Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a transport device
for transporting a load, e.g. tree trunks, along a path by
means of an elongated element enabling the load to be released
at a desired location. The elongated element i6 given a re-
ciprocating movement in its longitudinal direction and at
least one holding member is attached to the elongated element.
The holding member is arranged to move the load in one of the
directions of motion of the elongated element and in the
opposite direction to slide on the elong~ted element without
moving the load.
In forestry work the transport of cut tree trunks to
a road which is accessible to large transport vehicles is of-
ten a problem. This problem is today solved in many different
ways. One way is to employ a cross-country forwarder or wheel
tractor transporting the tree trunks to the road.
This is however notalways the most convenient solu-
tion, e.g., when only certain trees have been cut for thinning
purposes and other trees are left standing. These remaining
trees reduce the passability considerably for forwarders and
similar vehicles.
A winch, e.g. mounted on a timber truck, is another
alternative. When the tree trunks, which often are sporadi-
cally placed over a large area and in different distances from
the road, are dragged to the road and loaded on the transport
vehicle, the wire is manually drawn from the winch to the tree
trunk to which the wire is connected.
The distance from the winch to the tree turnk is
however limited to the length of the wire which often is insuf-
ficient. The manual drawing of the wire to a new tree Lrunk-
after each trailing of another tree trunk is a time consuming
and labour intensive procedure which also increases the costs
for loading and transport.
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In the US patent specification 3l566,801 a transport
device is described which comprises a wire or a rope extending
between two supporting means, means foroscillating the rope
in the direction of its length at a very low amplitude (about
6 mm at a frequency of 50 vibrations per second) and a car-
riage, which by way of a holding device is connected with
and driven by and along said rope.
This transport device cannot be used for the purpose
for which the present invention is intended. Firstly, the
amplitude of the oscillating movemer.t of the rope i6 too low
for trailing tree tr~nks, considering the self-elongation of
the rope. Great forces are required for the trailing of tree
trunks ana these forces tend to temporarily stretch the rope.
Secondly a holding device comprising shafts, teeth and toothed
wheels cooperating with pawls or similar, is not sufficiently
reliable and durable for use in forestry where such a device
has to withstand rough handling, foreign matter such as soil,
stones, springs, twigs and ice, and very low temperatures.
Furthermore, since large tractive forces have to be applied
to the rope, it is also very important that the holding de-
vice can bring about a complete locking in one of the direc-
tions of motion of the rope and at the same time it can be
easily freed from the rope in the opposite direction of motion.
This has proved very difficult to achieve.
In the Swedish printed publication 7409119~0 a
warping system is described having an endless wire and shifting
means in front of the pulley wheels of the wire. The shifting
means moves jaw means from the incoming to the outgoing wire.
The jaw means require an exact guiding to the shifting units,
which is very difficult to achieve, and since the jaw means
have a clamping effect only in loaded condition, a safe re-
turn of the jaw means cannot be guaranteed. The system com-
prises many units cooperating with each other and each com-
prising a number of moveable parts, which in forest areas,
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where sand, gravel etc. easily can come into the structural
members after a short time, are put out of operation.
Also clamping devices of different kinds are pre-
viously known, e.g., through the British patent specification
651,556, which lock to the wire in one of the directions of
motion of the wire and release in the opposite direction
of motion. In order to provide an effective locking, the angle
or taper of the clamping wedge has to be small which means that
for releasing the wire a large force is re~uired, which can
not be achieved by means of aspring, elastic band or the like.
The object of the present invention is to eliminate
the above mentioned drawbacks and to provide a simple and re-
liable transport device, which facilitates the trailing of
tree trunks, reduces the transport costs, has holding members
comprising no or only a few moveable parts, which withstands
rough handling, coarse lumps of foreign matter a~d low temper-
atures, and which fulfills the demand for providing an effec-
tive locking of the band and which can take up large loads
while at the same time being very easy to loosen.
Since the transport device can be used in very
rough country and environment it can also be used for military
purposes as transport of ammunition, supplies and/or injured.
The invention has for this purpose been so arranged that
it can maintain transport in both directions between two or
maybe more points with relatively large distances between
them, and even across lakes, watercourses, etc.
Accordingly, the present invention provides a
transport device for transporting a load along a path of
transport between at least two points comprising, an elongated
element extending along the path of transport, an anchoring
member attached to one end of said elongated member, a dri-
ving means attached to the other end of said elongated element
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for producing a reciprocating movement of said elongated
element in its longitudinal direction, at least one unidirec-
tional~load carrying gripping member releasably engaging said
elongated element and operable to grip said elongated ele-
S mentwhen it is reciprocating in the desired direction of trans-
port and release said elongated element when it is reciprocating
in the opposite direction, and means for attaching a load to
be transported to said gripping element, said gripping ele-
ment comprising a hollow casing member having a bore extending
therethrough, a longitudinal slot extending through the wall
of said casingthroughwhich said elongated element is insertable
so that said gripping element may be engaged with and removed
from said elongated element, releasable retaining means for
retaining said gripping element in engagement with said
elongated element, unidirectioned locking members in said
casing operatively associated with said elongated element to
move said gripping member along the path of transport, and a
releasing member attached to said elongated element at a
desired unloadingpositionto cooperatively engage said grip-
ping member to release said retaining means and remove said
gripping member from enyagement with said elongated member.
The invention will now be described in more detail,
by way of example only, with reference to the accompanying
drawings:-
Figure 1 is a schematic side view of the transport
device according to the invention,
Figure 2 is a view from above of the transport de-
vice according to Figure 1,
Figure 3 is a side view of a holding member,
Figure 4 is a cross-section through the holding mem-
ber according to Figure 3,
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Figure 5 is a longitudinal section through the
holding memher according to Figure 3,
Figure 6 is a view from above of a releasing member,
.
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Figure 7 is a cross-sect~.on throu~h the releasing mem-
ber according to Fi~ure 6,
Figure 8 illustrates a workin~ moment when a holdin~
member is released,
Figure 9 is a longitudinal section through an alterna-
tive embodiment of a holding member,
Fiyure 10 is a section according to the line X-X in
Figure 9,
Figure 11 is an end view of the holaing member accord-
ing to Figure 9,
Figure 12 is a longitudinal section through a pull band
according to the invention,
Figure 13 is a cross-section throuyh the band according
to Figure 12,
Figures 14 and 15 show a further embodiment of a hold-
ing member with the pull band in two different positions,
Figures 16 and 17 show a longitudinal section and a cross-
section through a further embodiment of a holding member~
The transport device 1 comprises mainly a winch 2
driven by a driviny means, a pull band 3, a flexible element 4
and at least one, preferably a plurality, of holding members 5
intended to be attached on the pull band 3.
The driviny means is preferabl~ a hydraulic motor of
conventional kind, but can of course as well be an electric motor,
a pneumat;`c motoX or an internal combustion motor. The band 3
is given a reciprocat~ng motion by the winch 2, the amplitude of
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which can be ~aried within broad lim~tsr but should at least
exceed some dec~mete~s in order to have the transport de~ice
working satis~actory. Practical test have shown that a recipro-
cating motion with an amplitude between 1-10 and up to 30 ~eters
is p~rticularly favourable. The winch 2 is prov;ded with a fix-
ing device 7, by means of which it can be connected to a support
8, e.g. a tree, a vehicle or similar.
The band 3 preferably comprises a woven, flat strip with
a low self-elongation, e.g., made of a synthetic textile material.
The band 3, which has a substantially square cross-section, has
several advantages, which will be mentioned later.
The end of the band 3 facing the winch 2, to so called
driving end 3a, is connected to the winch drum and the oppositeend
of the band, the coupling end 3b, is connected to a further sup-
port 9, e.g. a tree, by way of a flexible element 4. This flex-
ible element can e.g. consist of a rubber member, a spring-loaded
wire or one or more tension springs, and exerts a substantially
uniform tractive force in the coupling end 3b of the band 3 and
opposed to the tractive force exerted by the winch. The tractive
force of the flexible element 4 is much smaller than the tractive
force exerted by the winch 2 and its only purpose is to keep the
band 3 stretched and to pull the band towards the support 9 when
the winch 2 after having wound in a predetermined length of the
band released it again. The band 3 is thus given a reciprocating
motion along its entire length, the force of which in the direc-
tion towards the winch is sufficient for e.g. moving one or more
tree trunks or another load.
The holding member 5 must be ef~ectively locked to the
band in the transport direction and release the band at the re-
turn motion thereof, in order to have the load - the tree trunks -
moved in the transport direction of the band.
The holding member 5 according to the embodiment shown
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in Figures 3-5 com~rises a cylindrical casing 12 of steel,
on the underside of which a loop ll is a~ranged ~or connection
of the object to be transported. The cylindrical casing
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12 is pro~ided with first 13 and second 14 tapered
r-ecesses extending from the res~tive end portions of the casing
12 and in towards the central part of the casing, where
the recesses 13 and 14 meet and form a free passage through
the casing 12. This free passage has a substantially circular
cross-section and has a diameter somewhat smaller than
that of a locking member 16, e.g. a ball, placed therein.
The first tapered recess 13 is somewhat larger than the
second recess 14 so that the locking ball 16 is given
enough free space and for providing a suitable taper. This
is important as the locking ~all 16 is intended to loc~
the band 3 extending through the holding mem~er 5 and the
tapered recesses 13, 14 by wedge action. A part circular
-end wall 17 is attached at ,the opening Or the first tapered
recess 13 and is arranged to prevent the locking hall 16
from ~alling out of the holding member 5,
The holding member 5 is provided with means for enabling
a simple engagement and disengagement Or the holding mem~er
5 to and off the band 3. This is achieved by a longitudinal
slot 18 extending along one side of the holding member
5, The holding mem~er is further provided with means,20
preventing the hand 3 from leaving the cylinder through
the slot 18 in other cases than when a special releasing
device is in its way. The slot 18 is according to this
embodiment blocked by a spring-actuated 19 slide 21, which
is displaceably arranged in the cylinder 12.
The front edge of the slide 21, as seen in the d;rection
Or motion (to the right according to figure 5), is somewhat
chamferred as well as the gu;ding edges 22 Or the ~lot
18~ This'facilitates the engagement and disengagement of
the holding mem~er 5 on the band 3.
A releasing member 23 (figures 6-8) is preferablv arran~ed
close to the driving end 3a of the band 3 for providing
an automatic releasing of the holding member 5 and the
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load connected thereto. The releasing memher 23 prefera~lv
comprises a piece of sheet metal fixed to the band 3, e.g.
by means of a screw union or similar and compri~es a suhstan-
tially flat taper portion 24 which i 8 arranged to partly
extend into the slot o~ the holding memher 5 from thè
front and displace the slide 21 t~ an open position.
By the action of the taper portion 24 o~ the releasing
member 23 the holding member 5 is d~splaced sideways (figure
8) andoff the band 3 whereby the holding member 5 and
the load connected thereto can be taken care of manually
Also other types of releasing members 23 càn be used, e.g.
they can be made of the same material as the band 3 and
even be made integral with the band.
In figures 9-11 is shown a modified embodiment of the holding
me~ber 5, which differs from the em~odiment described ahove
by the fact, that the taper of the casing 12 and the angle
of the surface 25 cooperating with the locking mem~er 16
is considerably steeper, at which a considerably worse
wedging effect Or the locking member is achieved, but on
the other hand a releasing of the band 3 without substan-
tial tensile forces. The efrective wedging of the band in
the holding member has been achieved by the fact that the
band 3 is provided with fixed raised portïons 26, prefera~ly
consisting of rubber blocks 27 arranged in the textile
band 3. l~en a raised portion Or the band 3 contacts the
locking member 16 an effective loc~ing of the hand is achieved
without wedging the lockin~ member 16 against the inclined
surface 25. Th;s is preferably curved in accordance with
the radius of curvature of the locking ball 16.
Unlike the embodiment of figures 3-5 the slot 18 is per-
manently open and the mem~er 20, which shall prevent the
band 3 from leaving the holding member 5 throu~ the slot
18, comprises partly a curved end portion 28~ at one of
the openings o~ the casing 12 and partly an extended portion
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29~ at which the slot 18 within this opening portion will
be located at the lower edge of the outlet, The curved
portlon 28 causes the band 3 to be curved in its longitudinal
direction ~Yhen it leaves the holding member and thus obstructs
the band from l'slipping" out through the slot 18.
There is only one moving part, namely the locking member
16, in this whole holding member construction, at which
the reliabilit~ is very high even under very un~aavourahle
conditions .
An even more simple variant o~ the holding memher is shown
in figures 14 and 15 and comprises a casing 12 with a slot
18 and a load hook loop 11. The coupling together ~f the
holding member 5 with the band 3 is made by way of locking
member 16 fixed on the band and according to the embodiment
shown consisting Or plastic or metal cones. The cone is so
designed that its base is somewhat smaller than the inner
diameter of the casing~ while the top Or the cone is tapered
to the width and thickness of the hand. rleans 20 preventing
the band from leaving the casing 12 can compris~ a special
shaping of the slot 18, which according to the embodiment
shown is slightly S-shaped. Also in this embodiment the
band will he curved against the inside of the casin~ during
its active transport phase, which means that the band ~
not leave the casin~ other~ise than when the releasing means
forces the casing to this.
During the transport phase the band will take a position
shown in figure 14~ at whic~ the base surface o~ the locking
memher 16 contacts one of the end edges of the casing 12.
When the band 3 makes its return movement the locking member
16 will find its way through the casing 12 with its thillner
end as is shown in figure 15.
Another way of preventing the band 3 from slipp-ng out Or the
holding member 5 is to make the rubber blocks 27 so thick,
that the band cannot slip out of the slot 18 b~ itself. ~he
re~easing member must in this case be so arran~ed, that it
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pulls oif the holdin~ membe~ ~o~ the band.
Tn the embbdiment accordiny to Figures 16 and 17 the
holdin~ member ~s axially divided into two halves 30 and 31 con-
nected with e~ch other by a hinge 32. The two halves 30 and 31
can by a locking means 20 be locked to each other. Said locking
means compr~ses a number of locki~g pins 33 fixed in the upper
half 30 and extending into corresponding recesses 34 in the lower
half 31 when the halves are put together. The locking pins 33
are each provided with a recess 35 so located that an axle 36 can
be pushed throu~h them and lock the pins 33. Also the axle 36
i~ provided with recesses 37, which by displacing the axle against
the action of a spring 38 can be brought just in front of the pins
33, which by that are released. The axle 36 projects outside the
inner end of thetapered end portion of the hoIding member and
is intended to cooperate with a releasing member 23 fixed on the
band 3. The releasing member is at its end facing the holding
member designed with substantially the same taper as the tapered
end of the holding member 5 and said releasing member 23 actuates
the projecting end of the axle 36, so that the holding member
opens and falls off the band.
In order to prevent that the locking member 16 is drop-
ped when the holding member is opened, the locking member is se-
cured to one of the holding member halves e.g. by means of a
ball retainer 30 as is indicated in Figure 17.
The invention is not limited to the above described em-
bodiment, but alternative embodiments, e.g. regarding structural
members, are possible within the scope of the invention. Such
an alternative embodiment (not shown) can comprise a device with
double parallel pull bands between the supports. When one of
the pull bands is moved forwards the other is moved backwards.
For enablin~ th~s course b~ motion a winch with double drums
is arran~ed at one o~ the supports. The device i~ in this way
giVen double capac~:ty or the second pull band can be used for
transport in the opposite direction.
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