PROTECTION SCREEN FOR PRINT READERS

Abstract

The present invention relates to a protective screen for fruit crops defining a roof sized to cover at least one plant (1) or part of a plant bearing one or more fruits (3) or fruit buds to be protected, said screen comprising an element for receiving a support for suspending said screen, characterized in that said screen comprises a thermally reflective lower face (40), preferably made of aluminum. The screen will allow the thermal energy escaping from the ground to be transferred to the plant, and thus prevent the formation of radiative frost on these parts. The invention also relates to a method for protecting fruit crops against radiative frost, in particular vines. Fig. 3

Description

Title of the invention: PROTECTIVE SCREEN AGAINST SPRING FROSTS Technical field

[0001] The present invention relates to the field of devices for protecting fruit crops, and in particular grape buds, against radiation-type frosts.

[0002] The invention relates in particular to a protective screen having at least one metallized reflective thermal lower face to reflect the infrared rays escaping from the ground during a radiative frost episode, and to thus redirect them onto the herbaceous parts. Preferably, said screen also comprises an absorbent thermal upper face, and making it possible to accumulate the heat from the sun's radiation below said screen. The invention also relates to improved means of attaching said protective screen and a method of protecting fruit crops by means of said screen. STATE OF THE ART

[0003] Patent FR 2 843 276 B1 in the name of the present applicant describes a protective screen against the runoff of rainwater falling on bunches of grapes at advanced stages of maturity and close to harvest. This device illustrated in [Fig.l] and 2 of the present application consists of a plate 4 in the general shape of a double-sloped roof 4a, 4b, provided substantially in the central part of the edge 5 of the roof with an opening 6 bordered by two sides 9 and extended by an access slot 7 running along said edge 5 to one of the edges of the roof.

[0004] The slot 7 allows the engagement of a wood 2 of the vine stock up to the right of said opening 6, so as to form above the fruit or fruits to be protected 3 an inclined surface with a double slope permanently fixed by pinching on the wood 2. The sides 9 of the opening allow to ensure a good pinching of the wood and the fixing of the screen on the wood, that is to say on a branch of vine inserted through said slot up to the right of the opening. This screen is also designed with accordion folds 11, arranged parallel to the edge 5 in the slope areas 4a, 4b furthest from the edge, and on opposite sides 12. These accordion folding areas allow to adapt the length of each slope according to the space available between two woods as illustrated in [Fig.l].

[0005] This screen effectively protects the bunches of grapes from the rain, however it is not effective against radiative frost.

[0006] The present invention aims to propose a new protective screen to enable its use against radiation-type frosts, which in particular threaten vine buds in spring. Radiative frost occurs on clear nights and calm winds, when the ground loses heat accumulated during the day by emitting infrared radiation into the sky. When the ground temperature drops below freezing, moisture in the air begins to condense and freeze. Frost forms directly on objects close to the ground such as plants, grass, fruit crops, etc.

[0008] Radiative frost also generates an inversion of air layers naturally following an air temperature gradient decreasing with altitude. However, when the ground loses heat rapidly and generates radiative frost, a colder layer of air is formed at ground level and then finds a warmer layer of air about 2m above the ground. One of the mechanical solutions to protect fruit crops from radiative frost is to use turbines to mix the air layers, and thus increase the air temperature at ground level. This solution is of course very restrictive to put into practice, because it involves the installation of numerous turbines to protect an entire field of crops. In France, some wine estates use helicopters as air turbines, effectively mixing the air over an entire plot. Of course, this solution is not accessible to most winegrowers and farmers.

[0009] The present invention therefore aims to propose a new solution for protecting fruit crops, and in particular vine buds, from radiative frost. Description of the invention

[0010] The present invention provides a protective screen and a method for protecting fruit crops against spring radiation frosts. The invention relates in particular to the protection of vines, but can be used to protect other plants, and in particular other fruit crops such as kiwi, peach, apricot, etc. More particularly, the invention provides a protective screen defining a roof comprising a reflective thermal underside for reflecting infrared rays escaping from the ground. This protective screen makes it possible to redirect the thermal energy escaping from the ground so that it is absorbed by the plant it protects and to create a microclimate of increased temperature below the protective screen.

[0011] More particularly, the invention relates to a protective screen for fruit crops defining a roof sized to cover at least one plant or part of a plant bearing one or more fruits or fruit buds to be protected, said screen comprising an element for receiving a support for suspending said screen, characterized in that:

[0012] -said screen comprises a thermally reflective lower face, preferably made of aluminum.

[0013] In particular, the lower face of thermal reflective material is defined by a layer of metallized thermal reflective film and comprising a silver face and a gold face, and in which

[0014] - said silver face is arranged towards an external and lower side of the screen intended to face the ground to reflect infrared rays coming from the ground, and

[0015] - said golden face is arranged towards an upper part of the screen, and so as to absorb the heat from solar radiation.

[0016] In a preferred embodiment, said screen consists of a plate, and the screen further comprises a fixing support comprising a vertical rod connected on one side to said plate, preferably detachably and intended to be connected on the other side to a means for fixing a wood of said plant, and said support is configured to keep the plate a few centimeters from the wood fixed by said fixing means, preferably less than 15 centimeters or less than 10 centimeters.

[0017] Advantageously, said means of fixing to the wood of the plant is a spring clip and said rod of the support comprises a connection to snap into one of the branches of said clip. This support allows easy and rapid installation of the screen.

[0018] According to one embodiment, the plate incorporates an opening as a support receiving element, and the vertical rod of the support is provided with a crosspiece for supporting said screen, and so that the support is connected to said screen by inserting an upper part of the rod of the support through said opening, and up to abutment with the crosspiece.

[0019] In other embodiments, the plate incorporates a snap-on, screw-on, or push-fit connection as a receiving element for the support rod.

[0020] When the plate incorporates an opening as a support receiving element, said opening may be extended by a slot extending to an edge of the plate, and the vertical rod may incorporate at least two crosspieces. The screen will thus be fixed to the support by sliding the vertical rod at a height between the two crosspieces through said slot, and up to the right of the opening. This method of fixing between two crosspieces provides greater stability to the screen. Alternatively, said slot makes it possible to fix the screen directly to the wood of the plant without the use of the support.

[0021] In one embodiment, said vertical rod has a flat shape, and the opening has a substantially elongated shape and having a neck narrowing said opening at an intermediate portion of said opening.

[0022] In one embodiment, the plate is parallelepipedal in shape and has accordion folds on opposite sides of the plate, said folds making it possible to modulate the weight and / or the length of said sides.

[0023] In particular, the lower face of the screen made of thermally reflective material is defined by a layer of thermally reflective film chosen from a film of survival blanket or reflective thermal insulating film, and preferably being fixed with an intermediate layer of air, continuous or discontinuous.

[0024] Finally, the invention generally relates to a method for protecting fruit crops against radiative frost, said method being characterized in that it comprises a step of protecting a plant with a protective screen comprising a lower face made of reflective thermal material configured and installed to reflect infrared radiation emanating from the ground towards said plant. Preferably, the protective screen is produced as described above, and is fixed to the plant in proximity to one or more fruits or buds to be protected, and in particular less than 15 centimeters, preferably about 10 cm or 5 cm. Alternatively, wherein said screen is sized as a roof covering one or more plants and said screen is installed by means of one or more ground supports. BRIEF DESCRIPTION OF THE FIGURES

[0025] Other advantages, aims and particular characteristics of the present invention will emerge from the following non-limiting description of at least one particular embodiment of the devices and methods which are the subject of the present invention, with reference to the appended drawings, in which: • [Fig.l] illustrates the installation of a protective screen on the wood of a vine according to the state of the art. • [Fig.2] illustrates the design detail of the protective screen of [Fig.l] according to the state of the art. • [Fig.3] illustrates an example of installation of a protective screen of the invention according to an embodiment of the invention. • [Fig.4] illustrates an example of support for installing the protective screen of the invention according to the embodiment of [Fig.3]. • [Fig.5] illustrates a second embodiment of a support for fixing the protective screen of the invention. • [Fig.6] illustrates an embodiment of the protective screen of the invention optimized for its attachment by means of the support of figures 4 and 5. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention proposes a new solution for protecting fruit crops against radiative frost. The invention proposes in particular to protect a plant by means of a protective screen comprising a lower face made of reflective thermal material. The screen will make it possible to transfer the thermal energy escaping from the soil to the plant, and thus prevent the formation of radiative frost on these parts.

[0027] In addition, the screen will form a roof also limiting condensation of the ambient air. on the plant, and thus limit the layer of condensation likely to create a layer of frost. Depending on the means deployed to install this screen, it can be sized to cover at least one plant or several plants. The screen can be made of flexible, semi-flexible or rigid material, waterproof or not.

[0028] In a preferred embodiment of the invention, the screen is designed to allow its installation with a reduced investment. As seen in [Fig.3], in this embodiment the protective screen consists of a plate 4 configured as a roof sized to relatively individually cover one or more fruits 3 or buds of a vine 1, said plate having a thermally reflective lower face 40, preferably made of aluminum.

[0029] The lower face 40 of the plate 4 will have the effect of reflecting the infrared rays escaping from the ground 13, and redirecting them towards the fruits 3 or buds which it protects, as well as the parts of the plant and the atmosphere below said roof.

[0030] The protective screen will be fixed near the fruits 3 and buds to be protected using a support 20 or fixing means allowing said screen to be installed as a suspended roof without side walls. The screen will be sufficiently close to the parts of the plant to be protected to be able to generate an effective thermal concentration in the covered area, for example it will be fixed a few centimeters or tens of centimeters away. For the protection of the vine, the screen will for example be rectangular with dimensions of the order of 40 to 50 cm in length and approximately 30 cm in width.

[0031] The screen may also have an upper surface made of absorbent material, so that when the sun rises, the screen can absorb the heat and concentrate it in the area protected by said screen. In this embodiment, care will be taken to ensure a space of at least a few centimeters between said screen and the areas of the plant to be protected to avoid burning the latter.

[0032] Several embodiments can be envisaged for the protective screen, and in particular concerning its shape and its fixing. For example, the screen could be made as a double-sloped roof, and according to the shape and fixing characteristics described in patent FR 2 843 286 B1, and described above with reference to figures 1 and 2 of the present patent application. The screen could also form a flat or semi-flat roof of parallelepiped, circular, or conical shape with a circular or polygonal base. The shape characteristics of the roof are not limiting.

[0033] Once again, the essential characteristic of the screen for protecting against radiative frost is that said screen has a lower face 40 made of thermal material reflecting infrared rays. In a preferred embodiment, the screen is made of rigid or semi-rigid and waterproof plastic material, or of waterproofed cardboard and its lower face incorporates a layer of aluminum. Preferably, the screen has a continuous or discontinuous layer of air between the main material of the screen plate and the aluminum layer.

[0034] In a preferred embodiment, the screen is coated on a lower face with a polyethylene terephthalate film covered with an aluminum film, with a reflective silver face and an absorbent gold face, this film is for example a survival blanket film. The silver face of this film will of course be oriented downwards and to define the thermally reflective lower face 40 of the screen, and the gold side towards an upper part of the screen.

[0035] The silver face reflects infrared onto the buds and supporting wood, and the buds and supporting wood re-emit IR into the water vapor under the screen.

[0036] For its part, the golden face only reflects a part of the atmospheric radiation received, due to its brilliance cools very little and allows the majority of the radiation to pass through, thus generating a thermal accumulation under the screen.

[0037] This embodiment therefore allows:

[0038] - a reflection of up to 95% of infrared rays by the silver side of the film in the environment close to the herbaceous and woody parts which re-emit part of it;

[0039] - absorption of atmospheric radiation by the golden surface with low reflection, allowing thermal accumulation below the screen and its absorption for the buds or fruits protected by the screen.

[0040] Advantageously, it is thus possible to accumulate infrared rays coming from the sky and the ground below the screen. Preferably, in this embodiment, the screen is made of transparent plastic material to allow solar radiation to pass through to the reflective thermal film.

[0041] The buds of the vine and fruit trees have an adaptive capacity to resist a temperature of -5°C, this provided that they have 15 to 45 minutes necessary for the migration by osmotic pressure of the water contained in their cells towards the intercellular juice in order to prevent the crystallization of the latter. Cells emptied of their water will be more resistant to frost.

[0042] The screen of the invention makes it possible to gain this period of time at daybreak during the sudden and temporary drop in temperature. Indeed, the screen of the invention allows the accumulation of thermal infrared rays on the protected fruits or buds. Without wishing to be bound by a mechanism of action, it would seem that the molecular vibrations induced by the infrared rays in the cells of the herbaceous parts allow the cells to adapt quickly and resist frost. On the other hand, the screen protects against humidification by rain the day before and therefore keeps the buds dry during the drop in temperature at daybreak. As already mentioned, this screen is intended to be fixed close to the parts of the plant to be protected. In a preferred embodiment and illustrated in Figures 3 to 6, the invention proposes to fix the screen by means of a cross-shaped support 20 having a vertical rod 21, also called rising and at least one horizontal crosspiece 22. An upper part of this rising rod 21 is intended to be inserted into an opening 6 of the screen until it stops with said crosspiece 22. The screen will thus be supported by the crosspiece 22 in a horizontal plane.

[0043] In a preferred embodiment, said support is connected on one side to said screen in a detachable manner, and on the other side to a spring clamp 14 making it possible to pinch a wood 2 of the plant bearing the fruits 3 to be protected. By wood is meant any stem, twig or branch of the plant (woody or not) making it possible to fix the screen of the invention to said plant.

[0044] Several fixing means can be envisaged by those skilled in the art to connect said support 20 to the clamp 14, for example nailed, welded, glued etc. [Fig.4] shows a preferred embodiment of said support 20 integrating a crosspiece 22, and a connector 23 to snap into one of the branches of a spring clamp 14. This support 20 is manufactured from a flat rod profiled to form said connector 23, the rising rod 21 and the crosspiece 22. [Fig.5] illustrates a second embodiment of this support integrating a second horizontal crosspiece 22-bis, of slightly reduced length compared to the first crosspiece 22. This support can be made of metallic material or thermoformed plastic. The clamp can also include a transverse lug 15 allowing the clamp 14 to rest on the wood.

[0045] The support is in particular designed to be connected to the screen by means of the upper part of the rising rod 21 intended to be received in a receiving element of the screen, in particular in the opening 6 of the screen. The rod 21 is inserted into this opening 6 and slid up to the stop of the first crosspiece 22. In one embodiment of the plate 4, the central opening 6 is extended by an access slot 7 allowing said opening 6 to be inserted at different heights of the rising rod 21, for example between the two crosspieces 22, 22bis.

[0046] [Fig. 6] illustrates a preferred embodiment of the screen intended to be fixed with the fixing means illustrated in [Fig. 4] or 5. In particular, the central opening 6 has an elongated shape and has a neck c tightening said opening to an intermediate part to pinch the rod of the support. This elongated opening is particularly suitable for facilitating the insertion of the flat rod of the support, and for holding it in position without excessive play thanks to the neck. More particularly, the opening comprises a first opening 6a of substantially circular shape extended on one side by an access slot 7 and on the other side by a second circular 6b ​​of greater diameter than a diameter of the first opening 6a. The central opening 6 and the slot 7 are provided with raised sides 96, 97 making it possible to reinforce said elements.

[0047] As illustrated in [Fig.6], in this embodiment the plate incorporates also accordion folds 11 on opposite sides 12 of the plate. The accordion folds make it possible to modulate a length of the plate 4, and on the other hand, to generate an excess weight on each side of the plate causing said ribs of the plate to fall and slightly bend the latter when it is made of semi-flexible material.

[0048] The invention thus provides a protective screen that can be easily installed and uninstalled with simple means and with a reduced investment cost. Alternatively, the screen may be sized to cover one or more plants and be fixed by means of a support installed on the ground and making it possible to hold said screen above the plant or plants to be protected. The screen of the invention may also be produced as a net-type frame incorporating a lower layer of reflective thermal film, and be positioned above a row of plants to be protected using supports on the ground.

Claims

Claims

1. Protective screen for fruit crops defining a roof sized to cover at least one plant (1) or part of a plant bearing one or more fruits (3) or fruit buds to be protected, said screen comprising an element for receiving a support for suspending said screen, characterized in that: - said screen comprises a thermally reflective lower face (40), preferably made of aluminum.

2. Protective screen according to claim 1, in which the lower face (40) of thermal reflective material is defined by a layer of metallized thermal reflective film and comprising a silver face and a gold face, and in which - said silver face is arranged towards an external and lower side of the screen intended to face the ground to reflect infrared rays coming from the ground, and - said gold face is arranged towards an upper part of the screen, and so as to absorb the heat from solar radiation.

3. Protective screen according to claim 1 or 2, wherein said screen consists of a plate (4), and the screen further comprises a fixing support (20) comprising a vertical rod (21) connected on one side to said plate (4), preferably detachably and intended to be connected on the other side to a means for fixing a wood (2) of said plant, and said support (20) is configured to keep the plate (4) a few centimeters from the wood (2) fixed by said fixing means, preferably less than 15 centimeters or less than 10 centimeters.

4. Protective screen according to claim 3, in which said means for fixing to the wood of the plant is a spring clip (14) and said rod (21) of the support comprises a connection (23) to snap into one of the branches of said clip (14).

5. Screen according to one of claims 3 to 4, the plate (4) incorporates an opening (6) as a support receiving element, and the vertical rod (21) of the support is provided with a crosspiece (22) for supporting said screen, and said support (20) is connected to said screen by inserting an upper part of the rod of the support through said opening (6) and up to abutment with the crosspiece (22).

6. Screen according to one of claims 3 to 4, in which the plate (4) comprises an opening (6) as a support receiving element, said opening (6) being extended by a slot (7) extending to an edge of the plate, and said vertical rod (21) incorporates at least two crosspieces (22, 22-bis), and so that said screen is fixed to the support by sliding the vertical rod at a height between the two crosspieces through said slot and up to the right of the opening.

7. Screen according to one of claims 5 to 6, in which said vertical rod (21) has a flat shape, and the opening (6) has a substantially elongated shape and having a neck (c) narrowing said opening to an intermediate part of said opening.

8. Screen according to one of the preceding claims, in which the plate (4) is parallelepipedal in shape and has accordion folds (12) on opposite sides of the plate (4), said folds (12) making it possible to modulate the weight and / or the length of said sides.

9. Screen according to one of the preceding claims, in which the lower face (40) of reflective thermal material is defined by a layer of reflective thermal film chosen from a survival blanket film or reflective thermal insulating film, and preferably being fixed with an intermediate layer of air, continuous or discontinuous.

10. Method for protecting fruit crops against radiative frost, said method being characterized in that it comprises a step of protecting a plant with a protective screen comprising a lower face (40) made of thermally reflective material configured and installed as a roof over at least one plant, or part of a plant and for reflecting infrared radiation emanating from the ground towards said plant.

11. Method according to claim 10, wherein said protective screen is a protective screen according to one of claims 1 to 9, and which is fixed on said plant in proximity to one or more fruits (3) or buds to be protected.

12. The method of claim 10, wherein said screen is sized as a roof covering one or more plants and said screen is installed by means of one or more ground supports.

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