Note: Descriptions are shown in the official language in which they were submitted.
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Title
A portable ski tow.
Background to the invention
Ski tows for assisting skiers up ski slopes are well known. Known ski tows
consist
essentially of an endless rope loop between a fixed driving station and a
fixed slave station.
The rope passes around a rope drive pulley driven by a winch of the driving
station and passes
also around a slave pulley of the slave station. The driving station and the
slave station are
1o appropriately positioned to maintain a desired tension on the endless rope
loop. Generally but
not always the driving station is located at the bottom of the ski run and the
slave station is
located at the top of the run. Both the slave wheel and the winch must be very
securely
located at a predetermined position so as to maintain adequate tension on the
ski rope and to
maintain the winch and the slave wheel braced against any movement out of the
desired
~5 location.
Generally a ski tow is a comparatively large installation and the manner in
which the
winch and the slave wheel are located means that once fixed in the desired
location, it is rare
for the apparatus to be moved to another location.
In an endeavour to overcome that disadvantage, it is known to provide portable
forms of ski tows. One such form is disclosed in US Patent Specification
4423502 (Elsing)
which has a first portable frame assembly with a motorised rope wheel and a
second portable
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frame assembly for the return pulley for the rope. Both frame assemblies have
means
whereby the assemblies can be anchored to the ground.
Another form of portable ski tow rope apparatus is disclosed in US Patent
Specification 4920892 (Pesek) which discloses a portable ski tow unit which
consists of an
upper station and a lower rope return station. The upper station has a drive
unit with a motor
power drive pulley and with guide pulleys to guide the tow rope around the
pulley. The rope
return station is positioned at the base of the ski slope and has an idler
pulley which guides
the tow rope. The two rope is in the form of a continuous loop passing between
the drive
1o pulley and the idler pulley and the skier is able to grasp the upwardly
moving rope to be
towed up the hill. The disclosure is mainly concerned with a means to ensure
the rope passes
satisfactorily around the drive pulley of the winch.
United States Patent Specification 5205219 (Groskreutz) discloses another form
of
portable ski tow rope mechanism which consists in a mechanism for supporting
the extreme
ends of an endless loop of a ski tow rope. A series of pulleys are utilised to
guide the tow
rope about an elongated enclosed path. A motor driven winch is located so the
tow rope will
pass through the winch at a location which is within the ski rope path and
displaced from
either extreme end. The winch includes a pinch wheel to ensure the ski rope
passes around at
least 180° of the circumference of the drive wheel.
United States Patent Specification 3739728 discloses a portable winch far a
ski tow.
A tow rope for the skiers serves also as a control link to enable the winch to
be actuated to
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wind up the cable under power or release the cable. The winch is able to pull
itself to the top
of the ski run and when anchored, skiers can grasp the rope and be pulled to
the top of the
hill. The rope can be pulled in a downhill direction either by a weight or it
can be pulled
downwards by a skier. -
US Patent application 3874303 includes an endless belt supported by
intermediate
rollers and by end rollers. The belt includes conveyor means which are
resiliently connected
to the belt so that skiers can hold the conveyor means between their knees or
by their hands
to enable the skiers to be pulled up the hill.
to
While the known forms of ski tow rope mechanisms as exemplified in the prior
art
referred to above are described as 'portable', they are not in fact portable
or if they are
portable are of insufficient size to make them practical as a viable
alternative to fixed ski tow
installations. A further disadvantage with known forms of portable ski tow
rope mechanisms
is that they can generally only be located where a clear run for both the
upward and
downward legs of the loop of the ski rope can be obtained. This severely
restricts the
locations and the manner in which the mechanisms can be used.
Object of the invention
It is therefore an object of the invention to provide an improved form of
portable ski
tow rope mechanism which does not require an endless tow rope and which can,
with a
minimum amount of effort, be re-located from one position to another and which
is capable of
operating a tow rope of an adequate length.
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Disclosure of the invention
Accordingly one form of the invention may be said to comprise a portable ski
tow
mechanism including a first winch having
drive means to rotate a cable drum to wind a main ski rope onto the drum,
clutch means to connect or to disconnect the drum to the drive means
the construction and arrangement being that the winch is adapted to be
transported
to and anchored adjacent one end of the intended ski slope,
the main ski rope is wound onto the cable drum
the clutch is operated to disconnect the drum from the drive means, and
to the main ski rope is withdrawn from the cable drum by transporting the free
end of
the rope to a distant location whereupon a skier or skiers can grasp the ski
rope
the clutch is engaged to commence rewinding of the ski rope onto the cable
drum to
haul the skier or skiers up the ski slope.
1s Preferably the winch includes guide means to guide the ski rope onto the
drum and
brake means to enable rotation of the drum to be retarded when the drum is
disconnected
from the drive means.
Preferably the mechanism includes a second winch adapted to be anchored
adjacent
2o a.n end of the ski run, said second winch including
drive means to rotate a cable drum to wind an auxiliary ski rope onto the
drum,
clutch means to connect or to disconnect the drum to the drive means,
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means to initiate operation of the second winch to wind the auxiliary ski rope
onto
the drum of the second winch and
means to disconnect the drum from the drive means to enable the auxiliary ski
rope
to be withdrawn from the drum,
the construction and arrangement being that the first and second winches are
adapted
to be utilised in unison by attaching the free end of the main ski rope to the
free end of the
auxiliary rope to thereby couple the two winches together and by operating the
two winches
in a manner that as the main ski rope is being withdrawn from the cable drum
of one winch,
the auxiliary rope is being wound onto the cable drum of the second winch.
to
Preferably the first winch is located adjacent a first end of the ski run, and
the second
said winch is located adjacent a second end of the ski run, and in operation
the clutch means
of a winch is disengaged to disconnect the cable drum from the drive means,
the free end of the rope is withdrawn from the disengaged cable drum and
transported to the second winch and is connected to the free end of the rope
of the second
winch,
the drum of the second winch is disconnected from the drive means and
the clutch means of the first winch is engaged to commence re-winding of the
rope
onto the cable drum and to withdraw the rope from the drum of the second
winch.
Preferably the ski tow mechanism includes a single winch is located adjacent
the top
of the intended ski run, and in operation
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the free end of the main ski rope is manually transported to the desired
location on
the ski run to thereby withdraw the main ski rope from the cable drum and
the winch is activated to rewind the main ski rope onto the cable drum to
enable the
main ski rope to be utilised to haul a skier or skiers up the ski run.
Preferably the method of operating a ski tow including two winches comprises
locating the first winch having a cable drum on which the main ski rope is
wound adjacent the
top of the intended ski run and locating the second winch having a cable drum
on which the
auxiliary rope is wound adjacent the bottom of the ski run and releasing the
clutch means of
to one of the winches and withdrawing the rope from the cable drum until it
can be connected to
the free end of the rope on the cable drum of the second of the two winches
and activating
the winch having the cable drum to which the main ski rope is connected to
wind the main ski
rope onto the cable drum and to withdraw the auxiliary ski rope from the cable
drum of the
second winch.
Preferably at least one of the winches is controlled remotely.
Preferably the remote control is by an electronic signal.
2o Preferably the first and second winches are situate adjacent each other at
one end of
the ski run, and the rope is withdrawn from the cable drum of one winch and is
passed around
pulley means situate at the second end of a ski run and the free end of the
rope from the first
winch is joined to the free end of the rope from the second winch, the winches
being operated
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so the first winch having the cable drum on which the main ski rope is wound
is utilised to
haul a skier or skiers up the ski slope and the second winch having the cable
drum on which
the auxiliary rope is wound is utilised to withdraw the main ski rope from the
cable drum of
the first winch.
Preferably the first and second winches are under the control of a single
operator.
Preferably the first and second winches share the same motive power.
1o Preferably the motive power comprises an engine driving a hydraulic pump
and
wherein hydraulic lines connect the hydraulic pump to a hydraulic motor for
the cable drum of
the first winch and to the cable drum of the second winch.
Brief description of the drawings:
Figure 1 is a schematic elevational drawing of one side of a first winch
mechanism
for the main ski rope.
Figure 2 is a schematic elevational drawing of the second side of the winch
mechanism illustrated in Figure 1.
Figure 3 is a schematic elevational illustration of the front of the winch
mechanism
illustrated in Figures 1 and 2.
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Figure 4 is a schematic view of a highly preferred form of the invention
utilising a
second winch.
Description of the preferred forms of the invention
As illustrated in Figures 1, 2 and 3 of the accompanying drawing, the
apparatus
includes a winch mechanism one form of which has a frame 1 to house a rotary
power means
which may be an internal combustion engine 2. The engine is coupled either to
a gear train or
chain drive or in a highly preferred form to a hydraulic pump 3. The pump is
in turn coupled
through hydraulic lines 4 to a hydraulic motor 5 which drives a cable drum 6
through a
1o suitable clutch mechanism 7. The clutch is designed so that when it is
released, the cable drum
6 can freely rotate with a minimum of frictional resistance. Preferably also
the cable drum is
provided with braking means such as a disc brake 8.
The cable drum is of a width and diameter that a considerable length of main
ski rope
9 can be wound onto the drum. A suitable rope is formed of polypropylene or
other tough
non degradable material which has sufficient strength for the task. It has
been found that a
rope of polypropylene of no more that 6mm diameter can lib up to 1.5 tonnes
and that is
suitable for the task although other weights and sizes of rope can also be
utilised in the
required circumstances. The length of the rope 9 will vary as required but
preferably the rope
2o should have a length of up to 1.5 kilometres and the cable drum must
therefore be of a size
that such a length of rope can be fully wound onto the drum. To assist with
the most efficient
winding of the rope onto the cable drum, the mechanism preferably also
includes a known
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type of cable feeder 10 which can be suitably driven such as by a chain drive
11 from the
cable drum.
Suitable lifting handles or the like (not shown in the drawings) are also
provided so
s that the unit can be transported. In a highly preferred form, the winch
mechanism is
manufactured so that it can be lifted by a helicopter so that it can be
transported easily and
simply from one location to another.
To use the mechanism, it is first transported, such as by ground transport or
by
1o a flying machine such as a helicopter to a suitable location where it is
firmly secured in
position at or adjacent to one end of the ski slope using suitable anchors,
such as snow
anchors and pegs. An appropriate length of rope 9 will have been wound onto
the cable drum
and the clutch can then be released so the cable drum can freely rotate. The
free end of the
main ski rope 9 can then be grasped and can be transported to a remote
location. One
15 method of this is for a skier to take the rope and ski to the remote
location. In a modification,
the free end of the rope can be attached to a harness which can be worn by the
skier. The
distance the free end of the main ski rope can be transported will preferably
be up to 1.5
kilometres, depending upon the length of the rope and the topography of the
country. The
skier can then disengage if desired from the ski rope and intending skiers can
grasp the ski
2o rope either at this time or later as desired. A signal is then sent to the
operator to activate the
winch to commence winding the main ski rope which will haul the skiers up the
ski run. The
second operator can if desired grasp also be hauled to the top of the ski run.
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The signaling to the operator of the first winch can be effected by any known
means
such as by direct sight, by radio telephony or whatever suitable means it is
decided to use.
As illustrated in Figure 4, the apparatus preferably also includes a second
winch 20
which is of a size that it is highly portable. The ancillary winch includes a
drive means to
drive a cable drum on which an ancillary rope 21 is wound. The ancillary rope
21 is
preferably at least as long as the main ski rope but is of a lighter
construction. In one method
of operation, the second winch will be stationed at or near the bottom of the
ski slope or run.
In this mode, the free end of the main ski rope is permanently or temporarily
joined to the free
1o end of the auxiliary rope. One means of effecting this comprises the steps
of anchoring the
first and second winches in position, drawing the main ski rope from the cable
drum of the
first winch down the ski slope, for instance by a skier or skiers to the
location of the second
winch. The second winch will already have the auxiliary rope 21 wound onto the
cable drum
and the end of the main ski rope 9 may then attached to the free end of the
auxiliary ski rope.
Such attachment can be by a simple knot or by other mechanical means as is
known in the art.
The second winch is then configured to free the cable drum and the first winch
activated to
draw the main tow rope up the ski run together with the skiers. Since the
auxiliary rope 21
has been connected to the main ski rope 9, the auxiliary rope will be
withdrawn from the
drum of the second winch as the main ski rope 9 is being wound onto the cable
drum of the
first winch.
The second winch can be either manually controlled or remotely controlled. If
it is
manually controlled, it is necessary for the winch to be attended by an
operator. In this mode
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of operation, when the main ski rope 9 has been wound the desired amount onto
the drum of
the first winch, the drum of the main winch can be released and a signal sent
to the operator
of the second winch by any known means, such as by a landline type telephone,
radio
telephony or other means as will be apparent, to activate the second winch.
This will
commence winding of the auxiliary rope onto the drum of the second winch and
thereby
withdraw the main ski rope from the cable drum back down the slop until a
sufficient amount
of the rope has been withdrawn. The operator will then disengage the drive
means to the
cable drum of the second winch to allow it to rotate freely and the first
winch can be operated
to commence winding the main ski rope onto the drum of the first winch for the
next cycle of
to hauling the skiers up the ski run.
If the second winch is to be remotely operated, it will not require an
operator.
Instead all the required fixnctions can be initiated or completed remotely
under the control of
the operator of the first winch. Such remote control can be by electrical or
electronic signals
send either by wireless telegraphy or by landline or other means as will be
known in the art.
In yet another mode of operation, the first and second winches can be situate
at one
end, preferably at the lower end of the ski run. In this mode both winch can
be under the
direct control of one operator. To effect this a pulley means is first
anchored adjacent the top
of the ski run and the free ends of either or both the main ski rope and the
auxiliary ski rope
can be transported from the winches to the pulley where one rope is passed
around the pulley
and the free ends of the two ropes are joined. To utilise the arrangement in
this mode, the
winches are set so that as the main ski rope is being wound onto the cable
drum of the first
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winch, the auxiliary rope will be withdrawn from the cable drum of the second
winch. It will
be understood that the main ski rope is utilised to haul the skiers up the ski
slope and the
auxiliary rope will be utilised to return the main ski rope back to its start
position. While it is
possible to adapt the two winches so that each can utilise the same type of
ski rope so that
both runs of the ski rope can be utilised alternately to haul skiers up the
ski run, it is highly
preferred that one of the winches be smaller than the other and to have an
auxiliary rope
which is a lighter grade than the main ski rope so that skiers can be hauled
up the ski run only
by the main ski rope.
1o While in one form both winches can have independent motor drive means, inn
the
configuration where the first and second winch are situate close together, it
can be convenient
for the two machines to use the same power source. For instance if the engine
of one winch
drives a hydraulic pump, the secondary hydraulic lines cann be connected to
the second winch
to provide the motive power.
The main advantages provided by the ski tow rope mechanism of the present
invention are the mechanism is very portable and does not require complicated
anchoring
system for the winch or winches. The system also eliminates any problem of
having to
arrange all of the mechanism to cope with a particular length of looped ski
rope so that the
2o mechanism can be used for any distance up to the maximum length of rope
capable of being
wound onto the cable drums of one winch if only one winch is used, or onto
both cable drums
if two winches are used.
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If a single winch is used, the free end of the main ski rope will generally be
transported by a skier to the distant location. If two winches are used, the
free ends of either
or both the main ski rope and/or auxiliary rope can be transported by a skier
or other means
to a location whereby the free end of the two ropes can be joined. The second
winch
therefore can be of particular assistance since it can eliminate the necessity
for a skier to tow
the main ski rope down hill after each run. In addition, should the ski run be
of a considerable
length it could be difficult for the skier to tow the rope down the ski slope
unaided and
consequently the second skier can work in conjunction with the second winch to
considerably
ease this task. Should the second winch not be required for any reason, the
auxiliary rope can
to be simply detached from the main ski rope.
Since the winch mechanism is entirely self contained, to remove the apparatus
to a
new location, all that is necessary is to disconnect the main ski rope from
the auxiliary ski
rope, if the second winch has been used and wind the main skip rope 9 onto the
cable drum.
The first and second winches can then be released from the anchoring means and
transported
to the new location where they can be anchored and so ready for operation.
Having disclosed the preferred forms of the invention, it will be apparent
that
modifications and changes can be made to the particular apparatus and method
of carrying the
2o invention into effect and yet still come within the basic concept of the
invention. All such
modifications are intended to come within the scope of the present invention.
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