WO2013066257A1

WO2013066257A1 - Luminous road sign

Info

Publication number: WO2013066257A1
Application number: PCT/SE2012/051190
Authority: WO
Inventors: Jan Lindberg; Joakim Lindberg
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-11-01
Filing date: 2012-11-01
Publication date: 2013-05-10
Anticipated expiration: 2014-05-01
Also published as: SE1151020A1

Abstract

The present invention relates to a luminous road sign (1), intended to be used together with some form of carrier/support, comprising a luminous road sign symbol (2) applied onto an information carrier (4) of a flexible material, wherein said road sign symbol (2) comprises diodes (8), e.g. LEDs, applied onto said information carrier (4) which comprises vibration damping means (4, 5, 6).

Description

LUMINOUS ROAD SIGN

TECHNICAL FIELD

The present invention relates to a luminous road sign, intended to be used together with some form of carrier/support, comprising a road sign symbol applied onto an information carrier of a flexible material.

STATE OF THE ART

The present invention pertains to the field of road signs, and especially to the field of lightweight road signs, primarily for road construction sites, but permanent use may also occur. Methods, arrangements and constructions related to the above-mentioned technical field are previously known in a plurality of different embodiments.

Since a long time, it has been known to use so-called VMS signs (Variable Message Signs) at road construction sites, which signs consist of an assembly of lights, preferably diodes (LEDs), mounted on a panel. These signs provide information to vehicle drivers in the form of luminous road sign symbols, the message of which can be varied in that some lights forming a message suited to the purpose can be switched on, while others are kept switched off. The assembly is smooth to use, but has the disadvantage that it is very expensive, since tens of thousands of diodes mounted on the panel are required to be able to produce the different messages prescribed by the law in these situations. Another problem is that the assembly is heavy, with the consequence that the assembly is, as a rule, mounted on a truck, making the assembly even more expensive and resulting in the disadvantage that a truck is tied up for use together with a sign and thus cannot be used for anything else during the time the sign is posted.

Furthermore, the lights tend to break prematurely, resulting in expensive maintenance.

Another luminous road sign is known from WO 2010/071575. This road sign is a lightweight road sign intended for use together with a lightweight support, which can be set up alongside the road. The support can also be mounted on a lighter trailer, towable by a car which is uncoupled after the posting. The road sign consists of flexible material onto which a road sign symbol of a flexible material is applied. The entire road sign symbol or certain parts of it, for example an arrow indicating that one should keep to the left or numerals indicating the maximum allowable speed at the road construction site, can be designed to be luminous by using a luminous film onto which the message is printed, wherein the luminous film emits light when it is supplied with current. By means of different screen densities of the printed image, e.g. a blue area on a road sign can be made luminous, whereas an arrow, a numeral etc. can be made more light- intensive through the absence of print and then appear as a white light. These signs are easy to handle, relatively inexpensive, but the production of them is complicated, e.g. to achieve the correct screen density of the printed image. Furthermore, the luminous film has a relatively short service life, approx. 5000 hours, which should be compared with diodes, which, in optimum conditions, are said to be capable of lighting up for up to 100000 hours. Neither is the light intensity of the luminous film sufficient to meet the demands placed on it by use in daylight, where higher light intensity is required, which is the reason why the road sign symbol also has to be printed correctly shown in its true colours, for example yellow background and black symbol, to be noticeable to vehicle drivers in daytime.

BRIEF DESCRIPTION OF THE INVENTION

It is an object of the present invention to eliminate or at least minimize the above- mentioned problems, which is achieved by means of lightweight and luminous road sign according to claim 1. The design of the road sign makes it revolutionary in the field of road signs in that it enables the use of diodes as a light source for lightweight road signs.

Thanks to the invention, a road sign can be provided that enables at least one of the following advantages to be achieved: sufficient light intensity for daytime use;

longer service life of diodes, resulting in reduced maintenance and cost savings associated therewith;

a price structure enabling smaller operators in the field of signposting at road

construction sites to enter the marketplace;

simpler and cheaper manufacture;

energy savings;

quicker and simpler signposting along road construction sites;

lower weight of luminous road signs;

avoids advanced software programs for controlling the diodes.

BRIEF DESCRIPTION OF THE FIGURES

In the following, the invention will be described in greater detail with reference to the attached figures of the drawings, in which: shows a frontal view, according to a first embodiment, of a lightweight and luminous road sign according to the invention;

shows a frontal view, according to a second embodiment, of a lightweight and luminous road sign according to the invention;

shows in detail a suspension device at the upper edge of a road sign according to a first embodiment of the invention, in frontal perspective;

shows a printed circuit board array with diodes for forming a road sign symbol;

shows a printed circuit board array with diodes in the shape of a road sign symbol;

shows a principal diagram of a cross-section of a road sign according to the invention.

DETAILED DESCRIPTION OF FIGURES

Figure 1 shows a frontal view of a first embodiment of a lightweight and luminous road sign 1 according to the invention. A road sign symbol 2, "Road work in progress", applied onto an information carrier 4 via a light-carrying assembly unit 3 in the form of a flexible material, e.g. a thin plastic panel to which the road sign symbol 2 is attached, is seen in the figure. Along the upper edge, the information carrier 4 is provided with a suspension device 5, suitably in the form of a keder strip, for suspension from a carrier or a support. The road sign symbol 2 consists of a printed circuit board array of a shape suited to the purpose, in this case a digging person, which comprises tightly spaced diodes (LEDs) and necessary electrical components and control circuits. The term road sign symbol refers to a "symbol present on road signs", wherein "road signs" designates such road signs which are intended in the regulation "VagmarkesfSrordningen (SFS 2007:90)". According to § 2, "symbol" refers to a "picture used instead of a text".

Within the scope of the invention, the term road sign symbol also refers to road signs provided with numerals, e.g. signs regulating the maximum allowable speed, and signs with information in the form of text. The term "carrier" refers to some kind of vehicle with the aid of which the road sign 1 can be transported to the site for signposting, but also a vehicle intended to transport the road sign 1 along a road section where a construction vehicle is operated, in order to alert road users of this. The term "carrier" can also refer to the devices on which the road sign 1 is mounted by its suspension device, e.g. a bar on a vehicle. Figure 2 shows a frontal view, according to a second embodiment, of a lightweight and luminous road sign 1 according to the invention. A road sign symbol 2, "Keep left", in the form of an arrow pointing diagonally downward to the left, is applied onto the information carrier 4 via a light-carrying assembly unit 3 of a flexible material, e.g. a plastic panel of a flexible material. In this case, the arrow is formed by elongated, straight, printed circuit board arrays 7 onto which tightly spaced diodes are applied. The information carrier 4 comprises suspension devices 6, at least at each upper corner, in the form of edge-reinforced holes, for example eyelet rings.

Vibrations arise when transporting the road sign 1 and in different operations during the progress of the road construction. Since the road sign according to the invention is intended to be usable together with a support standing directly on the ground, it is of great importance to be capable of damping these vibrations to the greatest possible extent. According to the inventive idea, the road sign therefore comprises a vibration damping unit which efficiently minimizes vibrations in the road sign, which otherwise might influence the diodes so that their service life is shortened.

Figure 3 shows a detail of the suspension device 5 at the upper edge of a road sign according to a first embodiment of the invention, in frontal perspective.

At least along a portion of the upper edge, the information carrier 4 comprises a suspension device 5 for suspending the lightweight and luminous road sign 1 from a support. According to the first embodiment, the vibration damping unit is constituted by this suspension device 5, whereby it has been possible to achieve a very advantageous synergy effect. In this first embodiment, the suspension device 5 is suitably a keder strip 5. The actual keder 50 at its upper end has a diameter in the range of 3-20 mm, more preferred 5-10 mm, and comprises a wire 51, preferably a plastic wire, which is enclosed by a vibration damping material, e.g. an elastic fabric, which is joined together in a neck portion 52, transitioning into a holding portion 53 where the elastic and moreover vibration damping material forms two lips enclosing and retaining the upper edge of the information carrier 4, e.g. by means of sewing, gluing or vulcanizing the lips to the information carrier.

In the second embodiment shown in Figure 2, it is instead the information carrier 4 which constitutes the vibration damping unit, in that the information carrier 4 is at least partially formed of a material which is non-selfsupporting and vibration damping.

Examples of such a material can be a PVC-coated elastic textile fabric and a rubber fabric. The vibration damping portions of the information carrier should be positioned such that they reduce the vibrations propagating from the ground via the support as efficiently as possible. One possible way of arranging the vibration damping unit is to make the information carrier include a vibration damping material in the region where the road sign symbol is applied. Another possible way is to provide the information carrier 4 with vibration damping material in the region of the suspension devices 6, or to design the suspension devices 6 of vibration damping material, e.g. rubber. Naturally, the entire information carrier 4 can be formed of a vibration damping material.

Accordingly, also in this embodiment, very advantageous synergy effects are achieved.

A combination of the solutions is of course possible, i.e. the road sign 1 can comprise a suspension device 5 of a vibration damping material and an information carrier 4 which at least partially comprises a vibration damping material. Figure 4a and 4b each show a printed circuit board array 7a and 7b, respectively, with diodes 8 for forming a road sign symbol. According to the inventive idea, the formation of road sign symbols 2 can be facilitated in that the diodes 8 are applied onto a printed circuit board array 7a, 7b. The printed circuit board array is modular and comprises modules of varying sizes, which can be interconnected electrically to enable the formation of different road sign symbols. A module preferably has the shape of a square, see Fig. 4b, or a rectangle, see Fig. 4a. The diodes 8, which are preferably systematically arranged in diode units 13 of 2x2 diodes, are placed across substantially the entire surface of the module. Each unit of 2x2 diodes preferably forms a controlled unit, which units are controlled jointly.

The printed circuit board array comprises electrical components and control circuits for controlling the diodes, not shown. Furthermore, the printed circuit board array comprises terminals 9 for electrical wiring 10. The printed circuit board array comprises one or several attachment devices 11 for fixing the printed circuit board array to the light-carrying assembly unit 3, here in the form of holes for fixing by means of screws 12, which results in simple mounting, but also possibility of demounting.

In order to enable a large number of road sign symbols, modules comprising anything from 1 diode unit up to, for example, 100-200 diode units placed in a row, or in parallel rows, can be used. Modules with even more diode units can of course be formed in cases where really large road sign symbols are to be manufactured, providing manufacturing advantages. However, in the event that a module needs to be replaced, smaller modules result in the advantage that the service engineer can have a smaller stock of module sizes. Due to the fact that each module includes fewer diode units, this will result in a lower cost for replacement, since the number of undamaged diode units possibly replaced "in the bargain" is reduced. Smaller module units will also mean that the risk of a module breaking is reduced, since each connection forms a flexible joint. This also results in an increased flexibility of the road sign, which is part of the inventive idea, with the purpose, inter alia, of reducing the vibrations. Each module connection also provides a vibration suppressing effect since any vibrations reaching a module do not necessarily have to propagate to the next module.

Figure 5 shows a road sign array according to the first embodiment of the invention. Here, the printed circuit board array 7c has been given the shape of a road sign symbol. Similarly as described above, diode units 13 are placed across substantially the entire surface of the printed circuit board array. This embodiment is most advantageously used when the road sign symbol has a complex shape, which cannot easily be formed from the above-mentioned modules, and results in a relatively fast production. However, all the advantages obtainable when using smaller modules will not be achieved.

According to the inventive idea, the light intensity of said diodes can be varied depending on ambient light conditions so that the road sign symbol, for example, produces more intense light during the day and less intense light during the night. For this, said printed circuit board array comprises regulating devices for controlling the light intensity of the diodes. Another advantage is to be able to adjust the light intensity depending on whether the road sign should be visible from a long or short distance. Thanks to this, the same type of diodes can be used, which diodes are disposed with a constant spacing on the printed circuit board array. This results in a cost effective production, since the same modules can be used irrespective of the type of road sign which is to be manufactured. Also the risk that, for example, modules producing too weak light would come to be used is eliminated. The diodes are suitably disposed with a centre spacing of no more than 20 mm, preferably no more than 15 mm, and even more preferred about 10 mm, but the spacing will of course be adapted to the choice of diode. Another advantage is that energy is saved in this way, which is a great advantage since the power supply to these road signs, as a rule, is provided by batteries, and exchange of batteries is a time consuming operation for the operator.

Figure 6 shows a principal diagram of a cross-section of a road sign according to the invention. The information carrier 4 forms a back member to which the light-carrying assembly unit 3 is attached. The printed circuit board array 7a, 7b, 7c, in its turn, is mounted on the light-carrying assembly unit 3. The assembly is preferably protected by a transparent plastic covering 14. The plastic covering 14 encloses at least the light- carrying assembly unit 3 and the printed circuit board array 7a, 7b, 7c, but preferably the entire front side of the information carrier 4. The protecting plastic covering 14 is preferably attached by welding by means of high frequency welding, which is a fast and simple process, but it is of course also conceivable to attach the plastic covering by sewing or gluing. The information carrier 4 suitably consists of a durable material with good resistance to water penetration, but, in case another material is considered more suitable for achieving other objects according to the invention, the protecting plastic covering can be adapted to enclose both the front side and back side of the road sign. Furthermore, the road sign comprises terminal devices for connecting a current source.

Also included within the scope of the invention is an embodiment where the road sign 1 is used on a vehicle, e.g. an escort car displaying a wide load warning, a truck driving behind a construction vehicle in road construction such as paving work, ditch clearing, etc. By providing these vehicles with a bar, hooks, or other devices from which the road sign 1 can be suspended, a vehicle can very easily be provided with a suitable message, and the message will become easily replaceable. A suitable position for the road sign 1 is installation on the vehicle roof, flatbed, or at the rear of the vehicle. The road sign 1 is suspended by its suspension device 5, 6 of vibration damping material. Since vibrations are evident on a vehicle being operated, and especially on a construction vehicle, it will be appreciated that this application results in great advantages. The installation can of course also be done by mounting a support on the vehicle from which the road sign 1 can be suspended by its vibration damping suspension device 5, 6.

In addition to the advantages mentioned above, it can be added that smaller operators thus are given an opportunity to enter the marketplace, in that they can purchase a range of road signs at a comparatively much lower cost than is otherwise the case for a single VMS sign. If the cost of purchasing a truck for transporting such a sign and for setting up the truck with this sign at the site during the time signposting will take place is added, it will be appreciated that the road sign according to the invention brings a revolution in the field as far as costs are concerned. Since the diodes 8 meet the light requirements placed on use in daylight, the road sign symbol 2 does not have to be shown in its colours on the road sign. The printed image can therefore be dispensed with. The background, i.e. the light-carrying assembly unit 3 and the information carrier 4 can instead be made completely black, which is an approved appearance of luminous road signs.

Road signs with moving symbols can be obtained by controlling the diode units.

For instance, several road sign symbols, lighting up in a sequence, can be placed next to each other, e.g. road sign symbols in the form of arrow-shaped square brackets to indicate a prescribed route to the left.

ALTERNATIVE EMBODIMENTS

The invention is not limited by what has been described hereinabove, but can be varied within the scope of the following claims. For instance, it is appreciated that the use of the road sign holder is not limited to signposting on roads, etc., but a sign according to the invention can of course be used for other kinds of information, e.g. for advertising purposes.

It is appreciated that the fixing of the printed circuit board array 7a, 7b, 7c forming the road sign symbol 2 to the light-carrying assembly unit 3 can be done in another way than by screws. For example, rivets can be used, but also glue or silicone or another adhesive compound, which may also have a certain vibration damping effect, can suitably be used. The light-carrying assembly unit 3 can be attached to the information carrier 4 in the same manner. The light-carrying assembly unit 3 does not need to be constituted by a single piece, but can consist of several parts to, inter alia, increase the flexibility of the actual road sign symbol. The information carrier 4 can comprise vibration damping suspension devices 5 along several sides, and thus provide several road sign symbols in one and the same road sign. Thus, the transports and storage space of the information carriers 4 are considerably reduced. To be able to provide several road sign symbols 5 on one and the same side of the information carrier 4 also results in large cost savings. Changing a road sign symbol 5 e.g. at a road construction site involves risks. It is therefore desirable to reduce the time on the roadway, and with a road sign 1 according to the invention it will be very smooth and easy to just rotate the information carrier 4, for example in the embodiment shown in Figure 2, a quarter of turn to obtain an alternative road sign symbol 2. The information carrier 4 can comprise transparent pockets into which modular numerals can be inserted to thus indicate a speed limit. In this way, the sign with the speed limit will be well illuminated and easy to see for motorists. Several road sign symbols can share the space side by side, or be disposed in the vertical direction, or in horizontal rows on a common information carrier and be made controllable independently or jointly.

Claims

1. A luminous road sign (1 ), intended to be used together with some form of

carrier/support, comprising a luminous road sign symbol (2) applied onto an information carrier (4) of a flexible material, characterized in that said road sign symbol (2) comprises diodes (8), e.g. LEDs, applied onto said information carrier, which information carrier (4) comprises vibration damping means (4, 5, 6). 2. The luminous road sign (1) according to claim 1, characterized in that said vibration damping means (4, 5, 6) comprise an attachment means applied along the upper edge of the information carrier, preferably a keder strip (5) comprising a vibration damping material. 3. The luminous road sign (1) according to claim 1, characterized in that said vibration damping means (4, 5, 6) comprise said information carrier (4), wherein the information carrier (4) is at least partially formed of a material which is non- selfsupporting and vibration damping. 4. The luminous road sign (1) according to claim 1, characterized in that said diodes (8) are applied onto a printed circuit board array (7a, 7b, 7c), and that said printed circuit board array is applied onto a light-carrying assembly unit (3) of a flexible material.

The luminous road sign (1) according to claim 4, characterized in that said printed circuit board array (7a, 7b, 7c) is modular and comprises modules of varying sizes, which can be interconnected electrically to enable the formation of different road sign symbols (2).

The luminous road sign (1) according to claim 5, characterized in that said module has the shape of a square or rectangle, wherein diodes (8), which are preferably arranged in units of 2x2 diodes being controlled jointly, are placed across substantially the entire surface of the module.

The luminous road sign (1) according to claim 4, characterized in that said printed circuit board array (7a, 7b, 7c) has the shape of a road sign symbol (2), wherein diodes (8), which are preferably arranged in units of 2x2 diodes being controlled jointly, are placed across substantially the entire surface of the printed circuit board array.

8. The luminous road sign (1) according to claim 6 or 7, characterized in that said diodes (8) are disposed with a spacing of no more than 20 mm, preferably no more than 15 mm, and even more preferred no more than 10 mm.

The luminous road sign (1) according to any one of the claims 4 - 7,

characterized in that the light intensity of said diodes (8) can be varied depending on ambient light conditions, for example to produce more intense light during the day and less intense light during the night, and that said printed circuit board array (7a, 7b, 7c) comprises regulating devices for controlling the light intensity of the diodes.