Note: Descriptions are shown in the official language in which they were submitted.
CA 02320024 2000-09-21
METHOD AND APPARATUS FOR MAINTAINING A GOLF COURSE
WATER HAZARD FREE OF DEBRIS
SCOPE OF THE INVENTION
The present invention relates to an apparatus for maintaining a water body
such as a well,
pond, stream or fountain free of debris, and more particularly an apparatus
operable to remove litter
and unwanted reptiles and plant life from a golf course water hazard, and its
method of use.
BACKGROUND OF THE INVENTION
The maintenance of golf course ponds and water hazards presents a challenge
for
greenskeepers. By their nature and purpose, golf course water hazards are
positioned to entrap the
golf balls of all but the most skilled golfers. As a result, a significant
industry has developed in the
reclamation and resale of golf balls from golf course streams and ponds. In
addition, golf course
water hazards are also susceptible to the accumulation of twigs, unwanted
plant life and litter which
creates an unsightly appearance, and which may detract from the overall
favourable aesthetics of
the golf course.
In an effort to maintain a pleasant golf course environment, greenskeepers
periodically clean
the bottom of ponds, streams and other such water hazards to remove debris
such as golf balls, litter,
twigs and any unwanted plant life which accumulates therein. Pond and stream
cleaning is usually
done manually by a scuba diver who enters the water hazard, and manually
collects the debris from
the pond or stream bottom.
Manual cleaning of golf course water hazards is both inefficient and time
consuming. As
well, the use of scuba equipment necessitates that the diver is wholly
immersed in the water, which
may possibly lead to infection or diseases if water borne bacteria is present,
or even death in the
CA 02320024 2000-09-21
2
event of equipment malfunction. 1n addition to the inherent dangers associated
with the use of scuba
equipment, in various areas in the southeast United States, the presence of
alligators in golf course
water hazards places the diver in further jeopardy.
SUMMARY OF THE INVENTION
The present invention seeks to overcome at least some of the disadvantages of
the prior art
by providing a flexible mesh liner adapted to overlie at least part of the
bottom surface of a pond,
stream, fountain, wishing well or other water body, and which may be raised
from the water body
at least in part, to permit easy collection and removal of any debris which
has accumulated therein.
Another objective of the invention is to provide an apparatus which may be
used to maintain
the bottom surface of a pond or stream substantially free of debris such as
litter and/or any unwanted
plant life, without requiring a user to physically immerse him or herself in
the pond or stream.
Another objective of the invention is to provide an apparatus for facilitating
the removal of
debris, such as golf balls, litter, and/or unwanted plant life, from golf
course water hazards.
A further objective of the invention is to provide a flexible mesh liner for a
pond or stream
which has a mesh opening size selected to substantially prevent the movement
of golf balls and litter
therepast, while permitting substantially unrestricted water movement
therethrough.
Another objective of the invention is to provide an apparatus for a golf
course water hazard
which is sized to overlie at least part of the bottom surface of the hazard,
and lifting mechanism
adapted to raise part of the mesh above the water hazard to a height to permit
the easy removal of
any debris, litter or golf balls which has collected thereon.
Another objective of the invention is to provide an apparatus which may be
used to
periodically disturb growing plant vegetation in a pond, stream or other water
body, to substantially
CA 02320024 2000-09-21
3
prevent unwanted plant life from taking root therein.
A further objective of the invention is to provide an apparatus used to lift
debris from the
bottom surface of a water body, and which includes a mesh which is movable
between a submerged
orientation substantially in overlying juxtaposition with the bottom surface
of the water body, and
a raised orientation where at least part of the mesh is lifted above the water
surface to facilitate the
collection of any debris thereon from an adjacent bank.
The present invention provides an apparatus used to maintain the bottom
surface of a pond,
fountain, wishing well, stream or other water body substantially free of
debris, such as litter,
unwanted plant life and/or golf balls. The apparatus includes a flexible mesh
which is sized to
overlie at least part of the bottom of the water body, and a lifting mechanism
used to lift part, and
preferably almost all of the mesh from the water. A peripheral edge portion of
the mesh is secured
adjacent an edge bank of the water body by anchors such as metal bars driven
through the mesh into
the ground, wire rope, weighted payers placed over the edge of the mesh, or by
other spikes or other
fasteners configured to hold the edge of the mesh firmly in place. The lifting
mechanism is
positioned to engage and lift a portion of the mesh which is remote from the
secured edge portion
between a submerged position and a raised position above the water surface.
Numerous possible lifting mechanisms may be used with the present invention.
In one
simplified embodiment, the lifting mechanism includes a keeper member, such as
a hook or clamp
which releasably engages a coupling member secured either directly to the
mesh, or to a pole or other
mounting structure which in turn is fastened to the mesh. Suitable coupling
members would therefore
include hooks, rings, loops, lifting bars or any other structures suitable for
coupling with the keeper
member. The coupling member is secured to the mesh at a remote location spaced
a distance from
the secured edge portion, and most preferably at a location spaced towards the
centre of the water
body. The keeper member may be mounted on a lift boom or beam and may be
vertically movable
to selectively raise and lower the remote portion of the mesh either by the
operation of pulleys and
wires, or by raising or lowering an end of the lift boom or beam. The lift
boom can be either
CA 02320024 2000-09-21
4
permanently mounted, or mounted on a vehicle or trailer for mobile deployment.
Once the keeper member is joined to the coupling member, the keeper member is
raised, lifting with it both the coupling member and the portion of the mesh
liner which is secured
to the coupling member. The keeper member is raised to a height so that part
and preferably almost
all of the mesh is lifted above the surface of the water body. More
preferably, the keeper member
is used to raise the mesh above the water surface so that substantially all of
the mesh is raised above
and slopes towards the secured edge portion of the mesh. This advantageously
permits any debris
collected on the mesh to move towards its secured edge portion. Raising the
mesh to such a position
thereby facilitates any debris collected thereon to be washed, swept, vibrated
or to move on its own
toward the pond or stream edge, where it may be collected by an individual
standing on the banks
of the stream or pond.
Once the accumulated debris has been cleared from the surface of the mesh, the
keeper
member and coupling member are lowered, permitting the mesh to return under
its own weight to
the submerged position, and most preferably in overlying juxtaposition with
the bottom of the stream
or pond. If a mobile lifting mechanism is provided, the keeper member and
coupling member may
thereafter be uncoupled, and the lifting mechanism repositioned for use
elsewhere.
Although a lift boom and keeper member may present one simplified lifting
mechanism used
to raise and lower the mesh, other lifting structures are also envisioned.
Possible lifting mechanisms
include the use of lift wires mounted on permanently positioned poles and
telescoping pneumatic
and/or hydraulic lift cylinders. In one such alternate embodiment, the portion
of the mesh remote
from the secured peripheral edge is coupled to a telescoping section of a
hydraulic lift cylinder, and
is vertically movable therewith. In a collapsed configuration, the telescoping
section is preferably
partially or wholly submerged beneath the surface of the pond or stream, so
that substantially all of
the mesh lies directly on the bottom of the water body. By extending the
telescoping segments of
the lift cylinders, the portion of the mesh which is remote from the secured
edge is moved to the
raised position, carned by the telescoping cylinders.
CA 02320024 2000-09-21
In a more elaborate construction, the telescoping members may be combined as
part of a
fountain construction, which, when fully extended, directs a water spray onto
the mesh to assist in
moving any accumulated debris towards the secured edge portion, and which when
retracted,
operates as a conventional water fountain.
Accordingly, in one aspect the present invention resides in an apparatus for
maintaining a
bottom surface of a pond or stream in a substantially debris free state,
comprising,
a flexible mesh sized to overlie at least part of said bottom surface,
hold down means for securing an edge portion of said mesh adjacent to an edge
of said pond
or stream,
lifting means for selectively raising a remote portion of said mesh which
spaced from said
edge portion from a submerged position wherein said mesh is substantially in
juxtaposition with said
bottom surface, and a raised position wherein said remote portion of said mesh
is raised vertically
from said pond or stream to a height to permit debris which has accumulated on
the mesh to be
moved away from the raised remote portion in a direction towards the mesh edge
portion.
In another aspect, the present invention resides in a golf course water hazard
liner for
maintaining a bottom surface of a water hazard substantially free of debris,
comprising,
a flexible mesh sized to' overlie at least part of said bottom surface,
wherein said mesh is
characterized by mesh openings having a size which permit substantially
unrestricted movement of
water therethrough while preventing the passage of golf balls therethrough,
said mesh having a peripheral edge portion permanently secured adjacent to an
edge of said
water hazard,
means for selectively moving a remote portion of said mesh which is spaced
from said edge
portion between a submerged position wherein said mesh is substantially in
juxtaposition with said
bottom surface, and a raised position wherein said remote portion is raised
vertically relative to said
edge portion sufficiently to lift substantially all of the mesh from the
water.
CA 02320024 2000-09-21
6
In a further aspect, the present invention resides in a method of maintaining
a bottom surface
of a golf course water hazard free of golf balls, weeds or litter by the use
of a liner comprising,
a flexible mesh sized to overlie at least part of said bottom surface,
an edge portion of said mesh being secured adjacent to an edge of said water
hazard,
lifting means for selectively moving a remote portion of said mesh which is
spaced from said
edge portion between a submerged position where said mesh is substantially in
juxtaposition with
said bottom surface, and a raised position where said remote portion is raised
vertically above said
pond or stream to a height to permit any debris which has accumulated on the
surface of the mesh
to move from the raised remote portion towards the edge portion,
said method comprising the steps of
activating said lifting means to move said remote portion of said mesh to said
raised position,
removing any debris which accumulates towards the edge portion, and
activating said lifting means to lower said remote portion of said mesh to
said submerged
position substantially in juxtaposition with said bottom surface.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more readily understood, a preferred
embodiment of the
invention and variations thereof is described by way of example with reference
to the accompanying
drawings in which:
Figure 1 shows a partial side view of an apparatus for maintaining a golf
course pond free
of debris in accordance with a first embodiment, and in which a mesh pond
liner is shown in a fully
submerged position;
Figure 2 shows a partial side view of the apparatus shown in Figure 1 with the
mesh liner in
a fully raised position positioned substantially above the pond surface;
Figure 3 shows an enlarged perspective side view of a coupling rod used in the
apparatus
CA 02320024 2000-09-21
shown in Figure 1;
Figure 4 shows an enlarged partial perspective view of the mesh liner used in
the apparatus
shown in Figure 1;
Figure 5 shows a partial side view of an apparatus for maintaining the bottom
of a golf
course pond free of debris in accordance with a second embodiment of the
invention, with the mesh
liner moved to a fully submerged position;
Figure 6 shows the apparatus of Figure S with the mesh liner moved to a fully
raised position
suspended above the pond surface;
Figure 7 shows an apparatus for maintaining the bottom surface of a golf
course pond free
of debris and in accordance with a third embodiment of the invention;
Figure 8 shows an enlarged side view of a modified lifting mechanism for use
in the
apparatus of Figure 5 in a retracted position;
Figure 9 shows a side view of the lifting apparatus of Figure 8 in a fully
raised position;
Figure 10 shows a side view of the apparatus of Figure 5 in accordance with
another
embodiment of the invention; and
Figure 11 illustrates a top view of the apparatus of Figure 10.
DETAILED DESCRIPTION OF THE INVENTION
Reference is now made to Figure 2 which shows an apparatus 10 which is used to
maintain
a golf course pond 12 or other golf course water hazard substantially free of
golf balls, litter, twigs,
leaves and other such debris 14. Figure 2 shows best the apparatus 10 as
including a flexible mesh
CA 02320024 2000-09-21
g
liner 16 which is sized so as to substantially overlie the entire bottom
surface 20 of the pond 12 as
is shown in Figure l, and a lifting assembly 18 which, as will be described,
is used to raise and lower
the mesh liner 16 in the pond 12.
The mesh liner 16 is secured along its entire peripheral edge 22 by a series
of spaced V or
U-shaped steel anchors 26. The tines of the U-shaped anchors 26 are inserted
through the mesh
openings 30 (Figure 4) and driven into the ground along the banks 24 of the
pond 12, permanently
securing the peripheral edge 22 of the mesh liner 16 and preventing its
lateral shifting.
Preferably, the mesh liner 16 is formed having the same general configuration
as the bottom
surface 20, so that its peripheral edge 22 extends, at most, only marginally
onto the pond banks 24,
where it may otherwise present an impedance to golf course play. The mesh
liner 16 is formed from
a corrosive resistant material selected to ensure that the liner 16 maintains
both tensile integrity, and
flexibility over extended periods of use. Suitable materials used in the
manufacture of the mesh liner
16 would therefore include corrosive resistant metals and alloys, stainless
steel, either reinforced or
unreinforced nylon, rubber and plastics, although coated wire mesh may also be
used.
Figure 4 shows a preferred mesh configuration wherein the mesh liner 16 is
provided with
a series of generally square openings 30. Each opening 30 has an elongated
dimension D which is
selected large enough to permit substantially unrestricted flow of water
through the mesh liner 16,
while preventing passage of golf balls, litter, twigs or the like. Preferably,
the mesh openings 30
have an elongated dimension D selected at between approximately 1/2 to 1 inch.
Figures 1 to 3 show the apparatus 10 as further including a coupling rod 32.
As will be
described hereafter, the coupling rod 32 is used in the coupling of the mesh
liner 16 to the lifting
assembly 18 for raising and lowering a central portion 34 (Figure 2) of the
mesh liner 16 from and
to the juxtaposed position with the pond bottom 20 shown in Figure 1. The
coupling rod 32 is
secured to the mesh liner 16 at a position spaced towards the centre of the
pond 12, and which is
remote from the anchored peripheral edge 22. As shown best in Figure 3, the
coupling rod 32
CA 02320024 2000-09-21
9
includes a support plate 36 which is approximately 6 to 18" in diameter and
which presents a
generally flat lower surface 38 for resting on the pond bottom 20. A steel
cylindrical post 40 is
mounted perpendicularly on the support plate 36. The post 40 extends from the
plate 36, through
the mesh liner 16 to an uppermost steel ring 42. The vertical post 40 has a
preferred length selected
so that when the support plate 36 rests on the bottom 20 of the pond 12, the
ring 42 locates at a
position marginally above the pond surface 43. A disk-shaped clamping plate 44
is positioned over
the post 40, sandwiching part of the mesh liner 16 between the support plate
36 and clamping plate
44. The clamping plate 44 is secured to the support plate 36 by inserting
threaded fasteners 46
through aligned bores formed in the plates 36,44. It is to be appreciated that
clamping part of the
mesh liner 16 between the support plate 36 and clamping plate 44 achieves a
better distribution of
load forces on the mesh liner 16 at the point where the liner 16 is raised and
lowered.
Figure 2 shows the lift assembly 18 for use in the present apparatus 10 as
comprising a
hydraulically movable lift boom 48 mounted for mobile use on the flatbed of a
truck 50, and a hook
52. The hook 52 is pivotally coupled to a movable free end 54 of the lift boom
48, whereby the
raising and lowering of the free end 54 vertically raises and lowers the hook
52. The boom 48 is
operable to move the free end 54 to a position wherein the hook 52 is
positioned immediately above
the pond surface 43 to engage the ring 42 of the lifting rod 32, and the
raised position shown in
Figure 2.
Figures l and 2 show the operation of the apparatus 12 in use to clean golf
balls, litter, twigs
and other such debris 14 from the bottom surface 20 of the pond 12.
As debris 14 accumulates in the pond 12, it settles on the upper surface of
the mesh liner 16.
To remove the debris 14 from the pond 12, the lift boom 48 is positioned so
that the hook 52
locates vertically above the ring 42. The lift boom 48 is then moved so that
its free end 54 and the
hook 52 move downwardly to the surface 43 of the pond 12 and the ring 42. The
hook 52 is then
brought into engagement with the ring 42 coupling the lift assembly 18 and
coupling rod 32. Once
the hook 52 is coupled to the ring 42, the free end 54 of the boom 48 is moved
upwardly, lifting the
CA 02320024 2000-09-21
rod 32 and the portion 34 of the mesh liner 16 off of the bottom surface 20.
By raising the end 54 of the lift boom 48, the coupling rod 32, and thereby
the central 34
portion of the mesh 16 which is attached thereto may be raised above the pond
surface 43 to the
position shown in Figure 2. Preferably, the rod 32 is lifted so that almost
the entire mesh liner 16
is lifted above the pond surface 43. More preferably, the central portion 34
of the mesh 16 at the
coupling rod 32 is raised above the secured peripheral edge 22 to a sufficient
extent so that in the
raised position, the mesh liner 16 slopes from the central portion 34 to the
secured peripheral edge
22. In this position, any debris 14 which has accumulated on the mesh 16
either moves under
gravity, or may be easily blown, washed by high pressure water spray or swept
to the edge 22.
Alternately, the lift assembly 18 may be provided with a vibrator (not shown)
which imparts
vibratory movement to the hook 52 to vibrate the raised mesh 16 and assist in
movement of the
debris 14 towards the edge 22 and pond banks 24.
It is to be appreciated that on moving the mesh 16 between the raised position
shown in
Figure 2 and the submerged position shown in Figure 1, the mesh openings 30
permit the mesh 16
to pass substantially unobstructed through the water. The sizing of the
opening 30 further prevents
the debris 14 which has collected on the mesh liner 16 from moving through the
openings 30 as the
liner 16 is raised where it may otherwise remain in the pond 12. Once the
debris 14 moves from the
raised central portion 34 to the anchored peripheral edge 22, it may be
collected and removed by
groundskeepers from the pond banks 24, without necessitating the use of divers
or emersion into the
pond.
After the debris 14 has been collected and removed from the mesh 16, the free
end 54 of the
boom 48 is lowered, lowering the hook 52 vertically to reposition the support
plate 36 of the
coupling rod 32 on the pond bottom 20. As the coupling rod 32 is lowered, the
weight of the mesh
16 causes it to return under its own weight to the submerged position shown in
Figure 1,
substantially in overlying juxtaposition with the pond bottom 20.
CA 02320024 2000-09-21
11
It is envisioned that in addition to facilitating the retrieval of lost golf
balls and the cleaning
of the pond 12, periodic raising and lowering of the mesh liner 16 will
advantageously disrupt
sedimentation on the pond bottom 20. This periodic disruption, in turn will
discourage both the
habitation of the pond 12 by large reptiles as well as plants from taking
root, ultimately reducing
unwanted plant growth in the pond 12.
It is to be appreciated that providing the vertical post 40 with a length
selected so that the
ring 42 rests above the pond surface 43 facilitates the connection of the ring
42 and the lifting
assembly hook 52. The invention is not, however, so limited. If desired, the
post 40 could have a
length selected so that when support plate 36 rests on the pond bottom 20, the
ring 42 is fully or
partially submerged. Similarly, while the use of a ring structure facilitates
coupling to the lift boom,
other configurations of connectors are also possible and will now become
apparent, including the
use of hooks and the like. Although not shown, to create a more aesthetically
pleasing appearance,
the ring 42 could further be either provided with ornamentation, or
incorporated as part of a water
statue or other ornamental feature.
While Figures 1 and 2 disclose the use of a coupling rod 32, lift boom 48 and
hook 52 as the
mechanism for raising and lowering the central portion 34 of the mesh 12, the
invention is not so
limited. Figures 5 and 6 show an alternate embodiment of the invention where
like reference
numerals are used to identify like components.
In Figures 5 and 6, the lift assembly 18 consists of a hydraulically operable
(or alternately
pneumatically or mechanically operable) telescoping lift 58 and a remote
control unit 61. The lift
58 includes three telescoping sections 60a,60b,60c (Figure 6) and is operated
by the remote control
unit 61 which controls the movement of the sections 60 by submerged cable 63.
The telescoping
sections 60a,60b,60c are positioned towards the centre of the pond 12 for use
in raising and lowering
the mesh liner 16 in the pond 12. Although not essential, the central portion
34 of the mesh 16 is
preferably coupled to at least telescoping section 60c which may, for example,
include equivalent
sandwiching support and clamping plates 36,44 to better distribute tensile
stresses on the mesh 16
CA 02320024 2000-09-21
12
as it is raised and lowered.
Figure 5 shows the lift assembly 18 with the telescoping sections 60 in a
fully retracted
position, and wherein the mesh liner 16 is in a submerged position beneath the
surface of the pond
12.
In an extended position shown in Figure 6, the telescoping sections 60b,60c
are raised
relative to section 60a. As the sections 60b,60c are extended, section 60c
carnes with it the central
portion 34 of the mesh liner 16. As with the embodiment shown in Figures 1 and
2, the central
portion 34 of the mesh liner 16 is raised above the pond surface 43, so that
substantially all of the
mesh 16 is moved above the anchored peripheral edge 22, and that any debris 14
collected on the
mesh 16 will move towards the pond banks 24. As with the embodiment shown in
Figures 1 and
2, once the mesh 16 is moved to the fully raised position, brushes, blowers
and/or high pressure
hoses may be used to assist in moving the collected debris 14 towards the
secured peripheral edge
22.
To return the mesh liner 16 to the fully submerged position, the controller 61
is used to
retract the telescoping sections 60b,60c, and the mesh liner 16 is permitted
to settle under its own
weight onto the pond bottom 20.
Although the embodiments of the invention described with reference to Figures
1 to 6
illustrate the invention as including a single coupling rod 32 or telescoping
lift 58 used to raise the
mesh 16, the invention is not so limited. Figure 7 shows an alternate
embodiment of the invention
in which like reference numerals are used to identify like components.
Figure 7 shows the use of the apparatus 10 on a larger, and more irregular
shaped pond 12,
wherein a number of telescoping lifts 58a,58b are used to raise and lower the
mesh liner 16. The
telescoping lifts 58a,58b are essentially identical to that described with
reference to Figures 5 and
6 and are spaced from the anchored peripheral edge 22 of the mesh liner 16
towards the centre of the
CA 02320024 2000-09-21
13
pond. The telescoping sections of each lift assembly 58a,58b may be either
sequentially or
simultaneously extended to lift part or substantially all of the mesh 16 above
the pond surface to
remove any accumulated debris 14 from the pond bottom 20.
In a more elaborate construction shown in Figures 8 and 9, the telescoping
lift 58 carries with
it a fountain assembly 70. In such an embodiment, the lift 58 includes a
conventional fountain head
72 which operates as a conventional pond fountain when the telescoping
sections 60b,60c are
retracted as is shown in Figure 8. When the sections 60b,60c are extended, as
is shown in Figure
9, a valve (not shown) is operated to divert the fountain water spray to
secondary water outlets 74.
The outlets 74 are positioned radially about the upper end of the section 60c.
The outlets 74 direct
water spray onto the upper surface of the mesh liner 16 to assist in moving
the debris 14 thereon to
the peripheral edge 22.
Although the preferred embodiment of the invention discloses the use of V or U-
shaped
anchors 26 as used to secure the edge 22 of the mesh liner 16 in place, the
invention is not so limited.
Numerous other anchoring structures are also possible and will now become
apparent. By way of
non-limiting examples, suitable anchors used to secure the peripheral edge 22
of the liner 16 would
include payers, spikes and the like.
Although the preferred embodiment of the invention discloses the coupling of
part of the
mesh 16 in a sandwiched configuration between the support plate 36 and the
clamping plate 44, other
mesh supporting structures may also be used. By way of one non-limiting
example, support wires
may be positioned underneath the mesh 16 extending from the secured edges 22
to the central
portion 34 of the liner 16 which is to be directly raised and lowered by the
lift assembly 18. In lifting
the mesh liner 16, the support wires would operate to cradle the mesh liner 16
and reduce the
likelihood that it may tear under its own weight.
Although Figure 1 shows a pivoting lift boom 48 as raising and lowering the
hook 52, the
invention is not so limited. If desired, the lift boom 48 could be rigidly
mounted, and the hook 52
CA 02320024 2000-09-21
14
could be raised or lowered by a series of wires and pulleys coupled to the
boom 48.
Figures 1 to 9 describe the use of the apparatus on a golf course pond 12. It
is to be
appreciated, however, that the present invention is equally suitable for use
in pools, water fountains,
wishing wells, streams and other water bodies where the accumulation of litter
and the like poses
a problem.
Figures 10 and 11 illustrate a lift assembly similar to that shown in Figure
5, and wherein like
reference numerals are used to identify like components. In Figures 10 and 11,
the lift assembly 18
is operated by two pneumatically telescoping lifts 58a,58b, spaced towards a
central portion of the
pond 12. The lifts 58a,58b are operable by means of a portable or mobile air
pressure unit 80 which
supplies the necessary air pressure to extend the lifts 58a,58b and raise the
mesh via air hoses 84,86.
If desired, the submerged air hoses 84 may be provided as a fixed line with
quick connect couplers
88 used for coupling the air hose 86.
While the use of V or U-shaped anchors 26 permits the simplified securement of
the
peripheral edge 22, the invention is not so limited. If desired, the edge of
the liner 16 could be
retained by placing weighted payers on the edge 22, or alternately, by the use
of rope and/or wire.
Although the disclosure describes and illustrates preferred embodiments of the
invention, it
is not so limited. Many variations and modifications will now occur to those
skilled in the art. For
a definition of the invention, reference is made to the appended claims.
