FR2729536A1 - Polyethylene@-based plastic film covering material for agricultural crops e.g. ridge-grown asparagus - Google Patents

Abstract

The covering material is a polyethylene-based plastic film with parallel tubular edges (3) made from the same or a different material, each containing a rod or cord (4a,5a). The ends of the rods or cords are attached by elastic tensioners (6) to pegs (7) driven into the ground. The edge tubes can also have holes at intervals along their length for additional tensioners (8) and fixing pegs (9). The rods or cords can be made from a rigid or supple material, and have loops on their ends for fastening to the tensioners.

Description

DEVICE FOR FIXING AND HOLDING A FILM
PROTECTIVE COVERING AND COVERING FOR
AGRICULTURAL CULTURE
The invention relates to the technical sector of the means used for covering arable land and established in the form of tarpaulins or films.

 We already know, to ensure the protection of cultivated areas and promote the growth of crops, the use of plastic films based on polyethylene. These films which constitute both a protection but also allow to create an environment favoring growth, are of a low cost price. These films are intended to remain permanently for a long period from the working of the soil with sowing until the harvest. They are therefore subject to constraints linked to a climatic environment, but they must remain in place for the entire period desired.

 Various tarpaulin films have thus been produced. It has been proposed for example in French patent 2,689,726 plastic films having at their longitudinal ends extruded pipes which can be obtained jointly by extrusion with the manufacture of the films or be attached and fixed in any suitable manner. These pipes have the function of allowing the insertion of a liquid or solid ballast. Thus, after laying the film manually on the cultivated area, the pipes are filled with ballast.

 Considering this solution, it was found that it was impractical, resulting in many troublesome operations for the operator to insert the weights, regardless of the impractical aspect for harvesting the crops, and in particular asparagus which is one of the particular applications of this type of film. We must indeed remove the ballast to lift the film and have access to the product to be harvested. This process is tedious and painful when carried out over a large length of cultivated land.

Other solutions have been sought and in particular by the applicant who proposed, in the French patent application
N. 94.09725, a particular tarpaulin film whose ends arranged beyond the pipes are arranged to be buried on the ground directly during the mechanical laying of the film on the crops to be protected. This solution is advantageous and perfectly reliable when it is subjected to climatic constraints in particular of strong winds.

 However, in the context of a simplification of production and reducing the manufacturing cost of this bachage film, the applicant is interested in another solution having the same function of protecting crops, and which is perfectly reliable whatever climatic conditions and easy use during harvest.

 These and other objects will become apparent from the following description.

 According to a first characteristic, the device for fixing and maintaining a protective and covering covering film for agricultural cultivation, the film being of the type comprising two parallel pipes established over its length and each authorizing the insertion of a cord, this film being made of plastic material based on polyethylene, the device being remarkable in that the ends of the cords are associated with tensioners, of high elastic capacity, fixed to ground pegs, and in that the along the longitudinal sides of the film, complementary fastening zones are produced using tensioners associated with the cords, said tensioners being fixed to lashing stakes, the fixing of the film allowing it to be used in the manner of a tent to adapt to climatic conditions.

 These characteristics and others will become apparent from the following description.

To fix the object of the invention illustrated without limitation to the figures of the drawings where
Figure 1 is a perspective view of the device ensuring the holding and maintaining of the bachage film according to the invention
Figure 2 is a longitudinal sectional view along the line
AA of figure 1, the film being lifted by the wind
Figure 3 is a cross-sectional view along the line
BB of figure 1, the film being in a laying situation under normal climatic conditions.

Figure 4 is a cross-sectional view along the line
BB of figure 1, the film being subjected to climatic conditions of strong winds.

 In order to make the object of the invention more concrete, it is now described in a nonlimiting manner in the figures of the drawings.

 The bachage film, according to the invention, is referenced as a whole by (1). It is made of plastic material based on polyethylene. It presents, directly formed or attached, two parallel pipes (2 - 3) established longitudinally along the length of the film, these pipes being of the same material as the film itself or possibly being of another nature. The tarpaulin film is intended to cover crops established in the form of embankments for example, in particular in the context of the cultivation of asparagus. This film is therefore produced over a very long length depending on the nature of the cereal crops.

 According to the invention, the bachage film is stowed in the following manner. Inside each pipe (2 - 3) is introduced a cord (4 - 5) passing entirely through each pipe projecting from the ends thereof. Each cord is established in the form of a flexible or rigid material and has, at its ends (4a - 5a), hooking means (4b - 5b) in the form of loops for example allowing the attachment of tensioners (6) to high elastic capacity. Each tensioner (6) is fixed relative to the ground by means of a stake (7) or hook buried in a substantial manner to allow an excellent hold and stowage. Along the longitudinal sides of the film, additional fixing and securing zones are provided using tensioners (8) thus arranged in a transverse plane while also being secured to stakes (9) buried on the ground. (8) are fixed in any suitable manner to the cord (4 - 5) passing through the pipes of the covering film, for example by interlacing, in the form of knots (8a), or other connecting means. The longitudinal pipes of the covering film then have openings (2a - 3a) allowing the lateral overflow of the various tensioners (8). The number of tensioners arranged laterally and along the film is a function of the length of the film. The device for fixing and holding a covering film, according to the invention, on a crop is therefore of a very simplified design and allows the film to be used in the manner of a tent canvas. When the weather conditions are good, as shown in Figure 3, the film normally follows the cultivated area such as embankment and the tensioners (6 8) are not stressed.In case of wind, it can rush into the space (e) formed between the slope and the film by lifting the latter. However, by the judicious arrangement of the various tensioners (6 - 8), on the one hand at the ends of the bachage film in its length and on the other hand transversely, the latter is always kept in position in recovery of the cultivated soil. When the unfavorable climatic conditions cease, the bachage film naturally falls by gravity on the cultivated area, and the tensioners are no longer stressed.

 The desired function, for this covering film and its holding and securing device, is essentially to ensure, in all circumstances, the recovery of the cultivated area, and not mainly an isothermal function capable of creating, under the film. , an ambient temperature significantly different from that of the outside environment.

 Without departing from the scope of the invention, the various cords (4 - 5) passing through the pipes may also have a certain elasticity to allow a very satisfactory adaptation of the covering film and to take account of its length and the effects of wind which may vary.

The invention is simple to carry out. The film and the fixing device are installed as follows
The film can be positioned on the culture area to be covered either manually or automatically. The cords are previously introduced into the film pipes. Then just grab their end zones or intermediate tensioners to secure them to the ground using stakes. This last operation can be carried out as the film unfolds or after.

Claims (5)

-1- Device for fixing and holding a protective and covering tarpaulin film for agricultural cultivation, the film being of the type comprising two parallel pipes (2 - 3) established along its length and each allowing the insertion of '' a cord (4 5), this film being made of plastic material based on polyethylene, the device being characterized in that the ends (4a - 5a) of the cords (4 - 5) are associated with tensioners (6), of high elastic capacity, fixed to stakes (7) for securing to the ground, and in that along the longitudinal sides of the film, additional fixing zones are made using tensioners (8) associated with the cords (4 - 5), said tensioners being fixed to stakes (9), the fixing of the film allowing it to be used in the manner of a tent canvas to adapt to climatic conditions. -2- Device according to claim 1, characterized in that the cords (4 - 5) are made of flexible or rigid material. -3- Device according to claim 1, characterized in that the ends (4a - 5a) of the cords (4 - 5) are established in the form of loops to cooperate with the fixing of the end tensioners (6). -4- Device according to claim 1, characterized in that the longitudinal pipes have openings (2a - 3a) allowing the lateral overflow of complementary tensioners (8) arranged on either side of the film. -5- Device according to claim 4, characterized in that the tensioners (8) are fixed to the cords (4 - 5) in the form of knots, interlacing or other.