FR2781825A1 - Granular material spreader for road surface has bin articulated to vehicle at forward end, base conveyor and intermediate hopper - Google Patents

Abstract

The spreader, e.g. for gravel, consists of a tipping bin (2) articulated to the vehicle at its forward end, a conveyor (3) in the base to carry the material to the rear, and an intermediate hopper (7) between the output end of the bin and the spreader mechanism (4) intake. The intermediate hopper can be fixed to the vehicle chassis (1) or tipping, pivoting about an axis (71). The bin and hopper are controlled by separate hydraulic cylinders (200, 70).

Description

The present invention relates to a device for spreading aggregates on

a roadway.

  For making and / or repairing pavements, aggregates spreading devices, in particular gravel, are used, which include a movable frame which supports a tilting skip containing the aggregates, at the rear.

  from which are mounted means for distributing and distributing aggregates.

  Certain devices, usually called "bi-spreaders", are suitable for also coating the roadway with a binder, in this case a bituminous emulsion or a bitumen. To this end, the mobile chassis also supports a binder tank, which is located in front of the bucket, and is equipped in the rear part with a projection ramp supplied with binder by appropriate distribution means. Thus, the spreading of

  aggregates and their insertion into the binder are carried out during the same operation.

  The present invention relates to a device of the above-mentioned type, and

  applies to both a conventional gravel spreader and a two-spreader.

  On known devices, the bucket is articulated on the chassis at its rear part. During spreading, it tilts upwards, its front part rising, in order to ensure a regular flow of aggregates out of the grab, and to supply the means of distribution and distribution of aggregates located at

the back.

  These means are often integrated into an assembly which acts as the rear wall of the bucket, as described for example in FR-B-2 528 085, to which

can refer to if necessary.

  The tilting of the bucket is carried out by means of hydraulic cylinders.

  The tilt angle of the bucket generally reaches about 40 degrees per

compared to the horizontal.

  Due to the large length of the bucket, this results in a significant rise in the center of gravity of the device when it is deployed. This poses stability problems, and it is difficult, if not impossible, to operate on certain roadways which are not perfectly flat or horizontal. Difficulties also arise when working under obstacles of low height (bridges, electrical wires by

example).

  The invention aims to solve this difficulty.

  To this end, in accordance with the invention, the spreading device is remarkable in that: - the bottom of the bucket is equipped with a conveyor capable of conveying the aggregates towards the rear, and of removing them from the grab; - the bucket is articulated on the chassis at its front part; - A buffer tank is provided, which is interposed between the outlet of the bucket and the inlet of the distribution and distribution means. This buffer tank can be fixedly mounted on the chassis. However, in a preferred embodiment, it is articulated around an axis located at the base of its rear part and means are provided, which make it possible to tilt concomitantly towards

  the top, but in opposite directions, the bucket and the buffer tank.

  This buffer tank is an intermediate box which corresponds in a way to a section of skip, of limited length, playing the same role as a skip

  conventional in terms of the supply of aggregates, the means of distribution

tion and distribution.

  Because its length is limited, the intermediate box only rises

  slightly above the chassis, even when tilted to the maximum.

  As for the bucket itself, its tilt angle is relatively small; it simply needs to be sufficient for its rear portion to overhang in

  permanently the buffer tank, so that the aggregates are discharged there, under the effect of gravity.

  As an indication, the angular strokes for lifting the bucket and the buffer tank are, respectively, of the order of 15 to 20 degrees and of the order of 30 to 50 degrees. Furthermore, according to a certain number of additional, non-limiting characteristics of the invention: - the bucket is articulated around an axis located at the upper end of its front part; - the bucket is articulated around an axis located at the base of its front part, and movable in longitudinal translation, so that the tilting upwards of the bucket causes the recoil of this axis; - the tilting of the bucket and the buffer tank are controlled by separate hydraulic cylinders; - the tilting of the bucket is controlled by a hydraulic cylinder (or a pair of cylinders), kinematic connecting members such as a set of rods being provided between the bucket and the buffer tank so that the movement of the grab induces that of the buffer tank; the conveyor comprises at least one movable belt (endless belt);

  - the conveyor consists of a pair of movable belts placed longitudinally-

  side by side, and the rear end of which comes out of the bucket, these two belts being able to be controlled independently of one another; - It is suitable for coating the roadway with a binder, said chassis supporting a binder tank located in front of the bucket, and being fitted at the rear with a ramp of

  projection of the binder on the road.

  Other characteristics and advantages of the invention will become apparent from the

  description and attached drawings which represent, by way of example not

  limiting, possible embodiments.

  In these drawings: - Figure 1 is a schematic front view of a spreading device

  corresponding to a first embodiment of the invention, the bucket being represented therein

  tee in horizontal position; - Figure 2 shows, schematically, a view of the bucket in cross section; - Figure 3 is a partial schematic view, similar to Figure 1, but showing the bucket in the working position (raised position); - Figure 4 is a view similar to Figure 3, intended to illustrate the operating principle of the device; - Figure 5 is a detail showing the rear part of the device of Figure 4, this view being intended to illustrate the manner in which the aggregates are conveyed and spread from the exit of the bucket on the road; - Figures 6 and 7 are views similar to Figure 4, which show

  respectively a second and a third possible embodiment of the invention.

  The device shown in the drawings is of the bi-spreader type.

  This device comprises a chassis 1, mounted on wheels 11, intended to be coupled to a tractor, not shown, to form a road assembly, as is well known.

  In Figures 1 and 3 to 7, the front of the device is turned to the right.

  The front part of the chassis 1 supports a reservoir 10 intended for

contain the binder.

  The tank has been shown only in Figure 1, so as not to weigh down

unnecessarily the other figures.

  In FIG. 1, the reference 12 designates a stand for the ground, which keeps the chassis substantially horizontal when it is not in use,

and is not coupled to the tractor.

  The chassis supports, behind the tank 10, over its entire central part and up to the rear, a bucket 2 intended to receive the aggregates G. The bucket 2 is a box of generally rectangular shape, open upwards. At the rear of the chassis are mounted means 4 for distributing and distributing the aggregates on the roadway C, a binder ramp 9, and a footbridge intended

  to receive an operator - referenced O in Figure 4 - as is well known.

  In the bottom of the bucket 2 is installed a conveyor 3, which is composed of two movable belts (endless belts) 3a, 3b mounted parallel and side by side according to the

  longitudinal direction of the bucket.

  They are guided by idler rollers 6 located at the two ends of the bucket. The rear rollers are powered. Their direction of rotation, symbolized by the arrow F1 in FIG. 4, makes it possible to move the upper forward leg of the carpet towards the rear.

  of the bucket, as symbolized by the arrow F2.

  Preferably, the return and drive rollers 6a, 6b of the two belts can be controlled separately, which makes it possible to obtain displacements at different speeds, or even to move only one of the two belts. This can be interesting

  especially when spreading aggregates over a reduced road width.

  The rear wall of the bucket allows the rear downstream end 30 of the conveyor to pass, which projects beyond towards the rear, out of the bucket; a flap (not shown) can be provided at this level, which makes it possible to close the rear wall of the bucket when the

  device is not used, especially during transport.

  As shown in Figure 2, which is a very schematic sectional representation of the bucket, it comprises a frame 20 supporting the side blanks 21; a central deflector 24, in the form of a dihedral, as well as inclined lateral guides 23 channel the flow of the aggregates on the belts 3a and 3b; these guide elements bear on the belts by means of suitable flexible flaps 25, which prevent

  the unexpected exhaust of the aggregates, transversely towards the edges of the carpets.

  The rollers 6a and 6b are rotated by suitable means.

  required, such as hydraulic motors, which have not been shown in the figures in order

not to weigh them down unnecessarily.

  At its upper front part, the bucket 2 is articulated around a horizontal and transverse axis 100. More specifically, this axis is materialized by two pins

  lateral carried by vertical uprights 13 provided on both sides of the chassis 1.

  The pivot axis 100 is at a level located a little above the plane of the opening of the bucket. We understand that, thanks to this arrangement, when the bucket pivots upwards around this axis 100, its rear part not only lifts but moves

  also slightly backwards, due to its arcuate path.

  A hydraulic cylinder - or a pair of parallel hydraulic cylinders arranged laterally - designated 200, makes it possible to tilt the bucket upwards around

  of axis 100, this movement being symbolized by arrow A in FIG. 3.

  The angular travel of this lifting is of the order of 20 at most.

  Therefore much lower than the lift races of

  traditional skips, which are articulated at their rear part on the chassis.

  At the rear of the chassis is articulated a box 7, which constitutes an element

  essential of the present invention.

  It is a buffer tank whose opening is located under the portion 30 of the conveyor. This box is therefore suitable for collecting by gravity the aggregates which are extracted from the grab, and for transferring them, still by gravity, to the means of

distribution 4.

  This box 7 has a bottom open towards the bottom and towards the rear,

  providing a passage for the aggregates which is designated 72 in FIG. 5.

  It has a section approximately in the shape of a "U'L", the angle of which is directed downwards and rearwards, and is articulated at this angle by a horizontal transverse axis 71. As for the bucket, this axis 71 can be materialized by a pair of

  lateral pins articulated on the chassis 1.

  The tilting of the buffer tank 7 is controlled by a hydraulic cylinder - or a pair of parallel lateral cylinders - whose body is articulated by an axis 700

  on the frame and the rod by a pin 701 on the tank (see figure 5).

  As shown in Figure 3, the lifting of the tank 7 is angular-

  lying around the axis 71, in a direction B opposite to the direction A of raising the bucket,

  this by extension of the jacks 70 and, respectively 200.

  The retraction of the two cylinders brings the assembly back to its initial position

  horizontal, resting (position in Figure 1).

  The maximum angular travel of the tank 7 is approximately 40 to 50.

  This bin constitutes, in a way, a section of a conventional bucket,

limited length.

  Thanks to this arrangement, when the assembly is in the deployed position

  as a maximum, as illustrated in FIGS. 3 and 4, the assembly remains in an obstruction-

  much lower in height than traditional skips. Thus, the stability of the device is very little affected, which makes it possible to work on pavements having uneven surfaces, or inclined parts,

  as well as on non-horizontal soils.

  This space requirement limited in height also has the advantage that it is possible to pass under bridges, trees of telephone or electric wires situated at relatively low height, below which it would not be possible to work.

with a traditional device.

  Referring to Figures 4 and 5 we will now explain how the device is used to pour the aggregates on a pavement C in progress

making or repairing.

  The device rolls on the road from left to right, this advance

  being symbolized by the arrow H in the figures.

  The bucket 2 and the tank 7 being initially lowered and the bucket 2 containing the aggregates to be spread, we will gradually and jointly actuate the two cylinders

  200, 70, to simultaneously lift the bucket (arrow A) and the bin (arrow B).

  The control means of the two cylinders are adapted so that these two tiltings are made according to a well-defined angular relationship, the speed and the stroke

  angular of the container being approximately double that of the container.

  The conveyor 3 being put into operation, the aggregates G present in the bucket 2 are removed and conveyed by the conveyor 3 to exit the bucket through the end portion 30 of the conveyor. This portion overhanging the opening of the tank 7, the aggregates fall by gravity into the tank. They are designated therein. The means for distributing and distributing the aggregates are of the same general type as those described in the aforementioned FR-B-2 528 085 or of FR-B-2 647 131; we

can refer to it if necessary.

  The driving speed of the conveyor belts 3a, 3b is adapted, of course, to the spreading rate and the feed speed. The buffer tank 7 must always contain a sufficient quantity of aggregates to adequately supply the

  means 4. Appropriate means, such as level detectors, are advantageous-

  planned to control the situation.

  These means essentially comprise a set of hatches 40 which are capable of selectively closing, or on the contrary releasing the outlet passage 72

Tray.

  By means of these hatches, it is possible to act on the dosage of the aggregates, and on the spreading width, as is well known. At the outlet of the tank 7 is also mounted a rotary extractor roller 41, the direction of rotation of which is symbolized by the arrow R in FIG. 5. Its role is to extract the aggregates in the form of a layer, the thickness of which is controlled; the aggregates then fall on a curved flap 42 and on a double skirt 43; they then form a curtain of aggregates G "which is deposited on pavement C in the form

of a thin layer.

  Simultaneously, the binder ramp 9 projects jets of binder Ljuste in front of this layer during deposition. The aggregates are therefore deposited in the binder layer,

and are stuck there.

  The operation is constantly monitored by the operator O located on

the gateway 5.

  It will be noted that during the lifting, in the direction of tilting B, of the buffer tank, the opening of the latter tends to move slightly backwards, due to its trajectory in an arc of a circle. It is therefore important that the bucket also moves back during its next tilting A. As already mentioned above, the positioning in height of the axis 100

achieves this result.

  In the second embodiment of the invention, which is illustrated by the

  Figure 6, the solution adopted is different.

  The pivot axis of the bucket 2, designated 101, is this time positioned

  the base of the front part of the bucket.

  However, this axis is mobile. It is guided in longitudinal translation and

  horizontal in a light 102 integral with the frame.

  Thus, under the thrust of the actuator 200, the bucket not only pivots along A around the axis 101, but also moves in translation from the front towards

  the rear as symbolized by the arrow A '.

  Under the effect of gravity, when the cylinder 200 is retracted, we observe

  reverse movements, the bucket becoming horizontal as it advances.

  In the third embodiment illustrated in FIG. 7, a single control cylinder (or a pair of parallel cylinders) is used. This is the cylinder 200

  interposed between chassis 1 and bucket 2.

  Between the buffer tank 7 and the bucket 2 there is provided a kinematic connecting member. This consists of a pair of lateral links 8, one end 81 of which is articulated to the rear part of the bucket, and the other, via a crank pin or an eccentric

  , at the front of the bottom of the tank 7.

  It is understood that, thanks to this arrangement, the lifting according to A of the

  bucket induces lifting and tilting along buffer tank 7.

  In a variant not shown, it would be possible to provide, in addition to the main cylinder 200, a secondary cylinder interposed between the box and the bucket which

  would control the relative movements of these two elements.

  Finally, as indicated at the beginning of this description, the buffer tank

  could be fixed, its walls being shaped to adequately supply the

  means 4 when it contains aggregates.

  As already said, the present invention applies equally well to

  conventional gravel spreaders only with dual-spreader devices.

  It also applies equally to load-bearing assemblies, in

  which the bucket is integrated into a truck, than a towed trailer.

  The tank bottom conveyor may consist of a single conveyor, or even

  other types of conveyor, scraper or bucket chain or worm, for example.

  The dimensions and capacities of the device are naturally adapted to the

  kind of work for which it is intended.

  As this is a bi-spreader, the characteristics are given for information

  following ques: Tank volume 10: from 3,000 to 8,0001; Length of bucket 2: 3 to 6 m; Bucket 2 capacity: 4 to 12 m3; Capacity of buffer tank 4: 1 to 2m3;

  Maximum pressure used in the cylinders: approximately 200 bars.

Claims (10)

  1. Device for spreading aggregates on a roadway, comprising a movable frame (1) which supports a tilting skip (2) containing the aggregates (G), at the rear of which are mounted means (4) for distribution and distribution of these aggregates, of the bucket (2) on the roadway (C), characterized in that: - the bottom of the bucket (2) is equipped with a conveyor (3) capable of conveying the aggregates (G) backwards, and take them out of the bucket (2); - the bucket (2) is articulated on the chassis (1) at its front part; - a buffer tank (7) is provided, which is interposed between the outlet of the bucket   (2) and the inlet of the distribution and distribution means (4).   2. Device according to claim 1, characterized in that the tank   pad (7) is fixedly mounted on the frame (1).   3. Device according to claim 1, characterized in that the tank   buffer (7) is also tiltable.   4. Device according to claim 3, characterized in that the buffer tank (7) is articulated around an axis (71) located at the base of its rear part and that means (200, 70; 8) are provided , which allow to switch concomitantly towards   the top, but in opposite directions (A, B) the bucket (2) and the buffer tank (7).   5. Device according to Claim 4, characterized in that the angular strokes for lifting the bucket (2) and the buffer tank (7) are, respectively, of   in the range of 15 to 20 degrees and in the range of 30 to 50 degrees.   6. Device according to one of claims 1 to 5, characterized in that   that the bucket (2) is articulated around an axis (100) located at the upper end of its front part.   7. Device according to one of claims 1 to 5, characterized in that   that the bucket (2) is articulated around an axis (101) located at the base of its front part, and movable in longitudinal translation, so that the tilting (A) towards the top of the   bucket (2) causes the recoil (A ') of this axis (101).   8. Device according to one of claims 4 to 7, characterized in that   that the tilting of the bucket (2) and the buffer tank (7) is controlled by jacks separate hydraulics (200, 70).   9. Device according to one of claims 4 to 7, characterized in that   that the tilting of the bucket (2) is controlled by a hydraulic cylinder (200), kinematic connecting members such as a set of rods (8) being provided between the bucket (2) and the buffer tank (7) for that the movement of the bucket (2) induces that of the bin buffer (7).   10. Device according to one of claims 1 to 9, characterized in that   that said conveyor (3) comprises at least one movable belt.   1 1. Device according to claim 10, characterized in that said conveyor (3) consists of a pair of movable belts (3a, 3b) placed longitudinally side by side, and the rear end (30) of which the bucket (2), these two belts (3a, 3b)   can be ordered independently of each other.   1 2. Device according to one of claims 1 to 11, characterized in that   that it is suitable for coating the roadway with a binder (L), said chassis (1) supporting a binder tank (10) located in front of the bucket (2), and being equipped at the rear with a   ramp (9) for projecting the binder onto the roadway.