Patent Publication Number: US-2002007725-A1

Title: Mine clearance system

Description:
[0001] The invention concerns a mine clearance system as set forth in the classifying portion of claim  1 .  
       [0002] DE 42 30 769 C2 discloses a mine clearance arrangement which is in the form of a front-mounting apparatus for vehicles, in particular armoured vehicles, for clearing land mines. That known mine clearance arrangement has clearance shield elements with excavating or digging teeth which are arranged adjustably on a mounting frame on a line inclinedly relative to the direction of travel. Each clearance shield element comprises a concavely curved upper portion and is extended by the excavating or digging teeth for the clearance depth. Each clearance shield element can be guided on the ground by way of associated sliding surfaces. The individual upper portions are held on the mounting frame adjustably individually transversely with respect to the direction of travel by way of horizontal pivot axes and can be automatically guided on the ground by way of associated sliding surfaces. The sliding surfaces are connected to the upper portions by way of inclined portions which are disposed in front thereof in the direction of travel. The upper portions carry the excavating or digging teeth and/or the clearance teeth for displacement of the upper portions of the clearance shield elements.  
       [0003] DE 44 41 075 C1 discloses a mine clearance vehicle with a frontal attachment which is connected to the vehicle in such a way that it can be raised and lowered, by way of hydraulically or pneumatically operating piston-cylinder arrangements and possibly by way of frame limbs pivotably mounted to the vehicle. The frontal attachment is equipped with a casing which is at least partially open in the direction of travel forwardly and downwardly, with a milling or cutting drum which is arranged therein substantially transversely with respect to the direction of travel and which is preferably hydraulically driven in rotation and which rotates in opposite relationship to the direction of travel and conveys the respective mine to be cleared, to a position in front of the drum, and there causes it to explode by application of pressure thereto. For the selection of magnetic materials, the frontal attachment is of such a design configuration that a magnet or a magnet arrangement is disposed in front of the milling or cutting drum for picking up magnetic pieces.  
       [0004] DE 44 42 153 C1 discloses a clearance apparatus for mines, grenades and other explosive bodies which are disposed in or on the ground. That clearance apparatus has elements which rotate in opposite relationship to the direction of forward travel and it is in the form of a front-mounting apparatus for a vehicle, in particular for an armoured vehicle. In that known clearance apparatus the rotating elements are in the form of disc bodies which have cutting or saw elements at least at the outer periphery. The arrangement has a plurality of disc bodies which are oriented vertically and arranged in side-by-side relationship.  
       [0005] All the above-described clearance apparatuses and arrangements and vehicles are in the form of front-mounting apparatuses or vehicles with a frontal attachment. However the clearance certainty level of clearance arrangements of that kind can leave something to be desired, that is to say, the clearance certainty level required by the United Nations of at least 99.6% in the case of humanitarian mine clearance procedures still cannot be reliably attained by those known arrangements.  
       [0006] DE 94 06 207 U1 discloses an apparatus for seeking mines which are laid on or in the ground, wherein an apparatus towed by a tractor vehicle has a horizontally mounted roller which is drivable by a drive motor in the opposite direction to the towing direction. Mounted on the roller are tools which are such that earth material in front of the roller, down to its predetermined depth, is conveyed upwardly and rearwardly onto a sifting and/or conveyor apparatus which moves along behind the roller, the sifting and/or conveyor apparatus being so designed that the earth material drops therethrough.  
       [0007] The object of the present invention isthat of providing a mine clearance system of the kind set forth in the opening part of this specification, with which the requirement set by the United Nations for a clearance certainty level of at least 99.6% is reliably met.  
       [0008] In accordance with the invention, in a mine clearance system of the kind set forth in the opening part of this specification, that object is attained by the features of the characterising portion of claim  1 . Preferred embodiments and developments of the mine clearance system according to the invention are characterised in the appendant claims.  
       [0009] The mine clearance system according to the invention has the advantage that economic clearance of relatively large minefields can be effected within the context of humanitarian clearance, in a timesaving manner, that is to say quickly, wherein the frontal attachment of the mine clearance vehicle, with the milling roller, causes destruction of mines to be cleared, and the mine-seeking apparatus provides for seeking of or destruction of mines which are not caught by the frontal attachment. Items which are larger than an order of magnitude of 5 cm are transported by means of the conveyor device of the mine-seeking apparatus to a sifting device.  
       [0010] The mine clearance vehicle or the mine-seeking vehicle may be a modified Leopard tank, that is to say the chassis of a Leo 1 A4, in which the transmission unit, the ABC-installation, the munitions bunker, the track aprons or guard plates and the like are removed for weight reduction purposes. In order to achieve the above-indicated clearance safety level, the clearance speed, that is to say the speed of travel of such a modified Leo 1 A4 may not be higher than 30 m/min, preferably between 8 and 16 m/min. That can be achieved if a step-down transmission is fitted to the existing cross-shaft unit of the Leo 1 A4. With a diesel-hydraulic drive of that kind, two oil motors are used as drive motors, wherein the oil pump is driven by way of a pump distributor gear unit and an intermediate coupling means by the motor of the Leo 1 A4 at a constant motor speed of for example 1600 min −1 .  
       [0011] As the mine clearance system according to the invention is intended and provided for the clearance of defensive mines and also so-called jumping mines and for the clearance of tank mines, the respective armoured vehicle must be absolutely safe for the operator. For that purpose the driving cabin of the respective armoured vehicle is mounted on shock-absorbing damper elements. To afford protection from jumping mines the driving cabin itself is made from a suitable armour steel in its front region. The viewing windows preferably comprise armoured glass and may additionally be covered with protective panels or shutters. The bottom region of the undercarriage and/or the inner region of the shell structure of the vehicle preferably have additional armouring. Thus the bottom region of the undercarriage may be reinforced with armour steel to afford protection from possible hollow-charge mines. Additional bulkhead means may be provided in the internal region of the shell structure of the vehicle. They may comprise polyethylene plates.  
       [0012] In order to be able to carry the weight of the corresponding milling roller, the tread rollers of the vehicle and/or the support arms on which the corresponding milling roller is disposed in such a way that it can be raised and lowered are provided with a reinforcement. For that purpose the rubber covers on the tread rollers can be replaced by coating means of Vulkolan and/or the front support arms can be supported by additional hydraulic shock absorbers.  
       [0013] The mine clearance system according to the invention provides that the destruction of mines is effected by the first milling roller engaging into the ground with the mines being simultaneously triggered or cut up by the cutting bit elements or roller teeth which project radially away from the corresponding milling roller. The depth of engagement is desirably up to 40 cm. The cutting bit elements which are arranged in a helical configuration in one or more pitch flights at the milling roller peripheral surface are arranged in dependence on the roller geometry, the roller speed, the advance or travel speed and the nature or type of ground. The corresponding milling roller is connected to the associated armoured vehicle in such a way that it can be raised and lowered by means of a carrier arm structure. For reasons of weight that carrier arm structure preferably comprises hollow profile elements of suitable mechanical strength. The carrier arm structure can be pivotable, that is to say raised and lowered, about a pivot axis, by means of hydraulic piston-cylinder arrangements. Adjustment and control in respect of height of the respective milling roller can be implemented electrohydraulically. Preferably disposed between the respective milling roller and the associated undercarriage of the armoured vehicle is a thick-wall barrier which upon detonation in particular of tank mines reliably prevents damage to the hydraulic installation or feed lines and damage to the vehicle chassis and the tracks of the armoured vehicle.  
       [0014] The structural configuration of the milling roller, the arrangement of the bit elements, the geometrical shape of the bit elements, the diameter of the respective milling roller, the spiral angle of the bit elements and the roller speed crucially determine the clearance probability, that is to say the clearance certainty level.  
       [0015] A further quite considerable advantage of the mine clearance system according to the invention is that ground cultivation is involved in the mine clearance procedure by means of the mine-seeking vehicle or mine-seeking apparatus. The ground is correspondingly loosened up being worked with the first and second milling rollers so that after the mine clearance work has been carried out, it is possible to build on the land or to re-afforest it. In addition the mine clearance system according to the invention is designed in such a way that the front attachment or the mine-seeking apparatus of the first armoured vehicle or the mine-seeking apparatus of the second modified armoured vehicle which is independent of the first modified armoured vehicle can be removed in order thereafter to be able to transport the individual components even over bridges of correspondingly reduced load-bearing capability. That is an aspect of significance in particular for Third World countries. 
     
    
    
     [0016] Further details, features and advantages will be apparent from the following description of a mine clearance system according to the invention which is diagrammatically illustrated in the drawing in which:  
     [0017]FIG. 1 is a side view of an embodiment of the mine clearance system,  
     [0018]FIG. 2 is a side view of substantial parts of a modified armoured vehicle of the mine clearance system shown in FIG. 1, and  
     [0019]FIG. 3 is a diagrammatic view of a drive unit. 
    
    
     [0020] Referring to FIG. 1 shown therein as a side view is a mine clearance system  10  with a mine clearance vehicle  12  and a mine-seeking vehicle  14 . The mine clearance vehicle  12  and the mine-seeking vehicle  14  are each formed by a respective modified armoured or tank vehicle  16 , as is also clearly shown in FIG. 2. In the case of the respective armoured or tank vehicle  16 , the tank turret is replaced by a driving cabin  18 . As can be seen from FIG. 2, the driving cabin  18  is supported on shock-absorbing damping elements  20 . FIG. 2 also clearly shows that the bottom region of the undercarriage has additional armouring  22  and that the inner region of the shell structure of the vehicle  16  has additional armouring  24 .  
     [0021] Provided at the, front end of the mine clearance vehicle  12  is a milling roller  26 . The milling roller  26  is provided with cutting bit elements  28  which project radially away from the peripheral surface  30  of the milling roller  26 . The milling roller  26  is drivable about a horizontal axis  34  in a shielding housing  32  in the opposite direction to the direction of travel, as is indicated by the arrow  36 . The milling roller  26  with the associated housing  32  is held on two lateral carrier arms  38  which are temporarily fixed to the mine clearance vehicle  12 , which are pivotable about a horizontal pivot axis  40  and which are thus pivotable in respect of height or for setting a desired depth of penetration into the ground. The drive for the milling roller  26  and the pivotable drive for the carrier arms  38  are afforded by means of a drive device  42  which is provided in the tail region of the mine clearance vehicle  12 .  
     [0022] The mine-seeking vehicle  14  is formed by a modified armoured or tank vehicle  16  which is similar to the mine clearance vehicle  12  and which is releasably combined with a second milling roller  44  which is disposed pivotably about a horizontal axis, as indicated by the arcuate double-headed arrow  46 . The second milling roller  44  is combined with a shielding housing  48  and, like the first milling roller  26 , it has cutting bit elements  50  which project radially away from the peripheral surface  52  of the second milling roller  44 . A conveyor and sifting device  56  is arranged downstream of the second milling roller  44  which, like the first milling roller  26 , is driven in opposite relationship to the direction of travel, as is indicated by the arrow  54 .  
     [0023]FIG. 3 is a greatly simplified view of the drive unit  58  of the mine clearance vehicle  12 . The drive motor  60  is drivingly connected by the drive output or motor shaft  62  to a coupling means  64 . The pump distributor gear unit  66  is connected to the coupling means  64 . The pump distributor gear unit  66  and the coupling means  64  are enclosed by way of a transition ring  68  which is in the form of a bell housing. The pump distributor gear unit  66  drives oil pumps  70 , of which a first is used for the left-hand travel drive  72 , a second for a cooler or radiator  74 , a third for a reserve  76  and the fourth for the right-hand travel drive  72  of the mine clearance vehicle  12 .  
     [0024] As shown in FIG. 3 the drive unit  58  includes a second drive motor  78  which in this example is provided for the drive for the milling rollers  26 . The drive motors  60  and  78  are arranged vertically one above the other in the mine clearance vehicle  12 . It is however expressly emphasised that the arrangement of two drive motors  60  and  78  is one possible way of driving different items of equipment. All devices such as milling rollers, travel drive, cooler or radiator and the like may also be operated by a single drive motor or engine  60  if that drive motor or engine  60  is suitably provided with coupling means and pump distributor gear unit.  
     [0025] From the second drive motor  78  an output drive shaft  80  goes to the coupling means  82  which is in turn connected to the pump distributor gear unit  84 . The pump distributor gear unit  84  drives by way of suitable oil pumps the milling rollers  26  of which two are used as right-hand milling rollers and two are used as left-hand milling rollers.  
     [0026] Travel speeds of down to 0.72 m/min can be achieved with the drive unit  58 . That low travel speed which is not possible with the usual drives of a combat tank, together with corresponding working speeds in respect of the milling rollers  26 , guarantees optimum mine clearance. The working speeds of the milling rollers  26  are between 14 and 30 m/min.