FR2640848A1 - Plastics film deposition on sloping ground surface - uses trolley-type machine to unroll strip layer of film on ground, with winch controlling upward and downward movement - Google Patents

Abstract

The method uses an unrolling machine (1) which moves alternately upwardly and downwardly over the slope in successive strip passes, following the line of the steepest gradient (S). Movement of the machine in both directions is controlled by means of a winding cable assembly (5). During passes in the upward direction (f), the machine deposits a strip layer of plastics film (F) on the slope surface. During downward passes, the machine rolls freely over the ground without depositing film. The tracks of successive upward passes are spaced from each other by a distance greater than the width of the film strip. USE - Deposition of film layer to protect and boost growth of seeded ground surfaces on steep inclines.

Description

METHOD AND INSTALLATION FOR DEPOSITING A FILM
PLASTIC ON HIGHLY INCLINED GROUND
The cultivation technique by sowing or planting under plastic film is having an interesting success because of its high yield, the film retaining the humidity conducive to the development of the plant while smothering weeds.

Various machines for spreading the film on the ground have already been proposed. They are generally adapted to be mounted - like a plow - on the so-called "three-point" carrying mechanism of an agricultural tractor, and to be moved by this tractor on the ground that one wishes to cover with plastic film.These machines generally include the following elements, arranged from front to back
- a pair of plowshares, called tracers, capable of digging into the ground a pair of parallel grooves, of shallow depth, the spacing of which is slightly less than the width of the film
- a rotary drum receiving the roll of film to deposit
- a pair of wheels, called plumbers (or tampers), intended to roll on the lateral edges of the film previously deposited on the ground in order to push these edges slightly into the grooves
- a pair of plowshares, known as covering, adapted to cover these same edges with earth so as to immobilize the film on the ground.

 A peeling machine of this type is described for example in the document FR-A-1 356 657.

Some machines are also provided with means for transversely cutting the film at the end of the row (see for example
FR-A-2 453 600), or even transverse cutting and covering the cut end (FR-A-2 580 146).

 If these machines give satisfaction under the usual conditions of culture, on a relatively flat and horizontal ground, it is not the same in certain particular applications, when the ground is strongly inclined; "sharply inclined" means a sloping ground whose line of greatest slope forms an angle greater than or equal to about 200 with the horizontal. Indeed, in such a terrain configuration, the tractor cannot be used correctly for obvious safety reasons (difficulty in carrying out the maneuvers, balance problems).

 However, there are different applications in which a strongly inclined ground is encountered. This is particularly the case for cultivation on hillsides and for horticulture on the flanks of holes dug in the relief to provide rapid communication routes (four-lane roads, motorways, high-speed rail lines). So, it is common to meet at the edge of highways soils with a gradient between 30 and 500, soils which must be covered with a plastic film to be then planted with shrubs.

 These steep soils are inaccessible to current equipment and removal techniques, the unwinding and installation of plastic films is done manually which, as is easily understood, requires a large staff while being slow, expensive and tedious .

 The present invention aims to solve this problem by proposing a method and an installation allowing this kind of operation to be carried out quickly and easily with a small staff.

 To this end, the process which is the subject of the invention, according to which the strips of film are placed side by side and arranged substantially along the line of greatest slope of the ground, is characterized in that the plastic film is supplied by a roller carried by a mobile unwinding machine, and which this machine is made to carry out successive strokes, alternately in the direction of ascent and in that of the descent, this substantially along the line of greatest slope of the ground, by pulling the machine in the upward direction using a cable and controlling its movement in the downward direction always using this same cable, so that during the races - say go - in a certain direction, the machine deposits the film on the ground while during the races - say return - in the other direction, the machine rolls freely on the ground without depositing the film.

 In a preferred embodiment, each return race has a trajectory which is offset laterally from that of the previous outward race by a distance greater than the width of the film, this trajectory substantially coinciding with that of the following outward race .

 Advantageously the outward strokes (during which the film is deposited) are carried out in the direction of ascent, while on the contrary the return strokes (during which the film is not deposited, the machine rolling freely on the ground) are carried out in the direction of descent.

 In a particular mode of implementation, after each outward stroke (at the top of the slope) the end of the strip of film which has just been deposited is cut - either manually or using an appropriate device equipping the machine -, the unrolling machine is raised above the ground, it is transported laterally by the distance corresponding to the offset between the trajectories (which was mentioned above), after which it is placed on the ground in order to the return race.

The installation for implementing this process, which also forms part of the present invention, is characterized in that it comprises
a) a mobile unwinding machine carrying a roll of plastic film and equipped with a pair of retractable carrying wheels capable of ensuring the rolling of the machine on the ground when they are in the active position, during said return stroke, and which can be retracted upwards with a view to said outward race
b) a device for moving said unwinding machine, which comprises a motorized winch receiving said traction cable.

Furthermore, according to a certain number of interesting but non-limiting characteristics of the invention - The unwinding machine comprises, arranged from front to rear (when we consider its displacement in the outward stroke)
- coupling means integral with the chassis of the machine
- a pair of steerable steerable wheels
- a pair of plowshares
- a drum receiving the film roll
- a pair of press wheels
- a pair of cover coulters.

- The supporting wheels are articulated on the chassis of the machine and are locked in each of their tilted positions (active or retracted upwards) by means of a ratchet lever.

- The unwinding machine is equipped, on the one hand with a stretcher fixed to the rear of the chassis, which allows the operator to maneuver the machine during return races, on the other hand with a steering lever which allows it to orient the steering wheels in order to steer the machine properly.

- The movement device of said unwinding machine is equipped with a crane for lifting this machine.

- This displacement device has the form of a self-propelled vehicle comprising a horizontal platform mounted on wheels, on which are mounted said motorized winch and said crane.

- The crane boom can pivot around a vertical axis.

- The motorized winch can also pivot around a vertical axis.

- The different movements of the winch and the crane are hydraulically controlled.

 Other characteristics and advantages of the invention will appear from the description and the appended drawings which represent preferred embodiments and embodiments.

On these drawings
- Figures 1 to 4 are very schematic views intended to illustrate the process according to the invention, Figure 1 showing in top view how the strips of plastic film are laid side by side, and Figures 2, 3 and 4 showing in side view the different main steps of the process
- Figures 5 and 6 are side views of the unwinding machine, shown respectively during a forward race (retractable load wheels) and a return race (load wheels bearing on the ground)
- Figure 7 is a top view of the unwinding machine of Figure 6
- Figures 8 and 9 are respectively front and top views of the movement device of the unwinding machine, this machine consisting of a specially equipped self-propelled vehicle.

 In FIGS. 1 to 4, a strongly inclined ground (S) is shown which constitutes the edge of a fast communication lane (VC), for example a motorway. This ground (S) is strongly inclined relative to the horizontal, for example by an angle of the order of 20 to 250.

 In the figures, the lines of bottom and top of slope have been designated by the references (A) and (B) respectively and by (F) the plastic film.

 As seen in Figure 1, according to the invention, the plastic film is deposited substantially in the direction of greatest slope (perpendicular to the lines (A) and (B)) in the form of strips placed side by side, with between them a reduced spacing. We have designated by (1) the width of the band and by (d) the center distance of the different bands (center distance which corresponds to the width of a band increased by the interval separating two bands).

 The installation for installing the strips comprises two main parts, namely an unwinding machine 1 and a movement device 2 for this machine 1; these parts are shown very diagrammatically in FIGS. 2, 3 and 4.

 The machine 1 comprises means known per se for depositing on the ground a plastic film (F) supplied by a roller carried by the machine; the device 2 is a vehicle placed at the top of the slope and equipped, on the one hand with a motorized winch 7, on the other hand with a crane 6. The winch 7 receives a cable 5 which is hooked to the front part of the unwinding machine 1.

 According to an advantageous characteristic of the invention, the machine 1 has retractable supporting wheels 3; these wheels 3 are retracted upwards during the laying of the film so as not to interfere with the work of the tracer and covering plowshares, or that of the press wheel; when in the active position, on the contrary, they allow the unwinding machine to roll freely on the ground, without removing the film.

The film strips are placed side by side on the slope (S) as follows
The operator (O, - responsible for working with the unwinding machine 1 is located at the bottom of the slope, and causes the retracting of the load wheels 3. A second operator (not shown) having charge of the device 2 is located near this device (or on it) at the top of the slope. It controls the winding of the winch 7 so as to pull the cable 5 upwards. As an indication, the cable winding speed is the order of 20 to 30 meters per minute. The operator (0) follows machine 1, directing it (using means which will be described later, with reference to FIGS. 6 and 7), the film (F ) takes place and is set up in the traditional way on the ground; it will be noted that during the ascent - outward stroke, represented by the arrow (f), figure 2 - the operator (0) walks on the film (F) which has just been tabled.

 When it has reached the top of the slope, near the device 2, the operator in charge of this device stops the rotation of the winch 7; the operator (O) cuts the end of the film and optionally covers it with soil (either manually or using means specially provided for this purpose on machine 1), then hooks the crane hook 7 to a lifting ring 9 carried by the chassis of the machine 1; by means of the crane, the boom of which is advantageously pivotally mounted about a vertical axis (arrow (j), FIG. 3), the machine 1 is moved laterally by a distance corresponding to the distance (d) and then rested on the ground; this movement is shown by the arrow (g) in Figure 1.

 Then takes place the return stroke of the unwinding machine 1; for this the operator (O) picks up this machine from the crane 6, causes the downward movement of the carrier wheels 3 so that they occupy their active position; the winch 7 is started in the direction of unwinding of the cable, at moderate speed.

The operator (0) controls the descent of the machine when empty (1 arrow (h), FIG. 4), keeping this machine in balance on the carrying wheels using a stretcher 12 which will be described later. The unwinding of the cable 5 takes place naturally in a regular manner, the cable developing on the machine a braking traction (H) insufficient to counteract the descent of the machine under the effect of gravity, but nevertheless sufficient to prevent a rapid descent and uncontrollable.

 When he arrived with the machine at the bottom of the slope, the operator places the end of the plastic film on the ground, and covers it with soil; it retracts the carrying wheels 3, and a new outward stroke, during which the film will be deposited can begin (arrow (f), Figure 1); this outward journey is made along substantially the same trajectory as the return journey which has just been carried out.

 We will now describe in more detail a preferred embodiment of the unwinding machine 1 (with reference to FIGS. 5, 6 and 7) and of the displacement device 2 (with reference to FIGS. 8 and 9).

 The unwinding machine comprises a chassis made of mechanically welded metal tubes or sections 10, this chassis having, when viewed from above, an approximately square shape. This chassis is provided at its front part (located to the right of the figures) with coupling means 11 comprising a metal bracket on which is mounted an eyelet 110 allowing the cable 5 to be hooked. As is well known on this kind, the chassis is equipped, from front to rear, with a pair of tracer coulters 14, with a rotary drum 18 receiving the film roll (F) to be deposited, with a pair of press wheels or tampers 15 and a pair of covering plowshares 16. These various members are suitably mounted on the chassis, using means suitable for those skilled in the art, for example by welding or bolting.

 On the rear part of the chassis is attached a stretcher 12 which, as has been said previously, helps the operator to control the balance of the machine on the carrying wheels during return races. At its front part, according to an advantageous characteristic of the invention, the machine is equipped with a pair of steered wheels 4; these preferably have a central cutting edge (as seen in Figure 7) so as to penetrate well into the ground. They are articulated around a horizontal axis 40, and their pivoting is ensured by means of a linkage of known type comprising rods 44 integral with the pivoting axes 40, a transverse rod 41 connecting the two rods 44, a pivoting lever 42 which can laterally move the rod 41 thanks to a light engaging in a finger carried by this rod, and an operating lever 17 (of the handlebar type) which can pivot around an axis 43 and transmitting this pivoting movement to the lever 42. Thus the operator, by pivoting the handlebar 17 to one side or the other causes the orientation of the two wheels 4 in one direction or the other, which allows him to steer the machine correctly, especially during races go.

 According to another very important characteristic of the invention, the machine is equipped with a pair of retractable carrying wheels 3. These are carried by a doubly bent pin 30 which is articulated in bearings 31 provided on the lateral side members of the chassis 10. The bent parts of the axis 30 therefore play the role of levers, and their pivoting is controlled by a rod 32 by means of a rod 33 whose other end is actuated by a locking ratchet lever (34) of known type, this pawl cooperating with a rack in an arc of a circle 35. As can easily be understood from the comparison of the two figures 5 and 6, when the ratchet lever 34 is in the raised position, the link 32 is pushed to the right and, correspondingly, the wheels 3 are raised; on the contrary, when the lever 34 is lowered, the carrying wheels 3 are supported on the ground, all of the members serving to lay the plastic film, namely the plowshares 14 and 16 and the press wheels 15 being on the contrary at -above the ground, in the inactive position.

 FIG. 5 shows how the plastic film is laid in the forward phase: the plowshares 14 dig a shallow groove in the ground; the film (F) is unrolled and deposited on the ground so that its lateral edges cover these grooves, the press wheels 15 drive the lateral edges into the grooves, and the plowshares 16 cover them with soil, which ensures immobilization of the film.

 It will be noted that above the chassis 10 is provided a bent spar 100 carrying an eyelet or ring 9 which allows the gripping and lifting of the machine 1 by the crane 6 equipping the device 2.

 An embodiment of this device 2 is shown in Figures 8 and 9. It is a van type vehicle having a pair of front steering wheels 22 and a pair of rear wheels 23, suitable drive members serving on the one hand to the movement of the vehicle and on the other hand to control the winch 7 and the crane 6; these known type members, not shown, are housed under a cover 8. The vehicle also has a driving cabin 20 which has glass walls allowing the driver to observe on the one hand the space located in front of the vehicle in order to allow normal driving on the road, on the other hand the rear and sides of the vehicle during the lifting and moving phases of the unrolling machine. The vehicle comprises a platform 21 on which are mounted, at the rear of the cabin 20, the winch 7 and the crane 6.

 The winch 7 comprises a winding drum 70 for the cable 5, which is mounted on a support 71, the latter being articulated around a vertical axis (Y-Y ') on a fixed base 700. A hydraulic motor 72, double direction of rotation, allows to drive the drum 70, either to wind the cable 5, or to unwind it. A double-acting hydraulic cylinder 74, the body of which is articulated on the platform 21 by an axis 75, makes it possible to control the rotation of the support 71 around the axis (Y-Y ') in one direction or in the other, by means of a part 73 integral with the support 71 and actuated by the rod of the jack.

 The crane 6 has a vertical column 61 whose base 60 can pivot relative to a fixed support 600 about the axis (Z-Z ') of the column. The boom 62 of the crane has a telescopic end 63 carrying the hook 64 for hooking the loads. The boom 62-63 is raised and lowered by a double-acting hydraulic cylinder 65, while the pivoting of the column 61 about its axis and controlled by a double-acting hydraulic cylinder 66 whose body is articulated by an axis 67 on the platform 21 and whose rod is engaged with a part 65 carried by the base 60.

 The hydraulic motor 72 as well as the various jacks 74, 66, 65 (and the jack not shown controlling the movement of the telescopic part 63) are supplied from a source of suitable hydraulic liquid housed under the cover 8, and are controlled by suitable means located in the cockpit 20.

 The device 2 therefore allows on the one hand by means of the motorized winch 7 to develop on the cable the tensile forces (F) necessary during the outward stroke, by winding the cable, and <H) necessary during the return stroke (unwinding of the cable), on the other hand by means of crane 6, to lift the machine when it has reached the top of the slope, to move it laterally by appropriate pivoting of the crane boom, and to put it back on the ground in view of the return race. Of course, after each of these operations, the vehicle is always advanced to the top of the slope, by a distance which corresponds substantially to the offset distance, with a view to the next operation.

 The possibility of pivoting the winch around the axis (Y-Y ') allows the cable to be drawn obliquely (with an angular offset relative to the line of greatest slope).

 It is understood that instead of providing an autonomous device, this device 2 could be replaced by a non-powered machine equipped with a winch and a crane, coupled to a tractor.

Claims (13)

 1. Method for depositing on a strongly inclined ground, according to strips placed side by side and arranged substantially along the line of greatest slope of the ground, a plastic film which is supplied by a roller carried by a mobile unrolling machine, characterized in that that this unwinding machine (1) is made to carry out successive strokes, alternately in the direction of ascent and in that of the descent and substantially along the line of greatest slope of the ground (S), this by towing the machine ( 1) in the direction of ascent using a cable (5) and controlling its movement in the direction of descent using this same cable (5), so that during races - say go in a certain direction (f), the machine (1) deposits the film (F) on the ground (S) while during the races - say return - in the other direction (g), the machine (1) rolls freely on the ground without depositing the film (F).  2. Method according to claim 1, characterized in that each return stroke has a trajectory which is offset laterally with respect to the preceding outward trajectory by a distance (d) greater than the width (1) of the film (F) , this trajectory substantially coinciding with the next outward travel trajectory.  3. Method according to one of claims 1 or 2, characterized in that the outward strokes (during which the film is deposited) are carried out in the direction of ascent, while on the contrary the return strokes (during which the film is not deposited) are made in the direction of descent.  4. Method according to claims 2 and 3 taken in combination, characterized in that after each outward stroke, at the top of the slope, the end of the film strip which has just been deposited is cut, the machine is lifted uncoiler (1) above the ground, it is transported laterally by the offset distance (d) after which it is placed on the ground for the return race.  5. Installation for implementing the method for depositing a plastic film on a strongly inclined floor according to one of claims 1 to 4, characterized in that it comprises  a) a mobile unwinding machine (1) carrying a roll of plastic film (F) and equipped with a pair of retractable carrying wheels (3) capable of ensuring the rolling of the machine on the ground when they are in the active position, at during said return race, and which can be retracted upwards for said outward race  b) a device (2) for moving said unwinding machine (1), which comprises a motorized winch (7) receiving said traction cable (5).  6. Unwinding machine (1) constituting the installation according to claim 5, characterized in that it comprises, arranged from front to rear (when considering its movement during the outward races)  - coupling means (11) integral with the chassis (10) of  the machine  - a pair of steerable steerable wheels (4)  - a pair of plowshares (14)  - a drum (18) receiving the film roll (F)  - a pair of press wheels (15)  - a pair of cover coulters (16).  7. Machine according to claim 6, characterized in that the supporting wheels (3) are articulated on the chassis (10) of the machine and are locked in each of their tilted, active or retracted positions, by means of a lever ratchet (34).  8. Machine according to one of claims 6 or 7, characterized in that it is equipped on the one hand with a stretcher (12) fixed to the rear of the chassis and making it possible to maneuver the machine during return races , on the other hand a steering lever (17) for orienting the steered wheels (4).  9. Movement device (2) constituting the installation according to claim 5, characterized in that it is equipped with a crane (6) for lifting the unwinding machine (1).  10. Device according to claim 9, characterized in that it has the form of a self-propelled vehicle comprising a horizontal platform (21) mounted on wheels (22-23), on which are mounted said motorized winch (7) and said crane (6).  11. Device according to one of claims 9 or 10, characterized in that the jib (62-63) of said crane (6) can pivot around a vertical axis (Z-Z ').  12. Device according to one of claims 9 to 11, characterized in that the motorized winch (7) can pivot around a vertical axis (Y-Y ').  13. Device according to one of claims 9 to 12, characterized in that the different movements of the winch (7) and the crane (6) are hydraulically controlled.