Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
This invent.ion relates to a process :Eor taking soil
samples, wherein a core sample is -taken from the ground
which .is to be analysed, and a section of the soil is removed
from ~he core for subsequent analysis or other after-treatment.
The invention also relates to a device for the performance
of this process.
In order to enable optimization of the yield of
harvests within the agricultural industry, it is normal
current practice -to determine the soil's content of addi-
tives, such as fertilizers, by taking a number of soil
samples from over a field and -then to analyse them. Using
the result of the analysis, it is possible -to de-termine the
type and quanti-ty of additive to be put into the soil i.n
order -to improve the harves-t yield. ~t the same time, the
costs of fertilization and o-ther soil treatments is reduced,
as is also environmental damage, since no excess of additive
is put in-to the soil. Sampling is normally carried out
along at leas-t one sampling line over the field, whereby,
using a drill steel, screw conveyor or ~he like, core samples
are extracted from a number of poin-ts, or e~ample 20, along
the sampling line, and, from the core sample extracted in
this way, a required sample volume is removed ~rom a number
of points correpsonding -to various soil depths.
The results of sampling and the subsequen-t analysis
are naturally dependent on the precision in the sampling
process, i.e. the same volumes being ta]~en at the same
levels along the whol e of the sampling line. To date, how-
. ever, removing samples from the core has been carried out
manually, which has not led -~o satisfactory reproducibility
of the sampling process and has also resulted in a number of
drawbacks in o-ther respects. Manual removal of a required,
suit~ble volume, for example about 5~ cm3, of sample has
been performed by employing a -tool to remove scrapings from
3S the various levels of the core sample, whic}l method, besides
the disadvantages of the sampling process being time-consum-
ing, has no-t provided precision in the sampling process.
Thus the volume of sample scrapings has varied considerably,
due -~o the difficulty of estima-ting the correct volume and
because accompanying lumps of earth, stones,etc., have in~
creased the volume to an indeterminable ex-ten-t. Neither has
it been possible to define exactly the levels on which the
samples have been removed. In order to reduce handling time,
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removal of samples ha~ had to be performed at the same time
as moving the drilling equipment between the drilling points
in -the ield, although this is further detrimental to accur-
acy, since the work has had to be performed at the same time
as the equipment has been moving over the uneven surface of
the field. A further disadvantage is that the residue of the
core sample, after sample extraction, has had to be removed
rom the drill steel before the next drilling begins. This
manual removal of the remains of the previous core sample is
also time-consuming and laborious.
The present lnvention provides a process and dev-
ice for taking of core samples, wherein these disadvantages
are eliminated, so that it is possible for the rate of sampl-
ing to be substantially increased and precision improved,whereby the reliability of the test result obtained is im-
proved considerably.
According to the present invention therefore there
is provided a process for extracting soil samples, wherein a
core sample is extracted from the ground to be analysed and
part of the soil is removed from the core for subsequent
analysis or other after-treatment, the core sample, during
its removal from the ground, being enclosed in an encasing
in which it is essentially maintained in the form and posi-
tion that it had in the ground prior to extraction, required
volumes of soil samples being removed via openings in the
encasing at pre-determined points, and the extracted soil
samples being collected for further treatment. Suitably the
removal of the soil samples is carried out in a vertical
direction at a desired height. Desirably the soil samples
are removed simultaneously at several levels in the core
sample.
The present invention also provides a device for extracting
soil samples comprising means for extraction of a core sample and a unit
for rem~ving a section
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of the soil from the core in the form of a soil sample, an
encasing adapted to enclose the extending means and the core
sample held inside the extending means while beiny raised,
said encasing being provided with openings through which a
plurality of cutters can be inserted and moved in relation
to the extending means and the core sample for the re~oval
of the required soil sample the volume of which is determined
by the dimensions of the cutter. Suitably the extxacting
means is a drill and the encasing comprises a pair of tube
halves adapted to be swivelled between an open position
where the tube halves are drawn apart and a closed position
in which the drill is enclosed. Desirably the drill is
adapted to be raised and lowered on a frame provided with
a steering device for the drill, which steering device also
serves as a scraper for material outside the turns of the
drill. Preferably the cutters are arranged in pairs, a
first cutter being of shorter length than a second cutter
and the soil scraped off by the first cutter is carried away
from the device while the second cutter is connected to a
container for the soil samples.
In one embodiment of the invention sampling me-
chanisms are arranged to bear the cutters, said sampling
mechanisms being movable in a vertical direction along the
encasing, the cutters entering through vertical slots in the
encasing, and th~ turns of the drill being provided with cor-
responding slots, the drill having a stopping device which
stops the drill in a precisely defined point directly in
front of the slots in the encasing. Desirably the stopping
device includes a vane mounted on the axle of the drill,
which vane is adapted to be moved by s-teering surfaces of
the encasing into a position where the slots in the drill
lie directly in front of the slots in the encasing, a limit
switch being adapted to stop the drill within an angle range
in which the vane comes ir.to contact with control surfaces
of the encasing when the encasing is moved to the position
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enclosing the drill.
In a further embodiment of the invention the cut-
ters are mounted in a holding arrangement, which i5 sprung
for removal of the cutters from the slots in the encasing
when the cutters come into contact with a hard object.
Suitably the cutter for removing -the soil sample is swing-
ably journalled and biased towards the soil removing position.
In the following, the invention will be described
in greater detail, together with apre~erred embodiment of a
device for the performance of the me-thod for taking samples.
Figure 1 is a perspective view of the essential
part of the core sampling device, and the parts contained
therein;
Figure 2 is a perspective view of the rear of a
section of an encasing shown in Figure 1, which is used to
enclose the core sample extracted, together with the sampling
mechanism arranged on the reverse of the encasing;
Figure 3 shows a longitudinal section through the
drill steel enclosed by the encasing, together with one o~
the sampling mechanisms arranged on the encasing; and
Figure 4 shows a section through another embodiment.
The core sampling device, illustrated in Figure 1,
comprises a base plate 10, which bears a tubular steering
device 12, and two uprights 14 and 16. The steering device,
12, is disposed above a circularhole (hot illustrated) in
the base plate 10, and the inner diameter of the steering
device and the hole corresponds to the outer diameter o~ the
core sampling device's drill or screw 18l which is described
in greater detail below. The uprights 1~,16 act as steering
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guides for a slide unit 20, which is movable in the longi-
tudinal direction of the uprights 14,16, and which in turn
bears a drill holder 22. In the drill holder 22, the rear,
squared end-fitting 24 of the clrill 18, is pivoted in a hear-
ing 26, which also incorporates a power connection, such as
a cog wheel or chain transmission from a drive mo~or 28, for
example a hydraulic motor also fi.tted on the drill holder
22. To the upper end 30 o:E the sli.de unit 20 is connected
a control device.
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(not illustra-ted), for example a hydrualic cylinder ormotor,
which during operation is disposed to move the slide unit 20
and -therewith the drill holder 22 and the drill 18 fitted
-thereto wi-th drive motor 28, in the longitudinal direc-tion
of the uprights 14,16 for raising and lowering of the drill.
In Figure 1, the slide uni-t 20 is shown in i-ts uppermost
position, and when the slide uni-t 20 is moved downwardly in
the Eigure, the drill 18 will pass through the steering
device 12 and the hole in the base plate and down into the
ground below, while at the same time the drill 18 is rota-ted
via -the drive motor in order to bore out a core sample.
The drilling device is sui-tably arranged on a means
of transport, such as a wagon or powered vehicle so as to
be capable of being easily moved over the ~ield in which the
samples are to be taken. In this connection, the vehicle
should be of the type with a low weight pressure on the
ground, which is normally achieved by the vehicle having
several wheels, for example six, eigh-t or more having a
broad area of contact with the ground. Of course, tracked
vehicles or the li]ce may be used to carry the core sampling
equipment illustrated in Figure 1. The uprights 14,16 and
the drill 18 are of suitable lengths for the extraction of
a core sample from the required depth, for example a depth
o~ approximately 1 metre in the field.
After drilling, the drill 18 is raised with the
soil (core sample) remaining in the turns, by means of -the
slide unit 20 and the hydraulic device connected thereto.
When the drill 18 passes through steering device 12 on the
plate 10, the soil outside the turns of the drill 18 will
be scraped off, so that a core sample is ob-tained with the
same outer diameter as the turns.
35For the removal of the desired samples from the
core sample extracted, an extraction mechanism is provided
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comprising -two tube halves 32,34 which are secured to axles
36, one of which is ilustra-ted in Figure 1. The axles 36
are in turn swivel--moun-ted in brackets 38 secured to -the up-
rights 14,16 on the drilling device. The tube halves 32,34
can be swivelled by means of a control mechanism, no-t illus-
trated in greater detail, from the open position shown in
Figure 1 to a position in which they enclose -the drill 18
and the core sample extracted (see Figure 3). The tube hal-
ves 32,34 thus enclose, as shown in Figure 3, in their swivel-
led-together position, the drill 18 and the core sample with
extremely small play. In this way, the core sample extrac-ted
will be maintained in the dimensions and form which it had in
the ground prior to extraction, and samples can be bored out
wlthout any soi.l falling off or changing position.
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l o rernove soil samples from the enclosrd core sample, a number o~ cutters 40, 42
are used, in the case illustrated three pairs of cutters which are rnovable
vertically, i.e. in the longitudinal direction o~ the drill 18. In order for this
moYement along the core sample to be possible, the turns of the drill lB are
provided with a number of recesses 44, which are located opposite each other along
the longitudinal direction of ~ the drill. These recesses 44 have a width so much
greater tllan the cutters 40, 42 that the cutters are able to pass unirnpeded through
the recesses 44. The cutters 40, 42 enter through slots 46 in the tube half 34 on
which the extraction mechanism is fitted, and are moved along the slot 46 by a
mechanism which is described in greater detail below.
In order to enable the soil samples to be removed in the way described, the
recesses 44 in the drill 18 must be located opposite the slots 46 in tube half 34.
This is achieved with the aid of a vane 48 Fitted to the upper squared end-fitting 24
of the drill, which vane 48, when the drill 18 is stationary, is arranged to rest in the
plane of the surface of division between the tube halves 32, 34, when the latter are
v swivelled into the position enclosing the drill 18. The prerequisite for this to
function is that the vane 48, when rotation of the drill ~r~ is stopped, comes to
rest at some point within a total angle of about 120 around this plane, which
prerequisite is achieved by the means of causing the drive rnotor 28 for the drill lB,
when the drill is raised by the limit switch, to stop within the said angle range.
When the tube halves 32, 34 are thereafter brought together, the vane will come
into contact with the edge of one of the tube halves and will be brought into the
position described above in the surface of division between the tube halves, by
which means the position of the screw 18 is defined exactly in relation to the slots
46 and the cutters 40, 42. The position is also secured inasrnuch as the squaredend-fitting 24 is fixed irlto the corresponding recess in the tube halves. In order to
enable the drill to be turned to the said position when the drive motor 28 has been
stopped, the pressure fluid circuit for the drive motor 28 is suitably provided with a
mechanical clutch or the 1 ike.
Tlle vertical rnovel-nent of the cutters 4û, 42, i.e. along the drill 18, is performed
with the assistance of a hydraulic cylinder 52 with piston rod 54, which cylinder 52
is mounted in a bracket 50 arranged on tube half 34. The piston rod 54 is, as isshown in greater detail in Figure 2, connected to a bearing bracket 56 arranged on
a plate 58 which bears the upperrnost sampling mechanism. The plate 58 is secured
to a square tube 60 which slides along guides 62 which in turn are secured to tube
half :~4 by means of arms (Figure 1). At an equal distance frorn th0 square tube 60,
two f~lrther clamp plates 66, 68 are fitted for two further sarnpling mechanisms.
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Since all three sampling mechanisms on the plates 58, 66, 6a are identical, only one
of them will be dsscribed in the Following in relation to Figures 2 and 3.
Beneath the plate 58 is pivot-mounted a clamp 69, which at its lower end bears the
cutters 40, 42 which enter through the slot 46 the tube half 34. The clamp 69 isheld in the position shown in Figure 3 by means of a spring 70 which is arrangedbetween outer end of the plate 58 and the lower part of the clamp 69. The position
of the clamp 69 in relation to the plate 58 can be adjusted using the adjustrnent
screws 72, 74 shown in Fiyure 3. The sprung suspension allows the clamp ~9 with
the cutters 4û, 42 to give way to the force from the spring 70 round the point of
pivotiny in the event that during upward movement of the mechanism along the
slot 46, the cutters 40, 4~ should corne i~to contact with a stone or other hardobject in the core sample.
The sampling mechanism described functions in the ~ollowing way: when the tube
halves 32, 34 have been closed around the drill 18 and the core sample found in the
turns oF the drill, the hydraulic cylinder 52 is actuated such that the square tube 60
and the samplirg'mechanisms fitted thereon move upwardly along the guides ~2
along the drill 18. The upper cutter 40 thereby cuts away an approximatel)! 7 mmdeep layer of soil which is carried via the upper side of the cutter 40 and a channel
76 of sheet steel or a sirnilar material arranged at the end ~0 of the drillt to a
position outside the mechanisrn and falls away. This layer of soil, which is on the
surface of the core sample and which contains impurities and surface soil (top soil),
is not required in the sarnple, and thus is removed with the cutter 40 in the manner
described. The lower cutter 42 cuts a further depth of 15 mrn and a length of 250
mm, removiny thereby a soil sample, which is carried along the upper side of thecutter 42 to, and falls down into a removable tray or box 78 which is disposed
below the end of the cutter 42, for example on a holder ~0. The 3 sampli'ng
mechanisms shown are suitably arrange(i such that the cutters remove samples
30 from the core sample within areas on different depths in the soil.
After ramoval of the soil samples, the tube halvss 32, 34 are swivelled apart to the
position illustrated in Fiyure 1 and the hydraulic cylinder S2 returns the sampling
35 mechanisms to the lower position also illustrated in Figure 1. While the wagon or
truck carrying the drilling equipment is being moved to the next sampling location,
the residues of the core sample are removad, which is suitably performed by means
oF an in itself known percussion device ~2, which is illustrated diagrammatically
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above the upper end 2~ of the drill 1~, and whose impact is applied axially
on the drill, by which means any residual core sample is effectiv~ly re-
moved ~rom the turn. The device may be replaced by other suitable mech-
anisms.
In the embodiment shown in Figure 4 th~ par~s corresponding to the embodi-
ment in Figure 3 has the addition o~ an "a"~ The di~ference between Figures
3 and 4 lies in the ~act that the lower cutter 42a i~ swingable journalled
on the pin 180. A spring 182 bi~ses the cu~ter 42a into the position shown
with unbroken lines in Figure 4. When the square tubé 60 and the samplin~
mechanism fitted thereon ~re in the lowest position and the tube halves 32,34
are closed around the drill 18, the cutter 42 will be swinged towards the
posi~ion engagi~g the cutter 40a, as shown with dotted lines in Figure 4,
due to contacting the lower edge of the slot in the tube hal~. Soil cannot
~ then enter the space between the cutters40a and 42a so that contaminted
soil will not fall into the box 78a. I~hen the sampling mechanisms
are moved upwardly the cutter 42a is for~ed i~to the position shown by
unbroken lines in Figure 4 by sprin~ 182 and will cut uncontaminated soil
from a position deeper in the soil column. Soil ~rom the surface which
possible may contain impurities will thus not be ~ut out.
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From the above, it is evident that a sampling devîce has been obtained which offers
a nurnber of advantages. The enclosing of the core sample during extraction
provides the maximum guarantee that the sarnpla will reproduce exactly the
conditions at the corresponding location in the ground. As the samplcs are taken in
a vertical direction, a representative sarnple is obtained for the whole level despite
the smallness of the sample volume, while sarnpling at several strictly defined
levels allows the possibility of separats analysis o~ the samples. The sarnple volume
extracted on each occasion, approximately 20 cm3, which is determirled by the
dimensions of the cutter 42 is very precise, since no lumps of earth or the like can
30 affect the sampling process, which is thus uninfluenced by the nature of the
ground.
Even if the device has been described as being powered by pressure fluid, such as
hydraulic ~luid, it is clear that other sourcbs of power are conceivable, also
35 including, for example, manual operation of the mechanisms. It is thus clear that
the illustrated and described embodiment is only an example o~ application o~ the
invention and that this can be modified and varied within the scope of the following
patsnt claims.
