FR2780079A1 - METHOD AND DEVICE FOR BACKFILLING A TRENCH - Google Patents

Abstract

The method according to the invention consists in towing with the aid of a hydraulic shovel (1), parallel to the trench, a frame (3) mounted on wheels or on tracks (4), supporting a loading hopper (12 ) equipped with a grid at its lower part, to load this hopper (12) with backfill material using the hydraulic shovel (1), to transfer the backfill material by gravity through the grid on a vibrating screen arranged below the hopper (12), then on a continuous conveyor, arranged below the vibrating screen on the frame (3), transversely to its direction of movement, the vibrating screen and the conveyor being driven by motor means carried by the frame, and to discharge the filling material laterally into the trench using the conveyor.

Description

METHOD AND DEVICE FOR BACKFILLING A TRENCH.

  The present invention relates to a method of backfilling a trench and a device for implementing this method. It is known that, for the transport of fluids over long distances, of gas, for example, or of petroleum, pipes of the pipeline type are used, which it is customary to protect by burying them in trenches. The backfilling of these trenches is usually carried out by reusing the cuttings from the trench, after screening them, and a screening and backfilling device is generally used for this purpose, which is carried laterally by a

  tractor, which moves along the trench.

  A screening and backfilling device of this type usually includes a hopper for receiving the materials used for backfilling, a continuous conveyor arranged below the hopper, and a vibrating screen system fed by the continuous conveyor and intended to fill the trench of successive layers of materials having a determined particle size. The whole is united

  a frame, which itself is supported, cantilevered

  above the trench to be backfilled, by a carrying arm of a tractor or similar device. It is thus possible to backfill a trench, possibly by carrying out several passes with a device, with different layers of the same material or of different particle size materials. Such a device is described for example in detail in US Pat. No. 4,955,756, but numerous variants exist on the market and the Applicant has itself proposed various improvements made to a device of this type, which are the subject of his European patent application

N 0 709 526.

  These devices are entirely satisfactory, but are

  are relatively expensive due to the fact that they are self-

  engines. The chassis also has the disadvantage of being

  cantilevered relative to the tractor.

  Finally, the filling of the hopper with backfill material must be carried out using a machine

  independent of the backfill system.

  To overcome these drawbacks, the invention proposes to use no longer a self-powered backfilling system, but a screening and backfilling system towed by a hydraulic excavator of a conventional type, which also ensures the loading of material. of backfilling the screening device, the hydraulic shovel-screening device assembly being able to move as well on the cuttings bead of the trench as on a track disposed of

the other side of it.

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

conveyor.

  The subject of the invention is also a device capable of being towed, for screening a backfill material and pouring it into a trench, and intended to be used 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.

  The link with the hydraulic shovel 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 relative to the frame, at least one jack being provided on the frame to straighten it by pivoting relative to the latter, in order to evacuate the largest constituents of the material of

  backfill not passing through the grid.

  This can consist 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 with which it is made integral. This conveyor is advantageously movable in translation under the stress of a double-acting cylinder, so that it can protrude at will both on the left side and on the right side of the device. It is also driven by at least one reversible motor, for example a hydraulic motor, so as to be able to pour the backfill material to the right or to the left of the device. The subject of the invention is finally a set for backfilling a trench, characterized in that it comprises a hydraulic shovel and a device for screening and discharging a backfill material of the type which has just been defined, this device being integral with the movement of the hydraulic shovel 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 comprise at each of its ends means making it possible to fasten it in displacement of the hydraulic shovel, 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

  annexes, in which: FIG. 1 is a side elevation view of a hydraulic excavator-screening and backfilling 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; Figure 4 illustrates the position of this screening and backfilling device on uneven ground, in position

  lateral to the trench to be backfilled.

  In these drawings, the self-propelled hydraulic shovel is designated by the reference 1, while the screening and backfilling device towed by this shovel 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 jack 11, so as to be able to maintain the chassis in a horizontal position whatever the inclination of the ground on which are supported. the tracks 4. A hopper 12, one end of which adjoins the shovel 1 is pivotally mounted relative to the chassis 3 under the action of jacks 13, receives from the shovel 1 the raw materials intended for backfilling the trench 14 (see FIG. 4 ), for example in order to bury in this

  cut a tube 15 which is housed there.

  The backfill materials are most often made up of the cuttings themselves from trench 4 and

  should be screened before backfilling this one.

  For this purpose, the hopper 12 comprises a bottom part constituted by a grid 16, here constituted by parallel bars arranged longitudinally and intended to retain excessively bulky cuttings, which can then be evacuated

  by lifting the hopper (see figure 2).

  The material passing through this grid falls on a vibrating screen 19, disposed below it, then

  on a continuous conveyor 17, carried by the chassis 3 above

  below 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 in the latter the fill 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, so as to be able to project laterally from one side either side of the chassis, so that the material can be

  filling both right and left of it.

  The various jacks of the screening and backfilling device and the drive motors of the conveyor 17 and the vibrating screen are supplied and actuated from a hydraulic cabinet 18 carried by the chassis 3. All of these members 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 means for backfilling trenches, since the device used for backfilling is not self-propelled, but is towed by a hydraulic shovel, which also has the function of feeding the device of

backfilling with backfill material.

  It will be noted that the two ends of the chassis 3 are substantially identical, so as to be able to make the screening device 2 integral in displacement of the

  hydraulic excavator 1 by one or other of these ends.

  As can be seen in FIG. 4, the tracks of the screening and backfilling device can adapt to very uneven terrain and advance, for example, on the cut bead 20 of the trench 14 or on a track 21

  provided on the other side of this trench.

  As can also be seen in FIGS. 1 and 2, the hydraulic excavator-screening and backfilling device assembly is capable of climbing or descending slopes

  relatively high, up to 25.

Claims (8)

  1. A method of backfilling a trench (14), in particular using cuttings from the digging of this trench, this method consisting in towing with a hydraulic shovel (1), parallel to the trench ( 14), a chassis (3) mounted on wheels or on tracks (4), supporting a loading hopper (12) equipped with a grid (16) at its lower part, to load this hopper (12) with backfill material using the hydraulic shovel (1), to transfer by gravity the backfill material through the grid (16) on a vibrating screen placed below the   hopper (12), then on a continuous conveyor (17), placed above   below the vibrating screen on the frame (3), transversely to its direction of movement, the vibrating screen and the conveyor being driven by motor means carried by the frame, and pouring the filling material laterally into the trench (14) at using the conveyor. 2. Device capable of being towed, for screening a backfill material and pouring it into a trench (14), and intended to be used in the method according to claim 1, this device being characterized in that that it comprises: - a chassis (3) mounted on wheels or on tracks (4) and equipped with at least one member (8) for connection with a hydraulic shovel capable of towing it; - On this chassis, a hopper (12) for loading the filling material equipped with a grid (16) at its lower part; - below the grid (16), a vibrating screen (19); - below this vibrating screen, a continuous conveyor (17), one end of which projects laterally with respect to the frame (3); - And means for driving the vibrating screen and the   conveyor (17) carried by the chassis.   3. Device according to claim 2, characterized in that the conveyor (17) is movable in translation under the stress of a double-acting cylinder, so as to be able   protrude from either side of the chassis (3).   4. Device according to claim 3, characterized in that the conveyor (17) is driven by a reversible motor.   5 Device according to one of claims 2 to 4,   characterized in that the connecting member with a hydraulic shovel is a drawbar (8) articulated relative to the chassis (3) and adjustable in position using a system of levers and cylinders (5, 6, 7).   6. Device according to one of claims 2 to 5,   characterized in that the chassis is equipped at each of its ends with a means enabling it to be secured to a   member (8) for connection with a hydraulic shovel.   7. Device according to one of claims 2 to 6,   characterized in that the hopper (12) is pivotally mounted relative to the chassis (3) under the stress of at least a jack (13).   8 Backfill assembly for a trench (14), characterized in that it comprises a hydraulic shovel (1) and a device (2) for screening and discharging a   backfill material according to one of claims 2 to 7,   this device (2) being integral with the hydraulic shovel by a connecting member such as a drawbar (8), so as to   be able to be towed by the shovel (1).