The present invention relates to a device for placing at least one
elongate element, such as a drainage wick, in a ground, comprising:
- a frame displaceable over the ground and having thereon a mast which is upright
at least during use;
- a lance which is movable reciprocally with a drive relative to the mast forming
a guide therefor, and which comprises in the longitudinal direction thereof a passage
for receiving therein the elongate element at least during a downward movement
of the lance, and for feed there through of the elongate element during an upward
movement of the lance.
Such a device is generally known, for instance from the European
patent application EP-A-0 672 795.
Such devices are commonly, though not exclusively used to place drainage
wicks as elongate elements vertically in the ground.
In such devices for inserting for instance drainage wicks it is usual
for an operative to walk along with the device. This operative arranges a ground
anchor on the drainage wick before the drainage wick is placed in the ground.
The ground anchor forms a closure for the open end of the lance when the lance
is forced along the mast into the ground. After the furthest depth has been reached,
the lance is brought back up again, wherein the ground anchor ensures that the
drainage wick remains behind and is pulled through the passage in the lance. When
the lance is lifted out of the ground again, wherein the drainage wick has been
left behind in the ground as a result of the action of the ground anchor, which
is usually designed as an element in the form of a steel plate, the operative manually
severs the wick. The device is then once again available to place a following
drainage wick. The wick is usually unrolled from a spool or reel so that the above
described operations can be repeated for each drainage wick to be inserted until
a spool or reel has to be replaced.
The above described technique has a number of drawbacks.
The elements in the form of a steel plate, which serve as ground
anchors and to close and protect the open underside of the lance when the lance
is forced into the ground, remain behind in the ground without these elements in
the form of a steel plate playing any actual part in the function of the drainage
wick. The elements in the form of a steel plate are not particularly expensive
per se. However, when drainage wicks are placed this usually takes place in large
numbers. Large numbers of these elements in the form of a steel plate are therefore
also used, whereby the cost of using such a known device is not quite so negligible.
The arrangement of the elements in the form of a steel plate on the free end of
the drainage wicks to be inserted is moreover very tedious and still onerous work
for the operative, who must walk along with the device for this purpose. In view
of the large number of elongate elements (drainage wicks) for placing, said operative
must also sever the wicks often. In view of the frequency with which this must
be done, this operative will not often feel inclined to cut the wick very close
to the ground, but rather at waist height so as not to have to bend. The use of
drainage wick material is therefore also considerable. The presence, in addition
to the operator of the device, of the operative for arranging the ground anchors
and severing the wicks is a further cost factor.
The present invention has for its object to alleviate the above stated
problems of the known art, and in some embodiments even obviate them completely.
A device according to the present invention is distinguished for this purpose by
two measures, which can be taken together or individually, namely: engaging means
in the passage close to the lower end of the lance during use which co-displace
an element for placing in the downward movement of the lance, and/or sticking
means which, in or close to the lowest position of the lance, carry the element
out of the lance and stick it in the ground prior to or at the start of the upward
movement of the lance.
As component of the lance, the engaging means fulfil a co-displacing
function for carrying along the drainage wick, for which purpose the ground anchor
was used in the known art, and which is therefore no longer necessary. The sticking
means ensure that a wick becomes fixed in the ground in or close to the deepest
point of the inserting lance, for which purpose the ground anchor has in the past
been used in the known art, and which is therefore no longer necessary to fulfil
this function. Particularly in an embodiment with engaging means and sticking means
in or close to the lower end of the lance during use, the need for a ground anchor
in the form of a steel plate disappears completely.
In a very favourable embodiment the sticking means and the engaging
means can be designed as a unit. This enhances the simplicity of the device and
is favourable for the number of components in or close to the lower end of the
lance. Such a unit can comprise a pull rod extending in the passage in the longitudinal
direction of the lance and a spring element arranged thereon close to the lower
end of the lance during use, wherein the unit is arranged movably in the passage.
During the downward movement the spring element holds the drainage wick fast by
clamping against the inner wall of the lance, and thus fulfils the function of
engaging means. The pull rod is movable in the lance. When the deepest point is
reached, first the lance and only later the pull rod are carried upward. The spring
element is here wholly or partially released from the interior of the lance and
therefore then fulfils the function of the sticking means, whereby the wick is
stuck into the ground surrounding the pull rod.
In a favourable embodiment the lance can comprise a closing part
on the lower end during use for the purpose of closing the passage at least during
a downward movement of the lance. This closing part can form part of said pull
rod, or be a separate component on the lance itself. As is achieved in the known
art with the ground anchor, such a closing part prevents the interior of the lance
being blocked with earth. In one embodiment wherein the closing part is arranged
on the unit, or more specifically on the pull rod, this closing part can be a spherical
head. Such a spherical head will of course have larger dimensions than the opening
on the underside of the lance to enable effective closing thereof during said
Alternatively however, the closing part can be a valve on the lower
end of the lance during use. This is a particularly favourable embodiment for loose
soil compositions which, when the lance is moved upward, collapse on and around
a spherical head arranged for instance on the end of the pull rod, which can prevent
the drainage wick being left behind in the ground in the desired manner. The spherical
head is well suitable for a firmer ground, wherein the closing part, when it forms
part of the pull rod in particular and the unit in general, is not precluded from
having a form other than a spherical head. It is for instance possible to envisage
a conical head etc. In one embodiment with a valve on the lower end of the lance
during use, such a valve can be a flap of tough, strong and flexible material,
such as rubber with a strengthening reinforcement. It is possible for instance
to envisage rubber strengthened with steel wire such as is for instance applied
for car tyres.
In yet another embodiment the lance can itself comprise cutting means
for the purpose of severing the elongate element after an upward movement of the
lance, once it has been brought back above ground. In a favourable embodiment
use is herein made of the horizontal displacement of the device to a new location
where another drainage wick must be placed in the ground. The cutting means can
simply be designed here as a stationary knife positioned in accordance with the
direction of displacement.
The invention will be further described hereinbelow with reference
to the annexed drawings which show embodiments of the invention and in which the
same reference numerals are used for the same or similar components, and wherein:
- Fig. 1 shows a schematic side view of a device according to the present invention;
- Fig. 2 shows a detail of the inserting lance of a device in a first embodiment
according to the present invention;
- Fig. 3 shows a detail of an inserting lance of a device in a second embodiment
according to the present invention;
- Fig. 4 shows a detail of the top side during use of a mast of a device in another
embodiment of the invention; and
- Fig. 5 shows a detail of the inserting lance shown in
- fig. 4 as alternative to the configuration shown in fig. 3.
Fig. 1 shows a device 1 according to the present invention. This
comprises a frame in the form of a crane 2 which can travel over the ground 4 in
which drainage wicks must be placed. On crane 2 is arranged a mast 3 along which
an inserting lance 5 can be moved. Mast 3 thus forms a guide for inserting lance
5. Arranged on mast 3 is a drive motor 6 which forms a drive for inserting lance
5 to move it reciprocally along guide 3. Inserting lance 5 and motor 6 are mutually
connected via a tensioned cable 7.
In the arrangement shown in fig. 1 the device 1 is ready for use.
When motor 6 is set into operation the inserting lance 5 is forced into the ground
4. When the furthest depth has been reached, which is preferably adjustable, the
inserting lance is moved upward again while leaving behind a drainage wick which
is unrolled from a spool 8 during the downward movement of inserting lance 5. When
the inserting lance has been brought back again above the surface of ground 4,
the drainage wick left behind in the ground is severed and the crane 2 is driven
to a subsequent location where a drainage wick has to be inserted.
Fig. 2 shows a cut-away schematic view of an inserting lance 5 in
a first embodiment according to the present invention. Inserting lance 5 is hollow
and has a passage 10. Extending in passage 10 is a pull rod 11 having on the end
thereof a spherical head 12 closing the passage 10. Further arranged on pull rod
11 is a leaf spring 13 which forms the engaging means in the sense of the present
In addition to pull rod 11, a drainage wick 9 also extends through
passage 10. Drainage wick 9 is pressed by leaf spring 13 against the inner wall
of lance 5 and thus co-displaced when the inserting lance 5 is forced into the
Once inserting lance 5 has reached the deepest point, pull rod 11
is temporarily held stationary while a start is already made with pulling the inserting
lance 5 back up. The spherical head 12 is herein released from the opening of
passage 10 on the underside of the inserting lance. The inserting lance 5 is pulled
so far up that leaf spring 13 is moved clear of the passage. Leaf spring 13 herein
presses the drainage wick 9 into the surrounding ground so as to thus fix and
position drainage wick 9. The inserting lance 5 is then moved upward together with
pull rod 11. Drainage wick 9 herein slides through the interior of the passage
10 and remains behind while inserting lance 5 is moved upward while therefore
leaving drainage wick 9 in the ground.
As soon as the inserting lance 5 has arrived above the ground surface,
for instance only a few centimetres there above, the spherical head 12 is once
again pulled against the opening of passage 10. A horizontal displacement of the
device shown in fig. 1 subsequently takes place to a new location where a drainage
wick 9 must also be placed in the ground. During this displacement the drainage
wick 9 is severed with a knife 14, wherein the spherical head 12 presses drainage
wick 9 against the knife. Displacement of device 1 is then preferably in the direction
of arrow A in order to realize the most efficient possible action of knife 14.
It is noted that further measures can be taken to make more certain
that drainage wick 9 is left behind. Protrusions 15 can thus be arranged in the
interior of inserting lance 5 between which the drainage wick 9 can unwind freely.
During the upward movement of inserting lance 5 out of the ground the leaf spring
13 can then rest on these protrusions 15. This is brought about by carrying the
inserting lance, with the pull rod 11 therein and the spherical head 12 on the
opening of passage 10, to the deepest point. The inserting lance is then moved
upward until leaf spring 13 is moved clear of the interior of passage 10 to stick
the drainage wick in the surrounding ground. Pull rod 11 is then moved upward
again relative to inserting lance 5 until the leaf spring once again rests on said
protrusions 15 in the interior of passage 10. During this pulling-up movement of
pull rod 11 relative to inserting lance 5 this latter can be held stationary for
a moment or the upward movement thereof can be continued.
Fig. 3 shows an embodiment as a possible alternative to the embodiment
of fig. 2. This relates particularly to an alternative for the spherical head 12
of fig. 2. In the embodiment of fig. 3 the pull rod has constant dimensions along
the whole length thereof, which is advantageous when the inserting lance 16 is
used in looser soil which collapses onto the pull rod when inserting lance 16 is
moved upward to release the leaf spring 13. In the configuration of fig. 2 the
collapse of soil onto the spherical head 12 can result in the drainage wick 9 adhering
to the spherical head 12 and/or pull rod 11. This is obviated, to a considerable
extent if not entirely, in the configuration of fig. 3, although in such a configuration
alternative measures do however have to be taken for the spherical head so as to
prevent passage 10 becoming blocked with earth. A flap 18 is placed for this purpose
over the opening of passage 10 on the underside of inserting lance 16. This flap
closes the opening during a downward movement of inserting lance 16. When the inserting
lance is moved upward again while pull rod 11 remains temporarily stationary,
the pull rod 11 pushes the flap 18 aside, where after leaf spring 13 is released
in order to stick the drainage wick 9 (not shown in fig. 3) in the ground.
It is noted that flap 18 is manufactured from rubber reinforced with
steel wire. Such rubber reinforced with steel wire is comparable to the way in
which a car tyre is designed. A steel wire reinforcement is very desirable to be
able to withstand the high forces generated when the inserting lance is forced
into the ground.
It is noted that, in addition to the spherical head 12 or flap 18,
many other random solutions are also possible within the scope of the present invention
for the purpose of closing the opening of passage 10 on the underside of the inserting
lance during the downward movement thereof. A steel hinged valve could thus be
used, provided measures are taken to protect a hinge thereof from the action of
sand and earth. It is in any case important that the passage 10 of the inserting
lance does not become blocked, for which purpose some form of closing part is necessary,
the spherical head 12, flap 18, a valve (not shown) only being examples thereof.
In fig. 3 use is further made of a slide block 17 in the interior
of inserting lance 16. The pull rod slides over this slide block 17 during a movement
of pull rod 11 and inserting lance 16 relative to each other, thus also enhancing
the action of the leaf spring in co-displacing the drainage wick and sticking
thereof in the surrounding ground. Without such a slide block the pull rod 11 is
pressed sideways by leaf spring 13, to the left in the drawing, which could affect
effective operation thereof. Slide block 17 effectively prevents this.
Fig. 3 further shows that a stop 18 is arranged on pull rod 11 and
a stop 19 is arranged on the interior of inserting lance 16. The distance between
these stops 18, 19 corresponds to the distance which the inserting lance 16 covers
on the way up again after reaching the furthest insertion distance into the ground,
before the pull rod begins to co-displace upward again. At this moment the stops
18, 19 come into mutual contact and pull rod 11 is carried upward with the inserting
lance. At least one of the stops 18, 19 can preferably be positioned adjustably
so that the above mentioned distance is adjustable.
In the configuration shown in fig. 4 the pull rod 11 extends through
the whole inserting lance 5, even to a point beyond the upper end during use of
inserting lance 5. In the position of pull rod 11 relative to inserting lance 5
in which it protrudes under inserting lance 5 during (at least the start of) the
upward movement of the inserting lance, as described above, the upper end of pull
rod 11 also protrudes above the upper end of inserting lance 5.
As shown in fig. 5, pull rod 11 comprises on the top side thereof
a slotted hole 21 in which is placed a slide block 22. Slotted hole 21 has a limited
length and, because slide block 22 is mounted fixedly on inserting lance 5, the
freedom of movement of pull rod 11 relative to inserting lance 5 is bounded thereby.
The part 20 of pull rod 11 above slotted hole 21 protrudes above
the upper end of inserting lance 5 because slide block 22 is arranged close to
the upper end of inserting lance 5. The part 20 of pull rod 11 is therefore available
to be engaged in or close to the upper position of inserting lance 5 relative to
By engaging said upper part 20 of pull rod 11 when the inserting
lance 5 is back again or moves into or close to the upper position thereof relative
to mast 3, the pull rod 11 can be moved upward again relative to the inserting
lance to the starting position thereof shown in for instance fig. 2 or fig. 3,
where after the construction can once again be used for a new operation.
In fig. 4 the engagement and pulling up of pull rod 11 is realized
with two pairs of tyres 23 on the top side of mast 3 which are selectively rotatable.
The tyres 23 of each pair are rotatable in opposite orientation as indicated with
arrows A and A'. When inserting lance 5 is in or returns to the upper position
again relative to mast 3, with the pull rod 11 in the lower position relative to
inserting lance 5, wherein the upper edge of slotted hole 21 lies against slide
block 22, the part 20 of pull rod 11 still protrudes so far above the top of inserting
lance 5 that the lower pair of tyres 23 engage this part 20 of pull rod 11 between
said pair of tyres 23. Through selective driving of tyres 23 which, as stated,
are rotatable in opposite orientation, pull rod 11 is now pulled upward relative
to the then (almost) stationary inserting lance 5.
As alternative to such a configuration, use can for instance be made
of a winch (not shown) or the like, wherein pull rod 11 can be pulled up on a cable.
However, the advantage of the embodiment of the invention shown in fig. 4 and
5 is that pull rod 11 remains behind in the deepest position under the influence
of its own weight when inserting lance 5 begins to move upward again after reaching
that deepest point. This is the case because pull rod 11 extends through the whole
inserting lance 5, although it is not inconceivable that weighting must be arranged
on the inserting lance for this purpose.
When inserting lance 5 is moved upward through a distance defined
by the length of slotted hole 21, pull rod 11 is carried along by slide block 22
to the range of engagement of tyres 23. Close to or at the highest point of inserting
lance 5 relative to mast 3 the pull rod 11 enters the range of engagement of tyres
23 and is lifted relative to inserting lance 5.
It may occur that inserting lance 5 does not reach the intended depth.
An obstacle such as a stone may for instance be encountered while the inserting
lance is being forced downward. If this happens, the inserting lance has to be
moved back up again. In a configuration wherein pull rod 11 is suspended with
a cable from a winch, the operation of this winch can be controlled by a control.
It is not possible here to take account of the intended depth not being reached.
In such a configuration the whole operation is therefore aborted, while in the
configuration shown in fig. 4 and 5 a drainage wick can still be placed to the
depth reached, even if this is less deep than the intended depth.
Tyres 23 thus form a lifting mechanism for pull rod 11 which only
acts on pull rod 11 in or close to the highest position of inserting lance 5 during
use. This does not however preclude use being made of a lifting device which is
continuously in contact with the pull rod so as to realize the function described
above for instance with reference to fig. 2, wherein in or close to the lowest
point of inserting lance 5 the pull rod 11 is also lifted some distance to cause
leaf spring 13 to rest on protrusions 15.
After examination of the foregoing it will be apparent to a skilled
person that many additional and alternative embodiments are possible within the
scope of the present invention as defined in the appended claims. Some attention
has thus already been paid in the foregoing to alternative designs of a closing
part required to prevent blockage of the passage. It is also possible to envisage
other embodiments of the engaging means, which are described in the foregoing as
a leaf spring, and of the sticking means, which also take the form of a leaf spring.
Instead of the leaf spring explicitly described above, use can also be made as
engaging means of a clamp selectively fixable with a spiral spring, although for
the clamp a control connection through the passage to the clamp is then necessary.
The sticking means and the engaging means do not necessarily have to form a unit,
although this is advantageous in respect of the number of components in the lower
end of the inserting lance during use.