Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE INVENT~ON
Skiing on ski slopes or trails terminates in the late winter and early spring with the
melting of the snow. The slopes and trails become bare over the summer months. Skiing
normally rcsumcs in thc fall or early winter when sufficient snow has fallen to provide
adcquate snow covcr on the slopes and trails.
In a few instances, early fall skiing has been achieved by the spreading of man-
made snow but the success of this process is dependent on the arrival of nights with below
freezing temperatures.
SUMMARY OF THE PRESENT INVENTION
The present invention is to a method whereby any selected ski slope or trail may
be placed in skiing condition earlier in the fall then would nor~nally be the case.
Hereinafter when the term ski slope is used it will also include a ski trail. The method
will be most commonly used on ski slopes.
According to one aspect of the invention there is provided a mcthod of seasonally
shifting snow covcragc on a dcsignated ski slopc in ordcr to achieve skiing on said
designatcd slope at a time of the year when said slope would otherwise be closed for
skiing because of inadequate snow cover which method comprises at a time of the year
when said designated slope could otherwise remain open for skiing, closing said
designated slope; collecting the snow remaining on said designated slope into a series of
piles distributed over the entire length of the slope; and, covering said piles with sheets of
insulating material by placing said sheets over said piles such that they are substantially
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supported by the snow in said piles; and, at a time of the year when said designated slope
would otherwise be closed for skiing, uncovering said piles and distributing the snow
rcmaining in said pilcs across said dcsignated slope so as to achieve a depth satisfactory
for skiing thcrcon.
According to another aspect of the invention there is provided a method of
seasonaily shifting snow coverage on a designated ski slope in order to achieve skiing on
said dcsignated ski slope at a time of the year when said slope would otherwise be closed
for skiing because of inadequate snow cover which method comprises at a time of the year
when said designated slope could otherwise remain open for skiing, closing said
designated slope; collecting the snow remaining on said designated slope into a series of
snow piles distributed over the entire length of the slope; and, covering said snow piles
with sheets of insulating material, wherein said sheets comprise two layers of aluminum
foil spaced about one-quarter inch apart between which are two layers of polyethylene
bubbles, by placing said sheets over said snow piles such that they are substantially
supported by the snow in said snow piles; and, at a time of the year when said designated
slope would otherwisc be closed for skiing, uncovering said snow piles and distributing
the snow remaining in said snow piles across said designated slope so as to achieve a
depth satisfactory for skiing thereon.
These piles are typically high in the center and tapering downwardly to the
surrounding ground. The piles preferably will be circular. The spacing of the piles will
be determined by the depth and location of the snow available.
The piles of snow are then covered with sheets of insulating material of such
character. It is therefore possible that a major volume of the piled snow will be preserved
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over the summer and early fall months. At a time of the year when said designated slope
would otherwise be closed for skiing, for example when the average ambient temperature
has dropped in the fall to a degree at which the snow will not melt away, the piles will be
uncovcred and thc snow redistributed, by hand and/or machine over the selected areas of
the slope. The dcpth of the redistributed snow now covering the selected slope area will
be satisfactory for immediate skiing, and typically will last until the arrival of natural
snow. Should the arrive of natural snow be delayed, the snow base can be augmented by
the application of man-made snow at the necessary locations after nighttime freezing
conditions have arrived in the fall.
BRIEF DESCRIPI'ION OF THE DRAWINGS
Fig. 1 is a plan view of a snow covered ski slope.
Fig. 2 is a vertical section on the line 2-2 of Fig. 1.
Fig. 3 is a section on the line 3-3 of Fig. 2.
Fig. 4 is a plan view of the ski slope of Fig. 1 with the snow thereon pushed into a
plurality of pilcs~ _ _
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Fig. 5 is a vertical section on the line 5-5 of Fig. 4.
Fig. 6 is a section on the line 6-6 of Fig. 5.
Fig. 7 is a plan view of the ski slope of Figs. 1 and 4 with
the piled snow of Figs. 4, 5 and 6 redistributed on the slope.
Fig. 8 is a vertical section on the line 8-8 of`Fig. 7.
Fig. 9 is a section on the line 9-9 of Fig. 8.
Fig. 10 is a view similar to Fig. 9 but showing the snow
covering a greater area.
Fig. 11 is an enlarged view illustrating a snow pile to
which man-made snow has been added.
DETAILED ~ESCRIPTION OF THE INVENTION
Fig. 1 is intended to represent any ski slope 2 which is
covered with snow 4. For help in explanation o~ the invention,
the snow covered area of the slope is shown as having top, side
and bottom boundaries indicated at 6, 8, 1~ and 12.
Fig. 2 is a vertical section taken on the line 2-2 of Fig. 1
showing the ground 14 with the snow 4 covering the sloping
surface 2. The upper li~it of the snow with which we are
concerned is at 6 and the bottom limit at 8. Fig. 3 is a section
taken on the line 3-3 of Fig. 2.
It is to be understood that the representation of Fiqs. 1, 2
and 3 is intended to include any ski slope havi~g thereon snow
(,natural, natural and man-made or man-made~ toward the end of the
skiing season when the operator elects to close the slope.
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It will be appreciated that the depth and disposition of the
snow at the time the slope is closed may vary greatly depending
upon the extent of the snow fall over the past winter and the
configuration of the ground surface.
The snow on the slope is pushed, preferably by machines,
into a plurality of piles of snow indicated at 16 in Figs. 4, 5
and 6. The location of the piles of snow on the slope will be
dictated by the configuration of the slope, the depth of the
snow and the judgment of the operator. The piles are made as
high as possible, preferably generally circular in plan and are
then covered with sheets of insulating material 18 of such
properties as to be capable of preserving a major portion of the
snow over the summer and early fall.
In places where the snow is deep, it may be pushed.into
suitably sized p$1es without using all of the snow adjacently
available. Where the snow cover is thin, it may be necessary to
;use all of the snow at that location to produce a large enough
'pile to survi.ve the summer. In all cases the object is to pre-
,serve enough snow by the pïling procedure plus the insulating
covering to have enough.snow available in the fall which when
spread on the slope will create ade~uate s~iing conditions.
Preferably the.area of the collected snow pile should be small
in relation to the area from which the snow was collected.
In ot~er words, a high pl.le on a small area is preferable to a
lower pile in a larger area because the percentage loss from
melting is approximately inversely proportional to the height
of the pile. Snow can readily be piled by machïne to a height
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of 20 feet or more at the center and s.loping to the s~ides in a
circular pattern. A pi.le of snow of thi.s character covered
with suitable insulating material will lose no more than 20 to
25% of its ~olume over the summer. Thus for example if there
was an average of tw.o fe.et of snow on .he slope when the piling
commenced and all of i.t was pushed into the piles, enough snow
would remain by fall to cover the slope to an average depth
more or le~s o~ one and one~half feet, adequate.for immediate
skiing.
Fi.gs. 7, 8 and 9 are illustratiYe of the condition of the
slope follow~i`ng di.stribution of the snow i'n the fall from the
piles 16 shown in Fïgs. 4, 5 and 6. In Fig. 7, the lines 20
and 22 suggest the somewhat reduced w.idth of the slope if the
original depth.is pro~i'ded whereas Fig. g suggests a width of
slope corresponding to boundaries 8 and 10 of Fi.g. 1 and 3 but
with a reduced dept~.determined by the extent of the melting.
It has ~een found desirable and practical in some
situati.ons. t~ i`ncrease the. volume,of the preserved pile of snow by ¦
removing the. cover 18, adding man-made snow and recovering the
pi.le. as sho~n in Fi.~. 11. Thi.s. procedure would be used when the
resi.dual layer of snow. available.in the spring was inadequate
for producing the. depth.ini.tially wanted in the fall. The,.
additi.on o~ man-~ade. sno~ can be ~ade wheneYer the temperature
falls. below free:zi`ng w~lch.conditïon usually'be.gins early in the
fall. Repeated addi.tions of ~an-made snow will create a pile
suffici~ent w~en spread to provide skiing condi.tions on the
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selected area. Fig. 11 suggests the condition existing after
man-made snow 24 has been added to the initial pile of snow 16
and the covering 28 replaced.
The process of accumulating the residual snow in piles
in the spring and distributing it in the fall will preferably
proceed from the top to the bottom of the slope as the snow
movement is aided bY gravity but this process may be varied
under the judgment of the machine operator.
Insulating covering ade~uate to preserve snow over the
summer is available in the open market. One such material
comprises two layers of aluminum foil spaced about ~ inch
between which are two layers of polyethylene bubbles. These
circular flattened bubbles, about 3/8 inch in diameter are
arranged so that each bubble is surrounded by six other bubbles,
all bonded to themselves and to the covering layers of aluminum
foil. This construction forms a strong sheet having the
capability of substantially limiting passage of the sun's radiant
heat and the heat of the ambient air to the snow thereunder.
The sheet may be further strengthened by a coating of clear
,polyethylene to both e~terior sides. This sheet is light,
j~flexible and durable and may be readily rolled on and off each
pile of snow.
`' The sheets must be firmly anchored to the ground to prevent
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the sheets from being dislodged by the wind and also to prevent
the entrance of warm air under the sheets which would cause
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excessive melting of the covered snow. The sheets may be
anchored for example by placing weights on the edge areas 26
or in any other manner available. The securing means must be
readily removable so that the sheets can be rolled off the piles
and saved for use the-following year.
In the drawings, it will be understood that the thickness
of the sheets in relation to the size of the piles of snow has
necessarily been exaggerated.for purpose of illustration.
It is intended to cover all changes and modifications of
the example of the invention herein chosen for purposes of the
disclosure which do not constitute departures from the spirit
and the scope of the invention.
