EP0965697B1 - Method and apparatus for filling trenches - Google Patents

Description

The present invention relates to a backfilling method a trench and a device for the implementation of this process.

We know that, for the transport of fluids over long distances, gas, for example, or petroleum, we use pipes such as pipelines, which it is customary to protect by burying them in trenches. Backfilling of these trenches is usually done by reusing the cuttings from the trench, after screening them, and a device is generally used for this purpose screening and backfilling, which is carried laterally by a tractor, which moves along the trench.

A screening and backfilling device of this type usually includes a hopper to receive materials used for backfilling, a continuous conveyor arranged below the hopper, and a sieve system vibrators fed by the continuous conveyor and intended for fill the trench with successive layers of material having a determined particle size. The whole is united a frame, which itself is supported, cantilevered above of the trench to be backfilled, by an arm carrying a tractor or similar device. We can thus backfill a trench, possibly by carrying out multiple passes with one device, with different layers of the same material or of grain size materials different.

Such a device is described for example in detail in U.S. Patent No. 4,955,756, but many variations exist on the market and the Applicant has itself proposed various improvements to a device this type, which are the subject of his European patent application No. 0 709 526.

These devices are entirely satisfactory, but are are relatively expensive because they are self-propelled.

The chassis also has the disadvantage of being cantilevered relative to the tractor.

Finally, the filling of the hopper with the material of backfilling must be carried out using a machine independent of the backfill system as disclosed in US-A-4,861,461.

To remedy these drawbacks, the invention proposes no longer to use a self-powered backfill system, but a screening and backfilling system towed by a hydraulic excavator of a conventional type, which ensures in addition to loading the device with backfill material screening, the hydraulic excavator-device assembly screen can move as well on the cord cuttings from the trench, only on a track laid out the other side of it.

The invention therefore has for first object a method of backfilling a trench, in particular using spoil from the digging of this trench, this process of towing with a shovel hydraulic, parallel to the trench, a chassis mounted on wheels or on tracks, supporting a hopper of load equipped with a grid at its lower part, load this hopper with backfill using the hydraulic shovel, to transfer the material by gravity backfill through the grid on a vibrating screen placed below the hopper, then on a conveyor continuous, placed below the vibrating screen on the chassis, transverse to its direction of movement, the sieve vibrating and the conveyor being driven by means motors carried by the chassis, and to pour the material from laterally filling in the trench using the conveyor.

• un châssis monté sur roues ou sur chenilles et équipé d'un moins un organe de liaison avec une pelle hydraulique apte à le remorquer ;
• sur ce châssis, une trémie de chargement du matériau de remblayage équipée d'une grille à sa partie inférieure ;
• au-dessous de cette grille, un tamis vibrant ;
• au-dessous de ce tamis vibrant, un convoyeur continu dont une extrémité fait saillie latéralement par rapport au châssis ;
• et des moyens d'entraínement du tamis vibrant et du convoyeur portés par le châssis ;

   ce dispositif étant caractérisé en ce que le convoyeur est mobile en translation sous la sollicitation d'un vérin à double effet, de manière à pouvoir faire saillie d'un côté ou de l'autre du châssis.The invention also relates to a device capable of being towed, for the screening of a backfill material and the pouring thereof into a trench, and intended for use in the process defined above, this device being characterized in that it comprises:

• a chassis mounted on wheels or on tracks and fitted with at least one connecting member with a hydraulic shovel capable of towing it;
• on this chassis, a hopper for loading the backfill material equipped with a grid at its lower part;
• below this grid, a vibrating screen;
• below this vibrating screen, a continuous conveyor, one end of which projects laterally with respect to the chassis;
• and means for driving the vibrating screen and the conveyor carried by the chassis;

this device being characterized in that the conveyor is movable in translation under the stress of a double-acting cylinder, so as to be able to project from one side or the other of the chassis.

The link with the hydraulic excavator can be a simple drawbar articulated at one end on the chassis and at its other end on the hydraulic shovel.

The hopper is preferably pivotally mounted by relative to the chassis, at least one cylinder being provided on the frame to straighten it by pivoting with respect to this, in order to evacuate the largest constituents of the backfill material not passing through the grid.

This can be made up of simple bars arranged in parallel, for example parallel to the direction of movement of the device.

As for the conveyor, it is preferably arranged transversely to the direction of movement of the chassis, under the stress of the hydraulic shovel which it is made united. He is also trained by at least a reversible motor, for example a hydraulic motor, so that the backfill material can be poured out right or left of the device.

The invention finally relates to a set for backfilling a trench, characterized in that it includes a hydraulic shovel and a device for screening and spilling a material of backfill of the type just defined, this device being integral with movement of the shovel hydraulic by a connecting member such as a drawbar, so that it can be towed by the shovel.

Preferably, the chassis of the screening device will include at each of its ends means allowing to make it integral in displacement of the shovel hydraulic, so that it can be towed by one or the other of its ends.

Other characteristics and advantages of the invention will appear in the detailed description which follows of a form of implementation thereof. In this description, refer to schematic drawings annexed, on which:

La figure 2 est une vue analogue à la figure 1, dans la position où la pelle gravit une côte ;

La figure 3 est une vue de dessus avec arrachement du dispositif de criblage et de remblayage remorqué par la pelle hydraulique ;

La figure 4 illustre la position de ce dispositif de criblage et de remblayage sur un terrain inégal, en position latérale par rapport à la tranchée à remblayer.

Figure 1 is a side elevational view of a hydraulic excavator-screening and backfill device towed by this excavator, this assembly being shown in a position where the excavator descends a slope;

Figure 2 is a view similar to Figure 1, in the position where the shovel climbs a hill;

Figure 3 is a top view with cutaway of the screening and backfilling device towed by the hydraulic shovel;

FIG. 4 illustrates the position of this screening and backfilling device on uneven ground, in a lateral position relative to the trench to be backfilled.

In these drawings, the self-propelled hydraulic excavator is designated by the reference 1, while the device screening and backfilling towed by this excavator is designated by reference 2.

The shovel 1 can be of any known type.

The device 2 comprises a chassis 3, mounted here on tracks 4, but which could as well be carried by wheels, on which is articulated, by levers 5 and 6, a drawbar 8 articulated at its other end on the chassis of the shovel 1.

The lever 6 is attacked by the rod of a jack 7 carried by the chassis 3 of the screening and backfilling device.

This chassis 3 is linked to the structure 9 carrying the tracks 4 by a system of levers such as 10, actuable by a cylinder 11, so as to be able to maintain the chassis in a horizontal position whatever the inclination of the ground on which the tracks 4.

A hopper 12, one end of which adjoins the shovel 1 is pivotally mounted relative to the chassis 3 under the actuation of jacks 13, receives from shovel 1 the raw materials for backfilling the trench 14 (see Figure 4), for example in order to bury in this cut a tube 15 which is housed there.

Backfill materials are most often formed by the same cuttings from trench 4 and it should be screened before backfilling this one. For this purpose, the hopper 12 has a bottom part constituted by a grid 16, here made up of bars parallel arranged longitudinally and intended to retain excessively large cuttings, which can then be removed by lifting the hopper (see figure 2).

The material passing through this grid falls on a vibrating screen 19, placed below it, then on a continuous conveyor 17, carried by the chassis 3 below of the vibrating screen and arranged transversely to the direction of movement thereof.

This conveyor 17 projects laterally with respect to the chassis above the trench 14 and pours into it backfill materials. The conveyor 17 is driven by two reversible hydraulic motors carried by the chassis 3. As indicated above, it can also be moved transversely using a double-acting cylinder, in order to ability to project sideways on one side or the other from the chassis, so that the material can be filling both right and left of it.

The various cylinders of the screening and backfill and the conveyor drive motors 17 and vibrating screen are fed and operated from a hydraulic cabinet 18 carried by the chassis 3. All of these organs are remotely controlled by a remote control placed in the excavator cabin or operated by an operator near the wiring device.

The invention therefore provides a simple and inexpensive to backfill trenches, since the device used for backfilling is not self-propelled, but is towed by a hydraulic excavator, which has also for the function of powering the backfilling with backfill material.

It will be noted that the two ends of the chassis 3 are substantially identical, so that the screening device 2 integral in displacement of the hydraulic excavator 1 by one or other of these ends.

As seen in Figure 4, the tracks of the screening and backfilling device can adapt to very uneven terrain and move forward for example on the cuttings 20 from trench 14 or on a runway 21 provided on the other side of this trench.

As can also be seen in Figures 1 and 2, the hydraulic excavator-screening and backfilling is able to climb or descend slopes relatively sharp, up to 25 °.

Claims (7)

1. Method for back-filling a trench (14), particularly using the spoil originating from the digging of this trench, this method consisting in towing, using a mechanical digger (1), parallel to the trench (14), a chassis (3) mounted on wheels or on tracks (4), supporting a loading hopper (12) equipped with a grating (16) at its lower part, in filling this hopper (12) with back-fill material using the mechanical digger (1), in transferring the back-fill material under gravity through the grating (16) onto a vibrating screen placed under the hopper (12), and then onto a continuous conveyor (17) arranged under the vibrating screen on the chassis (3), transversely to its direction of travel, the vibrating screen and the conveyor being driven by drive means carried by the chassis, and in tipping the back-fill material out laterally into the trench (14) using the conveyor.
2. Device able to be towed, for screening a back-fill material and tipping it out into a trench (14), and intended to be used in the method according to.Claim 1, this device comprising:

   a chassis (3) mounted on wheels or on tracks (4) and equipped with at least one member (8) for connection with a mechanical digger able to tow it;

   on this chassis, a hopper (12) for loading the back-fill material, this hopper being equipped with a grating (16) at its lower part;

   under this grating (16), a vibrating screen (19);

   under this vibrating screen, a continuous conveyor (17), one end of which projects laterally with respect to the chassis (3); and

   means for driving the vibrating screen and the conveyor (17), these means being borne by the chassis;

      this device being characterized in that the conveyor (17) can move laterally in translation under the influence of a double-acting ram, so that it can project from either of the two sides of the chassis (3).
3. Device according to Claim 2, characterized in that the conveyor (17) is driven by a reversible motor.
4. Device according, to one of Claims 2 and 3, characterized in that the member for connection with a mechanical digger is a drawbar (8) articulated with respect to the chassis (3) and adjustable in terms of position using a system of levers and rams (5, 6, 7).
5. Device according to one of Claims 2 to 4, characterized in that the chassis is equipped at each of its ends with a means allowing it to be secured to a member. (8) for connection with a mechanical digger.
6. Device according to one of Claims 2 to 5, characterized in that the hopper (12) is mounted so that it can pivot with respect to the chassis (3) under the influence of at least one ram (13).
7. Apparatus for back-filling a trench (14), characterized in that it comprises a mechanical digger (1) and a device (2) for screening and tipping out a back-fill material according to one of Claims 2 to 6, this device (2) being secured to the mechanical digger by a connecting member such as a drawbar (8) so that it can be towed by the digger (1).

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