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(11) | EP 1 645 689 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Semi-permanent road way |
| (57) Semi-permanent roadway on which a vehicle can be transported over a ground surface,
comprising a number of plate-like roadway elements which can be placed mutually in
line on the ground surface, wherein the roadway elements have dimensions such that
during use a left and right-hand wheel of the vehicle support simultaneously on the
same roadway element, and system for placing and removing a semi-permanent roadway,
comprising a crane for arranging on a mobile platform, wherein the crane is provided
with gripping means with which one or more roadway elements can be gripped, wherein
the gripping means comprise a support element which can be mounted on the crane, suction
elements arranged on the support element and a vacuum pump connected to the suction
elements, wherein the support elements and the vacuum pump are adapted to fixedly
hold the roadway elements through underpressure by the support element.
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[0001] The present invention relates to a removable, semi-permanent roadway on which a vehicle can be transported over a ground surface. The invention also relates to a system for placing and removing such a removable, semi-permanent roadway.
[0002] There are many types of semi-permanent roadways known with which a ground surface can be made passable for machines and road traffic. When machines have to drive for instance on a soft ground in order to lay a permanent roadway or a railway track, and these machines cause a relatively high ground pressure, the ground must first be provided with a removable, semi-permanent roadway so as to prevent damage to the ground or excessive compaction of the ground. A temporary roadway is likewise applied when machines have to be displaced over an existing, permanent roadway, which displacement could damage the existing roadway. Instead of being placed on the ground, the roadway plates are in this case placed on the existing permanent roadway. Temporary roadways are also used to limit the rolling resistance encountered by the vehicles, which has a positive effect on fuel consumption, and to allow higher speeds to be achieved.
[0003] Known from the German document DE 101 08 033 C1 is a system in which a number of roadway parts are laid successively, consisting of two longitudinal profiles having therebetween a large number of transverse profiles. The roadway parts must however be coupled to each other, which makes the construction complex and the reduces the speed of laying of the roadway. This system is therefore hardly applied in practice.
[0004] It is also deemed known to create a temporary roadway by placing on the ground surface two strips or tracks of steel roadway plates arranged mutually in line, wherein each track has dimensions and the mutual distance between the tracks is such that the wheels of the vehicle are guided precisely over the tracks.
[0005] The drawback of the known removable, semi-permanent roadway consisting of two tracks of successively laid steel plates is that material can be pressed up between the two tracks, which can cause the roadway plates to become soiled relatively quickly, to displace relative to each other and become unstable.
[0006] A further drawback is that the ground pressure resulting from road traffic on the semi-permanent roadway is still relatively high when the above mentioned double tracks are applied. This means that if the ground surface may not be loaded too heavily, the ground can suffer damage or undergoes excessive compaction.
[0007] A further drawback is that the known roadway plates are arranged overlapping, with the result that both tracks have a raised portion at a mutual distance roughly equal to the length of a roadway plate, which limits the maximum speed at which the vehicle can travel over the known roadway. The raised portions also cause a jolting effect, which is perceived as unpleasant and is harmful to the vehicles.
[0008] It is an object of the present invention to provide a removable roadway where at least one of the above stated drawbacks is obviated.
[0009] According to a first aspect of the present invention, there is provided a removable, semi-permanent roadway on which a vehicle can be transported over a ground surface, wherein the roadway comprises a number of plate-like roadway elements which can be placed mutually in line on the ground surface, wherein the roadway elements have dimensions such that during use the left and right-hand wheels of the vehicle support simultaneously on the same roadway element. Because both wheels rest on one and the same roadway element, pressing-up of material is avoided. Furthermore, because both wheels rest on one plate, there is no displacing of the roadway plate whereby it could become unstable. Owing to the relatively large dimensions, each plate can moreover be made sufficiently heavy and rigid so that it can hardly displace at all.
[0010] In order to ensure that during use both wheels support simultaneously on the same roadway element, the width of the roadway element is preferably chosen to be more than two metres, and still more preferably more than three metres. The length of the roadway element is furthermore chosen here to be relatively great, preferably more than eight metres, and still more preferably more than ten metres. With such large roadway elements only a small number of roadway elements have to be arranged per unit of length of the roadway, which increases the speed of arranging and removing the removable roadway.
[0011] According to a preferred embodiment of the invention, there are arranged close to at least one of the edges of a plate-like roadway element openings to which transport means can be connected for the purpose of transporting the roadway element. The openings for instance make it simple to drag roadway elements arranged on a ground surface to a desired position.
[0012] The openings are preferably provided close to both relatively narrow outer ends of a rectangular roadway element. Manoeuvring with the roadway elements is facilitated by engaging the roadway elements at the relatively narrow outer end. This makes it possible to place the roadway elements rapidly and in simple manner.
[0013] According to a further aspect of the present invention, there is provided a system for placing and removing a removable, semi-permanent roadway, wherein the roadway comprises a crane for arranging on a mobile platform, wherein the crane is provided with gripping means with which one or more roadway elements can be gripped, wherein the gripping means comprise a support element which can be mounted rotatably on the crane, suction elements arranged on the support element and a vacuum pump connected to the suction elements, wherein the support elements and the vacuum pump are adapted to fixedly hold the roadway elements through underpressure by the support element. The roadway elements can thus be readily sucked fast to the crane using the suction elements, for instance suction cups, whereafter the crane lifts the roadway element in question to the relevant position. An advantage of this construction is that the roadway elements can be of simple structure, for instance in the form of relatively smooth steel plates, without special gripping provisions being required on the elements themselves that are to be gripped.
[0014] In a particularly advantageous embodiment, the mobile platform is a semi-trailer and the crane is adapted to displace a roadway element between the first position, in which the roadway element is stored on the loading floor of the semi-trailer, and a second position in which the roadway element is placed on the ground surface in line with the semi-trailer. In this embodiment it is therefore possible, for instance when the crane is adapted to turn through an angle of about 180°, to place a roadway element on a ground surface, to drive the semi-trailer onto the roadway element that has just been placed, to place a subsequent roadway element, to then drive the semi-trailer onto the subsequent roadway element and so on, so that the semi-trailer then always rests on an already arranged semi-permanent roadway and displacement on the original ground surface can be omitted.
[0015] According to another aspect of the invention, there is provided a system for placing and removing a removable, semi-permanent roadway, comprising a roadway element shovel for displacing a roadway element, the roadway element shovel comprising:
- a bearing plate on which a roadway element can be placed;
- a support which is provided on the bearing plate and on which first coupling means are arranged for coupling the bearing plate to a mobile platform; and
- second coupling means extending from the bearing plate for coupling to the bearing plate the roadway element placed on the bearing plate.
[0016] The roadway element shovel is preferably used to drag the roadway elements on site by making use of a so-called mechanical shovel. A mechanical shovel is an excavator consisting of a tractor with a steel frame in which a bucket is rotatably suspended. Such excavators are known everywhere and for the sake of simplicity a description thereof is dispensed with here. The support to which the bearing plate is fixed can be coupled to the known mechanical shovel. The bearing plate can be pushed under one or more roadway elements for transporting, preferably under the end surface of one or more such roadway elements. The second coupling means then ensure that the one or more roadway elements are coupled to the bearing plate such that the roadway elements can be transported as required.
[0017] The second coupling means are preferably embodied as a protrusion which can be placed into one of the above mentioned openings in the roadway element. As a result of this construction it is simple to grip a roadway element on its end surface using the roadway element shovel and to transport it to the location intended therefor. Because the roadway elements are no longer picked up from the side by the mechanical shovel, the roadway elements can, as set forth above, be placed on the ground surface without the mechanical shovel having to travel directly over the ground surface.
[0018] A further aspect of the invention relates to a method for providing a removable, semi-permanent roadway, wherein the method comprises of placing a number of roadway elements on the ground surface such that the intermediate space between the ends of the successive roadway elements amounts to a maximum of five centimetres. When the roadway elements are thus placed or, more preferably, when the roadway elements are placed mutually abutting so that the end edges thereof make mutual contact, a relatively smooth transition is created between successive roadway elements. By moreover placing the roadway elements in successive alignment the above mentioned raised portions or bumps in the road surface do not occur, whereby greater speeds of the vehicle are possible on the roadway.
[0019] Further advantages, features and details of the present invention will be elucidated on the basis of the following description of a number of preferred embodiments thereof. Reference is made in the description to the following figures:
Figure 1 shows a perspective view of an excavator 1 and a mechanical shovel 11 with which roadway plates P can be transported;
Figure 2 shows a view of a preferred embodiment of a balanced element;
Figures 3 and 4 show a top view and a side view of a preferred embodiment of a plate shovel;
Figure 5 shows a top view of a preferred embodiment of the roadway plate; and
Figure 6 shows a top view of a part of a removable roadway over which a truck is travelling.
[0020] Figure 1 shows an excavator 1 which can travel over a ground surface O using caterpillar tracks 2. The excavator comprises a crane 3 which is constructed from a number of articulated arms 4, 5 and which can be displaced in up and downward direction and in sideways direction using lifting cylinders 6, 7, 8. Using a ball joint 10 a gripper or balanced element 9 is arranged on the free outer end of the articulated arm 3.
[0021] Balanced element 9 is shown in more detail in Figure 2 and comprises, among other parts, a support 20 on which the above mentioned joint 10 and a beam 21 are provided. Connecting rods 22 are also arranged between the outer ends of beam 21 and support 20. A number of suction elements 23, 23I, 23II, 23III (in the shown embodiment four, but this number can be larger or smaller) are arranged on the underside of beam 21 by means of a chain construction 24. Suction elements 23-23III are connected by means of pressure lines 25-25III to a vacuum pump 26. When the crane has placed balanced element 9 above a roadway plate P, for instance on the uppermost plate P of a stack of plates placed on the ground surface as shown in Figure 1, and the suction elements contact the top side of plate P, underpressure is applied in suction elements 23-23III so that balanced element 9 clamps fast to the top side of plate P. At sufficient underpressure a suitable clamping force is obtained to attach the balanced element firmly to and lift the plate P. Once the crane has lifted the roadway plate, the plate is set down at a position intended for the purpose.
[0022] In an embodiment which is not shown, the roadway plates are placed on the loading floor of a semi-trailer. The semi-trailer itself is herein provided with a crane of a construction similar to that of excavator 1. The crane is embodied such that roadway plates P can be transported from the loading floor to the rear or front side of the semi-trailer by rotating the crane through about 180°, whereafter the plates can be set down on the ground surface in front of or behind the semi-trailer. Each time a plate is set down the semi-trailer is driven onto the roadway plate that has just been set down, whereafter the process of unloading the following roadway plate is repeated. It is hereby possible to lay the removable roadway in rapid and simple manner without the semi-trailer herein coming to stand directly on the ground surface. This is because the semi-trailer can always be driven onto a previously laid roadway plate.
[0023] Figure 1 shows an alternative mobile platform in the form of a mechanical shovel 11 which can travel over ground surface O using wheels 12. Mechanical shovel 11 is provided in known manner with a lifting mechanism 3 to which a digging element or a lifting element is normally coupled. In the shown embodiment however, a so-called roadway plate shovel 19 is arranged on lifting mechanism 3.
[0024] A more detailed view of a preferred embodiment of a roadway plate shovel is shown in figures 3 and 4. Shown is a support 30, at right angles to which is arranged a bearing plate 31. In order to give the construction sufficient stability, two strengthening beams 32 are provided between support 30 and bearing plate 31. In the shown embodiment the width of the bearing plate decreases as the distance from the support becomes greater, this in order to facilitate "shovelling up" of a roadway plate P. Other forms are however also possible. The free outer end 35 of bearing plate 31 is moreover slightly chamfered. This chamfering also has the purpose of simplifying the "shovelling up". Further provided on support 30 are coupling elements 33 and 34 with which the support 30 can be attached in known manner to lifting mechanism 3 of mechanical shovel 11.
[0025] Displacement of the roadway plates takes place by driving the mechanical shovel 11 close to the front or rear end of a roadway plate P, sliding the bearing plate 31 with the chamfered part 35 under the relevant outer end of the roadway plate such that protrusion 36 slides into an opening 15 (see Figure 5) of roadway plate 5. In this manner the mechanical shovel can grip the roadway plate at the relatively narrow end surface of roadway plate P, whereby it is made possible to place the roadway plates mutually in line on the ground surface with relatively simple manoeuvres.
[0026] As noted above, figure 5 shows a top view of a roadway plate according to the invention. The length L of such a roadway plate is at least eight metres and preferably ten metres, while the width B of the roadway plate is at least two metres, and preferably three metres. With such dimensions the left and right-hand wheels of vehicles V (figure 6) making use of the removable roadway will always rest simultaneously on a single plate. The relatively great rigidity of roadway plates P, the relatively high own weight and/or the relatively large dimensions prevent plates displacing relative to each other and possibly becoming unstable.
[0027] In the above description the embodiments are limited to roadways over which vehicles can travel. The roadway elements can however also be applied to temporarily harden other terrain, such as to harden festival sites, construction sites and so on. The invention also extends to such embodiments. The rights sought are not limited to the above described preferred embodiments of the invention, but are rather defined by the following claims, within the scope of which many modifications can be envisaged.
1. Removable, semi-permanent roadway on which a vehicle can be transported over a ground
surface, comprising a number of plate-like roadway elements which can be placed mutually
in line on the ground surface, wherein the roadway elements have dimensions such that
during use a left and right-hand wheel of the vehicle support simultaneously on the
same roadway element.
2. Roadway as claimed in claim 1, wherein the width of a roadway element amounts to more
than 2 m, and preferably more than 3 m.
3. Roadway as claimed in claim 1 or 2, wherein the length of a roadway element amounts
to more than 8 m, and preferably more than 10 m.
4. Roadway as claimed in any of the foregoing claims, wherein the roadway elements are
formed by steel plates.
5. Roadway as claimed in any of the foregoing claims, wherein close to at least one of
the edges of a plate-like roadway element there is arranged an opening to which transport
means can be connected for the purpose of transporting the roadway element.
6. Roadway as claimed in claim 5, wherein openings are provided close to both relatively
narrow outer ends of a rectangular roadway element.
7. System for placing and removing a removable, semi-permanent roadway as claimed in
any of the foregoing claims, comprising a crane for arranging on a mobile platform,
wherein the crane is provided with gripping means with which one or more roadway elements
can be gripped, the gripping means comprising:
- a support element which can be mounted on the crane, wherein the support element is preferably mounted rotatably on the crane,
- suction elements arranged on the support element; and
- a vacuum pump connected to the suction elements, wherein the support elements and the vacuum pump are adapted to fixedly hold the roadway elements through underpressure by the support element.
8. System as claimed in claim 7, wherein the mobile platform is a semi-trailer and the
crane is adapted to displace a roadway element between a first position, in which
the roadway element is stored on the loading floor of the semi-trailer, and a second
position in which the roadway element is placed on the ground surface in line with
the semi-trailer.
9. System for placing and removing a removable, semi-permanent roadway as claimed in
any of the foregoing claims, comprising a roadway element shovel for displacing a
roadway element, the roadway element shovel comprising:
- a bearing plate on which a roadway element can be placed;
- a support which is provided on the bearing plate and on which first coupling means are arranged for coupling the bearing plate to a mobile platform; and
- second coupling means extending from the bearing plate for coupling to the bearing plate the roadway element placed on the bearing plate.
10. System as claimed in claims 5 and 9, wherein the second coupling means comprise a
protrusion which can slide in and out of an opening in the roadway element.
11. System as claimed in claim 9 or 10, wherein the mobile platform is a mechanical shovel.
12. Method for providing a removable, semi-permanent roadway as claimed in any of the
claims 1-6, comprising of placing a number of roadway elements on the ground surface
such that the intermediate space between end edges of successive roadway elements
amounts to a maximum of five centimetres.
13. Method as claimed in claim 12, comprising of placing successive roadway elements with
end edges mutually abutting.