EP0424297B1 - Method and device for the marking of lines in sports grounds - Google Patents

Abstract

The invention aims to carry out marking of grounds, particularly sports grounds such as football pitches, rugby pitches, etc., which is resistant to bad weather and to trampling, while meeting a certain number of requirements relating for the most part to player safety. The method according to the invention consists in hollowing out a cavity in the shape of the line to be produced; in filling it by forming therein an aggregate consisting of rubber in small pieces and of a binder preserving a flexible state, such that the pieces of rubber are coated only partially; and in painting the surface of the said aggregate with the desired marking. Advantageously, bitumen or derived products are used as binder, and recycled rubber in the form of chips. The invention also relates to devices for implementing the method. <IMAGE>

Description

The present invention relates to a soil marking process, more particularly intended for stabilized or turfed land. It also relates to machines used in the implementation of the method.

Currently, sports fields such as football, rugby, etc. are traced with a material, generally lime or plaster, which is deposited in a strip in the pulverulent state.

There are machines for tracing such as that described in document GB-A-11160 which comprises, mounted on wheels, a hopper whose trough-shaped bottom is provided with an endless screw. The latter, driven by the wheels, transports the marking product (s) to a pouring chute arranged centrally.

This type of marking has the disadvantages of having to be repeated practically before each event, of being very sensitive to climatic conditions such as rain and wind, and of becoming very approximate during a match, under the effect of only trampling. , with the consequence of making arbitration difficult and subject to discussion.

For the marking of hard floors of wood, concrete, bitumen, etc., it is known to use marking strips which are inserted in grooves made beforehand. A machine for digging these grooves is described in patent AU-B-8060940. To date, there is no equivalent for marking flexible terrains.

The object of the present invention is to overcome the drawbacks inherent in marking flexible, stabilized or lawn soils, by means of a new marking process, while also respecting a certain number of imperatives, in particular to preserve the safety of players.

Generally speaking, it is essential that the tracks do not generate abrupt variations in the physical characteristics of the terrain: a marking element must in no case be tripped over for athletes. It must also have a flexibility as close as possible to that of the ground so as not to be hurtful in the event of a fall. In addition, it is important that its surface characteristics, in particular its adhesion characteristics, are such that the players do not feel differences in the search for their supports (for example, it is not admissible that the marking be slippery) . Furthermore, the marking should not obstruct the flow of water parallel to the surface, as otherwise it could result in the formation of pits and puddles on each side of the strips.

The method according to the invention which provides a satisfactory response to these different conditions is characterized in that it consists in filling a previously dug cavity, the shape of which corresponds substantially to that of the layout to be made, with an aggregate consisting of rubber in small pieces and a binder retaining a flexible state, the aggregate being formed in such a way that at least most of the pieces of rubber are only partially coated; and painting the desired marking on the surface of said aggregate.

In practice, said cavity is generally a trench, to carry out all that is linear marking, or a circular hole for the representation of points.

The rubber pieces on the periphery of the aggregate form an irregular surface, the reliefs or asperities of which constitute anchoring points in the walls of the cavity. On the surface, the roughness makes the marking non-slip, even in the rain.

In the formation of the aggregate, the fact of dosing the quantity of binder so that the greatest number of the pieces of rubber are not completely drowned ensures the reservation of gaps. These give the aggregate good water permeability, so that the marking strips are not interrupted by the flow parallel to the surface. The presence of gaps also contributes to the flexibility of the aggregate.

As a binder, it is advantageous to use bitumen or derived products. Bitumen has the advantage of being cheap and relatively easy to work. By pouring it at a temperature of the order from 100 to 120 ° C, its viscosity is satisfactory for the reservation of said interstices.

Under normal temperature conditions, the bitumen remains relatively soft, so that the aggregate benefits from the elasticity (compressibility and shape memory) of the rubber. In addition, to match the flexibility characteristics of the aggregate to those of the ground, it is easy to modify the degree of hardening of the bitumen by adding sand. The addition of sand is also useful for two other reasons. On the one hand, it helps prevent bitumen from becoming too liquid again in sunny and hot weather. On the other hand, it increases the ability to crumble the aggregate, necessary so that it is not dangerous: a player performing a slide with a spiked shoe should not feel shock when crossing a marking strip. The ability to crumble also proves to be advantageous in the event of land renovation: the work can be done without prior removal of the marking aggregate which, under the action of agricultural machinery, behaves like soil and is simply finds it scattered and mixed with it.

In one way of carrying out the process of the invention, the formation of the aggregate in the cavity is carried out in several stages as follows: the cavity is first partially filled with rubber in pieces, for example halfway , then bitumen is poured in metered quantity and under temperature conditions as defined above for the reservation of interstices, without covering the surface pieces. The same process is then repeated to completely fill the cavity. In practice, this generally has a depth of 3 to 4 cm, approximately. As for the width of the trenches for the realization of linear markings, preferably, it is around 12 cm, a little larger than the width of the marking itself. This way of operating in several stages makes it possible to obtain a homogeneous aggregate, because in each phase, the descent of the bitumen to reach the lower rubber pieces is minimal and that, consequently, during this descent, the temperature of the bitumen does not vary significantly.

In another way of carrying out the process of the invention, the rubber-bitumen mixture is first produced, then it is applied in the cavity while the bitumen is still hot. This solution has the advantage of requiring only a single operation for filling the cavity with the aggregate.

A machine specially designed to carry out the process in the manner just described comprises, on a chassis mounted on wheels, a first container for the rubber in pieces, a second container for the binder, a conveying means starting from the base of the first container, an outlet for the binder above said conveying means, outside the first container, said outlet being provided with a stop and flow adjustment means, and, connected to the outlet conveying means, a means of supplying the rubber-binder mixture into the cavity to be filled.

For a better understanding, an exemplary embodiment of such a machine will now be described in relation to the attached drawing which schematically represents it in operation.

The machine frame, mounted on wheels 1, carries a container or hopper 2 for the rubber pieces C, at the bottom of which, in a groove 3 oriented longitudinally, is housed an endless screw 4 driven by a motor 5.

The groove 3 is extended outside the hopper 2 by a channel 3 'in which the worm screw 4 also extends. At the end of the channel 3', is connected a conduit 6, which is bent to open out towards the bottom. Preferably, at least part of the conduit 6 is flexible, so that one can, in operation, place its outlet end inside the trench 7 to be filled. In addition, in order to obtain a better discharge, the outlet of the conduit 6 is oblique with respect to its axis.

A tank 8 intended to receive hot bitumen B is attached to the hopper 8, above the channel 3 '. At its base, it is in communication with a conduit 9, the outlet end of which is located above the channel 3 ', which, at least in this zone, is uncovered. On the other hand, on the conduit 9, there is provided a stop valve 10 and adjusting the bitumen flow rate.

In operation, the machine previously loaded with pieces of rubber C and hot bitumen B is disposed above the trench 7 to be filled, the outlet end of the conduit 6 being placed inside the latter. The conveying of pieces of rubber C is then initialized from the hopper 2 by starting the motor 5, for example an electric motor. Then, as soon as the rubber arrives vertically from the duct 9, the tap 10 is opened to produce a flow of bitumen B on the rubber transported by the screw 4. In accordance with the invention, the flow of bitumen is regulated in such a way so that it is just enough to agglomerate the pieces of rubber together, only partially coating them. The agglomerate obtained, when it enters and passes through line 6, has a pasty consistency due to the fact that the temperature of the bitumen remains high, so that at the outlet in the cavity to be filled, it spreads therein. ensuring a correct filling. The filling height is determined by the speed of movement of the machine.

The machine can be designed light enough to be moved manually. However, a more elaborate machine, with motorized drive, may include additional means such as heating means to bring and / or maintain the bitumen at the temperature of use. In a more complete assembly, it is possible to provide, upstream, means for producing a trench, these means consisting, for example, of a conventional excavator disc.

In a particularly advantageous manner, the rubber used to implement the process of the invention is recovered in tire retreading units: it comes from the used tire tread, which is removed prior to retreading by means of machines chipping. The use of said chips as such in the process of the invention proves entirely satisfactory.

The marking produced in accordance with the invention has a lifespan of several years, only the paint having to be redone regularly, for example annually. Of course, the marking keeps clear contours and, moreover, it is more visible than the traces which are produced in a conventional manner with plaster or lime.

Claims (11)

1. A process for marking the ground, particularly for stabilised or turfed land, characterised in that it consists of filling a cavity previously hollowed out, the shape of which corresponds substantially to that of the line to be made, with an aggregate constituted by small pieces of rubber and a binder maintaining a flexible state, the aggregate being formed such that at least the most part of the pieces of rubber are only partly coated; and of painting the desired marking on the surface of said aggregate.
2. A process according to Claim 1, characterised in that the binder is made of bitumen.
3. A process according to Claim 1, characterised in that the binder is a product derived from bitumen.
4. A process according to Claim 1, characterised in that the binder contains sand.
5. A process according to any one of Claims 1 to 4, characterised in that the pieces of rubber are recycled chips from tyre reconditioning units.
6. A process according to one of Claims 1 to 5, characterised in that, in the cavity, the aggregate is formed in several stages, each stage comprising first the deposition in the cavity of pieces of rubber, followed by the pouring of the binder, without completely covering the pieces at the surface.
7. A process according to one of Claims 1 to 5, characterised in that the rubber/binder aggregate is first formed, then applied to the cavity to be filled.
8. A machine for implementing the process according to Claim 7, characterised in that it comprises, on a frame mounted on wheels 1, a first container (2) for the pieces of rubber (C), a second container (8) for the binder (B), a means of transfer starting from the base of the first container (2), an outlet (9) for the binder (B) above said transfer means, outside the first container, said outlet (9) being equipped with a means for stopping and regulating the flow (10) and, connected to the outlet of the transfer means, a means (6) for supplying the rubber/binder mixture to the cavity to be filled.
9. A machine according to Claim 8, characterised in that said transfer means is a system with an endless screw (4).
10. A machine according to Claim 8 or 9, characterised in that it further comprises heating means for bringing the binder (B) to and/or keeping it at the temperature of use.
11. A machine according to one of Claims 8 to 10, characterised in that it further comprises a means for producing trenches.

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