Tubular plant guards

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.

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 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.