Driveway grid

Abstract

A device for compensating thermal expansion in driveway grid paving consisting of a set of grid modules which are mutually coupled and assembled on the ground, wherein each grid module (M) is delimited along the perimeter by side walls (P1; P2) oriented vertically with respect to the support surface, which are positioned facing the same side walls as the other modules (M) so as to form, once mutually juxtaposed and coupled, the entire body of the grid paving. At each side wall (P1; P2) of each module (M), each first element (3) and each second element (4) of each module (M) are envisaged to couple with, respectively, a second element (4) and a first element (3) envisaged on a side wall (P2) and (P1) of another module (M). The coupling between each element (3) and the corresponding element (4) is achieved by means of opposing members which perform a mechanical action between the two mutually facing, juxtaposed modules with the intention of allowing the two modules (M) to be moved mutually closer or further apart by a pre-set distance in at least one main direction which is perpendicular to the facing side walls.

Description

[0001] DRIVEWAY GRID DESCRIPTION

[0002] This invention concerns a device for compensating the thermal expansion of driveway grid paving.

[0003] There is a commonly known technique for creating driveway grid paving, such as driveway lawns and / or gravel paving, using a reinforcement system consisting of a set of grid modules which are placed and assembled on the ground.

[0004] From a mechanical point of view, driveway grid paving fulfils the important function of stabilising the ground while, at the same time, making it "drivable”. The empty spaces in the grid allow grass to grow or, in the case of gravel - which is widely used a covering material in gardens due to its ease of installation and inexpensive cost - allow users to create a sturdy driveway surface, i.e. one capable of bearing the weight of vehicles, without limiting the permeability of the said support surface. In particular, in the case of driveways, these systems protect the said grass and the roots thereof from damage caused by foot traffic and from the parking of vehicles, as well as from damage (holes) caused by the presence of animals.

[0005] Most commonly, driveway paving systems - such as driveway lawns and / or gravel paving - are formed by putting together a set of prefabricated grid modules, which are prearranged on the ground, positioned one next to the other so as to form an essentially continuous grid-shaped support surface.

[0006] The grid modules are preferably manufactured in a standard form by moulding appropriate plastic materials that offer the desired characteristics for the use in question.

[0007] One of the drawbacks that arise with the commonly known systems consists of the negative consequences that occur in the driveways and, in particular, the thermal expansion that occurs, more specifically generated by the temperature changes to which the grids are inevitably exposed. Regarding this, it must be taken into account that paving of this kind is formed through the juxtapositioning of a plurality of modular grid elements which, once juxtaposed, can result in paving which is rather extensive and is therefore - even if made of plastic materials - subject to thermal expansion-induced stress. Such stress is not negligible and can also, given the structure of the individual modules, lead to undesirable deformation or even breakage of the paving reinforcement structure.

[0008] The present invention aims to overcome the aforesaid drawback or technical problem, solving the technical problem by introducing the invention based on a mechanism for compensation thermal expansion according to the description that follows, as illustrated in the figures and claims appended hereto.

[0009] Further characteristics and advantages of the device envisaged in the present invention will emerge more clearly in the description that follows of a preferred but not exclusive embodiment illustrated, in the form of a nonlimiting example, in the appended drawings, in which:

[0010] - Figure 1 shows a schematic axonometric view of a grid module of an embodiment;

[0011] - Figure 2 shows a first detail of Figure 1 on an enlarged scale;

[0012] - Figure 3 shows a second detail of Figure 1 on an enlarged scale;

[0013] - Figure 4 is a schematic top-down plan view of Figure 5 (below) showing a plan view of two mutually juxtaposed and coupled grid modules constituting simply part of a larger body of driveway grid paving;

[0014] Figure 4a shows, on an enlarged scale, detail B in Figure 5;

[0015] - Figure 5 shows a schematic sectional view taken according to plane line A-A in Figure 4;

[0016] - Figure 6 shows two mutually juxtaposed and coupled grid modules constituting simply part of a larger body of driveway grid paving; - Figure 7a shows a schematic sectional view taken according to plane line C-C in Figure 6;

[0017] - Figure 8 shows, on an enlarged scale, detail F in Figure 11 ;

[0018] - Figure 9 shows, on an enlarged scale, detail E in Figure 10;

[0019] - Figure 10 shows a schematic axonometric view of two mutually juxtaposed and coupled grid modules M constituting simply part of a larger body of driveway grid paving;

[0020] - Figure 11 shows a schematic axonometric view of two mutually juxtaposed and coupled grid modules M constituting simply part of a larger body of driveway grid paving.

[0021] With reference to the appended figures, M denotes modules with a grid structure (used to construct driveway lawns or to make gravel paving) which are laid on previously prepared ground, mutually positioned and assembled to form a continuous grid-shaped support body, or simply a grid that constitutes, as a whole, a support for the surface which will be defined as a driveable surface, i.e. a surface which is fit to support vehicles.

[0022] This driveable surface is made, overall, by assembling the modules M so that they are not subject to problems or drawbacks resulting from thermal expansion in the grid-shaped paving formed of the modules M.

[0023] Each of the said modules M, structured to form a grid, is shaped for this purpose and is delimited along the perimeter by side walls P1 ; P2 oriented vertically with respect to the surface supporting the grid.

[0024] These side walls P1 ; P2 are positioned facing the same side walls as the other modules M so as to form, once mutually juxtaposed and coupled, the entire body of the grid paving. They are equipped with first elements 3 and second elements 4 for mutual coupling, which comprise - at respectively each side wall P1 ; P2 of each module M - a plurality of first elements 3 and a plurality of second elements 4 which are positioned so that each first element 3 and each second element 4 of each module M are positioned to couple with a second element 4 and with a first element 3 present respectively on a wall P2 and on a wall P1 of another module M which is adjacent to the first.

[0025] The coupling of each first element 3 with the corresponding second element 4 is achieved by means of opposing members which perform a mechanical action between the two mutually facing, juxtaposed modules M with the intention of causing the two modules M to be moved mutually closer or further apart by a pre-set distance in at least one main direction which is perpendicular to the facing side walls thereof.

[0026] Each first element 3, of the plurality which is integral with a wall P1 , comprises a body protruding outwards from the side wall thereof that ends in a head 31. The said head is supported by a stem 30 and is equipped with a front active surface 32 and flat surfaces 33 facing parallel to the external side wall P1 which are designed to face corresponding portions 43 of the internal side surface of a second element 4 belonging to a second module M which is juxtaposed and assembled to the first module.

[0027] The head 31 of the said second element is positioned inside the side wall P2 of the said second module M with the surfaces 33 thereof facing the portions of the flat surfaces 43 of the internal side wall of the side wall P2.

[0028] The latter features, at the second element 4 thereof, an opening 44 sized to house the stem 30 of the first element 3 bearing the head 31. An elastically flexible tab 45 is fastened to the body of the said second module M and is aligned with the said opening 44 so as to interact with the active surface 32 of the first element 3 when inserted in the said opening 44.

[0029] On each module M, each wall P1 is opposite a wall P2.

[0030] Through a square configuration of the modules M, this allows the complete paving to be made following two mutually orthogonal directions.

[0031] The grid modules M that make up the driveway grid paving are preferably made of a plastic material. They are mutually coupled and assembled by simply inserting the elements 3 into the elements 4 with an action consisting of simply fitting all the elements 3 on a wall P1 into the corresponding elements 4 present on the side wall P2 of the module M to be coupled.

[0032] The coupling between the active surface 32 of each element 3 and the flexible tab 45 of each element 5 has the function of "absorbing" the dimensional variation in a perpendicular direction to the side walls bearing the mutually juxtaposed and coupled elements 3 and 4, acting as a device for compensating thermal expansion in driveway grid paving.

[0033] The result is obtained by arranging the grid modules M for assembly when the environmental conditions are such as to give rise to a pre-calculated minimum expansion of the said modules at which the distance between the two facing and coupled side walls P1 and P2 corresponds to a distance (gap) D as shown in Figure 4a, with a maximum allowed thermal expansion of the modules at which the distance between the two facing and coupled side walls P1 and P2 is D=0.

[0034] In the condition shown in Fig. 4a the flexible tab 45 is not activated and does not produce a significant reaction against the corresponding active surface 32 of the head 31. While in the condition shown in Figure 7a, the distance between the facing side walls is D=0 and the flexible tab 45 is bent under the action exerted thereupon by the active surface 32, which expresses the maximum allowed thermal expansion, beyond which the undesired condition of direct contact between the external surfaces of the side walls P1 and P2 would occur, together with the relative transmission of the thermal expansion action to the structures of the juxtaposed modules M forming the grid paving.

[0035] In short, thermal expansions - over the entire driveway paving - in mutually perpendicular directions and perpendicular to the side walls facing the modules are compensated by the devices comprising the elements 3 and 4, which work by allowing each module M to undergo limited expansions with respect to every other module juxtaposed thereto in perpendicular directions to the juxtaposed walls.

Claims

CLAIMS1. A device for compensating the thermal expansion of driveway grid paving of the kind usually used to build driveway lawns or for gravel paving installed using a reinforcement system consisting of a kind of grid, most commonly formed of a set of prefabricated modules with a grid structure positioned and assembled together on the ground to form a single grid support body, each of the said modules (M), with a grid structure, is delimited around the perimeter by side walls (P1 ; P2) oriented vertically with respect to the grid support surface; the said side walls (P1 ; P2) are positioned facing the same side walls of the other modules (M) so as to form, once mutually juxtapositioned and coupled, the entire body of the grid paving; the said side walls (P1 ; P2,) are endowed with first elements (3) and second elements (4) for the mutual juxtapositioning and coupling which comprise, at each side wall (P1 ; P2) of each module (M), a plurality of first elements (3) and second elements (4); each first element (3) and each second element (4) of each module (M) is envisaged to couple with, respectively, a second element (4) and a first element (3) envisaged on a side wall (P2) and (P1) of another module (M); the coupling of each element (3) with the corresponding element (4) is achieved by means of opposing members which perform a mechanical action between the two mutually facing, juxtaposed modules with the intention of causing the two modules (M) to be moved mutually closer or further apart by a pre-set distance in at least one main direction which is perpendicular to the facing side walls, characterised by the fact that each first element (3) of a first module (M) comprises a body protruding from the side wall (P1) thereof which ends in a head (31) which is endowed with an active front surface (32) and flat surfaces (43) intended to face corresponding portions of the internal side surface of a second element (4) belonging to a second grid module (M); the said second element (4) is located inside the side wall of the said second grid module (M) and features an opening (44) made in the same side wall andsized so as to house the stem (30) of the first element (3) with the head (31) and comprises an elastically flexible tab fastened to the body of the second element (4) of the said second module (M) and is aligned with the said opening (44) so as to interact with the active surface (32) of a first element (3) inserted into the said opening (44) .

2. A device for compensating the thermal expansion of driveway grid paving according to Claim 2 characterised by the fact that every single module (M) is perimetrally delimited by pairs of consecutive side walls (P1) and (P2); the two consecutive side walls of each of the said pair is endowed with first elements (3) in the case of the first and second elements (4) in the case of the second.

3. A device for compensating the thermal expansion of driveway grid paving according to Claim 3 characterised by the fact that the grid modules (M) are made of plastic.

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