Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: GOLF GREEN COVER
FIELD OF THE INVENTION
The present invention relates to flexible ground covers, and more
particularly, the present invention pertains to a water-impermeable, heat-
insulating golf green cover having breathing abilities to aerate and to
evacuate noxious gases from the covered grass.
BACKGROUND OF THE INVENTION
It is generally well known that golf greens have very short and
dense turf that is susceptible to freezing and wind burn during the winter
months, especially in regions where there is insufficient snow or belated
snow fall to protect the root systems of the grass. It is also known that too
much water absorption by the grass of a golf green that is later subject to
freezing temperatures, is often detrimental to the plants for expanding and
bursting the roots of the plants. It is therefore preferable to protect a golf
green with a water-impermeable cover during winter, to prevent excessive
water absorption by the grass and to shield the grass from winter
conditions.
A water-impermeable cover, however, is often airtight. It deprives
the soil of oxygen and tends to accumulate carbon dioxide, nitrous oxide
and methane. The lack of aeration together with a prolonged moisture
stress predispose the grass to rotting fungi and other plant diseases. It is
therefore also preferable to protect a golf green with a water-impermeable
cover which has breathing abilities to periodically aerate and evacuate
noxious gases.
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It is also believed that it is preferable to install a heat-insulating
cover over a golf green to protect the grass from freeze-and-thaw cycles in
case of an absence or a scarcity of snow.
A number of ground covers have been developed in the past to
protect the grass of recreational grounds. Examples of these covers are
illustrated and described in the following documents:
US Patent 974,091 issued on Oct. 25, 1910 to J.L. O'Donnell;
US Patent 1,576,888 issued on Mar. 16, 1926 to J.H. Woodward;
US Patent 1,580,396 issued on Apr. 13, 1926 to J.H. Woodward;
US Patent 1,966,687 issued on July 17, 1934 to J.A. Scott et al.;
US Patent 2,578,135 issued on Dec. 11, 1951 to C.J. Hoigaard et al.;
US Patent 2,540,380 issued on Feb. 6, 1951 to L.J. Schultheis;
US Patent 2,848,233 issued on Aug. 19, 1958 to H.D. Wynn;
US Patent 3,005,461 issued on Oct. 24, 1961 to R. Arganbright;
US Patent 3,099,444 issued on July 30, 1963 to F.E. Burt;
US Patent 3,108,804 issued on Oct. 29, 1963 to A.W. Wagner;
US Patent 4,050,972 issued on Sept. 27, 1977 to D.E. Cardinal, Jr.;
US Patent 4,590,714 issued on May 27, 1986 to S.F. Walker;
US Patent 4,632,329 issued on Dec. 30, 1986 to W.G. Burley;
CA Patent 1,272,027 issued on July 31, 1990 to C.A. Hinsperger.
Although the prior art ground covers deserve undeniable merits,
there is no known prior art cover which combines the advantages of
preserving a golf green from all the aforesaid winterkill conditions. As
such it may be appreciated that there continues to be a need for a golf
green cover which is water-impermeable, which has heat-insulating
properties, and which has means to periodically ventilate the covered
grass.
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SUMMARY OF THE INVENTION
The present invention provides for a heat-insulating, water
impermeable golf green cover which has water-resistant seams and non
collapsible air passages to evacuate offensive gases accumulating under
the cover.
Broadly, in a first aspect of the present invention, there is provided
a golf green cover comprising at least one flexible panel having first and
second layers bonded to each other. The second layer has heat-insulation
properties and perforations therein. There are also provided a plurality of
air passages between the first and second layers communicating with the
perforations. When this flexible panel is laid on a grass, the grass is
protected from winter conditions and the air passages and the perforations
are usable for aerating and removing harmful gases from the covered grass.
In accordance with another aspect of the present invention, the golf
green cover further comprises a ventilator connected to the air passages.
The ventilator is a wind-actuated-type rotary ventilator. A major
advantage of this installation is that noxious gases accumulating under the
cover are automatically evacuated by the action of the wind on the
ventilator.
In accordance with yet another aspect of the present invention, the
second layer is bonded to the first layer along bond lines extending across
each panel. The air passages mentioned before comprise transversal air
passages extending between the bond lines. Each of the transversal air
passages has a cross-section comprising a cord segment and an arc
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segment being longer than the cord segment. When the cover is
compressed under a substantial amount of snow, the arc segments tend to
buckle and form ripples without completely obstructing the transversal air
passages, whereby ventilation of the grass is still maintainable.
In yet another aspect of the present invention, there is provided a
golf green cover comprising at least one flexible panel laid on a grass and
having a water-impermeable top layer and a heat-insulating bottom layer
attached to the top layer. There is also provided a thermocouple bonded
to an underside surface of the bottom layer. This thermocouple is usable
to develop a history of the conditions of the covered golf green and to
develop knowledge of the best installation and removal time, the ideal
heat-insulating properties and so forth for a covered golf green. The
thermocouple is also usable to control ventilation equipment connected to
the aforesaid air passages, to automatically ventilate the grass and evacuate
noxious gases under preferred temperature conditions.
In still another aspect of the present invention, there is provided a
golf green cover comprising a pair of juxtaposed flexible panels each
having a central region, a water-impermeable top layer and marginal strips
bordering the central region and having spaced-apart grommets there-
along. The adjacent marginal strips in the juxtaposed panels are lashed to
each other and are set in an elevated mode relative to the central region.
This installation is advantageous for preventing water and melting snow
accumulating on the central region of the cover from seeping between the
juxtaposed panels.
In accordance with a further aspect of the present invention, the
adj acent marginal strips are lashed to each other by a string laced through
the grommets. The string has a series of spaced apart loops. A stitch is
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formed with one loop extending through a pair of juxtaposed grommets
and into an adj acent loop. The stitch is easily undone in the spring for
example, by pulling of the string such as on a broken thread in a garment.
Still another feature of the invention is that it is susceptible of a low
cost of manufacture with regard to materials, equipment and labour, and
which accordingly is then susceptible of low price of sale to the industry,
thereby making such golf green cover economically available to the golf
course owners.
Other advantages and novel features of the invention will become
apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the present invention selected by way
of examples will now be described with reference to the accompanying
drawings in which:
FIG. 1 illustrates an installed golf green cover according to the preferred
embodiment of the present invention;
FIG. 2 is a top view of the golf green cover;
FIG. 3 is a side view of the golf green cover;
FIG. 4 is a cross-section view of a raised seam or j oint between the panels
of the golf green cover and of the gas collection pipe, as seen along
line 4-4 in FIG. 2;
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FIG. 5 is a cross-section view of an upright seam or joint between the
panels of the golf green cover, as seen along line 5-5 in FIG. 2;
FIG. 6 is a cross-section view through the thickness of the golf green
cover as seen along line 6-6 in FIG. 2 and illustrating cross-
sections of the transversal air passages in the cover;
FIG. 7 is also a cross-section view through the thickness of the golf
green cover as seen along line 6-6 in FIG. 2 illustrating the
longitudinal air passages in a compressed mode, under a snow load
for example;
FIG. 8 is a cross-section view through the thickness of the golf green
cover as seen along line 8 in FIG. 4 showing the transversal air
passages near the slits across the transversal air passages along the
gas collection pipe;
FIG. 9 is a cross-section view through the thickness of a golf green cover
illustrating a first alternate arrangement forming transversal air
passages;
FIG. 10 is a cross-section view through the thickness of a golf green
cover illustrating a second alternate arrangement forming
transversal air passages;
FIG. 11 illustrates a top view of the upright joint between adjacent panels
of the golf green cover and a preferred lashing thereof;
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FIG. 12 is a side view of the lashed upright joint as seen along line 12-12
in FIG. 5;
FIG. 13 is a cross-section view through an edge of the cover showing a
preferred placement of the temperature probe under the cover;
FIG. 14 is a first perspective view of a preferred peg usable to retain the
golf green cover to the ground;
FIG. 15 is another perspective view of the preferred peg with a protective
liner installed over the crossbar thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
While this invention is susceptible of embodiments in many various
forms, there is shown in the drawings and will be described in details
herein a specific embodiment and alternate arrangements of some feature
of this specific embodiment, with the understanding that the present
disclosure is to be considered as an example of the principles of the
invention and is not intended to limit the invention to the embodiment
illustrated.
The golf green cover 20 according to the preferred embodiment is
illustrated in its entirety in FIGS. 1 and 2. The golf green cover 20 is
made of two or more flexible panels 22, 24, 26 that are laid side by side
and have combined deployed dimensions in excess of the area to be
protected. In common applications, the golf green cover 20 is
manufactured in panels having widths'A' of between about 30-40 feet (9-
12 m) and lengths'B' of 80-100 feet (24-30 m) or more.
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In use, the juxtaposed panels 22, 24, 26 are lashed to each other as
will be described later, and are pegged to the ground through grommets 28
in the marginal strips 30 along the outside edges of each panel. The
grommets 28 are spaced at about 12-14 inches (30-35 cm) intervals.
As will be understood from the following disclosure, the golf green
cover 20 has air passages 32 that are integrally formed in the structure of
each panel. The ventilation of the covered turf is effected through these air
passages and through one or more gas collection pipes installed under one
or more seams of the cover.
Refernng to FIGS. 2, 3, 4 and 5, there are two types of marginal
strips around each panel; the first type is a same thickness as the panel
itself and is referenced by numeral 30, and the second type is thinner than
the panel and is referenced by numeral 36. Both types are usable to make
different joints or seams between the panels. The marginal strips of the
first type 30 are attachable to each other and to the gas collection pipe 34,
as shown in FIG. 4 to make a first type of seam or joint, referred to herein
as a raised seam or joint 38. The marginal strips of the second type 36 are
usable to make a second type of seam or joint as illustrated in FIG. 5 and
referred to herein as an upright seam 40. Both types of seams 38, 40 have
distinct features and advantages and are usable together, or solely, in a
same cover depending on the conditions at the installation site.
In the raised joint 38, both marginal strips 30 of the first type are
set over each other and retained to the gas collection pipe 34 to prevent
water from seeping between the panels. Similarly, in an upright seam 40,
adjacent strips 36 ofthe second type are set in an upright mode flat against
each other, and retained in this manner by a string 42 or a light rope laced
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through the grommets 28 in these strips. This upright joint 40 also
prevents water or melting snow which may accumulate over the cover
from seeping between the panels.
When an outside edge of the cover 20 is laid over a depression 44
in the soil, a flat bar 46 made of malleable material is preferably laid over
the section of the marginal strip 30 or 36 immediately over the soil
depression, and is pegged down to retain the outside edge of the cover
down against the contour of the ground at that location. The preferred
malleable material of the flat bar is mild steel or low-yield-strength
aluminium. The use of such flat bars 46 along the outside edges prevents
the infiltration of cold air under the cover.
Referring specifically to FIGS. 4 and 5, the golf green cover 20
according to the preferred embodiment, comprises a top layer 50 made of
light-reflecting and water-impermeable material; an intermediate layer 52
made of a semi-rigid, closed cell, water-impermeable and insulating foam,
such as a closed cell polyethylene foam for example, and a bottom layer 54
also made of semi-rigid low density insulating foam. The intermediate and
bottom layers 52, 54 are made of juxtaposed strips of foam sheeting and
have seams at right angle to each other. The top layer 50 is bonded to the
intermediate layer 52 along the marginal strips 30 or 36. The marginal
strip 30 or 36 comprises a double thickness of the light-reflecting, water-
impermeable top layer material. The second thickness or flap 56 of the top
layer 50 extends under and is bonded to the bottom layer 54. This flap 56,
together with the top layer 50 contribute to securing both insulating layers
52, 54 to the marginal strips 30 or 36.
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The top layer 50 is preferably made with an ultraviolet-light
resistant, reinforced plastic fabric tarpaulin, being white in color and
having strength, stiffness and scratch-resistance to resist limited foot
traffic
and limited movements of small wheeled-vehicles.
Both insulating layers 52, 54 have thicknesses and heat-insulating
properties selected according to the location of the golf green to be
protected and the winter conditions at that location. The thickness of each
layer and the total insulating properties of the cover is preferably
determined to maintain a temperature under the cover of between about
minus 10 and minus 5 degree Celsius in cold weather, and of between
minus 5 and 0-degree Celsius during warm thaw periods.
As mentioned, the material of the intermediate layer is preferably a
closed cell water-impermeable foam. This material constitutes an
additional protection against infiltration of water through the cover,
whereas the top layer may be susceptible to damage from rough traffic,
from improper handling or from improper installation.
Referring now to FIGS.1, 2, 6 and 8, the bottom layer 54 is bonded
to the intermediate layer 52 along transversal bond lines 58 across each
panel. The width 'C' of each bond line 58 may vary according to the
adhesive or welding method utilized during the fabrication of the cover,
and according to physical properties and dimensions of the panels. Prior
to bonding the bottom layer 54 to the intermediate layer 52, the bottom
layer 54 is formed into a series of juxtaposed elongated valleys extending
across the panel. During the bonding of the layers, the intermediate layer
52 is maintained in a flat alignment. When the intermediate layer 52 is
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bonded to the bottom layer 54, the intermediate layer 52 and the valleys
formed in the bottom layer 54 define the transversal air passages 32 across
each panel. The forming of these transversal air passages 32 and the
bonding of the layers are not explained in details herein because various
methods are available to those skilled in the art of foam structure
fabrication.
The configuration of the transversal air passages 32 is advantageous
because the air passages do not completely collapse under heavy snow
loads. Each curved wall 62 of the bottom layer 54 has an arc length which
is longer than the width or the cord length of the straight segment 64 of the
intermediate layer 52. When the golf green cover is under pressure, such
as under a thick snow cover, the curved wall 62 of bottom layer tends to
buckle and form ripples as illustrated in FIG. 7. These ripples allow the
passage of air there-along such that the ventilation of the cover is
nevertheless maintainable.
It will be appreciated that the valleys formed in the bottom layer 54
also form air passages 68 between the bottom layer 54 and the covered
turf. These air passages 68 also contribute to aerating the covered turf.
The bottom layer 54 has perforations 70 therein to allow the passage
of gases from the covered grass to the transversal air passages 32. These
perforations 70 are also advantageous for selectively aerating the covered
grass as will be explained later.
Referring back to FIGS. 4 and 5, the extremities of the transversal
air passages 32 and 68 are in communication with each other across
longitudinal air passages 72, 74 extending under the raised seam 38 and
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the upright seam 40 respectively. The gas collection pipe 34 is installed
in the longitudinal air passage 72. The gas collection pipe 34 is preferably
a ribbed plastic pipe with perforations 76 therein. The gas present in the
covered turf, as represented by arrows 78, is therefore free to flow through
the perforations 70; along the transversal air passages 32, 68; across the
longitudinal air passages 74; along the longitudinal air passages 72 and
into the gas collection pipe 34. For this purpose, the bottom layer 54 has
slits 80 across the transversal air passages, at each end of each transversal
air passage 32, to allow gas to move under an upright seam 40, from one
panel to an adjacent one and into the longitudinal air passages 72. The
arced walls 62 of the bottom layer 54 contributes to opening the slits 80
between each panels across an upright seam 40. The arced walls 62 of the
bottom layer 54 as well as gravity contribute to opening the slits 80 near
the gas collection pipe 34, as illustrated in FIG. 4.
It will be appreciated that other arrangements are also possible to
form air passages under a golf green cover without departing from the true
spirit and scope of the present invention. Examples of alternate
arrangements are illustrated in FIGS. 9 and 10. In the first alternate
arrangement, the bottom layer 82 is made of spaced-apart sections. The
spaces 84 between the sections constitute transversal air passages under the
cover. In the second alternate arrangement the bottom layer 86 is pressed,
heated and bonded to the top layer along transversal bond lines 88. The
deformations 90 constitute transversal air passages under the cover.
Referring back to FIG. 1, 2 and 3 in particular, the gas collection
pipe 34 has one end thereof connected to a flexible hose 94 and to an air
valve 96. The air valve 96 is mounted to the inlet of a rotary ventilator 98.
The air valve 96 comprises control equipment, either manual or automatic,
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to regulate the amount of air entering the rotary ventilator 98. This control
equipment is preferably time and temperature sensitive and is not described
further herein for being known to those skilled in the art of ventilation.
The rotary ventilator 98 is a wind-actuated type, which function is
to periodically generate a negative pressure in the air passages 32, 68, 72
and 74, and in the perforations 70, to extract and vent out offensive gases
from the covered grass. The rotary ventilator 98 is also advantageous for
drawing fresh air inside the air passages for aerating the covered grass.
The frequency and duration of the venting periods are determined
according to the ambient temperature and the time left until spring time.
The air valve 96 and ventilator 98 are also useful to ventilate the covered
grass during warm fall periods or mid-winter thawing spells. The
ventilation system is also usable as a spring chiller for drawing dry cold air
at night from along the perimeter of the cover and for circulating this cold
air under the cover for preventing premature thawing of the covered soil.
At least one thermocouple 110 is permanently affixed to the bottom
layer 54 of the cover. The thermocouple 110 has leads extending out of
the cover and a connector mounted on a stake 112 for example above the
cover. The thermocouple 110 can be read from time to time to monitor the
temperature under the cover 20. This thermocouple is preferably used as
a learning tool to establish a history of the temperature variations under the
cover and of the conditions of the golf green protected by the cover. These
temperature measurements can be used to determine an ideal ventilation
schedule and a best time to remove the cover in the spring.
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Referring to FIG. 13, the thermocouple 110 is preferably bonded
to the underside surface of the bottom layer 54. Lead wire 114 extends
from the thermocouple 110 to the upper surface of the cover. The
preferred installation also comprises a connector 116 on the lead wire 114,
and an extension wire 118 having an extremity tied to the stake 112 at a
height above an anticipated snow accumulation. It will be appreciated that
the thermocouple 110 may also be permanently connected to the air valve
96 for automatic operation of the air valve 96 by a programmable
controller for example.
FIGS. 5, 11 and 12 are now referred to for describing a preferred
method for lashing an upright seam 40. In the preferred method, the string
42 is arranged in loops 120 at spaced intervals, which intervals correspond
in lengths to the spacings between the grommets 28 along the marginal
strips 36 of each panel. The length of each loop 120 is also about the
same, or slightly longer than the spacing between the grommets 28. Each
loop 120 is defined by a clip 122. In use, each loop 120 extends through
juxtaposed grommets 28 in the marginal strips 36 and around the strands
of an adj acent loop as illustrated in FIGS.11 and 12 in particular. The last
loop 120 of a stitch is pegged to the ground as illustrated in FIG. 2.
The width 'D' or height of the marginal strip 36 is preferably
between about 2 inches (5 cm) and about 6 inches (15 cm). It will be
appreciated that when a pair of adj acent panels, 24 and 26 for example are
laid side by side, with the adjacent marginal strips 36 set upward, it is
relatively easy for someone to lash both panels together. One does not
have to reach under a panel or to otherwise manipulate one of the panels.
As previously explained, the arrangement of both strips 36 provides for a
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sealed joint whereby water or melting snow which may accumulate on the
cover cannot get in between the panels. The thickness of the string 42
threaded through the grommets 28, prevents the juxtaposed strips 36 from
laying flat over the panel such that the effectiveness of the sealing joint is
maintained.
While the string 42 has been described as a continuous length of
string or a light rope formed into a plurality of spaced-apart loops 120, it
will be appreciated that a lacing string or rope may be supplied to a user of
the cover 20 in a plain form without knot nor clip, but with markings 124
at intervals, for assisting a user in finding the location where each loop 120
should be formed. In this case, the spacing on the rope between each mark
124 is proportional to the spacing between the grommets 28 in a particular
cover 20. This variant of the string 42 is particularly easy and inexpensive
to manufacture.
As illustrated in FIG.11, when the string 42 is a continuous length
of string or light rope with or without clip, the lashing described herein is
advantageous for being easily removable from the grommets 28 when
uncovering a golf green. The undoing of a stitch is effected by releasing
the first loop 120 from its peg and pulling on the string 42 at substantially
a right angle from the alignment of the juxtaposed strips 36 to cause a first
loop 120 to disengage from the first grommets 28 and from a second loop.
A further pulling on the string in a direction generally represented by
arrow 126 in FIG. 11, causes the second and subsequent loops to
successively disengage from the strips 36 in a manner which is similar to
the pulling of a broken thread in a garment.
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As to the raised joint 38, the marginal strips 30 are laid over each
other and over the rigid gas collection pipe 34. A series of individual
loops 130 are affixed to the gas collection pipe 34 and are lashed together
through the grommets 28 in a similar manner as just described, to retain the
marginal strips 30 to the gas collection pipe 34.
Referring now to FIGS. 14 and 15, there is illustrated therein a
preferred peg 140 for use in retaining the cover 20 according to the
preferred embodiment to the ground. The peg 140 is preferably made of
welded metal rod or stiff plastic. It has a threaded shank 142, a crossbar
144 near an upper end of the shank and a hook member 146 above the
cross bar 144. The cross bar 144 on each peg is advantageous for
preventing any concentration of stresses on the cover. The hook member
146 is advantageous for installing or removing the peg with a socket-type
tool.
The cross bar 144 is preferably concealed into a padding member
148 that is made of soft material such as closed cell polyethylene foam.
The padding member 148 is preferably tinted with a bright color. The
foam padding member 148 further protects the cover against excessive
pressure from the peg's cross bar 144, as well as from rust staining from
the peg being in contact with the cover for several months. The tinting of
the padding member 148 with a bright color is advantageous for providing
a visual indication of the contour of an installed cover 20, especially when
the top layer 50 is white for example, and for preventing excessive traffic
over a golf green.
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Although it is preferable to limit the traffic over an installed cover
20 to a minimum, the structure of the foam layers 52, 54 bonded to the top
reinforced fabric layer 50 described above has been found to be
sufficiently resistant to support a walk-behind type snowblower and few
people with plastic shovels, for the purpose of removing snow from an
installed cover 20. Upon removal of the golf green cover, the panels are
preferably rolled up along their lengths and stored away.
As to additional details related to the manufacturing, installation
and use of the golf green cover of the present invention, the same should
be apparent from the above description, and accordingly further discussion
relative to the manner of making and using the cover would be considered
redundant and is not provided.
It will also be appreciated by those skilled in the art that various
modifications, alternate constructions and equivalents may be employed
without departing from the true spirit and scope of the invention. For
example, one may appreciate that a ventilated cover as described without
the gas collection pipe and without a rotary ventilator may still provide to
some degrees, the advantageous results recited herein by venting gases
through a loosely tied upright joint for example, which partial results may
be sufficient to protect a golf green in certain conditions. Similarly the air
valve may be installed away from the ventilator at the far end of the gas
collection pipe or at the far end of another gas collection pipe under an
adjacent seam, to still provide to some degrees the advantageous
ventilation effects described herein. Therefore, the above description and
the illustrations should not be construed as limiting the scope of the
invention which is defined by the appended claims.
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