Implement for levelling grounds areas, such as roads, courtyards and the like, of unasphalted tamped material, to be coupled to a motor-driven towing vehicle

Abstract

 The implement is intended to be coupled to a motor-driven towing vehicle and comprises a roller-cutter (10) of substantially horizontal axis, to the cylindrical surface of which there is fixed a plurality of tools (11) able to crush and shift the ground (A) to be treated; means for rotating said roller-cutter about its axis are also provided, as are means for supporting the roller-cutter (10) arranged with its axis substantially perpendicular to or possibly inclined to the direction of advancement and for maintaining the lower surface of the roller-cutter (10) at the required depth below the surface of the ground to be treated; finally, means are provided for distributing the material crushed by the roller-cutter (10) in such a manner as to fill any recesses and flatten any projections.

Description

[0001] This invention relates to the problem of levelling or flattening the surface of ground areas of incoherent tamped material which have not been coated with asphalt (or another coherent covering material), ie ground areas formed from tamped (and hence compacted) material such as dust, sand, crushed stone, gravel, pebbles and mixtures thereof. In particular, the invention relates to unsurfaced roads (ie roads not coated with asphalt or like material), and uncoated courtyards and similar ground areas.

[0002] Machines for removing old asphalt layers from asphalted roads have been known for a considerable time, they using a rotating roller provided with teeth for disintegrating the asphalt layer, which is then loaded onto trucks and removed. These machines cannot be used for levelling unsurfaced roads (or courtyards or similar ground areas). Instead, mechanical shovels are used provided with a front tool in the form of a virtually vertical wall with which the upper layer of the ground area is scraped off. Alternatively further material is simply added to fill the cavities in the ground.

[0003] An object of the present invention is to provide an implement, in particular able to be towed by an agricultural tractor or an equivalent vehicle, which is of relatively simple and economical construction and is able to quickly and properly level tamped ground areas of incoherent material. This and further objects are attained by the present invention as characterised in the claims.

[0004] The invention is described in detail hereinafter with the aid of the accompanying figures, which illustrate a non-exclusive embodiment thereof.

[0005] Figure 1 is a side view of the implement according, to the invention coupled to an agricultural tractor.

[0006] Figure 2 is a section through the implement on the vertical plane II-II of Figure 3.

[0007] Figure 3 is a front view of the implement of the preceding figures.

[0008] Figure 4 is a rear view of the implement of the preceding figures.

[0009] Figures 5 and 5A show two different tool distributions on the surface of the roller-cutter 10, which is shown in single plane development.

[0010] The invention illustrated in the figures is a portable implement (indicated overall by 1) to be towed and driven by a tractor 2, in particular an agricultural tractor. It could however have its own dedicated drive part connected permanently to the implement 1. The implement 1 comprises a roller-cutter 10 of substantially horizontal axis, on the cylindrical surface of which there is fixed a plurality of tools 11 able to crush and move the ground to be treated.

[0011] The implement comprises a rigid frame 20 which supports the roller-cutter 10, arranged with its shaft 14 substantially horizontal and substantially perpendicular (or possibly inclined) to the direction of advancement. The frame 20 is provided with coupling points for connection to the coupling device of the tractor 2 (this device being usual for this type of machine) or a similar towing vehicle, Specifically, there is provided an upper point 21', carried by vertical lugs 25 fixed to the frame 20 and positioned in the vertical plane of symmetry of the implement 1, and two lower points 21'' located on the front end of the implement and carried by vertical lugs 26 fixed to the frame 20. The two points 21'' are intended to be directly hinged to the two lower arms 3 of the coupling device of the tractor 2. A linear actuator means, in particular a cylinder-piston unit 4, is interposed between the upper coupling point 21' and a point 5 rigid with the tractor 2.

[0012] The frame 20 also supports a vibrating plate means 30 positioned to the rear of the roller-cutter 10 and having a substantially horizontal flat surface 31 with which it batters on the ground, and means to cause the plate means to vibrate with a vertical component to compact the material crushed by the roller-cutter. The vibrating plate means 30 also acts as a ground support element for the implement 1.

[0013] By varying the length of the cylinder-piston unit 4 the geometrical attitude of the combined implement 1 and tractor 2 is varied, and as the implement 1 rests on the ground via the vibrating plate means 30 the implement 1 is caused to rotate in the vertical plane, hence varying the depth by which the lower surface of the roller-cutter 10 penetrates into the ground A.

[0014] In the particular case of an implement intended to operate on unsurfaced roads, the tools 11 are fixed to the cylindrical surface of the roller-cutter 10 in a manner positioned along one or more concordant helical lines about the cylindrical surface. In Figure 3 the reference numeral 12 indicates the ideal helical lines alone which the tools 11 are positioned. The tools 11 are however not shown for simplicity. Along each line 12 the tools are positioned relatively close together to define substantially a helically extending barrier for the larger pieces of crushed material, which is able to drag such pieces along with it. In the illustrated embodiment, said tools 11 are in the form of a thick steel nail, the point of which projects outwards from a tool holder element 13 fixed to the roller-cutter 10, and extends in the direction of movement. The axis of each tool 11 lies in a substantially radial plane (ie perpendicular to the axis of the roller-cutter) and forms an angle of about 45 degrees with the tangent to the direction of movement at that point. The main frame 20 supports a rigid hood 15 which covers the front, the top and the rear of the roller-cutter 10 and has its front wall 151, upper wall 152 and rear wall 153 spaced slightly from the cylindrical surface of the roller-cutter 10. Between the inner surface of the hood 15 and the outer surface of the roller-cutter 10 there is defined a chamber 19 which enables the material crushed by the roller-cutter 10 to be accumulated. The two end faces of the roller-cutter 10 are covered by respective vertical walls 16 joined to the hood 15 and by two skids 17 parallel to the walls 16, to rest on the ground. These are secured to the walls 16 by telescopic rods 171 which enable the skids 17 to move vertically. In the illustrated embodiment, the vibrating plate means 30 comprises two identical plates 32 which together cover the entire axial dimension of the roller-cutter 10. Said plates 32 comprise respective horizontal portions which together form the flat surface of the vibrating plate means 30.

[0015] Each plate 32 is fixed to the frame 20 by joints of elastomer material 33. For example, each plate 32 possesses ribs 34 projecting vertically upwards and extending in a longitudinal direction. In positions corresponding with the ribs 34, the top of the frame 20 comprises a like number of vertical stiffening walls 27 extending in longitudinal planes. The upper surface of the ribs 34 is joined to the lower edge of the walls 27 by the interposed joints 33, which are rigidly fixed to said surfaces. Alternatively, elastomer sheets can be provided directly fixed to the upper surface of the plates 32 and to the rear end of the frame 20.

[0016] The connection between the frame 20 and plates 32 provided by the joints 33 (or the elastomer sheets) is such as to enable the plates 32 to undergo substantially oscillations only in a vertical direction relative to the frame 20. Respective eccentric devices 35 are fixed onto the two plates 32 and rotated by a motion transmission deriving from the power take-off 6 of the tractor 2.

[0017] Said transmission comprises a gearbox 41 which receives motion from the power take-off 6. From the box 41 there emerges a longitudinal shaft 42 which, by way of pulleys 43 and 44, transmits motion to a gearbox 45 from which two transverse driven shafts 46 emerge, each of which drives the shaft 35' of the relative device 35 via two pulleys 47 and 48.. Rotating the eccentrics of the device 35 causes the plates 32 to undergo short oscillatory translational movements in a vertical direction relative to the frame 20.

[0018] From the gearbox 45 there also emerges a transverse shaft 49 which transmits motion to the shaft 14 of the roller-cutter 10 by way of a pair of transmission sprockets 50 and 51 and a chain 52. The roller-cutter 10 is rotated in the opposite direction to that of the wheels of the tractor 2 (indicated by the arrow R in the figures).

[0019] The implement 1 comprises, to the rear of the roller-cutter 10, a wall 24 inclined upwardly and forwardly relative to the ground, its lower edge 24' being positioned substantially grazing the ground surface A, in order to shift and scrape the material crushed by the roller-cutter 10. In the illustrated embodiment, said inclined wall 24 is joined to the front of the flat surface 31 of the plate means 30.

[0020] In operation, the tractor 2 tows the implement 1 with this latter resting on the around A via its flat surface 31. By suitably adjusting the length of the cylinder-piston unit 4 the implement 1 can be inclined by the required amount in a vertical longitudinal plane relative to the tractor 2, such that the lowest point on the circumferences B (Figure 2) along which the points of the tools 11 move is below the ground line A. This level difference represents the thickness of the layer of tamped material (dust, sand, crushed stone, grit, pebbles etc.) crushed by the roller-cutter 10. The implement 1 together with the tractor 2 are then moved along the ground to be treated, in particular along an unsurfaced road, while making sure that one of the sides of the implement 1 is substantially aligned with a lateral edge of the road. The roller-cutter 10 is rotated in the direction of the arrow R and the vibrating plate means 30 is vibrated. As the implement 1 advances, the roller-cutter 10 bites into and crushes the ground by means of its tools 11. These, having crushed the ground into pieces of various dimensions (depending on various factors, such as the physical characteristics of the material of which the ground is composed), partly allow the material to fall and partly drag it with themselves in rotation, to more or less completely fill the chamber 19 defined between the roller-cutter 10 and the inner surface of the hood 15, in particular the region to the rear of the roller-cutter 10 (against the wall 153). Hence, when the roller-cutter 10 passes over a recessed region of the ground, this accumulated material falls into that region to bring it up to the required filling level. Moreover, by virtue of the helical arrangement of the tools 11 (by which these at least partly behave as a screw conveyor means), part of the material crushed by the roller-cutter 10 is pushed sideways, in particular towards the centre line of the road, so that the material accumulates to a greater extent towards the centre. The purpose of this is to form in the usual manner an advantageous inclination in the road, decreasing from the centre towards the sides to cause any rain water to flow towards the two edges of the road. To increase the conveying action of the roller-cutter 10, a portion 18 of an actual helix can be provided for example at the beginning of the roller-cutter 10, and extending close to the tools 11.

[0021] In the tool distribution shown in Figure 5, the tools 11 are not only aligned along inclined rows (forming the helical lines 12) but are also aligned along vertical lines L. This distribution is the most suitable for coarser crushing of the ground. The distribution shown in Figure 5A differs from the preceding in that the vertical alignment lines 1' intersect the inclined rows, passing alternately through a tool and through the centre point between two tools. This distribution is more suitable for fine crushing of the ground.

[0022] To facilitate the formation of said road inclination, the axis of the roller-cutter 10 can be slightly inclined to the plane of the surface 31 so that the roller-cutter 10 penetrates into the ground to a greater depth along the outer edge than along the centre line of the road.

[0023] As the implement 1 advances, the lower edge 24' of the rear wall 24 shifts and levels the crushed material by providing an effective scraping action which very flatly levels the ground.

[0024] Immediately after being crushed and scraped, the material is compacted by the action of the vibrating plates 32 following the roller-cutter 10, such that considerable hardness is achieved enabling it to be again used (as a road). The result is that the longitudinal strip of ground subjected to the action of the implement 1 is, with a single passage, made perfectly flat and compacted to the extent that it is immediately able to perform its function.

[0025] Numerous modifications of a practical and applicational nature can be made to the invention, without leaving the scope of the inventive idea as hereinafter claimed. For example, the particular form of the tools could be different. These could be in the form of a chisel instead of a nail.

Claims

1. An implement for levelling ground areas such as roads, courtyards and the like, of tamped material not coated with coherent material, to be coupled to a motor-driven towing vehicle, characterised by comprising: a roller-cutter (10) of substantially horizontal axis, to the cylindrical surface of which there is fixed a plurality of tools (11) able to crush and shift the ground (A) to be treated;
means for rotating said roller-cutter about its axis;
means for supporting the roller-cutter (10) arranged with its axis substantially perpendicular to or possibly inclined to the direction of advancement and for maintaining the lower surface of the roller-cutter (10) at the required depth below the surface of the ground to be treated; and
means for distributing the material crushed by the roller-cutter (10) in such a manner as to fill any recesses and flatten any projections.

2. An implement as claimed in claim 1, characterised by comprising a vibrating plate means (30) positioned to the rear of the roller-cutter (10) and having a substantially horizontal flat surface (31) by which it rests on and batters against the ground (A), and means (35) for vibrating with a vertical component the plate means (30), in order to compact against the ground the material crushed by the roller-cutter (10).

3. An implement as claimed in claim 2, characterised by being a portable implement with coupling points (21' and 21'') for its connection to the coupling device of a tractor (2) or a similar towing vehicle, and further comprising:

- a rigid frame (20) supporting the shaft (14) of the roller-cutter (10) and the vibrating plate means (30), said plate means (30) acting as the element by which the implement (1) rests on the ground (A);

- a linear actuator means (4) connecting a coupling point (21) positioned on the main frame (20) to a point (5) rigid with the tractor (2), the depth of the lower surface of the roller-cutter (10) below the surface of the ground (A) being varied by varying the length of the actuator means (4).

4. An implement as claimed in claim 2, characterised by comprising, to the rear of the roller-cutter (10) and inclined to the ground, a wall (24) the lower edge (24') of which is positioned substantially grazing the surface of the ground (A) in order to shift and scrape the material crushed by the roller-cutter (10).

5. An implement as claimed in claim 4, characterised in that said inclined wall (24) is joined to the front of the flat surface (31) of the plate means (30).

6. An implement as claimed in claim 1, characterised in that said tools (11) are arranged aligned along one or more concordant helical lines (12) extending about the cylindrical surface of the roller-cutter (10).

7. An implement as claimed in claim 6, characterised in that the tools (11) are positioned relatively close together along each line (12) such as to substantially define for the coarser pieces of crushed material a helically extending barrier able to drag such pieces with itself.

8. An implement as claimed in claim 1, characterised in that said tools (11) are in the form of a thick nail the point of which projects outwards, in the direction of movement, from a tool holder element (13) fixed to the roller-cutter (10).

9. An implement as claimed in claim 1, characterised in that the axis of the tools (11) forms an angle of about 45 degrees with the tangent to the direction of movement at that point.

10. An implement as claimed in claim 1, characterised by comprising a rigid hood (15) covering the front, the top and the rear of the roller-cutter (10), its walls being slightly spaced from the surface of the roller-cutter (10) in such a manner as to allow material crushed by the roller-cutter (10) to be accumulated between the cylindrical surface of the roller-cutter (10) and the hood (15).

Drawing