A DEMINING MACHINE AND A METHOD OF DEMINING

Abstract: A demining machine utilises a roller (30-39; 72; 83, 84) that rolls on the ground. The roller has annular rows of teeth (58, 80) that penetrates the earth as the roller moves. There is a vibrator (60) inside the roller. The vibrations improve the penetration into the ground and the tips of the teeth transmit the vibrations to the ground so that the vibrations detonate mines deeper down in the earth. The root systems of the vegetation are left comparatively undisturbed.

Description: A demining machine and a method of demining This invention relates to a method of demining by moving a roller over the area to be demined, the roller having a large number of earth penetrating tools. It also relates to a demining machine comprising a roller that is adapted to be part of or mounted to a vehicle and has a large number of earth penetrating tools In war areas, there are numerous mines left in the soil when the war is over. Manual demining operation is extremely hazardous and slow and various methods have there- fore been developed for mechanical demining by detonating the mines in the ground. One prior art method employees a tank that has a rigid milling roller mounted at its front. The roller works as a cultivator to a depth of some decimeters and causes the mines to detonate. The energy consumption is extremely high and the method is slow which makes the method inadequate when large territories need to be demined. Also, the method is not always suitable since all vegetation will be destroyed. In another prior art method, vibrating rollers are employed to vibrate the ground when they roll on the ground. Various methods are also known in which chains or the like are used to beat the ground. It is an object of the invention to provide for a method that is fast and reliable, that is, it should not leave any undetonated mines in the ground. It should also be comparatively low in energy consumption and it should not destroy the soil. This is generally accomplished by a method and a machine in which the roller is vibrated while rolling over the ground, wherein the tools of the roller penetrate into the ground and transmit the vibration to the ground at a depth under the surface. The invention is defined by the characteristics defined in the claims. The invention will be described with reference to the drawings which show three embodiments of the invention. Figure lshows schematically a demining machine in a side section taken along lines 1-1 in Figure 2, Figure 2 is a schematic top plan view of the machine shown in figure 1 , Figure 3 is a section through one of a number of similar rollers shown in Figures 1 and 2, Figure 4 is a side view of a demining machine as a second embodiment of the invention, Figure 5 is a top plan view of the machine shown in Figure 4, Figure 6 is a side view of a demining machine as a third embodiment of the invention. Figures 1 and 2 show a demining machine which has a stiff frame that consists of the frame members 11-14. Two forward-directed beams 12,13 extend from a cross beam 1 1 , and a beam 14 extends rearwardly from the cross beam 1 1. The beam 12 carries two bogies 15,16, the beam 13 carries a bogie 17, and the beam 14 carries two bogies 18,19. The bogies 15-17 are pivotable about an axis I and the bogies 18,19 are pivotable about an axis II. Each bogie 15-19 carries two rollers 30-39. The rollers 32-37 are not shown complete as the rollers 30,31,38,39. The cross beam 1 1 is carried in bearings by two arms 45,46 so as to be turnable about its axis III, and the arms 45,46 are pivotably mounted in two supports 47 of a vehicle shown as a caterpillar carried vehicle, for example a tank 48. The arms are pivotable about an axis IV. The tank is shown in Figure 1 only. The arms are shown individually supported by the vehicle, but they can instead be united and supported as a unit to a universal joint, which would facilitate steering. Such a preferred design is, however, not shown. The steering will be still easier if the frame 11-14 is supported at its rear end and hydraulic cylinders or other means are arranged for lifting the arm or arms 45,46. Instead of a stiff frame 1 1-14, the frame can be articulated, which also improves the steering. These and other ways for improving the steerability can be used alone or in any combination. A roller is shown schematically in Figure 3. It has a drum 50 onto which a plurality of annular plates 51 and spacers in the form of rings 49 are piled. They are clamped together by means of non-illustrated means. The annular plates 51 are in the form of stars so that they will have a plurality of tools or tips 58 as can be seen on Figure 1. The annular plates can for example be about 1 cm thick and the spacers can for example be 5-10 cm thick. The drum has an annular shaft 53 that is joumaled in bearings 52 in the bogie that is denoted by 54 and represents all the bogies 15-19. Another shaft 55 extends through the shaft 53 and it is joumaled therein by means of bearings 56,57. An eccentric weight 60 is fastened to one end of the shaft 55 and a V-belt sheave 59 is fastened to the other end of the shaft 55. A protecting plate 67 is located under the weight 60. The eccentric weights 60 in the rollers 30-39 are driven by a common motor 61 which is mounted on the arm 45. The motor has a drive shaft 62 which rotates a shaft 63 by a V- belt transmission. Through the shaft 63, the motor 61 drives all the eccentric weights 60 by means of V-belt transmissions in the beams 12-14 and in the bogies 15-19. In Figure 1, the V-belt 65 in the bogie 16 and the V-belt 66 in the bogie 18 can be seen. The drums in a bogie have their tools, that is, the points 58 of the annular plates arranged in annular rows and the rows are offset so that the tools of a roller extend in between the tools of the other roller. As a result, the tools of a roller clean the spaces between the tools in the other roller and vice versa. Without such a cleaning, stones could get stuck between the tools and jeopardise the operation. The vibration improves the cleaning. Two rollers in tandem increase the chances of detonating all mines and the use of a bogie is a further improvement. If the first roller should have an insufficient penetration, the next roller will have its tools offset from the first roller and increase the chances of a good penetration. The vibration causes detonation and the chances of detonation increases because the vibrations are transmitted to the ground from the tools at a depth below the surface. The vibration gives the tips of the tools an impacting action and the vibration detonates mines that are considerably deeper down than the tips. Another advantage with the vibration is that it improves the penetration of the tools into the ground and the rollers need not be very heavy. The ground is left comparatively undisturbed after the operation. It will have narrow slots arranged in a pattern. These slots can often be advantageous since they aerate the soil and improves water penetration. The roots of the vegetation are left comparatively- undamaged and the risk of erosion is usually not increased. The annular plates and their tips will not be damaged from the detonation of troop mines and usually not even when larger mines detonate. Large tank mines may damage the annular plates, but if some plates are so damaged that the rollers in a bogie cannot rotate, another bogie is simply replaced for the damaged one; a switch that can normally be done in less than half an hour. The damaged rollers are then renewed by replacement of annular plates. Such a reparation is fast since the annular plates and the spacers are simply clamped together and the tools, that is, the annular plates, are not very expensive. The simple V-belt transmission for the vibration does not increase considerably the reparation time. Altematively to thin annular plates and spacers as shown, heavy rings with individually mounted exchangeable tools with hard metal tips can be used. Machines of various size can be built with the same elements, that is, with various numbers of short rollers of the kind described. Very large machines pushed forwardly b a tank can be used in sand deserts and the like. Figures 4 and 5 show a smaller, more versatile and light machine. It is made up of the rear part 70 of a tractor, a loading machine, or the like machine with articulated steering. A frame 71 carries a roller 72 and it is coupled to the rear part 70 by the conventional hinge connection 73. Thus, the roller 72 replaces the front wheels of the articulated tractor. The roller 72 is shown having rows of individual tools or teeth 80. The roller has a built-in hydraulic motor so that both the wheels on the rear part 70 of the machine and the roller 72 of the front part provide for the traction. Chains 74 extend loosely between the rows of teeth to provide for cleaning of the spaces between the rows of teeth. As an improvement over the roller shown in Figure 3, the roller is elastically mounted in rubber pads (not illustrated) so that the forces will not be transmitted directly to the frame 71 when the roller detonates a mine. Supports 85 are mounted on the frame 71 to limit the movement of the roller. A smaller roller 75 is mounted in arms 76,77 which are pivotably mounted on the frame 71 and extend forwardly so that the roller 75 rolls a few meters in front of the main roller 72. A tank mine will usually detonate when the small roller 75 rolls over the mine, and the arms 76,77 with the roller 75 will pivot upwardly and then again fall down onto the ground. The roller 75 is very rigid and will usually not be destroyed. Thus, the roller 75 will protect the main roller 72 from big mines. Heavy springs 78 apply a downward bias force on the small roller 75. The drivers cabin 79 is high up and as far back as possible and it is therefore safe to drive the machine. Figure 6 shows a remote controlled machine that is also articulated. Both the rear part 81 and the front part 82 have a roller 83 and 84 respectively. The rollers are of the same kind as the roller of the machine shown in Figures 4 and 5an they have rows of individually mounted teeth 80 in the same way. They apply the traction force to the ground and they apply vibration to the ground. Because of the combination of earth penetrating tools and the vibration, the machine need not be heavy and this machine can be made so light that it can move on ground which does not allow other demining machines.

Claims: Claims 1. A method of demining by moving a roller (30-39;72;83.84) over the area to be demined, wherin the roller has a large number of earth penetrating tools (58.80), characterised in that the roller is vibrated while rolling over the ground so that the tools penetrate into the ground and transmit the vibration to the ground at a depth under the surface. 2. A demining machine comprising a roller (30-39;72;83,84) that is adapted to be part of or mounted to a vehicle and has a large number of earth penetrating tools (58,80), characterised by a vibrator (60) for vibrating the roller to make the tools transmit the vibrations to the ground at a depth under the surface when the roller rolls on the ground. 3. A demining machine according to claim 2, characterised in that the roller (72,84)is mounted as the front part (71 ,82) of an articulated vehicle, the rear part (70,81 ) of which carries the engine. 4. A demining machine according to claim 2 or 3, characterised by drive means in the roller for propelling the roller. 5. A demining machine according to claim 4, characterised in that said drive means is a hydraulic motor. 6. A demining machine according to any one of the claims 2-5 characterised in that the tools (58,80) are arranged in annular rows and cleaning means (58,74)are arranged between the rows. 7. A demining machine according to any one of the claims 2-6 characterised in that the roller (72,83,84) is elastically mounted in a frame (71 ,82,83) and a support (85) is arranged to limit the upward movement of the roller relative to its mounting. 8. A demining machine according to claim 7, characterised in that said support (85) for limiting the movement is inside the roller. 9. A demining machine according to any one of the claims 2-8, characterised in that a roller (75) with smaller diameter is mounted in pivoting arms (76,77) forwardly of said vibrating roller (72).

Inventors: OESTHOLM MAGNUS, OESTHOLM, MAGNUS
Applicants: OESTHOLM MAGNUS, SWEDISH DE MINING EQUIPMENT AK, OESTHOLM, MAGNUS, SWEDISH DE MINING EQUIPMENT AKTIEBOLAG
Application year: 1997
Main classification: F41H11
IPC codes: F41H11