A CUTTING DEVICE, SYSTEM AND METHOD FOR CUTTING ROAD MARKINGS ON A ROAD SURFACE

Abstract

 The invention relates to a cutter device including a frame (12) for suspending a cutter unit (14) from a road traffic vehicle or its trailer and support equipment (35) for supporting the cutter unit (14) to the frame (12) movably in the vertical direction, said cutter unit (14) comprising a cutter frame (16), a cutter blade (18) and a support wheel (20), and the cutter device further including suction equipment (22) for sucking road surface (102) material produced that detaches during the cutting process. Height adjustment equipment (15) is arranged in the vicinity of the cutter frame (16) for moving the cutter frame (16) vertically relative to the frame (12) and the road surface (102) for adjusting the cutting depth of the cutter blade (18), and pressing equipment (25) is arranged in the vicinity of the cutter frame (16) for pressing the cutter blade (18) against the road surface (102) during the cutting process.

Description

[0001] The invention relates to a cutter device for cutting road markings on a road surface, the cutter device including a frame for suspending a cutter unit from a road traffic vehicle or its trailer, a cutter unit connected to the frame, and support equipment for supporting the cutter unit to the frame movably in the vertical direction, wherein the cutter unit comprises

• a cutter frame,
• a rotating cutter blade mounted with bearings to the cutter frame for cutting a road marking on a road surface, and
• a support wheel connected to the cutter frame for supporting the cutter unit against a road surface,

with the cutter device additionally including suction equipment arranged at least partially in the vicinity of said cutter unit for sucking road surface material produced that detaches during the cutting process from the road surface. The invention also relates to a corresponding system and method for cutting road markings on a road surface.

[0002] A cutter device, method and system according to the invention are specifically intended for machining road markings by cutting, also known as rumble strips, on a road surfaced with asphalt or concrete.

[0003] A device representing prior art is a cutter device for producing repeated road markings, manufactured by the German Wirtgen GmbH, marketed with a model name DC35, which is depicted in Figure 1. The cutter device 10' is a self-propelled, ride-on work machine equipped with three wheels driven by a hydraulic motor, which are set in a triangular form when viewed from above so that one wheel is in the front and two wheels are in the back. The front wheel and one of the rear wheels are normal wheels, whereas the other rear wheel is an asymmetrically formed support wheel 20 included in the cutter unit 14 having cavities for producing either continuous sinusoidal cuts or periodical cylindrical cuts on a road surface. The cutter unit integrated into the cutter device rotates continuously and is lowered into contact with the road surface always in accordance with the profiles of the cutter blade, whereat the cutter unit forms an individual road marking on the road surface.

[0004] Material detaches from the road surface during the forming of cuts and must be recovered. For this task, the cutter device is followed by a separate brushing machine, which collects the material in its container. For safety at work, since the cutter device only advances at a maximum speed of approximately 2 km/h, other road users must be warned with a separate front escort vehicle, which also checks that there are no obstacles for the cutting. In addition, traffic arriving from behind must also be warned with a separate rear escort vehicle, which can simultaneously collect material accumulating in the brushing machine. On completion of the work, the cutter device is transferred to the following work site with a separate chassis.

[0005] Publication US 5,484,228 is also known from the prior art which discloses a separate cutter device suspended from the front of a light-duty wheel loader. However, when using such a system consisting of a wheel loader and a cutter device, a separate brushing machine is required to collect the material that detaches during the cutting.

[0006] A problem with the aforementioned cutter devices is that it is necessary to have four separate units (cutter device, brushing machine, front escort vehicle and rear escort vehicle) to produce a road marking, each with a dedicated driver. For this reason, providing road markings by cutting is demanding in terms of both equipment and labour force and it is therefore expensive.

[0007] Publication EP 0298682 A1 which is known from prior art proposes a cutter device fitted in the rear of a tractor to cut a continuous groove. Suction equipment is integrated with the cutter device for recovering material that detaches during the cutting of the groove. However, a problem with such a construction is that the entire rear end of the tractor is lifted from the ground with auxiliary wheels, which are also drive wheels and thus those that bring the entity forward. Thus, the level of performance of the cutter device remains rather low. In addition, adjustment of the groove depth with a separate actuator is inaccurate. Furthermore, it is also a problem that vibrations produced by the cutter device are directly transferred to the tractor via the cutter device causing problems to the tractor's technical systems and the driver.

[0008] An object of the invention is to provide a cutter device that is more versatile than prior art cutter devices, integrating a cutter device, a brushing machine and a rear escort vehicle to enable production of road markings notably more cost-efficiently compared to prior art cutter devices, and preventing the transfer of vibrations further from the cutter device. The characteristic features of this invention are set forth in the appended claim 1. Another object of the invention is to provide a system that is more versatile than prior art cutter devices, integrating at least a cutter device, a brushing machine and a rear escort vehicle, and the system preventing the transfer of vibrations further from the cutter device. The characteristic features of this invention are set forth in the appended claim 9. An object of the invention is to provide a method that is more versatile than prior art cutter devices, integrating the cutting process, collection of material detaching from the road surface and warning of the traffic arriving from behind into a simultaneous work step that is performed with the same machine by a single operator. In addition, the method prevents the transfer of vibrations further from the cutter device. The characteristic features of this invention are set forth in the appended claim 13.

[0009] The object of the cutter device according to the invention can be achieved with a cutter device for cutting road markings on a road surface, the cutter device including a frame for suspending a cutter unit from a road traffic vehicle or its trailer, a cutter unit connected to the frame, and support equipment for supporting the cutter unit to the frame movably in the vertical direction. The cutter unit comprises a cutter frame, a rotating cutter blade mounted with bearings to the cutter frame for cutting a road marking on a road surface, and a support wheel connected to the cutter frame for supporting the cutter unit to the road surface. The support wheel is arranged to travel on an uncut surface of a road. In addition, the cutter device includes suction equipment arranged at least partially in the vicinity of the cutter unit for sucking road surface material produced that detaches during the cutting process from the road surface, height adjustment equipment arranged in the vicinity of the cutter frame for moving the cutter frame vertically relative to the frame and the road surface for adjusting the cutting depth of the cutter blade, as well as pressing equipment arranged in the vicinity of the cutter frame between the cutter frame and the frame or the cutter frame and the road traffic vehicle for pressing the cutter blade against the road surface during the cutting process.

[0010] A cutter device according to the invention integrates both suction equipment and a cutter unit allowing simultaneous cutting and material collection by using the cutter device. A cutter device according to the invention can be integrated into a road traffic vehicle or its trailer so that a separate and expensive self-propelled cutter device is not needed. The efficiency of the cutter device according to the invention is based on the fact that the cutter unit can be moved at a high working speed compared to prior art cutter devices when pressing down the cutter unit to overcome the upwards force generated by the road surface. The faster the cutter unit is moved in the road direction, the greater are the resistance and the upwards force that the road surface generates and the more pressing is needed to keep the cutter blade at a correct height for producing road markings. Since the necessary pressing force may even exceed 60 kN, adjustment of the machining depth of the road marking to be cut is performed by changing the mutual position of the support wheel and the cutter frame, thereby securely locking the correct machining depth. At the same time, the pressing actuator also presses the cutter unit supported by its support wheel against the road surface facilitating the rotation of the support wheel without slippage. When the cutter unit is supported to the frame movably in the vertical direction, it is possible to remarkably reduce the transfer of vibrations caused by the cutter unit further to the frame of the road traffic vehicle.

[0011] Advantageously, the support wheel is asymmetric for supporting the cutter unit against the uncut surface of the road in such a way that the cutter blade contacts the road surface periodically, while the support wheel profile follows the road surface for cutting repeated road markings on the road surface. In this way, repeated road markings can be efficiently produced without causing vibrations to the frame of the road traffic vehicle due to the asymmetric form of the support wheel. A device according to the invention is particularly advantageous for use when producing repeated road markings, since for these, vibrations and impacts caused by the cutter unit have been problematic in prior art devices, while this problem can be solved with a cutter device according to the invention.

[0012] Alternatively, the support wheel can also be circular, which allows formation of continuous road markings on the road surface.

[0013] In this context, a road traffic vehicle means a vehicle registered for the road traffic, which can be transferred self-propelled as a transfer drive with the cutter unit detached from the road surface essentially with the normal traffic at a minimum speed of 40 km/h. Thus, the transfer of the system and the cutter device can be performed without using a separate chassis or other transport equipment.

[0014] In this context, asymmetry of a support wheel means that the diameter of the support wheel is not constant but variable in the periphery of the support wheel at least at one point.

[0015] Advantageously, the road traffic vehicle is a lorry. A lorry has readily sufficient power for operating the cutter unit and the sucking equipment, as well as capacity for recovering material produced during the cutting process. In addition, when using a lorry, transfer drives are fast to perform and a lorry can be used for other applications in winter by removing the cutter device from the lorry.

[0016] Alternatively, the road traffic vehicle can be a tractor, wherein the cutter device is advantageously connected to the trailer of the tractor so that the suction container of the suction equipment can be placed in the vicinity of the cutter device.

[0017] Advantageously, the support wheel is mounted with bearings to the cutter frame and the height adjustment equipment includes an actuator for adjusting the position relative to the cutter frame. With such a construction, force applied to the cutter frame by the pressing equipment is supported to the road surface via the support wheel and the correct machining depth of the cutter blade is locked by the mutual position of the support wheel and the cutter frame.

[0018] Advantageously, the support wheel is located in the cutter frame in the travel direction of the cutter device, prior to the cutter blade. In this way, the support wheel profile only determines the periodical shape of the road marking to be cut.

[0019] According to an embodiment, the frame of the cutter device is detachably suspendable from the road traffic vehicle or its trailer. Thus, the cutter unit can be moved from one side of the road traffic vehicle or its trailer to the other side.

[0020] Advantageously, the support equipment includes a pivot arm pivoted to said frame and connected to the cutter unit for connecting the cutter unit to the frame. The pivot arm enables the vertical movement of the cutter frame when selecting the machining depth, as well as the pressing of the cutter blade against the road surface. With the pivot arm, it is possible to separate the preferably repeating vertical movement of the cutter unit from the frame that supports the cutter unit preventing transfer of vibrations of the cutter unit to the road traffic vehicle or its trailer that carries the cutter device.

[0021] Alternatively, the support equipment may consist of vertical guides and a carriage, to which the cutter unit would be connected.

[0022] Advantageously, the cutter device includes side-shift equipment for moving the cutter unit transversely to the road traffic vehicle or its trailer between the operating position and the storage position. With side-shift equipment, the same cutter device can easily be used for producing road markings on both the centre grooving and road sides without driving the road traffic vehicle in a wrong direction. Side-shift equipment also enables the road traffic vehicle to be set to its own maximum width applicable during the transfer drive, wherein the cutter unit is below the road traffic vehicle and, in turn, to an operating width larger than the permitted maximum width for the transfer drive, wherein the cutter unit is on the side of the frame of the road traffic vehicle.

[0023] The side-shift equipment may include transverse guides arranged between the road traffic vehicle and the cutter frame and a form-lockable counter-piece arranged to be moved along the guides, as well as a side-shift actuator arranged between the cutter frame and the frame or the cutter frame and the road traffic vehicle for moving the cutter frame transversely to the road traffic vehicle by means of the guides and the counter-piece by using the side-shift equipment. With such a construction, it is possible to slide the cutter frame along the guides from one side of the road traffic vehicle to the other.

[0024] According to an embodiment, the guides are formed as part of the pressing equipment and said counter-piece is fixedly fitted in the cutter frame.

[0025] In addition, the side-shift equipment may include second guides and a second counter-piece arranged between the pivot arm and the cutter frame. By using the pivot arm in this way, it is possible to carry out the side-shifting of the cutter frame.

[0026] According to an embodiment, the guides consist of an I-beam, and the counter-piece is a C-shaped component partially arranged around the I-beam enabling the movement of the cutter frame transversely to the road traffic vehicle but preventing the movement in the other movement directions.

[0027] According to an embodiment, the frame consists of beams or profiles, which are arranged to be connected to the road traffic vehicle or its trailer. With beams or profiles, force can be efficiently conveyed from the road traffic vehicle moving the cutter device to the cutter device.

[0028] According to another embodiment, the cutter device can be removably fastened, for example, to male or female counter-parts formed in the frame of the road traffic vehicle by means of beams. If the frame of the road traffic vehicle has male counter-parts, then the male counter-parts are pushed into the profiles in the cutter device, whereas, if the frame of the road traffic vehicle has female counter-parts, then the beams in the cutter device are inserted in the female counter-parts.

[0029] Advantageously, the suction equipment includes a suction container for recovering the material that detaches from the road surface. In this way, a greater amount of recovered material can be collected compared to a lorry equipped with a conventional load platform.

[0030] Advantageously, the cutter frame is supported to the frame of the cutter device at least partially via a pressing actuator. Thus, the pressing actuator serves as a shock absorber between the cutter unit and the frame advantageously preventing the transfer of vibrations caused by an asymmetric support wheel to the road traffic and via it to the driver. This saves both the driver and the road traffic vehicle from problems caused by repeated vibrations.

[0031] The pressing actuator can consist of air bellows. Air bellows efficiently dampen vibrations directed to the frame, whereupon it is possible to prevent the transfer of vibrations to the road traffic vehicle or its trailer. In addition, air bellows effectively resist vibrations without the medium heating up as a consequence of repeated pressure variations.

[0032] Advantageously, the cutter device includes traction equipment for conveying traction with the support wheel for rotating the support wheel at a speed that substantially corresponds to the travel speed of the road traffic vehicle. In this way, the support wheel cannot slip on the road surface but rotates causing a vertical oscillating movement of the cutter blade.

[0033] Alternatively, the support wheel can be freely rotating. In this case, it can be realised completely without separate traction, whereupon the cutter unit is simpler.

[0034] Advantageously, said suction equipment is arranged in the vicinity of the cutter device in the travel direction of the cutter device, after the cutter blade. Then the necessary suction is smaller, since the material that detaches from the road surface during the cutting process is automatically conveyed towards the suction equipment.

[0035] Advantageously, the height of the cutter unit is arranged so that it allows the cutter unit to pass below the frame of the road traffic vehicle. This enables the cutter device to be located over the distance between the wheel axes of the road traffic vehicle in its longitudinal direction so that the cutter device does not occupy any space in the rear of the road traffic vehicle.

[0036] The height of the cutter unit may range between 20 and 50 cm, advantageously between 30 and 40 cm. Thus, the cutter unit can be used in association with a conventional lorry.

[0037] When using a cutter device according to the invention, the cutter unit can be used in any position in the transverse direction relative to the road traffic vehicle and even 600 mm outside the external dimensions of the road traffic vehicle. In other words, road markings can be produced in any place under a lorry, for instance, and even laterally thereto in a limited manner. A cutter device according to the invention can also be used to produce cuts in the transverse direction relative to the road traffic vehicle by moving the cutter unit in the transverse direction by means of side-shift equipment.

[0038] The object of the system according to the invention can be achieved with a system for cutting road markings on a road surface, the system including a cutter device for cutting road markings and a road traffic vehicle or its trailer for carrying the cutter device, wherein the cutter device is a cutter device according to the invention similar to an embodiment proposed above. A system according to the invention can be used to perform the actions of a heretofore separate work unit by one operator, which remarkably increases the cost-efficiency of work.

[0039] In this context, 'arrangement of suction equipment at least partially in the vicinity of the cutter unit' means that at least the suction box included in suction equipment is associated with the cutter unit, although the other parts of the suction equipment may be located further away from the cutter unit in the road traffic vehicle.

[0040] The road traffic vehicle or its trailer may include suspension equipment on both sides of the frame of the road traffic vehicle or its trailer enabling the cutter device to be suspended from either side of the road traffic vehicle or its trailer. In this way, the system can be used to produce both cuts for centre lines and cuts for edge lines without having to transport the system in a direction opposite to the traffic direction.

[0041] Advantageously, the cutter unit is located in a lorry, behind its front wheel prior to the rear wheels. In this position, the lorry frame has an unoccupied space, to which the cutter unit can be fastened in a simple way. Furthermore, a cutter device located between the wheels of a lorry does not use the lengthwise dimension in the back or in the front of the lorry. When located in this way, the pressing equipment can lean to the frame of the road traffic vehicle receiving the torque support from it.

[0042] Advantageously, the system includes a warning sign placed in the rear of the road traffic vehicle or its trailer for warning the traffic arriving from behind, and a rear impact shield for dampening any impacts. Thus, the need of a rear escort vehicle is completely removed, since a cutter device integrated with the road traffic vehicle can simultaneously both warn the other road users and recover material.

[0043] Advantageously, the suction equipment includes a suction container connected to the road traffic vehicle or its trailer for collecting road surface material that detaches during the cutting, a suction unit for providing suction and a suction hose for sucking road surface material that detaches during the cutting from the surroundings of the cutter blade into the suction container by means of suction provided by the suction unit. With the suction equipment, waste material produced during the cutting process can be recovered and, if necessary, also recycled to provide new raw material without a separate work step or the use of a separate brushing machine.

[0044] Advantageously, the pressing equipment in the system is arranged to lean to the frame of the road traffic vehicle, which enables efficient delivery of force for the pressing of the cutter blade.

[0045] The output of the road traffic vehicle is in the range of 140 - 400 kW, preferably in the range of 200 - 300 kW. Thus, the output is sufficient for driving the road traffic vehicle, for operating the sucking equipment and for operating the cutter device.

[0046] Advantageously, the road traffic vehicle is a lorry. When using preferably a lorry as the road traffic vehicle of the system, the suction container can be carried in the same vehicle so that all parts included in the system can be arranged in the same lorry. In addition, lorry engines generally have sufficiently high outputs for simultaneous operation of both the suction equipment and the cutter blade.

[0047] Advantageously, the road traffic vehicle includes a power unit for providing a hydraulic flow by means of a power take-off included in the road traffic vehicle for operating the cutter blade of the cutter unit.

[0048] The object of the method according to the invention can be achieved with a method for cutting road markings on a road surface, in which method a cutter device is suspended from a road traffic vehicle or its trailer, a cutter unit is suspended from the frame movably in the vertical direction with support equipment, and the cutter unit is supported against the road surface with a support wheel and the road traffic vehicle is driven along the road surface to move the cutter unit. In the method, the cutter unit is additionally moved in the direction of the road surface by delivering force via the wheels of the road traffic vehicle to the road surface and repeated road markings are cut on the road surface by means of the cutter unit of the cutter device. Furthermore, in the method, the cutting depth of the cutter blade is adjusted with height adjustment equipment by moving the cutter frame vertically relative to the frame, the cutter unit is pressed against the road surface with the pressing equipment and the road surface material produced that detaches during the cutting process is sucked from the road surface simultaneously with the cutting process by means of the suction equipment included in the cutter unit.

[0049] In the method according to the invention, the cutter device suspended from the road traffic vehicle or its trailer can be used to perform the cutting and the collection of the material detaching at one time with one operator controlling all functions. At the same time, the suspension of the cutter unit permitting its vertical movement relative to the frame enables dampening of vibrations produced by the cutter unit before their transfer to the frame and thereby to the road traffic vehicle.

[0050] Advantageously, the cutter unit is supported to the road surface with an asymmetric support wheel in such a way that the cutter blade contacts the road surface periodically while the support wheel profile follows the road surface. In this way, it is possible to efficiently produce periodic cuts.

[0051] In the method, between 30% and 80%, preferably between 60% and 70% of the suction air volume can be recirculated back to provide an air blow in the vicinity of the cutter blade for lifting the material cut off from the road surface, while the rest of the air volume is sucked into a container for the recovery of loose material. Thus, the road surface material detached by the cutter blade by help of the air blow can be lifted off the ground, whereupon it is efficiently conveyed to the container with the suction air. In this way, a very good cleaning efficiency is achieved.

[0052] The road traffic vehicle can be driven at a working speed of 4-20 km/h, preferably 6-10 km/h. Thus, at least a double cutting speed is achieved compared to prior art devices.

[0053] In addition to the advantages mentioned above, the cutter device, system and method according to the invention improve ergonomics at work, as the user can sit in the lorry cab without harms caused by vibrations of the cutter unit. A cutter device and system according to the invention are capable of cutting markings at a progression speed of up to 10 km/h, where the efficiency of work is multiple compared to what was in place heretofore. Prior art cutter devices have generally been intended for cutting off all asphalt and thus their operating speed is not sufficient for efficient production of road markings contrary to the cutter device according to the invention, which is specifically designed for cutting road markings.

[0054] The invention is described below in detail by making reference to the appended drawings that illustrate some of the embodiments of the invention, in which:

Figure 1

is a side view of a prior art cutter device,

Figure 2

is a side view of the first embodiment of the cutter device and system according to the invention,

Figure 3

is a separate view of the frame of the road traffic vehicle and the cutter unit connected thereto of the first embodiment of the system according to the invention,

Figure 4

is a top view of a cutter device and system according to the invention,

Figure 5a

depicts a support wheel of a cutter unit intended for cylindrical cutting,

Figure 5b

depicts a support wheel of a cutter unit intended for sinusoidal cutting,

Figure 5c

depicts a second embodiment of the support wheel of a cutter unit intended for sinusoidal cutting,

Figure 6

is the first embodiment of the system according to the invention complete with a warning sign,

Figure 7

is an axonometric view of the second embodiment of the cutter device and system according to the invention, showing only the frame and wheels of the road traffic vehicle,

Figure 8

is an enlargement of the cutter unit of Figure 7,

Figure 9

is a side view of the second embodiment of the cutter device and system according to the invention, showing only the frame and wheels of the road traffic vehicle,

Figure 10a

is a separate front view of a cutter unit,

Figure 10b

is a separate side view of a cutter unit, cut along section B-B of Figure 10a.

[0055] According to Figure 2, the idea of the invention is to connect the cutter unit 14 and the suction equipment 22 to a conventional road traffic vehicle 1 or its trailer, thus enabling multiple work steps to be performed with the same machine and by one person. According to Figure 2, most advantageously, the system 11 and the cutter device 10 according to the invention are formed in the vicinity of a lorry 2 serving as the road traffic vehicle 1, advantageously behind the front wheel 30 of the lorry 2, mainly below the frame 3 of the lorry. Henceforth, when describing the embodiments, the term 'lorry' is used to refer to the road traffic vehicle; however, it will be obvious to those skilled in the art that instead of a lorry, a road traffic vehicle can also be a tractor or a wheel loader. The cutter device 10 includes a frame 12, by which the cutter device 10 can be fastened to the lorry 2, and a cutter unit 14 is connected to the frame 12 by using support equipment 35. The support equipment 35 enables the vertical movement of the cutter unit 14 relative to the frame 12.

[0056] The cutter unit 14 includes a cutter frame 16, a rotating cutter blade 18 mounted with bearings to the cutter frame 16 for cutting a road marking 100 on a road surface 102, and a preferably asymmetric support wheel 20 mounted with bearings to the cutter frame 16 for supporting the cutter unit 14 against the road surface 102. The support wheel 20 is advantageously fastened to the cutter frame 16. In the cutter unit 10 according to the invention, the cutter frame 16 is movable in the vertical direction relative to the frame 12 with the support equipment 35, while the frame 12 is fixedly fastened to the frame 3 of the road traffic vehicle 1. In addition, the cutter device 10 includes suction equipment 22 for recovering the material cut, pressing equipment 25 for pressing the cutter blade 18 against the road surface 102 and height adjustment equipment 15 for adjusting the cutting depth.

[0057] Advantageously, the support wheel 20 is fastened to the cutter frame 16 by means of the height adjustment equipment 15, which includes an actuator 92 for adjusting the position of the support wheel 20 relative to the cutter frame 16 and a push arm 90, shown in Figure 10b. One end of the push arm 90 is pivoted to the cutter frame 16 with a joint 94, and the support wheel 20 is pivoted to the other end by means of the shaft 96. The actuator 92 is pivoted to the cutter frame 16 by means of the joint 92.1 and to the push arm 90 by means of the joint 92.2. By varying the length of the actuator 92, the position of the push arm 90 changes and the distance from the road surface 102 of the cutter frame 16 leaning to the support wheel 20 changes. At the same time, the distance from the road surface 102, i.e. the cutting depth, of the cutter blade 18 also changes. When the lorry 2 advances, the support wheel 20 of the cutter unit 14 leans to the road surface 102 and, in accordance with the shape of the support wheel 20, the distance to the road surface 102 of the cutter blade 18 of the cutter unit 14 changes so that the cutter unit 14 periodically cuts road markings 100 shown in Figure 4 on the road surface 102.

[0058] Basically, the cutter unit and the suction equipment used can be equipment completely according to prior art and readily available on the market, integrated with a lorry or equivalent using components manufactured for the purpose. For example, the cutter unit can be a cutter unit of the DC35 cutter device manufactured by the German Wirtgen GmbH or the EX45 cutter unit manufactured by the German Erkat. The power requirement of such a cutter unit is in the range of 35 - 55 kW during the cutting and the speed of rotation of the cutter blade is approximately 150 rpm. The cutter unit is advantageously modified as regards the support wheel. Support wheels of prior art cutter units often provide traction for the entire cutter device, whereas, in the cutter device according to the invention, the support wheel can be arranged to rotate at the same peripheral speed as the road traffic vehicle for preventing support wheel slipping. In this case, however, the support wheel is not a traction wheel in the sense that it would produce the forward driving force to the cutter frame, but the forward driving force is delivered to the cutter unit from the road traffic vehicle via the frame of the cutter device and the support equipment by either pulling or pushing. Advantageously, the support wheel includes traction equipment in the vicinity thereof for rotating the support wheel at the working speed of the cutter device. Alternatively, the support wheel can also by freely rotating and thus more economical to manufacture. Correspondingly, suction equipment may consist, for example, of a high-power aspirator manufactured by the Finnish KEOX Oy, the output of which is in the range of 2200 - 9600 m³/h. The power requirement of a high-power aspirator may be 60-100 kW during operation. The high-power aspirator serving as suction equipment 22 advantageously includes the following parts according to Figure 2: a suction container 26 for the material detaching from the road surface 102, a suction unit 44 for generating suction, a suction box 42 for sucking the material detached with the cutter blade 18 from the road surface 102, and a suction hose 46 for moving the material from the suction box 42 to the container 26. The suction box 42 is advantageously fastened to the cutter frame 16 in the travel direction of the cutter device 10, behind the cutter unit 14. Between 30% and 80%, preferably between 60% and 70% of the air flow provided by the suction unit can be recirculated back to provide an air blow in the vicinity of the cutter blade for lifting the material cut off from the road surface, while the rest of the air volume is sucked into a container for the recovery of loose material. In this way, the material on the road surface, detached by the cutter blade, can be lifted off the ground and thereby taken to the suction container through the suction hose along with the suction flow. Although Figures 7 - 10b depicting the second embodiment of the cutter device do not show the suction equipment in its entirety, such as the suction hose exiting from the suction unit, it is obvious to those skilled in the art that it corresponds to the embodiment of Figures 2 - 6.

[0059] In a first embodiment according to Figures 2-6, in addition to the aforementioned cutter device 10, the system 11 according to the invention may include a road traffic vehicle 1 or its trailer and, according to an embodiment, suspension equipment 38 shown in Figure 3 arranged in the vicinity of the road traffic vehicle 1 or a trailer for supporting the cutter device 10 to the road traffic vehicle 1 or its trailer. With the suspension equipment, it is possible to realise the side-shifting manoeuvre of the cutter unit according to the first embodiment. In Figure 3, the frame 3 of the lorry 2 is shown separately, with suspension equipment 38 formed therein on both sides of the frame 3. Advantageously, the suspension equipment 38 consists of beams or profiles 50, which are welded to the frame 3 of the lorry 2. If the suspension equipment consists of beams, then the frame of the cutter device is made of profiles settling on the beams while the beams serve as guides for the profiles. Correspondingly, if the suspension equipment 38 consists of profiles 50 according to Figure 3, the frame 12 of the cutter device 10 is made of beams 28 that settle inside the profiles 50. At its simplest, the suspension equipment 38 may be placed on one side only of the lorry; however, in this case the use of the cutter device on both sides of the frame requires special arrangements, if it is desired to drive in the direction of the road traffic. Advantageously, suspension equipment 38 is arranged on both sides of the frame 3 of the lorry 2 allowing the cutter unit 10 to be suspended from either side of the lorry 2 by pulling the cutter unit 14 off from the suspension equipment in the transverse direction relative to the lorry 2.

[0060] According to Figure 3, in the first embodiment, the cutter device 10 is advantageously movable in the transverse direction relative to the frame 3 of the lorry 2 with separate side-shift equipment 45. Advantageously, the side-shift equipment 45 includes a side-shift actuator 48, which is preferably a hydraulic cylinder. A hydraulic cylinder can be fastened to the frame 3 of the lorry 2 by its one end and to the frame 12 of the cutter device 10 by its other end. Advantageously, the side-shift actuator 48 is fixedly fastened to the frame 12 of the cutter device 10 so that the side-shift actuator moves with the cutter unit when moving the cutter unit from side to side. Alternatively, there are specific side-shift actuators on both sides of the lorry frame.

[0061] The cutter device of the first embodiment of Figures 2 - 6 includes separate locking equipment 52 connected in the vicinity of the frame 3 of the lorry 2, the suspension equipment 38 or the frame 12 of the cutter device 10, with which it is possible, for example, to lock one end of the side-shift actuator 48, while the other end is already locked, to either the frame 3 of the lorry 2 or the frame 12 of the cutter device 10. With the locking equipment 52, it is also possible to limit the movement in transverse direction of the lorry in such a way that the frame 12 of the cutter device 10 cannot come loose from the support of the suspension equipment 38. The locking equipment 52 advantageously consists of quick connectors, which lock the cutter unit 14 and the frame 12 of the cutter device 10 hydraulically or pneumatically, for example.

[0062] When shifting the cutter unit according to the first embodiment from one side of the lorry to the other, the cutter unit 14 is supported on separate transfer wheels (not shown), the suction hose 46 of the suction equipment is disconnected from the suction box 42 and the locking equipment 52 is disengaged, enabling in this way the cutter unit 14 and the frame 12 of the cutter device 10 connected thereto to be pulled off, in the transverse direction relative to the lorry, from the locking of the suspension equipment 38, that is, for example, the frame beams 28 of the cutter device 10 can be pulled out from the profiles 50 in the frame 3 of the lorry 2. After this, the cutter unit 14 is moved to the other side of the lorry with the transfer wheels and pushed into the suspension equipment 38, the suction hose 46 is connected to the suction box 42 and the locking equipment 52 is engaged.

[0063] In the second embodiment of Figures 7 - 10b, the side-shift equipment 45 advantageously includes, as the side-shift actuator 48, a chain fastened in the vicinity of the guides 76 and a gearwheel connected in the vicinity of the cutter unit 16, not shown in the figures. In turn, the gearwheel can be driven with a hydraulic motor to provide the lateral movement of the cutter unit. With these, the cutter frame 16 can be moved along the guides 76 in the lateral direction via a form-lockable counter-piece 82 connected thereto. At the same time, the cutter frame 16 is advantageously also supported to a pivot arm by means of second guides 84 and a form-lockable second counter-piece 86 located between the pivot arm 32 and the cutter frame 16. Both the guides 76 and the second guides 84 extend over the entire width of the lorry. The side-shift equipment according to the second embodiment does not require the cutter unit to be removed from the lorry. As the side-shift actuator, alternatively to a chain and a gearwheel, it is also possible to use a cylinder, for example, or other equivalent actuator suitable for the application.

[0064] With a side-shift actuator, the cutter unit can be moved to a side of the lorry in such a way that the lorry does not drive on top of road markings. Advantageously, the amount of side-shifting is equal to the width of the cutter unit, i.e. approximately 500 - 1000 mm. In the first embodiment, the suspension equipment 38 locks the frame 12 of the cutter device 10 to the frame 3 of the lorry 2 in both the longitudinal and the vertical directions relative to the lorry while leaving free the transverse horizontal direction relative to the lorry. In the second embodiment, the frame is fixedly fastened to the lorry frame.

[0065] According to Figures 2, 3 and 7 - 10b, the cutter unit 14 is supported to the frame 12 of the cutter device 10 preferably with the pressing equipment 25 and the pivot arm 32 that advantageously forms the support equipment 35. The pivot arm 32 is mounted with bearings to the frame 12 of the cutter device 10 at one end by means of the joint 66. The other end can be pivoted to the cutter frame 16 or fixedly fastened to the cutter frame. The pivot arm 32 enables the cutter unit 14 to be moved vertically in a controlled manner yet preventing the horizontal movement of the cutter unit in both the longitudinal and transverse directions relative to the lorry. According to an embodiment, the pivot arm can also be replaced with vertical guides placed in the vicinity of the side-shift equipment.

[0066] In the first embodiment of Figures 2-6, the pressing actuator 34, consisting of air bellows 36, serves as the pressing equipment 25, into which compressed air of the lorry is fed. Alternatively, the pressing actuator 34 can be a hydraulic cylinder 88 according to Figure 8 illustrated with a broken line. With the pressing actuator 34, the cutter unit 14 can be pressed against the road surface 102 in such a way that when the cutter unit 14 moves supported by a preferably asymmetric support wheel 20, the cutter blade 18 of the cutter unit 14 always receives sufficient pressure against the road surface 102 at the lowest point of the support wheel 20. The pressing equipment 25 is necessary since the weight of the lorry is not applied to the cutter unit at any stage as is the case with the weight of a self-propelled machine of prior art cutter devices. Thus, without pressing, the cutter blade will rise up due to the resistance of the road surface and out from the correct machining depth without an external downward load. Advantageously, the cutter blade rotates against the travel direction of the lorry. In addition, the pressing equipment serves as a kind of a shock absorber between the cutter unit 14 and the lorry frame 3, since the air bellows 36, for example, dampen vibrations of the cutter unit 14 preventing their transfer to the lorry completely or at least for the most part. The necessary load generated for the cutter unit by the pressing may be in the range of 500 - 6000 kg, preferably 500 - 1500 kg. Air bellows can be better for their resistance compared to a hydraulic cylinder, for example.

[0067] In the embodiment of Figures 7 - 10b, the pivot arm is curved and one of its ends is pivoted above a wheel of the lorry. The pivot arm 32 advantageously consists of two parts placed on both sides of the frame. At the lower end of the pivot arm 32, there may be a triangular beam extending over the entire width of the lorry. Plate-like second guides 84, serving as part of the side-shift equipment, are fastened to the beam. Correspondingly, arranged on the front side of the cutter frame 16, there is a C-shaped second counter-piece 86, which locks the cutter frame 16 to the pivot arm 32 in a form-lockable manner in the travel direction of the road traffic vehicle and in the vertical direction, however, enabling the vertical movement. In Figures 7 and 9, number 68 refers to the compressor of the suction equipment and number 70 refers to the water container. Water contained in the water container is advantageously sprayed to the cutter blade periodically in order to cool it down.

[0068] In the embodiment of Figures 7 - 10b, the pressing equipment 25 is formed in such a way that the frame 3 of the road traffic vehicle 1 is surrounded by a transverse beam 72 and vertical beams 74 fastened thereto on both sides of the frame 3, forming a rigid entity. This entity is fastened to the frame 3 with a bolted connection, for example. Below the vertical beams 74, guides 76, consisting of an III beam 75, for example, are connected to the vertical beams 74. On both sides of the frame 3 of the road traffic vehicle 1, the guides 76 are connected to the vertical beams 74 preferably by means of a pressing actuator 34, which can be a hydraulic cylinder 88. Between the III beam 75 and the vertical beams 74, there may be vertical guides (not shown), along which the hydraulic cylinder moves the guides relative to the vertical beams. The pressing actuator enables the guides 76 to be moved in the vertical direction for pressing the cutter frame 16 against the road surface 102. In turn, the cutter frame 16 includes a C-shaped counter-piece 82, by means of which the cutter frame 16 is locked to the guides 76 in a form-lockable manner in the travel direction of the road traffic vehicle and in the vertical direction, however, being movable in the transverse direction. With the pressing equipment, the cutter unit can also be lifted off the ground during the side-shifting manoeuvre.

[0069] According to Figure 4, in the system 11 according to the invention, the container 26 and the suction unit 44 included in the suction equipment 22 of the cutter device 10 can be arranged on a load platform 56, allowing them to be easily lifted onto the lorry 2 and possibly also to be tipped. Alternatively, the suction equipment 22 can also be arranged directly in the tipping frame of the lorry. According to Figure 4, the cutter unit 14 can be used on either side of the lorry 2. By changing the support wheels 20 according to Figures 5a - 5c of the cutter unit, it is possible to change the pattern of road markings 100 to be cut on the road surface 102. In Figure 4, road markings 100.1 on the left of the lorry are formed by cylindrical cutting, wherein the support wheel has individual indentations 60 according to Figure 5a, which produce road markings 100.1 produced by cutting that are separate from each other. Between the separate road markings 100.1, there is an unbroken road surface 102. In Figure 4, road markings 100.2 on the right of the lorry are formed by sinusoidal cutting, wherein the support wheel is formed continuously in accordance with the sine wave according to Figure 5b or 5c, which produces a continuously cut road marking 100.2. The depth of a continuous road marking varies continuously between 3-10 mm according to the sine wave.

[0070] The width of road markings can be in the range of 100 - 500 mm, however, preferably it is either 300 mm or 500 mm as specified by standards. In Finland, the width of road edge markings is 300 mm on highways and main roads, whereas it is 500 mm on motorways. The width of the cutter unit may be between 300 and 1000 mm, preferably between 500 and 700 mm. An advantage of the road traffic vehicle, preferably a lorry, used in the system according to the invention is that it can transfer sufficiently big loads. In sinusoidal cutting, material detaching from the road surface is generated approximately in an amount of 2.85 solid cubic metres/km during 300 mm wide cutting, which corresponds to 4.3 thrown cubic metres/km. The amount of material that detaches during cylindrical cutting is a fraction of the corresponding amount in sinusoidal cutting. Advantageously, the cutter blade used is continuous, i.e. it has spikes around the blade, and the cutter blade rotates continuously. The cutter blade can be rotated with a direct-driven hydraulic or electric motor.

[0071] In the system according to the invention, the cutter device arranged as part of the lorry allows a working speed that is notably higher than in prior art cutter devices. Prior art cutter devices are generally designed for cutting asphalt, wherein the cutting speed cannot be high. Instead, the system according to the invention is specifically designed for cutting road markings, wherein, when connected to a lorry frame, the cutter device can be used at a notably higher speed, even at a progression speed of 10 km/h. Advantageously, all driving power required by the cutter device can be produced in the lorry, which can be equipped with a separate power unit providing an output of 80 - 150 kW during driving, preferably approximately 110 - 130 kW, of which two thirds is consumed by the high-power aspirator and one third by the drive of the cutter unit. The cutter device is connected to the lorry or its power unit preferably with a quick connector, as well as to the hydraulic, pneumatic and electric systems of the lorry.

[0072] The cutter device advantageously also includes an electric control unit located in the lorry cab. With the control unit, the operator can start the motor rotating the cutter blade of the cutter unit, the suction equipment, and perform side-shifting. The control unit may also include a display, which is connected to a camera that follows the road surface. In this way, it is easier for the operator to keep the cutter device aligned with the line of road markings to be cut.

[0073] According to Figure 6, the system according to the invention may also include, for example, a trailer 40 to be connected to the rear of a lorry 2 including a warning sign 62 for the traffic arriving from behind and a rear impact shield 64 for dampening possible impacts. In this case, the system can be used without a separate rear warning vehicle.

[0074] According to an embodiment, instead of a lorry or a tractor, for example, the cutter device according to the invention can also be arranged in a semi-trailer of a lorry or a tractor. In this case, too, the cutter device can appropriately follow the travel route of the road traffic vehicle that pulls it, which allows the operator to accurately position the cutter device at a desired place, where the road markings to be cut will be produced.

[0075] With the cutter device and the system according to the invention, a road marking is achieved, the bottom of which is plane in the transverse direction, conversely to prior art road markings. This is because in the cutter device according to the invention, the support wheel of the cutter unit is not a wheel that carries the entire vehicle, but the lorry moves on its own wheels allowing in this way more precise adjustment of the position of the cutter unit in accordance with the road surface to be cut.

Claims

1. A cutter device (10) for cutting road markings (100) on a road surface (102), the cutter device (10) including a frame (12) for suspending a cutter unit (14) from a road traffic vehicle (1) or its trailer, a cutter unit (14) connected to the frame (12), and support equipment (35) for supporting the cutter unit (14) to the frame (12) movably in the vertical direction, said cutter unit (14) comprising

- a cutter frame (16),

- a rotating cutter blade (18) mounted with bearings to the cutter frame (16) for cutting a road marking (100) on a road surface (102), and

- a support wheel (20) connected to the cutter frame (16) for supporting the cutter unit (14) against a road surface (102),

wherein the cutter device additionally includes suction equipment (22) arranged at least partially in the vicinity of said cutter unit (14) for sucking road surface (102) material produced detaching during the cutting process from the road surface (102), characterised in that the cutter device (10) further includes

- height adjustment equipment (15) arranged in the vicinity of the cutter frame (16) for moving the cutter frame (16) in the vertical direction relative to the frame (12) and the road surface (102) for adjusting the cutting depth of the cutter blade (18),

- pressing equipment (25) arranged in the vicinity of the cutter frame (16) between the cutter frame (16) and the frame (12) or the cutter frame (16) and the road traffic vehicle (1) for pressing the cutter blade (18) against the road surface (102) during the cutting process.

2. A cutter device according to Claim 1, characterised in that the support wheel (20) is mounted with bearings to the cutter frame (16), and said height adjustment equipment includes an actuator for adjusting the position of the support wheel (20) relative to the cutter frame (16).

3. A cutter device according to Claim 1 or 2, characterised in that the cutter device (10) includes side-shift equipment (45) for moving the cutter unit (14) transversely to the road traffic vehicle (1) or its trailer below the road traffic vehicle (1) between the operating position and the storage position.

4. A cutter device according to Claim 3, characterised in that the side-shift equipment (45) includes transverse guides (76) arranged between the road traffic vehicle (1) and the cutter frame (16) and a form-lockable counter-piece (82) arranged to be moved along said guides (82), as well as a side-shift actuator (48) arranged between the cutter frame (16) and the frame (12) or the cutter frame (16) and the road traffic vehicle (1) for moving the cutter frame (16) transversely to the road traffic vehicle (1) by means of the guides (76) and the counter-piece (84) by using the side-shift equipment (48).

5. A cutter device according to any of Claims 1 to 4, characterised in that the height of the cutter device (14) is between 20 and 50 cm, preferably between 30 and 40 cm.

6. A cutter device according to any of Claims 1-5, characterised in that said cutter device (10) includes traction equipment for delivering traction with the support wheel (20) for rotating the support wheel (20) substantially at a speed corresponding to the travel speed of the road traffic vehicle.

7. A cutter device according to any of Claims 1-6, characterised in that the cutter device (10) includes a pivot arm (32) pivoted to said frame (12) and connected to said cutter unit (14) for connecting the cutter unit (14) to the frame (12).

8. A cutter device according to any of Claims 1-7, characterised in that said support wheel (20) is asymmetric for supporting the cutter unit (14) against the uncut surface of the road in such a way that the cutter blade (18) contacts the road surface (102) periodically while the profile of the support wheel (20) follows the road surface (102) for cutting repeated road markings (100) on the road surface (102).

9. A system for cutting road markings on a road surface, the system (11) including a cutter device (10) for cutting road markings (100) and a road traffic vehicle (1) or its trailer for carrying the cutter device (10), characterised in that said cutter device (10) is a cutter device according to any of Claims 1 - 8.

10. A system according to Claim 9, characterised in that said cutter device (10) is arranged to be positioned over the distance between wheels (4) included in the road traffic vehicle (1) longitudinally to the road traffic vehicle (1) mainly below the frame (3) of the road traffic vehicle (1).

11. A system according to Claim 9 or 10, characterised in that the suction equipment (22) includes a suction container (26) connected to the road traffic vehicle (1) or its trailer for collecting the road surface material that detaches during the cutting, a suction unit (44) for providing suction, and a suction hose (46) for sucking the road surface material that detaches during the cutting from the surroundings of the cutter blade (18) into the suction container (26) by means of suction provided by the suction unit (44).

12. A system according to any of Claims 8 to 11, characterised in that the road traffic vehicle (1) is a lorry.

13. A method for cutting road markings on a road surface, wherein

- suspending a cutter device (10) from a road traffic vehicle (1) or its trailer,

- suspending a cutter unit (14) movably in the vertical direction from a frame (12) by means of support equipment (35),

- suspending the cutter unit (14) with a support wheel (20) against the road surface (102) in such a way that a cutter blade (18) contacts the road surface (102),

- driving the road traffic vehicle along the road surface for moving the cutter unit (14),

- cutting road markings (100) on the road surface (102) with the cutter device (10) and the cutter unit (14), and

- sucking road surface (102) material produced that detaches during the cutting process from the road surface (102) simultaneously with the cutting performed with the suction equipment (22) included in the cutter device (10), characterised in that

- adjusting the cutting depth of the cutter blade (18) with height adjustment equipment (15) by moving the cutter frame (16) vertically relative to the frame (12),

- pressing the cutter unit (14) against the road surface (102) with pressing equipment (25), and

- moving the cutter unit (16) in the direction of the road surface (102) by delivering force via the wheels (4) of the road traffic vehicle (1) to the road surface (102).

14. A method according to Claim 13, characterised in that between 30% and 80%, preferably between 60% and 70% of the suction air volume is recirculated back to provide an air blow in the vicinity of the cutter blade for lifting the material cut off from the road surface, while the rest of the air volume is sucked into a container for the recovery of loose material.

15. A method according to Claim 13 or 14, characterised in that the cutter unit (14) is supported to the road surface (102) using an asymmetric support wheel (20) in such a way that the cutter blade (18) contacts the road surface (102) periodically while the profile of the support wheel (20) follows the road surface (102).

Drawing