Abstract:
A plant guard is made of a sheet of material which is formed into a tubular shape. Side marginal edges of the sheet are secured together by a fastener. A flap is formed at one end adjacent one side marginal edge, the flap being folded, in use, over a supporting wire so that the wire passes in front of and adjacent the engaged marginal edges to prevent disengagement thereof.

Description:
FIELD OF THE INVENTION 
     This invention relates to improvements in tubular plant guards and relates particularly to an improved plant guard for protection of small plants, such as newly planted vines, e.g. grape vines, trees or the like. 
     BACKGROUND OF THE INVENTION 
     It is common practice in vineyards, for example, to use an elongate hollow guard placed around a young vine at the time of its planting to protect it during its early growth period. One such guard is described in the specification of Australian Patent Application No. 23516/92. This guard comprises a panel of flexible material adapted to be formed into a tubular body and releasably fastened in a tubular condition by means of cooperating tabs and slots provided along the vertical edges of the panel which are to be joined together. This allows the guard to be supplied as a blank in a flat, unfolded condition and subsequently formed into the tubular shape by a folding and interlocking operation 
     The guard disclosed in the specification has several disadvantages, including the difficulty of engaging the individual tabs into the appropriate slots. This is both time consuming and awkward particularly when the guard is of a length which makes it difficult to reach all tabs and slots. 
     U.S. Pat. No. 4,969,555 to Fitzgerald discloses another form of guard which uses fabric material having a plurality of sets of mating fasteners attached along opposite side edges thereof The material is placed around the base of a growing tree, and the bottom sets of mating fasteners are buckled around the trunk of the tree. Subsequently fasteners are in turn buckled which, in the case of a tree, progressively compresses the tree branches upwardly. This form of guard is relatively difficult to manufacture and requires substantial time and effort to engage in position. 
     U.S. Pat. No. 5,347,750 to Mills discloses plant protectors of a variety of forms including a form formed of extruded sheet material the opposite side edges of which are adapted to interlock. However, the edge portions of the panel material, in use, face in opposite directions and overly each other to enable one to be connected to the other. The join is, therefore, an overlapping join and disadvantage of this structure is the difficulty in interlocking the tab within the recess, particularly in the case of an elongated guard. 
     Another guard is described and illustrated in U.S. patent application No. 5,809,690. The guard of this patent is formed from a panel of plastics material which is folded into a tubular shape with adjacent vertical margins of the panel being connected together by means of a recallable zip type fastener which comprises fastener strips. Each strip has a locking profile portion which is adapt to releasably interlock with the locking profile portion of the other strip. The fastener strips arc secured to the opposite edge portions of the panel by heat welding or by means of an adhesive. The embodiments illustrated in the specification show the guard with an upstanding rear tab adapt to engage a wire of a wire trellis to secure the guard to the trellis. 
     The guards disclosed in the aforesaid prior patent specifications may be improved from the point of view of a user in terms of case and security of fasting together of the vertical margins of the guard panel. In particular, it has been found that the joining together of the vertical margins of the guard panel using cooperating tabs and slots is generally unsatisfactory in that the tabs, in some instances, become disengaged from their slots and gaps are created along the edges of the vertical margins. Such gaps allow entry points for chemical sprays such as herbicides, which can have a deleterious effect on a young plant. 
     It is also been found that the use of a zipper-type fastener as described in our U.S. Pat. No. 5,809,690 aforesaid, while a substantial improvement on tabs and slots and other fasteners for securing together the vertical margins of the guard panel, may also be unsatisfactory in some instances where pressure is exerted against the and of the fastener which may cause the fastener strips to disengage, particularly at the upper end. Thus, a vine within the guard may push against the upper edges of the fastener strips, or rest on the upper edges, and cause the strips to disengage. 
     SUMMARY OF THE INVENTION 
     It is therefore desirable to provide an improved plant guard which avoids the stated disadvantages of the prior guards. 
     It is also desirable to ode a plant guard having an improved structure but which is of simple construction and which allows the guard to be retained in its tubular shape quickly and simply. 
     It is also desirable to provide an improved plant guard which has a fastening means designed, when fastened, to in the fastened state, 
     In accordance with one aspect of the invention there is provided a plant guard comprising a sheet of martial which is adapted to be formed into a tubular shape, the sheet having opposed marginal edges which, in the tubular shape, are adjacent, fastener means to fasten the marginal edges together, flap means at one end of the sheet and adapted to be folded over a substantially horizontally extending support means, said flap means being adjacent said marginal edges of said sheet when in the tubular shape, with the said marginal edges and associated fastener means adapted to engage behind said support means when said flap is folded thereover. 
     In one preferred embodiment, the sheet of material comprises a panel of synthetic plastic, hollow profile sheet, such as “CORFLUTE” (trade mark) which is an extruded, synthetic plastics sheet material having outer facing layers interconnected by a plurality of closely spaced, substantially parallel webs forming a series of elongate, internal channels or flutes extending along the length of the panel. 
     Preferably, the fastener means comprises interlockable resilient flexible fastener strips respectively secured to and extending along the opposed marginal edges, said fastener strips having locking profile ribs which interlock with one another so as to provide a reclosable, essentially zip-type fastener. Such a zip-type fastener is disclosed in U.S. Pat. No. 5,809,690 aforesaid. However, other fastener means, may be used in the performance of this invention. 
     If desired, the base of the plant guard may be provided with outwardly projecting flap portions each of which is hinged to a lower end of a tubular guard along a hinge line so that, in use, the flaps can be buried in the ground to provide a support base for the guard. Such a guard panel is disclosed in the earlier Australian Patent Application aforesaid. 
     When the guard in accordance with the present invention is retained in its assembled tubular shape by fastener means, and the flap means is engaged over the horizontally extending support means, which is preferably a trellis wire, the opposed marginal edges and associated fastener means are engaged behind the support wire thereby preventing the fastener means becoming disengaged at least at the upper end by application of accidental external forces or the like. 
     In order that the invention is readily understood, an embodiment thereof will now be described with reference to the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a plant guard in its flat condition according to one embodiment of the invention 
     FIG. 2 is an and view of the guard shown in FIG. 1 in its folded, tubular shape and assembled to a trellis wire; 
     FIG. 3 is a side elevational view of the guard of FIG. 2; 
     FIG. 4 is an enlarged plan view of the fastened edge portions locked behind a trellace wire; and 
     FIG. 5 is a plan view similar to that of FIG. 4 but illustrating a modification of the invention incorporating a stake. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, there is shown a plant guard  10  produced form a sheet of synthetic plastic flute board material such as that sold under the trade mark “CORFLUTE”. This material, as indicated above, is an extruded synthetic plastics sheet material having spaced outer surfaces  31 ,  32  inter-connected by substantially parallel webs  33  (see FIG. 4) forming a plurality of elongate channels or flutes which extend the length of the sheet material. This material is well known and will not be described in detail. 
     The sheet of material is cut into a blank  11  of any suitable length with the core flutes running longitudinally as shown in FIGS. 2 and 4. A pair of lengthwise fold lines  12  allows the blank  11  to be folded into the tubular triangular shape as shown in FIG.  2 . One end of the blank  11 , which will form the upper end of the guard  10 , has a cut away section  13  which tapers downwardly from the upper end of the blank  11  and is designed to allow vine shoots or runners from a vine (around which the guard is placed in use), to pass laterally outwards from the interior of the guard as the vine plant grows upwardly) 
     Opposed marginal edges  14  and  15 , which extend longitudinally of the blank  11 , have elongate fastener strips  16  and  17  secured thereto, as by adhesive, stitching, heat welding, mechanical attachment or other securing means. In this embodiment, the fastener strips  16  and  17  arc of the type as shown in FIG.  4 . It will be appreciated, however, that other forms of fastener strips, may be used in the performance of this invention. Alternatively, the marginal edges  14  and  15  may be secured by interlocking tabs and slots, stitching, or by any other fastening means. 
     The end of the blank  11  between the edge of the cut away  13  and the marginal edge  14  is formed with a flap  18 . A horizontal fold line  19  enables the flap  18  to fold downwardly coplanr with the side of the blank  11  which, in use, forms the back of the guard  10 . It will be seen that the horizontal fold line  19  is located in such a position that, when he flap  18  is in its folded position, the upper ends of the marginal edges  14  and  15  and the attached fastener strips  16  and  17  extend beyond the folded flap  18 . 
     As illustrated in FIGS. 1 and 2, at the opposing end of the blank  11  projecting flap portions  20  are hinged to the opposing end of the blank  11  so that when projected outwardly they provide support for the Guard  10 . 
     FIGS. 2,  3  and  4  illustrate the guard  10  of this embodiment in use as attached to a trellis wire  21  commonly used in vineyards and the like to support the vines. The blank  11  is folded to the tubular guard ape which, in this embodiment, is triangular in cross section as shown in FIG.  2 . It will be appreciated that any other cross sectional shapes may be used in the performance of this invention. In the folded position, the fastener strips  16  and  17  are interlocked by engaging interconnecting ribs  22  and  23  as described in the U.S. Pat. No. 5,809,690 aforesaid In the assembled condition, the guard  10  is located with the flap  18  and the engaged upper ends  24  and  26  of the fastener strips  16  and  17  behind the trellis wire  21  while the cut away sides of of the guard  10  extend forwardly of the wire  21 . The flap  18  is folded forwardly over the wire as shown in FIG. 3, and is retained in the folded position by a U shaped clip  27 . 
     It will be seen that, in the assembled condition as shown in FIGS. 2,  3  and  4 , the upper ends  24  and  26  of the fastener strips  16  and  17  are locked together behind the trellis wire  21  by the folded flap  18 . This, then, prevents the fastener strip  16  and  17  becoming disengaged at their upper ends  24  and  26 . The locking of the fastener strips in the engaged condition provides substantial advantages over previous plant guards where fastener means have had a tendency to disengage in use, particularly when harshly treated by agricultural equipment and the like or when the vines grow and push out branches against the interlocked fastener strips  16  and  17 , particularly at their upper ends  24  and  26 . 
     The guard of the invention may be easily removed from engagement with a plant by relating the connection of the flap  18  with the trellis wire  21  and then disengaging the fastener strips  16  and  17  to enable the guard to be opened and removed from its engagement with a vine or young plant. 
     The guard of the present invention may be incorporated with a vine stake  30  whereby the fastener strips, rather than fastening together, engage respective sides of the stake which is adapted to engage the ground. With this arrangement, the stake  30  would also be located behind the wire  21  and held there against by the flap  18  as shown in FIG.  5 . The stake  30  is preferably of extruded plastics material having the fastener ribs formed integral therewith or subsequently attaches as separate strips.