The present invention relates to a modular device for simultaneously spreading cut fibers and binders on a roadway and to a spreading machine comprising such a device. It finds application in the field of civil engineering and, more particularly, in building and repairing roadways, including for automobiles, but it could find applications for any type of ground coating such as, for example, runways, harbour quays, sport surfaces, parking places, cycle paths . . . .
In the field of traffic roadway building or repairing, a method is known for adding cut fibers in a binder allowing to structure the binder layer so as to withstand tearing due to the traffic or to transversal stresses or to restrict cracking propagations. Such a method comprises nearly simultaneously spreading in the forwarding direction of a spreading system, a binder layer followed by a cut fiber layer, in turn coated with a second binder layer. Such an operation is generally followed by coating such layers with mineral or naturally occurring or synthetic granulates in order to allow for the traffic to run. The binder is generally a bitumen emulsion.
Such systems comprise continuous fiber-cutting bars provided with cutters in a number different from the number of bitumen emulsion spreading sprays which does not allow the supplying or spreading width to be varied without risking to compromise the performance of the method.
Such existing spreading systems do not allow for a reliably transversally dispensing fibers, a necessary requirement for the feasability and durability of such methods.
As to the flow rates, the existing systems allow for mean flow rates of 60 grammes/m2 of cut fibers and, more preferably, of 90 grammes/m2 of cut fibers at the most because of the technology being used. In addition, the cutter rotative speed, beyond a certain limit, make them inoperative as fibers curl about the cutters without being nevertheless cut, making the maintenance difficult all the more as this requires the full dismantling of the fiber cutting set, handling heavy and bulky mechanical parts, sometimes hazardous for the operator. This physical limitation of the cutting speed makes it impossible to increase the fiber flow rate through increasing the cutting tool speed.
Finally, the known systems require complex settings and skilled and/or numerous labour during such spreading operations for monitoring and setting. There could also result in spreading unevenness on the sites.
The present invention provides specially solving such problems with a device for simultaneously spreading cut fibers and a binder on a roadway width, the device comprising, in the longitudinal from front to back direction, a first binder spreading set, a second cut fiber spreading set and a third binder spreading set, the second set comprising tools allowing to at least cut continuous fibers, said tools being driven by a torque transmission member.
According to the invention, the device is modular, the modules being arranged transversally side by side and each allowing to spread on a longitudinal lane of the roadway binders and cut fibers, each module comprising from front to back:
The term <<binders>> means both the binders as such, as well as binder associations with other members such as powders, sands, even granulates, either ready-to-use stored, or mixed in use. It is understood that in such a case, the spreading means and more specifically, the nozzles and/or the pump and/or the means for storing binders and optional other members and mixers will be adapted accordingly.
In various embodiments according to the invention, the following means able to be used either alone or according to all the technically possible combinations, are used:
The invention relates also to a machine for simultaneously spreading cut fibers and binders on a roadway width, said machine being an automotive road vehicle with a driving and control station, comprising a device according to any or more of the above listed features as well as at least: one binder tank, a means for fluidizing said binders, a means for pressurizing said binders for directing towards the device nozzles, a continuous fiber supply, an air compressor and a pressurized air supply intended at least for overpressurizing the modules, said vehicle providing power for actuating the torque transmission member of the device.
In various embodiments of the machine, the following means able to be used either alone or according to all the technically contemplated combinations, are used:
The system and the machine according to the invention therefore comprise a number of cutters (continuous fiber cutting tools) identical to the number of lines of emulsion jets (there are two jets per line and per cutting tool) allowing to reach amounts up to 200 grammes/m2 of fibers, or even more. It allows for a more homogeneous transversal dispensing of the fibers with an accuracy being in all points within a 10% deviation, on the roadway width being processed through spreading. The modular structure allows for variations in the processing width while maintaining the fiber and binder proportioning on the width being processed. Such a modularity also allows for an increased mechanical availability and an easy maintenance. Using mostly easily dismantled and easy to handle equipments further improves an easy maintenance
In addition to the easy availability of all the mechanical members because of the modularity, each tool can be dismantled individually and is available in a few seconds for cleaning, adjusting, replacing the cutting blades or for a replacement through standard part exchange. By virtue of its structure, the hazard risks during maintenance are reduced as the tools are no longer functional when they are available.
The system and the machine allow for large flow rate variations both for cut fibers as for the binder, this being independent for the selection of the fiber/binder ratio and being dependent for a constant spreading of the material despite possible variations in the spreading speed and in changes of the working width.
Thus, the invention allows to reach an increased reliability and repetitiveness, a steadfastness in terms of respecting the objectives, the applied amounts, while providing for possibilities to adapt large volume variations. Additionally, the reduced pressure value of the binder for ejecting through the nozzles compared to the known systems allows for a considerable decrease in the parasitic emissions and splashings evaluated up to about 50%.
Finally, such a modular system is easily adapted in various widths while maintaining the same structure.
The present invention will be now exemplified without any limitation with the following description in conjunction with the following figures:
In
The machine, as will be seen, comprises an air compressor with a pressurized air tank. In order to direct from the front (reel supply trunk) to the back (modules with tools) passing through the line, a new continuous fiber from a new reel once the previous reel is exhausted and replaced by an operator, the latter manually engages the end of the continuous thread of the new reel into the front opening of the line and then, using an airgun, directs pressurized air through said front opening, creating a front-back air stream in the line which drives the continuous fiber to the modules. Once the thus driven continuous fiber gets out through the back opening of the line, the latter is grabbed by the corresponding tool, the latter being in a working position, and the operator can then stop the pressurized air blow in the line.
The vehicle 2 has an engine consuming liquid fuel of the light fuel oil type. A vessel/tank 18 with a capacity of about 1,000 litres for, preferably bitumen, binders occupies the frame part at the back of the cabin 5. The vessel comprises a hatch at the top thereof for filling. A heating means is used for fluidizing binders as a heater 8, preferably automatic, using light fuel oil being tapped from the fuel tank of the vehicle. It should be noted that in alternatives (not shown), the heating could occur by means of gas, heavy fuel oil or any fuel substance, even by means of electricity.
On the back of the vehicle and on the frame thereof is further located a pump 6 for pressuring binders as well as a pressurized air tank 7, with a capacity of about 30 litres, produced by an air compressor, preferably the vehicle own air compressor. A part of the binders passing through the pump can be redirected to the tank for recirculation. In an alternative (not shown), the binder pressurization could be achieved with pressurized air.
The spreading device 3 is arranged at the back of the vehicle frame by means of a controlled movable coupling device 4. The controlled movable coupling device is, on
The spreading device 3 being shown transversally on
The machine with the vehicle comprising the device at the back and the continuous fiber supply at the front has the following approximate dimensions: total length 4,750 mm, total width 1,300 mm, total height 2,300 mm, spreading width 1,200 mm. The operative weight of the machine is approximately 4,750 kg and it can travel from site to site at a maximum speed of about 40 km/hr. A automated monitoring system of the micro-computer type with a display screen allows an operator in the driving cabin of the vehicle to select operating modes (stop of some modules, respective flow rates of binders and/of cut fibers, progression speed . . . ), to monitor and regulate the operation of the machine (flow rates, more specifically depending on the progression speed, regulating the binder heating . . . ), to notify faults and to supply reports of the operational activity of the machine.
In the illustrated example, the device has 12 tools with cutters and 12 lines of binder jets (2 nozzles and therefore 2 jets per line). For such a machine operating in a maximum width of 1.20 m, but allowing to operate at lower widths per pitch of 100 mm (width of a module), stopping some modules (stopping the tool and the two corresponding jets), it is possible to vary the cut fiber flow rate under control and at request between 0 and up to about 200 grammes/m2 while maintaining a homogeneous transversal distribution which does not produce any deviation higher than 10%. It is understood that the flow rate indications as given in the present application are indicative as they more specifically depend on the progression speed of the device. In addition, the machine capacities as well in storing, flow rate, speed, autonomy and the like, could vary depending on the structures at all levels between machines for important work with a high working width comprising a large number of modules and therefore also large storing volumes for a satisfactory autonomy and machines with more reduced capacities.
Controlled valves are implemented in the fluidic binder circuit in order to be able to cut off the binder supply of each module (2 nozzles) individually, on request. Preferably, all the modules are kept in overpressure by pressurized air, even those not being functional so as to avoid emulsion vapour being redirected to the tools. The module overpressurizing could also have a favourable effect on the downward ejection of the cut fibers, the modules being only downwards opened in a working position (and, preferably also in a rest operation by means of a double hinge of the tools) and the air stream only be able to escape downwards. In an alternative, controlled valves could be provided for the pressurized air in each module. Means for regulating the pressure in the binder fluidic circuit acting on the pump 6 and/or for the pressurized air can also be implemented in order to maintain the pressure substantially constant at the level of the binder spraying nozzles or of the overpressure one of the modules. In a particular configuration, the engaging actuator of the tool and the binder supplying valve of both nozzles of a given module are controlled in parallel so that when the tool is stopped (or in a releasing position), the binder supply to the nozzles should also be stopped.
Each of the tools is removably mounted in its module between a releasing position where it is available to an operator outside the module and stopped and two positions where it is in the module: a working position where it is engaged and driven by the driving shaft and a rest position where it is stopped, being then no longer engaged. The removable mounting of the tool 13 occurs through rotation on a hinge 17, the tool being released from the module upwards tumbling for giving free access to the operator, to the back, to the rollers, cutting means, driving means and the like, the latter being on a tumbling tool frame, as can be subsequently seen in more detail on
Each of the tools of the modules comprises a fist axis 19 on which is located the part being engaged on the transmission member 12 through friction for transmitting the torque/rotation movement to a cutting roller. On said first axis 19, there is therefore mounted a cutting roller 20 with interchangeable blades. A rubber wheel (or any other material) is mounted interlocked with the transmission member 12 and this is by means of such a wheel that the cutting roller can be engaged. The tool further comprises on a second axis a pressing roller 21 mounted free in rotation allowing to hold the continuous fiber in contact with the cutting roller so as to allow it to be cut. The pressure of the pressing roller is ensured by a spring set system 23 allowing to compensate for the wear and the pressure setting. A holding roller 22 also mounted free in rotation on a third axis, allows to maintain the continuous fiber on the pressing roller 21 upstream the cutting roller 20 while avoiding the backwards release of the continuous fiber when the tool is at rest. The position of the holding roller 22 can be adjusted and it is mounted on a spring for compensating for the wear. Such members, axes and rollers, are mounted on a hinged support in 24 allowing, depending on its position, to place tool either in its working position or its rest position. Such a support is in turn hingedly mounted in 17 relative to the module frame so as to allow for the full tumbling of the tool outside the module in a tool releasing position for cleaning, maintenance or element replacement operations.
Preferably, pressurized air is directed in a part of the binder circuit in order to empty it and clean it at the end of a working site, more particularly with a view to prevent the nozzles from being clogged.
In other embodiments, the device could be associated to a specific trailer independent from the vehicle allowing it to be moved. In the latter case, the distribution of the associated members (binder tank, fluidizing means, pressurizing means, air compressor and pressurized air supply, continuous fiber supply) is achieved depending on the needs, from the trailer only comprising the spreading device with optionally the fiber supply, the other members being with the vehicle, up to the trailer comprising all such members. Similarly, the device being related to a spreading ramp could have a fixed or a variable width (telescopic or tumbling ramp type) optionally allowing for different spreading widths and a reduced space being used during conveying from one site to another. Similarly, the capacities of the tanks of binders, air and the like can be adapted depending on the machine, more particularly to larger volumes.
Finally, while the spreading device can be used for building or repairing traffic roadways (or the like) and wherein, in general, a subsequent coating is performed using granulates, it could also be implemented for building a primer layer being optionally structuring or, as well, be implemented for achieving a finish.
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04 51755 | Aug 2004 | FR | national |
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Number | Date | Country | |
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20060034653 A1 | Feb 2006 | US |