Note: Descriptions are shown in the official language in which they were submitted.
1~1Ç;~7~
The invention relate~ to a method and an appar~tus for
making holes in ths ground to fac~litate the su~sequent
implantation of poles, stakes or s~m~lar.
The implantation of poles, stakes or similar is a
customary operat~on, part~cularly in the agricultural field.
~hen ~t has to be performed manually a num~er of times, for
instance ~hen planting v~ne, the t~me needed for the operation
is proh~bitive. It is there~ore useful to provide an apparatus
for automating at least part of the planting operation of poles
or stakes.
Till now, such a planting operation is effected either
b~ plant~ng d~rectly the pole or stake in the ground through
t~e agenc~ o~ a hammer or sim~lar, or by previously digging a
hole with a tool and then driving the pole or stake into the
hole.
The first process ~direct planting) can be used in
practice only for planting poles or stakes in grounds which are
loose enough. Moreover, t~e side walls of the hole drillea by
t~e pole or stake crumble with time, which is prejudicial to
2Q -the stability of the planted pole or stake.
~ hen the planting is effected according to the second
method, and in order that the stake or pole ~e correctly
ma~ntained ~n the ground, it is necessary to seal the stake in
the ground with concrete, whic~ is a relatively complex
operation to practice.
In order to avoid working concrete into the holde
previously drilled, an apparatus has already been proposed which
allows, at the same time as holes are made, the introduction of
sleeves in the latter, said sleeves haring the same cross
section as the bases of the stake or pole to be subsequently
planted. However, such an apparatus is not usable in practice
since the sleeves, which have to be made of plastics to be of a
moderate price, collapse during insertion if the ground is not
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1008e enough.
It is therefore an o~ject of the present invention to
obviate or mitigate the a~ov~ d~sadvantages.
According to one aspect o~ t~e present invention
there is prov~ded a method of forming hole~ in the ground
where~n a compacting force is appliedrto the surface of an area
of ground around the lo~at~on of and simultaneously with the
making of a ~ole, the direction of appliaation of the compaating
force ~eing substantially parallel to the longitudinal axis of
the hole.
It has ~een established that while proceeding in this
way, the ground is firmly compacted around the hole and
practically over t~e w~ole he;ght of the hole.
In an advantageous ~m~odiment of the invention, a
compact~ng effort, which may be of variable intensity, i~
applied continuously to the ground, for instance by maintaining
a ram~ing bed-plate on the ground around the hole while the
hole i8 being drilled. I~ th~s manner, the ground is
partîcularly well compacted, in particular in the vicinity of
20 -its free surface.
~ A hole thus made forms a housing for the base of a
- pole or stake, the side walls of which resist crumbling ~even
at the mouth of the hole) even if subsequently side thrusts are
: applied by the pole on said walls. Moreover, the length of the
- pole or stake driven in the ground can be reduced.
Moreover, a simple drilling post is required for
digging such a hole. Said post may be easily extracted from
; the hold made, even if it is not provided with a draw-taper.
According to a further aspect-of the present
3~ invention there is provided an apparatus for forming holes in
the ground and comprising means for making a hole in the
ground and ground compacting means to be applied to the surface
of an area of ground around the location of the hole
37~3
simultaneously with the m~king of t~e ~ole, the direction of
applicat~on of the compacting means being su~stant~ally
parallel to the longitud~nal axis o~ t~ hole.
An em~odiment of t~e ~nvention will now ~e described
by wa~ o~ example only wit~ reference,to t~e accompanying
dra~ings ~n whIch:
FIGURE 1 s~ows ~n per~pective a hole forming apparatus;
FIGURE la is a schematia illustration of a vibrator
~or the apparatus sho~n in Fig. 1;
FIGURE 1~ is an enlarged cross sectional view of a
port~on of the apparatus shown in Fig. l;
FrGuRE 2 is a s~de view of the apparatus shown in
~g. l;
FIGURE 3 is a sectional v;ew along line III-III of
the apparatus shown in Fig. 2;
FIGURE 4 shows the control means for an apparatus
similar to that shown in ~ig. l;
FIGURE 5 s~ows a pole placed in a hole made with an
apparatus according to the invention;
FIGURE 6 is a top vi~w of a tractor equipped
with the apparatus according to the invention;
FIGURE 7 is a side view of Fig. 6;
FIGURE 8 is a sectional enlarged view of an element of
the apparatus shown in Fig. 1, and
FIGURE 9 shows schematically how the apparatus shown
in Fîg. l may ~e used for makihg holes with aligned axes.
The embodiment of the apparatus (or device) described
is intended for making holes with vertical axis in the ground
to facilitate the subsequent implantation of stakes or poles.
The device provides at least partial automation of the
implantation of stakes or poles such as are used in the
agriculatural field.
The device 120 is normally attached to a tractor
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121 (~igs. 6 and 7~ of a standard type and on which are mounted
the control means such as a compressor 122 for the various
members forming the dev;ce.
The device 120 comprises a horizontal telescopic
beam 2 having a ~ody 3 which èxtends over a retractable portion
4. The portion 4 may ~e slid inside the ~ody 3 by means of the
dou~le-action jack 5, the cyl~nder of which is fixed to the
~ody 3 and the-rod of w~ich 6 ~s attached to the retractable
portion 4. The ~ody 3 ~ of general parallelepipediC shape and
its upper and lowar faaes are formed with notches in which are
placed ~locks 7 protruding inside said ~ody 3 and forming a
guiding ~earing for the retracta~le portion 4. The blocks 7
are made of brass, nylon or any other material having a reduced
riction-coefficient ~;th the material forming the retractable
~ portion 4,
- The upper face of sa;d body 3 also includes ear~ 8
formed with openings 9 which ar~ aligned in a direction
parallel to beam 2. The ears 8 and their openings 9 are
connected to the lower portion of the frame of the tractor,
between its front wheels 123 and rear ~heels 124, ahead of the
`~ steering wheel 125. The beam 2 may therefore pivot about a
horizontal axis 2a of beam 1 relative to the tractor.
The side face 3a of body 3 of the telescopic beam 2
includes ears 10 to which is pivotally connected a piston rod
11 of a dou~le-action jack 12. The free end 13 of the jack
body 14 is attached to the frame of the tractor on one side,
for instance on the right hand side, of the hood 126 of the
engine of the tractor. The jack 12 controls pivotal movement
of beam 2, and thereby of the whole assembly, about the
3a horizontal axis 2a.
One end of the retractable portion 4 of the telescopic
beam 2 is pivotally attached by a horizontal pin lS to side
faces 16 and 17 of a U-shaped section 18 which extends in a
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generally vertical direction. ~he ~ase 19 of the section 18
is applied against an outer ~ace 20~ of a eleeve 20 which also
extends vertically and has a rectangular cross sectîon.
The ~ody 21 of a dou~le-action jack 22 is pivotally
attached to the retracta~le port~on 4 of beam 2 and the rod 23
is connected, also pivotally, to said face 20a of sleeve 20.
Vertical guid~ng mem~ers 24 made of a material having
a lo~ friction-coefficient suc~ as ~ron~e or a plastics
material are pro~ided inside of sleeve 20 to permit sliding
movement ~etween the sleeve and two vertical beams 25 and 26.
The ~eams 25 and 26 are made each of a tubular section of
rectangular cross section and are connected at their upper end
by a horizontal plate 27. A verti~al plate 28 depends from the
plate 27 and partially covers faceg 2Sa and 26a of the sections
25 and 2~ respectively.
At their lower portion, the sections 25 and 26 are
connected by a horizontal plate 30 formed with an opening 31 for
the passage of a post 1.
From the free face 2g of plate 28 protrude two vertical
flange~ or ears 32 between which is pivotally housed the upper
end of rod 33 of a dou~le-action jack 34, the lower end of its
~ody 35 ~eing pivotally attached, along a horizontal axis 36,
; to the side plate 16 of the section 18.
A vibrating hammer 37 operating on a post 1 is housed
between the sections 25 and 26 so as to be able to slide
vertically ~etween said sections. ~he vibrating hammsr 37,
known per se, acts on post 1 so that the latter exerts vertical
recurrent force directed downwardly toward the ground. The
hammer 37 includes automatic a~utment stop means to cause
automatic stoppage of hammer 37 when said abutment engages the
upper face of plate 30.
~ ith such a disposition, the post 1 does not have an
excessl~e length if the abutment is arranged on the lower face
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of the hamm~r body 37; in thi~ case, the length of post 1
does not exceed in practice that of the hole to be made.
The upper portion of the vibrating hammer 37 i8
secured to a horizontal plate 38 wh~ch i5 also housed between
the sections 25 and 26j The plat~ 38 has edges 39 to prevent
any dîsplacement other than a vertical mo~ion of said plate
(and therefore of hammer 37l. ~he upper face of the plate 38
is formed with ears 40 for th~ fixation of the end of the rod
41 of a vertical jack 42, tfie function of which is to provide
the retraction of post 1 once the ~ole has been made.
~ t the upper portion of the sections 25 and 26 and
on their side faces 25~ and 26~ are attached vibrating elements
of identical construction, respectively 43 and 44.
Th~ vibrating elements 43 ahd 44 are known per se.
Each o~ them comprises a wheel, respectively 43b and 44b
CFig. la~, adapted for rotat;ng a~out a horizontal axis 43a,
44a. Each of the wheels, of a dissymmetric shape, is
imbalanced and the wheels are driven at the same spped but in
opposite directions about parallel axes. The resultant of the
2Q vi~rations caused ~ said elements 43 and 44 comprise only a
vertical component, as the elements are mounted "out of phase".
The vi~rating elements 43 and 44 are associated with
a reaction device 45, the function of which is to amplify the
compacting effort provided ~y said vibrating elements. The
device 45 comprises a square shape horizontal plate 46 formed
with a central opening 47 through which extends the body of
jack 42. Openings 48 are formed in the vicinity of the four
corners of the plate 46 CFig. l~ through which extend vertical
rods 48a. The rods 48a are secured at their lower end to a
3a horizontal plate 49 ~h~ch is it~elf fixedly connected to plate
27. The plate 49 is formed on its upper face, in its central
portion, with a boss 50 provided~with an opening 50a through
which the ~ody of jack 42 can extend. The plate 46 rests on
the upper edge of boss 50.
The rods 48a protrude above plate 46 and thelr upper
end 48a is threaded to receive a nut 48c. A spring 48d
surrounds rod 48a between the upper faae of plate 4~ and nut
48c, a washer 48e being int~rposed ~etween the upper end of
spring 48d and the lower face of nut 48c.
W~en, during eac~ half period, the vibrating elements
exer~ an ef~ort in the upward direction, the springs 48d are
compre~sed, this effort pro~ecting plate 46 ~which is free in
translationl in the upward direction. When said vibrating
e~ements, during the following half period, exert an effort in
the downward direction, there is added to their effort the
effort exerted by plate 46 whia~ falls ~ack on boss 50 and the
~- force exerted ~y springs 48d which are released. An
`~ amplification of the effort provided by the vi~rating elements
is thereby obtained.
On the plate 30 forming a brace for the lower portions
of the vertical sections 25 ahd`26 is attached a plate 51
formed with an opening of a shape and size such that it just
2a allows passage for post 1. Under the plate 51 are attached
four poînts for anchoring in the ground; only two of which 52
and 53 are visi~le in Fig. 1. In the example, the plate 51 is
of general rectangular shape. It forms the active portion of
the compacting means for the ground in the vicinity of the hole
to be made with post 1, and it will be referred to hereafter
as the "rammîng bed-platen.
On a side face 20b of sleev~ 20 is attached a
detection and control device SS for the vertical determining
alignment of pole 1.
In the example, said device 55 comprises a cylindrical
casing 100 CFig. 8) attached to the sleeve 20. The casing has
a flat bottom 102 and its a~is is usually vertical. It is
closed ~y a cap 103 with a flange 104. A hole 105 is formed
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in the cap 103, coaxial with the casing 10~. A spider 106 is
located in the hole 105 and rotatably supports a ball 107
fixedly attached to the r;g~d rod 108 of a pendulum 109. The
open~ng 105 opens into the ~ns~de o~ the casing through a
coax~al opening 110 of smaller d~ameter, allowing passage for
rod la8. A hea~y ~ody 111 ~s attached to the rod 108 and is
immersed in o~l 112 fill~ng the lower portion of the casing and
damping the`movements of the pendulum.
A~ove the ball 107, the rod 108 has ball-and-soaket
joint 113 connecting it to a ~pool movable inside a valve
assem~ly 115 attached to the upper wall of cap 103. The
direct~on of the movement of the spool is therefore always
perpendicular to the casing axis.
Below the ball is provided likewise anotherball joint 116
for the articulated connection of rod 108 with a second spool
movable inside a body 115a attached to the bottom of opening
105. The movement of said latter slide is effected always in
a directàon ~hich is perpendicular to the casing axis as well
as to the direction of the movement of the other slide.
2a The lower portion of the heavy body 111 is formed with
a notch 117 engageable ~ith punch 118 forming the end of a
piston-rod 1-19 slidable in a motor-119a attached to the lower
face of base lQ2 of casing ~OG for securing the pendulum against
motion relative to the casing.
The first valve assembly 115 controls jack 12 whereas
the second slide and body assembly 115a controls jack 22.
Through this joint action on the two jacks, the axis of the
cylindrical casing 100 is brought to the vertical and the post
is thereby also brought to the vertical.
To the vertical face (Figs. 2 and 3) 20c of the sleeve
20 is secured a vertical beam 60 supporting a second drilling
device 61. The device 61 has a strength which is superior to
that of the first device and comprises a boring-bit 62, that
r~, 3
is a drilling mem~er of the rotary type. The axis o~ post 1
and the axîs 62a of borlng-~it 62 are, as seen in a plan view,
in the plane of the ~liding axis of the retracta~le portion 4
of the telescopic ~eam 2. It sfibuld also ~e noted here that
the retracta~le portion 4 may slide in the direction of arrow F
~Fig 21 over a length at least equal to the distance from the
axis of post 1 to axis 62a.
As can ~e seen from Tigs. 1 and 3, the jack 22 is not
arranged in the plane of symmetry of the beams 25 and 26 of
sleeve 20.
The operation of the apparatus for making holes which
has ~ust been described ~s the follo~s:
~ ith the ass~stance of the tractor 121, the post 1 is
placed above the hole to be made. In this position, with the
; assistance of device 55 the post is aligned exactly vertical.
If this.is not the case, the jacks 12 and 22 are operated
~; automatically ~y valve ass~m~lies 115, 115a until the pendulum
. . o~ device 55 indicated that the post 1 is vertical. The jack
1~ pivots.the beam 2 about the hori~ontal axis 2a, whereas the
jack 22 modifies the angle b~tween the beam 2 and the assembly
supporting post 1.
: During these operations, the post 1 is lifted by jack 42 relative to plates.30 and 51, as is shown in Fig. 2.
After post 1 has been placed in a vertical position,
: the rod 33 of the double action jack 34 is retracted so as to
lo~er the sections 25 and 26 until the ramming bed-plate 51
engag~s the ground and is anchored therein via points 52, 53.
The.jack 34 applies an effort through the plate Sl against the
ground in the area in.which the hole is to be made.
The jack 42 is then released so that the vibrating
hammer 37 may come down under the effect of its own weight and
the post 1 engages the ground. Then the hammer 37 and the
vibrating elements.43.and 44 are operated~
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Under thes~ conditions, the post drills a hole and at
the same time the ra~ming ~ed-plate 51 exerts on the ground
around the ~ole ~eing ~ored an effort which is constantly
directed downwardly ~ut with ~al~es ~arying recurrently.
In the example, the variation frequency of the
compacting effort Ccaused by elements 43 and 44) is between 1
~- and lQO pex~ods per second. Th~s frequency is in this example
hîgher th~n the variation ~re~uency of the efforts applied on
post 1.
10 When the stop abutment (not s~own) of the vibrating
hammer 37 engages the upper ~ace of plat~ 30, the operation of
the hammer.is interrupted. The abutment is therefore arranged
: to stop the hammer at a depth corresponding substantially to
the depth of the hole des;red.
~ The operation of the vibrating elements 43 and 44 is
; interrupted after that of hammer 37, then jack 42 is activated
for lifting back said hammer 37 and thereby releasing post 1
from the hole it has just made, ths ramming bed-plate remaining
resting on the ground. Thereafter, the ramming bed-plate and
2a post 1 assembly is lif~ed back by jack 34.
The boring-bit 62 drilling device.61, the power of
which is substantially superior to that of the post 1 device,
: is act;vated when the po~er of the.first device is insufficent,
for instance in a ground ~hich i6 loaally rocky. In this case,
the jack S is operated for displacing the retractable portion 4
of beam 2 in the direction of arrow F over a distance
corresponding to that separating the vertical axes of post 1 and
the borîng-bit 62 so that t~e latter assumes the position of
post 1. After having.made a.hole ~ith the boring-bit 62, the
retractable portion 4 is removed in a direction contary to that
of arrow.F for bringing back post 1 in its original position and
finish making the hole.
It may ~e advantageous, in order to provide the
-- 10 --
displac~ment of the retracta~le portion 4 to return po~t 1 to
its original position, to use compressed air ~lowing means
(not Qhownl for remov~ng the roc~y de~r~s which are in thQ
hole made by ~oring-B~t 62.
Fig. 4 sho~s as an exa~ple the operating mean~ for
jacks 42 and 34 and ~or the v~brat~ng'~ammer 37.
There is shown in th~s figure the piston 70 of jack
34. ThQ piston 70 is movable inside cylînder 35 and drives rod
33.
The lower portion of cylinder 35 is formed with an oil
feed input 7i ~hereas its upper portion is formed with a
compressed air intake 72.
Likewise, a piston 73 of jack 42 which is disposed in
cylinder 42a is shown. This piston 73 is r~gidly attached to
rod 41.
The upper portion of cylinder 42a carries a compressed
air intake 74 and said cylinder 42a is formed at its lower
portion with an oil feed intake 75.
The hammer 37 is operated by compressed air and has
a member 76 to supply through an opening 76a comprsssed air
from a compressor. The member 76 delivers also compressed air
to intakes 72 and 74 of cyl;nders 35 and 42A through flexible
ducts, respectively 77 and 78.
The oil supply through intake 71 provides the
possibility of exerting on piston 70 a force Fl directed
up~ardly and, as already discussed hereabove, of lifting the
beams 25 and 26, the bed-plate 51 and the vibrating hammer 37
assembly. When this oil pressure is stopped, the assembly
comes down under the action of its own weight until the bed-
3a plate 51 engages the ground.
In order to increase the pressure on the ground, thecompressor 76 provides compressed air at intake 72 of cylinder
35. A force F2 is thereby applied on the upper face of piston
7~. Although this force is small, it is ~ufficient to hold
the bed-plate 51 in contact ~th the ground~
The oil supply t~rough intake 75 of cylinder 42a
allows lifting ~ack post 1 through t~e application of a force
F4 on the lower face of p~ston 73~ In order to bring said
p~ston 73 down again, the force ~4 ~s cancelled, in other
words the oil pressure is reduced to zero. Thus, the
vi~rating hammer may come down under the action of its own
weig~t. ~owever, it ~as been esta~lished that if compressed
air is injected through intake 74, the penetration speed of
post 1 inside the ground is increased due to the application of
a force F3 directed downwardly on the upper face of piston 73.
The force F3 is maintained a~ a constant value during the
operation of the vibrating hammer 37. It has also been
o~served that with the applioatio~ of such a force F3 caused by
the compressed air, th~ device had only few undesirable
vîhrations. The increase of the penetration speed of post 1
in the ground has also as a consequence a large reduction of
the effect on post 1 of t~e vi~rat;ons caused by the tractor.
To determine the value of the oil pressure to be
injected through intakes 71 and 75 to cylinders 35 and 42a of
the jacks, respectively 34 and 42, account may be taken of the
following considerations: w~en the assembly formed by the
beams or sections 25 and 26 and the vi~rating hammer 37 is
-. being lifted, the force Fl has to ~e superior to the weight of
said assembly and the force F2 which may be applied by
compressed air to the upper face of pîston 70, if the air
pressure is maintained. When the vibrating hammer 37 is lifted
back, the ~orce F4 has to be superior to the weight of hammer
3~ 37 with its post 1, and t~e additional force F3.
The hole made îs well callipered, that is its cross
~ section has a shape and size well determined and corresponding
to the outer shape and size of post 1. The ground 65 (Fig. 5)
is quite hard around the hole made. Moreover and due to the
compactin~ action, the free surface 66 of the ground around
the hole is below the ~ree surface 67 of the non rammed ground.
In the reces~ thus formed can ~e ~orked concrete 68 once a pole
69 has ~een planted ~n ~he hole ~n order to improve the
fixation of the pole 6~.
A further consequence of ~he compacting quality of
the ground is that the post ~ is removed without any difficulty
from the hole made, whatever the shape of said post 1, and
even if the latter has now drau-taper.
The ground is well packed over the whole height of
the hola, particularly in the v;cinity of the free surface of
the ground. This may ~e attributed to the fact that the effort
applied for effecting the compacting action is never zero. A
hole thus made forms a housing for the base of a pole or stake,
the side wails of which do not crumble or crum~le little with
time in spite of lateral efforts transmitted to the hole walls
and exerted for instance by the ~ind on the poles. ~oreover,
the driven depth of the pole or stake may be reduced to the
minimum.
The anchoring of the ramming bed-plate with the help
of points 52, 53, etc. provides accurate positioning of the
device.
It has already been mentioned that the jack 22 is
not loca*ed in the plane of symmetry of the sections 25 and 26
~` and of the sleeve 20; more precisely, the jack is in a position
~hich is off-set relative to the vertical line passing through
~` the centre of gravity of the sleeve 20, the sections 25 and 26
and the hammer 37 assem~l~. It has been observed that such a
position of said jack provided compensation for the
tolerance on the varîous rotation axes of the described device.
On the side faces 20a and 20b of sleeve 20 are
attached containers 130 and 131 (Figs. 1 and 3) from the lower
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1 ~ ~f~
face of each of which depends an outlet nozzle 132 for injecting
ground wetting water in the po~ition where the hole has to be
made. Thl wetting water ~s brought to the containers 130 and
131 through flexi~le pipes from a tank 1~4 placed on the
tractor (Figs. 6 and 71.
On the face 25~ of the section 25 is applied a plate
14~ a portion of which protrudes from the face 25b in an
opposite direct~on relative to t~e ~eam 2. Said portion has a
mark 1~1 ~n the form of a vertical line.
As is shown in ~ig. 3, such a mark 141 facilitates
the drilling of holes hav~ng to receîve poles arranged in a
straight line. To t~is effect, a laser 142 secured through a
stirrup 143 on the side of a pole 144 planted in the first hole
of the straight line and the ~eam of saîd laser is directed
horizontally parallel to t~e straight line formed by the axes
of the poles to ~e planted. The appropriate position of the
device i5 obtained when the spot of the laser beam strikes the
mark 141. The adjustment is provided with jack 5. The
distance from line 141 of the projection of the stake axis on
plate 14a is equal to the distance separating the line of the
- poles axes to be planted from the projection on the ground of
the laser ray.
The two drilling devices may be of any known type.
For instance, as an alternative instead of a boring-bit 62
device 61, one may use another type of drilling hammer.
Also as an alternative and instead of providing a
stop a~utment for the operation of the vibrating hammer 37
which is at the lower portion of the body of the latter and
co-operating with the upper face of plate 30, it is possible
to arrange said abutment above the upper slice of sleeve 20
and to have it co-operate with a projection or abutment (not
shown) attached to the sections 25 and 26. The position of
said projection or abutment is advantageously adjustable in
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height.
In an alternative, no vibrating elements 43 and 44
are provided, the yariation o~ the compacting e~fort on the
ramming bed-plate ~eing provided b~ the vibrations resulting
from t~e operation of a vibrating ~ammer 37.
A device according to the invention is also usable for
making non vertical ~oles.
The method contemplated to insert pole or stake in
the ground results in t~e ground about the pole or stake being
of higher density than the ad~oin~ng ground.
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