement of a smooth and even grass surface. Another problem of using smoothing rollers that did not closely follow ground contours was that surface corrugations in the greens still remained after repeated roller operations. 
     However while this objective was achieved in U.S. Pat. No. 6,457,903 by the use of pivotal movement of each undercarriage to closely follow surface undulations or corrugations it will be appreciated that U.S. Pat. No. 6,457,903 still incorporated a conventional drive roller shaft which was provided with a pair of stub axles at each end thereof which were attached to mounting plates rigidly attached to the chassis of the rolling apparatus. Each stub axle was also mounted in bearing carriers carrying bearings for each stub axle so as to enable the drive roller to rotate relative to the chassis. Another conventional arrangement was that the drive roller was rigidly mounted to a support shaft which extended through each end of the drive roller thereby providing the pair of stub axles. However these conventional drive roller mounting arrangements had disadvantages in that (i) on uneven ground there was created greater ground pressure resulting in an uneven surface finish due to lines, marks or impressions left on the ground surface after passage of the drive roller. Other disadvantages were (ii) that the drive roller had reduced width compared to each smoothing roller, (iii) that there was less driving friction on the ground than desired which created loss of traction in certain driving conditions and situations, especially on increased slopes or wet turf and (iv) the drive roller was rigidly mounted to a support shaft which meant that the style of roller to be employed was limited being relatively short which was not adapted to follow ground contours. 
     It was also to be appreciated that in relation to each of the smoothing rollers in order to achieve an objective of each smoothing roller closely following ground contours it was necessary to mount a plurality of smoothing rollers in undercarriages as described above and this procedure was relatively complicated although it operated in a perfectly satisfactory manner. 
     SUMMARY OF THE INVENTION 
     It therefore is an object of the invention to provide a roller assembly that is adapted to follow ground contours during operation. 
     The roller assembly of the invention includes in a first embodiment a pair of roller components having respective inner ends connected to each other by a flexible and movable primary coupling and having their respective outer ends connected to a support shaft which extends through a hollow interior of each driven roller component by a secondary coupling. 
     In a second embodiment there may be one or more intermediate or floating roller components located between the pair of roller components, which may constitute end roller components. In this embodiment each of the end roller components are connected at their respective outer ends to the support shaft which extends through a hollow interior of each end roller component and each intermediate or floating roller component by the secondary coupling. However each of the inner ends of the end roller components are connected to an adjacent end of an adjoining intermediate or floating roller component by the flexible and movable primary coupling. In the case where there are more than one intermediate floating roller components, adjacent ends of each intermediate or floating roller components are connected to each other by additional flexible and movable primary couplings. 
     The flexible and movable primary coupling may comprise a disc or sleeve made from natural rubber, synthetic rubber or other form of flexible or elastomeric material. In one arrangement the flexible disc may have a plurality of holes to enhance flexibility or in another arrangement may have a relatively large central aperture to enhance flexibility. Preferably the flexible disc has a peripheral flange defining a pair of adjacent shoulders for supporting an adjacent end of a roller component. 
     In the case of the first or second embodiment the primary coupling may be provided with a plurality of spigots or sockets which engage with corresponding sockets or spigots of an adjacent end of an end or driven roller component. In the case of adjacent ends of intermediate or floating roller components each of these may be interconnected by a primary coupling having spigots or sockets engaging with corresponding sockets or spigots of each adjacent end of the intermediate or floating roller component. 
    
    
     
       Reference may be made to a shaft assembly as shown in the accompanying drawings wherein 
         FIG. 1  is an exploded perspective view of a roller assembly in accordance with the first embodiment of the invention; 
         FIG. 2  is a partially cut away view of an assembled roller assembly shown in  FIG. 1 ; 
         FIG. 3  is a side view of the roller assembly shown in  FIGS. 1 to 2 ; 
         FIG. 4  is a sectional view through line B-B of  FIG. 3 ; 
         FIG. 5  is a side view of the roller assembly of  FIG. 1  showing concave flexibility; 
         FIG. 6  is a side view of the roller assembly of  FIG. 1  showing convex flexibility; 
         FIG. 7  is a perspective view of the support shaft prior to attachment to each roller component; 
         FIG. 8  is a side view of the support shaft shown in  FIG. 7 ; 
         FIG. 9  is an end view of the support shaft shown in  FIG. 7 ; 
         FIG. 10  is a schematic view of the second embodiment of the invention; 
         FIG. 11  is a perspective view similar to  FIG. 1  showing another embodiment of the invention; 
         FIG. 12  is a perspective view similar to  FIG. 2  in respect to the  FIG. 11  embodiment; 
         FIG. 13  is a view similar to  FIG. 7  in respect to the  FIG. 11  embodiment; and 
         FIGS. 14 ,  14 A,  15  and  16  relate to a third embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The roller assembly  9  shown in  FIG. 1  has a roller support axle or shaft  1 , end or driven roller components  12  each having an inner metal roller sleeve  5  and outer rubber sleeve  7 , end coupling assemblies  14  each having inner support plate  2 , outer support plate  6  and flexible or secondary coupling  8  between roller support axle  1  and each roller component  12 , and fasteners  10  interconnecting each of secondary couplings  8  to inner support plate  2  and outer support plate  6 . Each of secondary couplings  8  include metal inserts  9  in apertures  4 A and  4 C to facilitate insertion of fasteners  10 . There is also provided a primary or floating coupling  3  between each of roller components  12 . Coupling  3  is also provided with flange  19  which abuts each of roller components  12  and shoulders  20  for seating in corresponding groove  21  of each roller component  12 . 
     In  FIG. 2  an assembled view of roller assembly  9  is shown and it will be noted that each of inner plates  2  is welded or otherwise attached to roller axle  1  and that each of outer plates  6  are welded or otherwise attached to inner surface  15  of drive roller inner sleeve  5 . It will also be noted that each of outer plates  6  have an aperture  16  as best shown in  FIG. 1  to facilitate insertion of inner plates  2  but that inner plates  2  are spaced from outer plates  6  as shown by spacing or gap  17 . Also primary or central coupling  3  is provided with a plurality of apertures  18  to facilitate flexing of central coupling  3  when required. Primary coupling  3  is suitably made from natural rubber, synthetic rubber or other types of elastomeric material and this also applies to each of secondary couplings  8 . 
     Roller shaft  1  is also provided with reduced diameter ends  22  and  23  for location of a bearing housing (not shown) of the type discussed above in relation to U.S. Pat. No. 6,457,903 and slot  24  for retention of a pulley wheel or sprocket also of the type shown in U.S. Pat. No. 6,457,903. 
     In  FIGS. 3 to 4  there is shown clear separation of each of roller components  12  on each side of central coupling  3  with each roller component  12  abutting flange  19 . Roller axle or shaft  1  as best shown in  FIG. 1  passes through each of central apertures  25  of secondary or end couplings  8 , central aperture  16  of each outer plate  6 , aperture  26  of each inner plate  2  and central aperture  27  of central coupling  3 . 
       FIG. 3  shows flexing of roller assembly  11  about central coupling  3  as indicated by the arrows wherein the lines in phantom shows both convex flexing and concave flexing. 
       FIGS. 5 to 6  show both concave flexing and convex flexing of each of roller components  12  about central coupling  3  which functions to keep each of roller components  12  aligned with each other. Each of end coupling assemblies  14  facilitate this flexing by allowing relative movement between roller shaft or axle  1  and each of roller components  12  to achieve a position as shown in  FIG. 5  or  6  wherein each of roller components  12  hug closely the contours of the ground  11 B in the case of a slight mound or hill in the case of  FIG. 6  having regard to a convex flex and also in the case of a slight valley or depression of ground  11 A in the case of  FIG. 5  having regard to a concave flex. 
     In the case of manufacture of roller assembly  11 , this is shown in  FIGS. 7-9  wherein central coupling  3  is located on roller shaft  1  before attachment of each of plates  2  by welding. Subsequently each of roller components  12  and their associated coupling assemblies  8  are attached to roller shaft  1  as shown in  FIG. 2  and fasteners  10  inserted in co-aligned apertures  4 A of end coupling  8  and apertures  4 B of plate  2  as best shown in  FIG. 1 . Also fasteners  10  are inserted through co-aligned apertures  4 C of end coupling  8  and apertures  4 D of plate  6  which are best shown in  FIG. 1 . 
     In  FIG. 10  there is shown a roller assembly  9 A having a support shaft  30 , secondary coupling assemblies  31  interconnecting end or driven roller components  32  to support shaft  30  and a primary coupling  34  interconnecting the floating roller component  33  and adjacent ends of each driven roller component  32 . Each secondary coupling assembly  31  has a flexible disc  35  with an aperture  36  to permit insertion of support shaft  30 , lugs  38  welded to roller components  32  which are connected to flexible discs  35  by fasteners  37  and further fasteners  39  interconnecting metal disc  40  welded to support shaft  30  with flexible disc  35 . Each of the floating couplings  34  has a relatively large aperture  41  to permit passage of shaft  30  and also to facilitate flexing of coupling  34  as well as spigots  42  engaging in corresponding sockets  43  of adjacent ends of roller components  32  or  33 . The support shaft  30  is also provided with deflection plates  44  welded to support shaft  30 . 
     In another embodiment of the invention is shown in  FIG. 11  which shows a view similar to  FIG. 1  in relation to roller assembly  49 . Plate  6  has now been replaced by opposed triangular shaped plates  50  each having an aperture  51  for passage of fasteners  10 . Each of plates  50  are welded to the internal surface of metal sleeve  5 A and plate  52  replaces plate  2  and is welded to shaft  1 A. Plate  52  has central aperture  53  for passage of shaft  1 A and attachment apertures  54  for passage of fasteners  10 . Central coupling  3 A has been modified to omit apertures  18 . 
       FIG. 12  shows a perspective view similar to  FIG. 2  in regard to the embodiment of  FIG. 11  and  FIG. 13  shows a perspective view similar to  FIG. 7  in relation to the embodiment of  FIG. 11 . 
     It will also be appreciated that the position of two opposed plates  50  gives adequate clearance for operation of the roller assembly  49  wherein plates  50  are spaced from plates  52  as shown in  FIG. 12  by gap  56 . 
     Reference may now be made to another embodiment of the invention shown in  FIGS. 14 ,  14 A,  15  and  16  showing roller assembly  49 A wherein there is shown roller support axle or shaft  1 B, driven roller components  12  each having an inner metal roller sleeve  5  and outer rubber sleeve  7  and coupling assemblies  14 A each having disc  2 A welded to shaft  1 B, disc  6 A welded to an internal surface of metal roller sleeve  5  and flexible coupling  8 A interconnecting discs  2 A and  6 A. Flexible intermediate coupling  8 A is located within disc  6 A and has projections  57  which engage with corresponding recesses  58  of disc  6 A, as shown. Flexible intermediate coupling  8 A is also provided with recesses  59  which engage with corresponding projections  60  of disc  6 A. As illustrated in  FIG. 14  A, the flexible intermediate coupling  8 A occupies the “irregular-shaped” “substantially-annular” clearance or gap G between the discs  2 A and  6 A. Thus, in other words, disc  6 A has a corrugated inner peripheral surface that engages with a corrugated outer peripheral surface of flexible intermediate coupling  8 A. Flexible intermediate coupling  8 A is also provided with a central aperture  61  having an inner corrugated surface having projections  63  and valleys or recesses  64  which engage with an inner corrugated disc  2 A welded to shaft  1 B, as shown. Disc  2 A has an outer corrugated surface having projections  66  and valleys or recesses  67  located between each pair of projections  66 . Disc  2 A is also welded to a support plate  68 . Disc  6 A is also provided with spaced water drain apertures  69 , as shown. There is also provided an inner locking ring  70  having fasteners  71  extending through attachment apertures  72  and outer locking ring  73  having fasteners  74  extending through associated attachment apertures  75 . 
     Each of coupling assemblies  14 A are assembled as shown in  FIG. 16  wherein flexible intermediate coupling  8 A engages with disc  6 A and disc  2 A as described above wherein fasteners  74  extend through aligned apertures  75 , recesses  59  and apertures  76 , as shown and apertures  71  extend through aligned apertures  72 , recesses  64  and apertures  77  in disc  2 A. 
     In the embodiment of the invention shown in  FIGS. 14-16  it will be appreciated that central flexible coupling  3  has been retained but apertures  18  have now been omitted in a similar manner as shown in the  FIGS. 7-9  embodiment or the  FIGS. 11-13  embodiment. 
     Also plates  2 ,  6  and  8  of the  FIGS. 1-6  and  FIGS. 7-9  embodiments have been replaced by discs  2 A,  6 A and flexible intermediate coupling  8 A in the  FIGS. 14-16  embodiment. In regard to the  FIGS. 11-13  embodiment plates  50  and  52  have been replaced by discs  2 A and  6 A and flexible coupling  8  has been replaced by flexible intermediate coupling  8 A. 
     In the embodiment shown in  FIGS. 14-16 , the drive or torque transmitted to shaft  1  has now been totally transmitted through flexible intermediate coupling  8 A to tube  12  without any torque being transmitted through locking pins or fasteners  71  and  74 . The tube will also flex as described in the  FIGS. 5-6  embodiment and thus, shaft  1  will always remain in a horizontal orientation and will not bend. Each of couplings  8 A at either end of shaft  1  facilitates flexing of tube  1  as shown in the  FIGS. 5-6  embodiment. 
     The roller assembly of the invention has advantages over the prior art fixed roller assemblies in that: 
     (i) an increased length of roller is obtainable which is in contact with the golfing green surface to provide increased friction, reduced pressure and thereby increased torque and increased traction; 
     (ii) superior ground hugging ability on flat surfaces or ground surfaces having variable curvature; 
     (iii) increased surface area with the ground lowering ground pressure; 
     (iv) increased traction in a driving situation; 
     (v) no ground ridging or line marks imparted to the ground; and 
     (vi) flexibility across concave or convex surfaces because of the fact that each roller component is not rigidly mounted to the support shaft.