EP0508859A1 - Device for splicing an insulating and/or draining apron in a trench - Google Patents

Abstract

Sliding box element for positioning a film of insulating or draining material in a trench. The said box element comprises a front part for receiving a roll of film and a rear part for distributing the film in the trench. Between the front part (2) and the rear part (13), the box element comprises a splicing chamber (4) provided, at each end, with a pair of rollers (5-6, 7-8) mounted in the said chamber by means making it possible to vary the lateral separation of the rollers from a same pair between an active position in which the two rollers clamp the film (3) and a separated position in which the film runs freely between the rollers. <IMAGE>

Description

The invention relates to the installation of a thin film filtering or insulating material in a trench made in the ground and more particularly the problem of the connection between two successive films when the reel from which the film is unwound in the trench is in the trench itself.

In French patent 2,000,531 a method of placing such a film in a trench is described by means of a vertical drum carrying the film roll introduced into the trench at the rear of the excavating machine which digs the trench, the film being unrolled directly at its service location as the excavator progresses.

In the Dutch patent 82.04737 is described a cassette containing the film roll and which constitutes a sliding box at the rear of the excavating machine which serves both to guide the unwinding of the film and to maintain the opening of the trench during this unfolding.

One problem with this type of technique is the connection between two successive films and in particular the maintenance of sealing in the junction zone between two successive films.

This problem is solved according to the invention by the fact that the sliding box which contains the film roll is extended by a connection chamber provided at its ends with two pairs of rollers synchronized two by two and mounted on devices making it possible to vary the lateral spacing between two rollers of the same pair between two positions, namely a position of maximum spacing in which the passage of the film is free and a pinch position in which the film is driven by the two rollers of the same pair.

Thus during the installation of a reel as the excavating machine progresses which pulls the sliding laying box inside the cut, the film can pass freely from the magazine to the exit zone of the box through the connection chamber.

When the film supply magazine is exhausted, the machine is stopped, a new reel is put in place in the magazine while in the connection chamber the pair of rollers close to the outlet of the box has pinched and immobilized the end of the previous film and the pair of rollers near the magazine causes the initiation of the next film towards the end of the previous film. A special connection piece is then introduced into the connection chamber and joins the two ends of the films together.

After this operation, the two pairs of rollers in the connection chamber can be moved aside and allow the free passage of the film to continue laying as the excavating machine progresses.

The invention thus makes it possible, by simple means, to work practically continuously and essentially to make repairs to the film being laid when it has been degraded.

This possibility of intervention on the film inside the trench makes it possible to envisage using the process in trenches of great depths (more than 6 m) which was previously excluded.

The invention will be better understood with the aid of the description which follows of nonlimiting exemplary embodiments with reference to the appended drawings in which:

Figure 1 is a general schematic view from above of a sliding box according to the invention.

FIG. 2 is a view in vertical section along line II-II of FIG. 1.

Figures 3 to 8 schematically show a top view of the connection operations between two films using a sliding box according to the invention.

Figures 9 and 10 show a schematic sectional view of a first embodiment of a connecting piece between two films.

Figures 11 to 14 schematically show in section the connection between two films with a second example of a connecting piece.

Figure 15 is a schematic sectional view of another embodiment of the connection between two films.

Figures 16 to 18 show alternative embodiments of the front part of a sliding box according to the invention in schematic view from above.

FIG. 19 shows an alternative embodiment of the rear part (outlet zone) of a sliding box according to the invention in schematic view from above.

The machines used for digging trenches and installing a draining or insulating screen are well known. They are generally constituted by a tracked vehicle carrying a steerable excavating chain or by a tractor pulling a cutting wheel, the assembly being followed by a box sliding in the trench intended for the installation of an insulating or draining film, of a perforated pipe forming a drain at the bottom of the excavation and the discharge of draining materials such as gravel gravel, porous concrete or bentolite.

Machines of this type being well known will not be described in more detail nor shown in the drawings. This description will mainly concern the structure of the sliding box, whether or not coupled behind the excavator machine.

According to the invention, the sliding box has a structure in three parts: a front part constituting a magazine magazine for the film to be unrolled, an intermediate part called the connection chamber and a rear part constituting the zone for leaving the film in the trench. .

Figures 1 to 8 schematically illustrate an exemplary embodiment of a connection operation using a box according to the invention

In this example, the front part 2 of the box 1 constitutes the receptacle for a roll 3 of film mounted vertically inside the box. The roller 3 is for example mounted with free rotation on a mandrel carried by bearings, one located at the bottom of the box and the other at its upper part. Preferably, the upper bearing is removable to allow the introduction and exit of the rollers. Advantageously, when the roller 3 is in place in the magazine 2, the latter is closed by a centering template which ensures a regular and straight course of the roller.

At the exit from the magazine 2, the side walls of the box 1 tighten and constitute a connection chamber 4. At the entrance to this chamber 4 two vertical rollers 5 and 6, which can be motorized, are mounted in bearings so to be able while turning on themselves to be moved laterally in the direction of one another for example under the action of jacks not shown. If they are driven, the two rollers 5 and 6 are counter-rotating and synchronized so that when they are supported on the film 3, their respective movements produce on said film no undesirable tension but only a uniformly rectilinear traction in the direction from the outlet of the box.

At the rear of the chamber 4, a second pair of rollers 7 and 8, identical to the first and mounted in the same way, also makes it possible to act on the drive of the film 3.

In FIG. 2, the rollers 5-6 and 7-8 have been shown in the form of a set of rollers juxtaposed on a common axis with interposition of bearings between the rollers of the same axis.

As a variant, the rollers of the same axis can be separated by collars surrounding the axis and intended to ensure the mounting of the axis on cylinders integral with the wall of the box.

It is understood that when they are in the retracted position near the wall of the box which carries them, the rollers 5 and 6 are inactive and allow the film 3 to pass freely, and any technically necessary excess thickness.

When they are in abutment against each other on either side of the film 3, they guide and / or drive them towards the outlet of the box.

A servo-control allows the two pairs of vertical rollers 5-6 and 7-8 to be operated together or separately. The rollers 5, 6, 7, 8 are normally vertical in the working position. It may however be useful to allow them to take an oblique position, in particular when it is necessary to compensate for differences in stretching of the film between its upper part and its lower part in the trench.

To this end, according to an advantageous variant of the invention, the rollers 5, 6, 7, 8 are each mounted on a beam which is itself pivotally mounted around a horizontal axis disposed at the bottom of the box and means are provided to allow each beam to be immobilized individually in a plurality of different positions according to the needs of the site. In Figure 2, there is shown in dashed lines an oblique position of the roller 5 and the arrows show the possible directions of pivoting of the rollers 5-6 and 7-8 on either side of the vertical.

The outlet of the chamber is closed by a transverse partition 9 provided with a vertical slot 10 sufficiently wide to allow the free passage of the film 3 and means of connection between two successive films which will be described later.

The two edges of the slot 10 are provided with flexible lips 11 and 12 which seal the connection chamber 4, in particular against the penetration of water or mud which may be in the trench.

At the rear of the connection chamber 4, the box 1 includes an outlet zone 13 which advantageously includes a deflector flap 14 articulated on an axis 15 located on one or the other side wall of the box. This deflector ensures correct application of the film 3 on the edge of the trench.

The outlet zone 13 can advantageously receive a guide 16 for the descent of a draining collector and a hopper 17 for the pouring of bulk material into the trench.

The sliding box according to this first exemplary embodiment operates in the following manner:

When starting a new roll, after it has been placed vertically on its bearings in the magazine 2, the end of the film 3 is passed between the first pair of rollers 5-6, the rollers 5-6 are brought into contact with the film and the latter is driven towards the exit zone. The film 3 then passes between the second pair of rollers 7-8 which are then brought into contact and provide, in cooperation with the first pair, very regular and rectilinear guidance and / or driving for the unwinding of the film.

When the film ends, the passage of the end of the film between the first pair of rollers 5-6 is detected, for example by means of an alarm strip secured to the end of the film. This alarm strip may for example be a metal strip the passage of which in front of a sensor will trigger an audible or light alarm. It can more simply be a colored strip giving a visual indication of the end of the film.

The machine is then stopped and the first pair of rollers 5-6 discarded to allow the installation of a new reel in magazine 2.

The start of this reel is passed between the first pair of rollers 5-6 and the rollers 5-6 are brought together to cause the start of the new film near the end of the previous film kept waiting in chamber 4 by the second pair of rollers 7-8 which will have been immobilized upon detection of the end of coil signal.

The connection between the two ends of the film 3 is carried out using special connection pieces inserted vertically in the connection chamber 4.

In the example shown in FIGS. 1 to 8, each end of the film 3 is provided with a vertical rod 18 or a bead which forms a support piece for the connection piece 19.

This vertical rod can be molded in one piece with the edge of the film or attached in a gusset formed by folding the film around the rod and gluing it as shown in FIG. 9.

The connecting piece 19 shown in section in FIG. 10 is a profile made of molded or injected material which comprises two oblong slots 20 and 21 open at their opposite ends by a slot 22, 23 for the passage of the film 3. The slots 20 and 21 are deep enough to allow easy threading of the connecting piece 19 on the two rods 18 of the ends of the two successive films.

Once this operation has been carried out, the two films are tensioned by driving the two pairs of rollers 5-6 and 7-8 in opposite directions. The empty space of the lights is optionally filled by injecting a sealant such as bentolite or quick setting polymer.

Advantageously between the two slots 20 and 21, the profile has a central slot 24 provided over its entire height with radial channels opening into the slots 20 and 21 and which is used for injecting the sealant.

When the latter is taken, the pair of rollers 7-8 close to the rear zone of the box is moved aside to allow the connection piece 19 to pass, then the rollers are rested on the film 3, the course of which resumes.

According to an alternative embodiment of the invention shown in Figures 11 to 14, the film is devoid of rod or end bead, or the connection is made following a rupture of the film 3.

In this case, after having stopped driving the pair of rollers 7-8, the two film ends 3 are superimposed with considerable overlap.

Two male-female parts 25-26 having concentric serrations along their contact plane and provided with a central recess 27 forming a housing for a key 28, are placed on either side of the film 3 and maintained in support against each other for example by claws provided inside the connection chamber 4. A cutting tool is lowered into the central recess 27 to cut the overlapping part of the screen 3. Then a key 28 of shape corresponding to that of the recess 27 is put in place and ensures the locking one on the other of the two parts 25 and 26 and the pinching of the two ends of film 3.

Alternatively, the key 28 has a central recess for injecting a sealant.

As before, the rollers 7-8 are separated to allow passage of the connecting piece 25-26, then brought back into contact for the continuation of the unwinding of the film.

Of course, the invention is not limited to the means of connection between films which have been described in relation to FIGS. 5 to 12. The connection chamber according to the invention allows any type of means to be used to ensure the joining of two film ends between them inside the trench.

It advantageously makes it possible, thanks to its motorized rollers 5-6, 7-8 capable of turning in two opposite directions of rotation, to ensure good stabilization of the two film ends which facilitates all the subsequent operations of joining the films, for example it is possible to use, instead of the female male parts 25 and 26 of the exemplary embodiment of FIGS. 9 to 12, two jaws which compress the two ends of the film in their region of covering and, while maintaining compression, an ultrasonic welding tool or any other known chemical or thermal means can be lowered along the film by an opening provided in the contact plane of one of the compression jaws to ensure the weld between the two films over the entire height of the trench.

A schematic example of such a device is shown in Figure 15, in which we see the two jaws 39 and 40 with their smooth bearing faces, the opening 41 for passage of the welding tool 42 in the jaw 39 , and the two overlapping films 3a, 3b pinched between the jaws 39 and 40.

In Figures 16 to 18 are shown alternative embodiments of a sliding box comprising a connection chamber according to the invention.

In FIG. 16 is shown a variant of the film supply magazine 2 in which the latter is wound on two spools 29-30 distant from each other, the two spools being wrapped by a reel strip 31 forming a belt , in order to avoid the phenomenon of self-tightening of the film 3 during its unwinding.

This arrangement allows a large film storage capacity in a relatively small space.

In FIG. 17 is shown a magazine 2 in which the film 3 is stored in the form of an accordion folding 32. In this case, a pressure plate associated with a spring ensures the progression of the film accordion in the magazine during its reeling.

As a variant and as shown in FIG. 17, the magazine is provided with an inflatable membrane 33 which ensures that uniform pressure is exerted on the accordion during its unwinding. This arrangement facilitates reloading of magazine 2 after deflating the membrane 33

In Figure 18 is shown another alternative embodiment of the film supply. In this case, the front part 2 of the box is not strictly speaking a magazine for the film stored vertically but a part for receiving and guiding the film unwound from a reel located outside the trench.

In this case, the film 3 is folded on itself around three substantially vertical fixed guides carried by the box. This particular arrangement for receiving and guiding the film is the subject of a separate patent application filed on the same day as the present application by the same applicant.

FIG. 19 represents a variant of the outlet zone 13 of the box in the case where there are two films to be deployed at the same time, each of them having to be pressed against a wall of the trench.

In this case, the outlet zone 13 carries a central fixed beam 34 provided on its rear face with two vertical distribution rollers 35 and 36 associated with two pairs of non-return scraper seals 37 and 38. In this case, the films 3 and 3 ′ pass directly from the pair of rollers 7-8 rear of the connection chamber 4 over the distribution rollers 35 and 36, the partition 9, the seal 11-12 and the deflector flap 14 of the exemplary embodiments previous ones are then deleted.

Of course, to ensure the supply of two separate films, the receiving chamber 2 must include a double bearing device to accommodate two juxtaposed rollers.

The invention is not limited to the exemplary embodiments which have been described above. Other variants and details of execution can be used without departing from the scope of the invention.

for example, the rollers of the connection chamber are coated with a slightly compressible material such as rubber in order to closely match the film over its entire height and ensure that the film is driven without slipping.

The box can be equipped with projectors to visualize the operations taking place inside.

The box can be equipped with cameras transmitting to a display screen located in the piloting, the images of the interior of the box, which allows remote monitoring of the progress of works.

The box can be equipped with a pump sucking the charged water which can possibly infiltrate despite the presence of the seals at the outlet of the connection chamber.

The bottom of the box can be fitted with a removable drawer for receiving and removing sludge and the like.

to limit the friction of the front part 2 forming a magazine for the rolls of film against the walls of the trench, said front part of the box can be of circular section.

Claims (21)

Sliding box for placing a film of insulating or draining material in a trench, said box comprising a front part for receiving a film roll and a rear part for leaving the film in the trench, characterized in that '' between the front part (2) and the rear part (13), the box comprises a connection chamber (4) provided at each end with a pair of rollers (5-6, 7-8) mounted in said chamber by means for varying the lateral spacing of the rollers of the same pair between an active position where the two rollers pinch the film (3) and a spaced position in which the film passes freely between the rollers. Sliding box according to claim 1, characterized in that the rollers (5-6, 7-8) are rotated, each pair of rollers being independent of the other. Sliding box according to claim 2, characterized in that the drive of each pair of rollers (5-6, 7-8) is reversible. Sliding box according to any one of the preceding claims, characterized in that the rollers (5-6, 7-8) are each mounted on a beam which is itself pivotally mounted around a horizontal axis disposed at the bottom of box and in that said box comprises means for immobilizing each beam individually in a plurality of different positions. Sliding box according to any one of Claims 1 to 4, characterized in that the connection chamber (4) is closed at its rear part by a partition (9) provided with a slot (10) whose edges carry two lips sealing (11, 12). Sliding box according to any one of Claims 1 to 5, characterized in that the outlet zone (13) located behind the connection chamber (4) is provided with a deflector flap (14) articulated on an axis (15) carried by one or the other of the walls of the box. Sliding box according to any one of Claims 1 to 6, characterized in that the outlet zone (13) carries a guide (16) for the descent of a draining collector. Sliding box according to any one of Claims 1 to 7, characterized in that the outlet zone (13) carries a hopper (17) for the discharge of bulk material into the trench. Sliding box according to any one of Claims 1 to 8, characterized in that the front part (2) is provided with bearings for receiving the mandrel of a film roll arranged vertically. Sliding box according to claim 8, characterized in that the front part (2) is of circular shape in section. Sliding box according to any one of claims 1 to 8, characterized in that the front part (2) comprises two pairs of bearings for receiving the mandrel of two rolls of films juxtaposed vertically. Sliding box according to any one of Claims 1 to 8, characterized in that the front part (2) constitutes a magazine for a film (3) folded in accordion (32). Sliding box according to claim 12, characterized in that the front part (2) comprises means for applying uniform pressure to the film (3) folded in accordion. Sliding box according to claim 13, characterized in that the front part (2) comprises an inflatable membrane (33). Sliding box according to any one of Claims 1 to 8, characterized in that the front part (2) has two coils (29-30) spaced from each other and wrapped in a reel strip (31) forming a belt on which the film (3) is wound. Sliding box according to any one of Claims 1 to 8, characterized in that the front part (2) constitutes the zone for receiving and guiding a film (3) unwound from a reel located outside of the trench. Connection system in a trench of two ends of a film of insulating or filtering material using a sliding box according to any one of Claims 1 to 16, characterized by the use of a connection piece ( 19, 25-26) inserted vertically in the connection chamber (4). Connection system according to Claim 17, characterized in that each end of the film (3) comprises a vertical rod or bead (18) cooperating with the oblong openings (20, 21) open at their ends of a connection piece (19 ). Connection system according to claim 18, characterized in that the connection piece comprises a central lumen (24) connected to the oblong lumens (20-21) by radial channels for the injection of a sealant. Connection system according to claim 17, characterized in that the connection piece is made up of two male-female parts (25-26) having matching serrations along their connection line and provided with a central recess (27) forming a housing for a key (28). Connection system in a trench of two ends of a film of insulating or filtering material using a sliding box according to any one of Claims 1 to 16, characterized by the use in the connection chamber (4 ) of two jaws (39, 40) compressing the connection zone of two ends (3a, 3b) of film, an opening 41 being provided in the contact plane of one of the jaws (39) for the passage of a welding tool (42).

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