Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention relates to the coating of milled or
peeled road surfaces with a coating in which the milled-off mater-
ial is reused, so that on one side new coating material is saved
and on the other side the transportation of the milled-off mater-
ial and its elimination is omitted.
When renewing road surfaces damaged by atmospheric
influences or by a hiyh density of vehicles, the road surface is
first milled or peeled and when the milled-away or peeled-off
material has been removed, a new coating is applied. In the
course of the milling or peeling as well as in the course of the
application the new coating the milled or peeled road surface may
be subjected to heating which ~oth simplifies the milling or peel-
ing and provides for a better adhesion of the new coating on the
exposed substrate. The milled or peeled material is loaded onto
trucks and transported to dumping sites.
In order to keep repair costs per unit road length as
low as possible, the milled or peeled material is, in accordance
with a prior suggestion, not transported to a dumping site but is
rather reemployed for the coating of the milled or peeled road
~; 20 surface. According to this method (the so-called recycling method)
the milled or peeled material is mixed together with the new coat-
ing material in a ratio conforming to the corresponding require-
ments and this mixture is then applied onto the milled or peeled
;~ road surface.
In prior art machines for coating milled or peeled road
surfaces, mixing of the milled or peeled material with the new
~; coating material is performed in a separate process and the mater-
ial mixture is subsequently transported by a truck to the storage
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or supply container of the coating machine. Although the mending
costs per unit road length may be lowered considerably by this
procedure as compared to the prior art methods, relatively high
transport efforts are still necessary causing correspondingly
high costs.
The present invention is intended to overcome this dis-
advantage. It is therefore the aim of the present invention so
to improve the prior art machines for coating millad or stripped
road surfaces that the application of the new coatiny in accor-
dance with the recycling method may readily be performed.
The invention provides in apparatus for coating stripped
road surfaces with a new surface material constituted by a mixture
of material previously stripped from the road and a new material,
comprising:
a vehicle including a chassis and a drive motor;
a supply container for the new material carried by said
chassis at a front region thereof;
a plank-type finisher for applying the new surface mater-
ial carried by said chassis at a rear region thereof; and
a mixing device carried by said chassis between said
; supply container and said plank-type finisher, the improvement
comprlsing:
said mixing device comprises a housing in which a pair
of rotatable mixers are arranged, said housing having an underside
region which opens in opposed relationship to the road surface,
said housing b~ing provided with a first filling opening at an
upper side region thereof adapted to receive material transported
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from said supply container and a second filling opening in the
area of the underside region thereof adapted to receive the mater-
ial previously stripped from the road;
first transport means for transporting material at a
selectively variable rate from said supply container into said
mixing device housing through said first filling opening; and
shoving and conducting sheets for collecting material
previously stripped from the road and guiding the same into said
mixing device housing through said second filling opening.
It is especially advantageous if the milled or peeled-off
material of the road surface is mixed with the new road coating
material and, if necessary, additional additives on the road sur-
face and then is built into a new surface. In this way it is
sufficient to collect the material distributed over the road sur-
face with the aid of the shoving and conducting sheets or similar
equipment, and to mix it with the new material and to redistribute.
The difficult process of the collecting of the milled or peeled-
off material from the road surface and the new application on the
road surface are completely eliminated. The transport costs are
reduced as only the new material has to be transported to the coat-
ing machine. No removal of milled or peeled material will be
necessary since it remains on the milled or peeled surface until
it is taken up by the coating machine and fed to the mixing device.
A particular advantage of the invention is se~n in that the mixing
ratio of milled or peeled material and of the new material may be
adjusted on the site so that an optimum adaptation of the mixing
ratio to the substrate, to different milling depths, different
composition of the milled or peeled material and other locally
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different requirements is possible.
In accordance with an advantageous embodiment of the
invention, the first transport means is a conveyor belt one end of
which is under a discharge opening of the supply container and the
other end of which is above the filling opening of the mixing
device. A further advantageous embodiment is seen in that the
first transport means is a screw conveyor comprising a conveyor
worm provided in a tube extending from the discharge opening of
the supply container to the first filling opening of the mixing
device. Such an embodiment has the advantage as compared to the
first described one, that there is a more uniform transport of the
material from the supply container to the mixing device and there-
fore the mixture comprising the material from the supply container
and the milled or peeled material from the road surface may more
precisely be adjusted. This is essentially due to the fact that
the screw conveyor effects transport even if the material in the
storage container becomes clotty while the belt of a belt conveyor
would run empty in such a case. It is a slight disadvantage that
maintenance costs are higher for a screw conveyor than for a belt
2C conveyor and there is particularly the danger that the screw con-
veyor might become clogged. Which of the two conveyors is to be
employed in the end, will have to be described with a view to the
requirements.
For precise adjustment of the mixing ratio of the material
transported from the supply container and of the milled or peeled
material, it is most suitable to provide a conveyor of variable
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conveying speed. By increasing or decreasing the conveying speed,
if the discharge from the supply container is uniform, the amount
of the material transported to the mixing device may be enlarged
or decreased. Another possibility lies in providing the supply
container with a discharge opening of variable cross section.
It should be mentioned however that for such a discharge opening
correct dosing is possible only above a certain transporting
amount since, dependent from the flowing properties of the material,
if the cross section of the opening is too small, uniform discharge
will not be possible. It is also possible to provide in combina-
tion a conveyor having variable conveying speed and a supply con-
tainer having a discharge opening of variable opening cross sec-
tion.
Depending on whether the milling or stripping device has
assembled the milled or peeled material in the middle area of the
treated road surface or whether it has left the milled or peeled
material on the whole road surface being processed, the shoving
and conducting sheets may either be restricted to the middle area
or may extend over the total width of the road surface being
treated. In order to also gather small-grained milled or peeled
material, it is recommended to provide brooms in the range of the
shoving and conducting sheets. Worm shaped brooms rotating around
the longitudinal axis thereof are found to be particularly suit-
able.
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The second filling opening for entry of the milled or
peeled material to the mixing device is so shaped that the mater-
ial already in the mixing device cannot leave through it. To
this end, a projection may be provided in the interior of the
housing of the mixing device above the second filling opening
which passes the flow of material directed from top to bottom
along the opening.
The housing of the mixing device has an underside open to
the road surface and forms with the road surface~ an almost closed
mixing chamber where however the material being mixed may, to a
certain extent, escape between the lower edge of the housing and
the road surface. If in accordance with an advantageous further
development the mixing device is vertically adjustable on the
chassis, the spacing of the underside of the housing of the mix-
ing device to the road surface, and thus the thickness of the
layer of material emerging from the interior space of the mixing
device, may be adjusted. If further on the mixing device is
tiltingly secured around an essentially perpendicular axis to the
chassis, the width of the track of material may, by correspondingly
tilting the mixing device, be adjusted within wide ranges.
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It is obvious that the mixing devices of other types
could be employed as well such as a common drum mixer including a
mixing drum rotating around a horizontal shaft. Particularly in
case of such a drum mixer, the charging with the material
collected on the road surface is not so simple since charging
should be performed at the upper edge of the drum and the material
must therefore be transported by means of a further transport
; device from the road surface level to the level of the upper edge
of the drum. All the other mixing devices have in common the dis-
advantage that a particular discharge opening for the mixed
material has to be provided which, as has been found, might
easily get clogged. ThiS is not the case in a mixing device
- having an underside open on the road surface.
For vertical adjustment of the mixing device and also for
tilting it around an essentially perpendicular axis, hydraulic
servomotors are suitably provided. As compared to electric or
pneumatic servomotors, these have the advantage that they may be
incorporated into the hydraulic systems already provided on the
machine.
It has been found desirable to provide a liquid gas driven
heating device for heating the milled or peeled road surface ahead
of the milling device in the travelling direction. By this heating
device, the milled or peeled road surface may be heated on one
side, which brings about, as has been mentioned above, an improve-
ment of the adhesion of the new road coating to the milled or
peeled surface. The heating of the milled or peeled material
prior to, or in the course of, the mixing process, if desired
together with the material transported from the storage container
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to the mixing device, leads to particularly favorable mixing
ratios. The latter may be improved only by the heating device
being secured to the mixing device and the heat generated by the
heating device ~ay thus penetrate via the housing of the mixing
device into the interior thereof.
The plank-type finisher distributes the coating material
on the processed road surface behind the mixing device in
travelling direction. Such a device is of particular advantage
if and when mixing devices of a different type are employed
instead of the aforementioned mixing device because in the former
the uniformity of the discharge may be subjected to substantial
variations. This finisher may however also be of advantage if in
special cases the machine works without a mixer, i.e. only the
material from the storage container is to be applied onto the
milled or peeled and cleaned road surface. In that case, the
material is passed from the storage container via the first con-
veyor device into the mixing device which is in another position
and through which the material drops directly to the milled or
peeled surface. As the device distributing the coating material,
a grading worm is provided.
The invention will now be explained in more detail based
on the drawing which incluaes, partly in a schematic illustration,
an exemplified embodiment.
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Figure is ~ si~ie view o~ a machin~ for coa ing rni.i~d or
peeled road surfaces,
Fl~ure ~? is a fr~nt view cf the mixt:ng device of the machine
according to Figure 1,
Figure 3 is a cr~s section of the ~ixing device according
to Figure 2 along the line III~
Figure 4 iS a schematic side view of anoth~r mixing device
according to the pres~nt invention, and
Fi~ure 5 is a front view of this mi~:ing device according to
` 10 Figure 4.
The chassis 1 of the co~ting machine is provided with a steer-
able front wheel pair 2 and a driven rear wheel pair 3. Tn the rear
portion o~ cha~si~ 1, there is the driver's cabin 4 including a seat 5,
a stearing wheel 6, and various operatin~ lever~ 7. In front of the
driver'~ cabin, the drive motor 8 of the ~achine is locatsd.
In the fro~t portion of chassi~ 1~ a storage container 9 for thema,erial 10 to be applied i8 provlded. Storage container 9 includes a
~~ dischar~e opening 11~ the opening cross ~ection of which may be varied
by means of a ~lide 72~ Below discharge opening 11~ there is one end
of belt conveyor 13, ,lhich tran~ports th~ material 10 from the storage
container 9 to a mixinz de~ic~ ~4~
~he mixin~ device 14 includer~ a central filling openin~ 15 for
the m~terial 10 above ~hich th~ dischar~e end 1~ of belt conveyor 13
i8 ~rovidsd. The mixin~ device 14 comprise~ a hou~ing 17 supported in
a hoLder 18 which on t8 part i~ connected to the movable part 19 o~
an hydraulic motor 20* By corrbspondin~ly controlling the hydraul~c
, 9
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motor 20, ..,lder 18, and thus ~he whole mixing d~vice, maV, be
lifted and `owared and tilted around axis 21.
~ iousinl; 17 of t':e m.ixin~ ~levice 14 i6 open at its un~ersids
~o ~hat the mi~in~ sJJa¢e 22 i~ de~ined b,y the hou6in~ wall sn o~
side and b~ the ground ~urfac~ 23 on the other. In the interior ~2,
tt~o mixing ~ollers ~4 and 25 votate in an oppoqing direction relatlve
to each othi~r, Operition of ~he two mixing roll~rs 24 and 25 iB
performed by mean~ of a~ hydraulic motor 26 as well as a gear compris-
in~ three tooth wheal6 279 28,~ and 29.
On the front sid~ of hou~.ng 17, there i8 an inlet aperture 30
for the mil.~ed or pe~.led material 31 on the ground ~urface 23. Thi~
ma~erial h~:~ already been as~embled in the middle range of the road
surface to be proce~d ~:o that a shovii~g she0t 32 having a relatively
small recepcion area is ~ufficient for rhe collection of the materialJ
In the interior 22 of houfiin~ 17, above opaning 30, there is a prc-
je~tion 33, which keaps Iha material rotated in the interior 22 away
from opening ~0,
On the front ~i~e o r' the mixing de~lce 9 two heatin~ de~ices 34
and 35 are "urth~r'on pro~id~d ~'ed with liquid 6a~ from a liquid gas
tank 36.
~etwee~l ~lanX~ aped finl,~.~hsr 37 loaded with a weight 38 and
the rear wh--3el palr ',j there iæ a ~rader worm 39 by which the coatin~
material 4~ applied .,nto the ~oad surfa~,e to be treated i~ uniformly
dijtrlbuteo ~heaa of ~,ne fini.~ner,.370
rhe m~er ~llu,~,~,rhted irl ~igure~ 4 and 5 is suitably mounted in
parallel re.Lati~e to vrhe lon~.t,udinal a;~i6 of the machine 9 preferably
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in the middl. u~der t~e cha6sis 80 that the two mixing ro3.1er~ 41
~nd 42 rotatf ~n parallal relat:7v~ to the longitudinal axis of the
machine the .ormer being drlven by the hydraulic motor 4~ via a
miter ~ear 44~ On the front side opposite to the hydraulic motor,
the mi:~led material i~l ~ei~ed while the aggregates required for the
production oi the de~ired road ;urface material are added via fill-
ing openlng 45.
The materlals to be mixed ~-ass the mixer and escape from the
front ~ide where the ~rive of the mixer rollers is locatedO
As shown ln Figure 5 in detail, the two m~xer shovels 41 and 42
are provided in a hou;in~ open ..o the road surface
The mill~d material collec~ed by the shoving sheets arrives
automaticallv into the reaction area of the two mixer shovels 41 and
42 and is in~imately mixed to~*ther with the aggregate filled via
funnel 45 and i8 then~ after leaving the mixer, uniformly distributed
over the mil~ed road .~urface by grader worm 39.
The distance relative to each other of the side walls 46 and 47
- of the mixer housing may be ad.~ted by means of worm-gear spindle 48
pro~ided with left and right-hand thread, respectively, and the
2~ appropriate ratche~ 4~ In thl~ ~ay, the mixing i.ntensity of the
mixer may iniefinitely be vari~d~
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