Patent Abstract:
An anti-mine unit or assembly is adapted for being mounted to a prime mover or transport vehicle to reduce the dangers when clearing minefields. The anti-mine unit includes a frame, a plurality of digging cables, a plurality of drag cables, at least one side curtain of curtain cables, a rear curtain of curtain cables, and a top plate. The anti-mine unit may include a wire cutting device and a plurality of deflector cables. Heavy tubes of thick sidewalls are welded together to form the frame from which heavy cables are supported. The digging cables, drag cables, curtain cables and deflector cables are secured to the frame such that the cables, frame, and thick top plate form a unit that digs up, exposes and/or explodes mines, keeps the explosions and shrapnel controlled, and clears a pathway for the vehicle&#39;s drive wheels or tracks.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/402,546, filed Aug. 12, 2002. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an anti-mine unit or assembly of very robust construction that will explode anti-personnel mines and will dig up, expose, exhume and/or explode anti-tank mines. The detonation of the mines is done under a complex cover of cables and plates in order to absorb and deflect shrapnel and blast. 
     2. Description of Related Art 
     Land mines are one of the weapons in the arsenal of modern warfare. There are land mines designed for different purposes, e.g., anti-personnel, anti-tank, etc. In time of war, it is frequently necessary to clear a minefield for the construction of an airfield, or to at least clear a path through the minefield for an advance. Minefields are often not completely cleared during wartime, and quite frequently civilians are injured by an exploding land mine years after the combat is over. Clearing minefields is hazardous duty. Several devices have been developed in an effort to clear minefields efficiently while reducing casualties which may otherwise occur while clearing minefields. 
     For example, U.S. Pat. No. 655,584, issued Aug. 7, 1900 to Schwartz, describes a combined roller and harrow consisting of a frame rotatably supporting a sectional or two-part roller and having a cross-strip detachably secured thereto at the rear. 
     U.S. Pat. No. 731,146, issued Jun. 16, 1903 to Wilmeth, describes a combined agricultural machine for multiple services in the tilling of soil. The invention provides for the operation of soil-working bits or members in a circular or rotative manner. 
     U.S. Pat. No. 1,102,326, issued Jul. 7, 1914 to Dalsing, describes a plow having means for swinging the cultivator blades laterally in and out between rows of plants so that the ground may be cultivated between the rows. 
     U.S. Pat. No. 1,679,628, issued Aug. 7, 1928 to Roby, describes an attachment mechanism between a plow and drill that insures proper travel of the drill, as well as permitting sharp turning thereof when necessary. 
     U.S. Pat. No. 2,920,405, issued Jan. 12, 1960 to Cole, describes a combination grading tool comprising a rake carrying frame member adapted to be hitched to a tractor for suspension from the rear thereof and a scarifier unit. 
     U.S. Pat. No. 2,964,863, issued Dec. 20, 1960 to Shepherd, describes a machine with movable trunnions. Various implements, such as a bulldozer blade, a ripper, a scraper blade, a push-loading scraper, a backfilling blade, or the like, may be provided. 
     U.S. Pat. No. 3,260,003, issued Jul. 12, 1966 to Rolfe, describes a bulldozer or like implement for attachment to a tractor. 
     U.S. Pat. No. 4,593,766, issued Jun. 10, 1986 to Gossard, describes a crawler tractor with a dozer blade and fitted with accessories to loosen the ground in the strafing pit area of a gunnery range and simultaneously remove from the ground rocks the size of a man&#39;s fist and larger and spent projectiles. The tractor is provided with an electromagnet positioned ahead of the dozer blade. Positioned to the rear of the tractor is a chisel bar with a plurality of chisel blades. Just ahead of the chisel bar is a rock rake that is supported with its tines at such an angle that their tips barely scrape the surface of the earth. Ahead of the rock rake, there is a drag consisting of a section of railroad rail suspended from the drawbars of the chisel assembly at a height sufficient to just scrape the surface of the ground during operation of the tractor. 
     U.S. Pat. No. 4,667,564, issued May 26, 1987 to Schreckenberg, describes an apparatus for clearing land mines that is provided with clearing elements which can freely move up and down independently of one another, and which are disposed in a movable carrier which is embodied as an attachment for a tracked or wheeled vehicle. Each clearing element is a small, rigid clearing plate having a supporting arm, which is suspended on a support associated with the movable frame, and is movable about a horizontal pivot axis which extends transverse to the direction of travel. The supporting arms of all of the clearing plates are the same length. All of the clearing plates, without contacting one another and at a slight distance from one another, are disposed in a compound arrangement which is parallel to the support and is arranged behind the latter in the direction of travel. The compound arrangement is either V-shaped, having its point facing in the direction of travel, or extends continuously at an angle to the direction of travel. 
     U.S. Pat. No. 5,183,119, issued Feb. 2, 1993 to Wattenburg, describes an anti-snag plowing system suitable for clearing mines. The plowing system comprises several digging-knife units, or plows, and a harrow. Both are attached in tandem to a chain matrix, which is pulled with either a helicopter or tractor. The digging-knife units rotate if the digging-knives hit an immovable snag. The harrow is covered with a chain blanket, and may have magnetic or sonic wave mine triggers if the system is used for clearing mines. 
     U.S. Pat. No. 6,330,920, issued Dec. 18, 2001 to Wanner, describes a mine stripper with numerous plow blades that rotate as they dig deeper to achieve an equilibrium depth of about nine inches and a basket that presses against the top of these blades to receive dislodged mines while sifting away attached soil. 
     WO93/11402, published Jun. 10, 1993 to Aardvark Clear Mine Limited, describes an apparatus for clearing mines. The apparatus includes a support on which is mounted a first impact device, such as a flail rotor. Also mounted on the support are a number of ground engaging members, each of which are adapted to extend below the surface of the ground being cleared so that when the support is moved across the surface, the members expose mines in their path. After being exposed, the first impact device generates an impact on the exposed mines. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant inventions as claimed. 
     SUMMARY OF THE INVENTION 
     The invention is an anti-mine unit or assembly for use with a tractor, bulldozer, or other implement that will explode anti-personnel mines and will dig up, expose and/or explode anti-tank mines. Heavy tubes having thick sidewalls, e.g., ¾″ thick, are welded together to form a frame from which heavy cables are supported. The heavy cables may be cut from 2″ and 3″ cables normally used in drag lines and other very heavy equipment. Digging cables, drag cables, curtain cables and deflector cables are attached to the frame with a thick top plate, e.g., ¾″ thick steel plate, to dig up, expose and/or explode anti-tank mines, explode anti-personnel mines, keep the explosions and shrapnel controlled, and clear a pathway for the vehicle&#39;s drive wheels or tracks. 
     The cables are arranged so that as the vehicle moves forward, a row of cables having digging blades penetrates the ground, then a row of drag cables having ground engaging blades rides over the ground detonating mines by contact and by weight. A pair of deflector cables is suspended from the frame in front of each track or front wheel to move any unearthed and undetonated mines out of the path of the vehicle&#39;s tracks or wheels. Curtain cables are suspended from the sides and rear of the frame and, together with the top plate, serve to diminish the force of detonations to protect the vehicle, the operator of the vehicle, and nearby personnel. 
     Accordingly, it is a principal object of the invention to provide an anti-mine unit for safe reduction of mines in minefields. 
     It is another object of the invention to provide an anti-mine unit that protects personnel assigned to dig up and/or explode mines in a minefield. 
     It is a further object of the invention to provide an anti-mine unit that not only explodes anti-personnel mines but dig ups anti-tank mines. 
     Still another object of the invention is to provide an anti-mine unit that will be able to withstand the shock of exploding mines, and still be useful to continue the minefield reduction without the need for placing individuals at risk to sweep the mines. 
     It is an object of the invention to provide improved elements and arrangements thereof in an anti-mine unit for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an environmental side view of an anti-mine unit according to the present invention mounted on a bulldozer. 
         FIG. 2  is a perspective view of the frame of the anti-mine unit with the top plate, rear curtain and side curtains removed. 
         FIG. 3  is a fragmented perspective view, partly in section, of the front portion of the frame of the anti-tank unit showing attachment of the digging and drag cables. 
         FIG. 4  is a side view of a deflector cable of the anti-tank unit of the present invention. 
         FIG. 5  is a fragmented rear view showing two adjacent deflector cables of the anti-tank unit of the present invention. 
         FIG. 6  is a fragmented side view of the left side curtain of the anti-tank unit of the present invention, partially assembled. 
         FIG. 7  is a fragmented perspective view of the top portion of a curtain cable of the anti-tank unit of the present invention. 
         FIG. 8  is a side view, partly in section, showing the relation of a curtain cable to the frame of the anti-mine unit of the present invention when under stress from an explosion. 
         FIG. 9  is a front perspective view part of a wire cutter blade holder bracket of the anti-mine unit of the present invention. 
         FIG. 10  is a side view of one of the wire cutters attached to the front beam of the anti-mine unit of the present invention. 
         FIG. 11  is a fragmented perspective view, partly in section, of the front beam of the anti-mine unit of the present invention showing staggering of the digging and drag cable brackets. 
         FIG. 12  is a perspective view of the top plate of the anti-mine unit of the present invention. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is an anti-mine assembly or unit  100  adapted for being mounted to a heavy equipment vehicle or other prime mover for digging up, exposing and/or safely exploding mines, such as anti-personnel mines and heavy mines like anti-tank mines. The anti-mine unit  100  includes a frame, a plurality of digging cables, a plurality of drag cables, at least one side curtain, a rear curtain, and a top plate. The anti-mine unit  100  also has a pair of deflector cables mounted in front of the vehicle&#39;s tracks or front wheels, and may optionally one or more wire cutters mounted on the front of the frame. 
     In  FIG. 1 , the frame  1  of the anti-tank unit  100  is shown mounted to a bulldozer C upon the hydraulically operated hoist H 1  in place of the bulldozer blade. Normally, bulldozers have caterpillar tracks, as shown. The anti-mine unit  100  may also be mounted or placed upon other heavy equipment, such as tractors, front end loaders, tanks, scout cars, armored personnel carriers, tank retrievers, and others. For example, the anti-mine unit  100  may be mounted on a tracked front end loader, or a hydraulic excavator, with a quick hitch plate and a hydraulic swivel, the front end loader having the bucket removed and the operator cab well protected. The frame  1  preferably extends substantially or entirely across an end of the prime mover, and may be welded of 5″ round stock material of abnormally thick sidewalls, e.g., ¾″ thick steel, to have sufficient strength to withstand explosions from exploding mines. It is also considered feasible that square or rectangular stock material may be used, but round or cylindrical stock material, such as a pipe, is more easily accessible. 
     As shown in  FIG. 2 , the frame  1  has a front, beam  2 , an upper rear beam  8 , a lower rear beam  9 , upper right and left side beams  4 , 5  extending from the front beam  2  to the upper rear beam  8 , lower right and left side beams  14 , 15  extending diagonally from the front beam  2  to the lower rear beam  9 , right and left vertical rear beams  6 , 7  extending from the ends of the upper rear beam  8  to the corresponding ends of the lower rear beam  9 , and mounting beams  17 , 18  extending from the upper rear beam  8  to the lower rear beam  9  parallel to and between vertical rear beams  6  and  7 . 
     Front beam  2 , upper rear beam  8 , and upper side beams  4  and  5  define a substantially rectangular support on which the top plate  40  is mounted. Upper side beam  5 , lower side beam  15 , and vertical rear beam  7  defines a substantial triangular shape, as does upper side beam  4 , lower side beam  14 , and vertical rear beam  6 , in order to rigidly support front beam  2  in an elevated position at the front end of the anti-mine unit  100 . 
     The front beam  2  is preferably of large diameter, such as ten inches, in order to provide more and better area for the many welds that will be placed upon it, such as attachment of the front wire cutters  31 . Each of the mounting rear beams  17 , 18 , generally not less than ¾″ thick, has mounts  19 , 20 , respectively, for mounting the frame  1  to the prime mover. The frame  1  also has a plurality of lifting eyes  16  positioned on the front beam  2  and upper rear beam  8  to permit a lifting machine or vehicle to lift the frame  1  onto or off of the prime mover. 
       FIG. 11  shows a portion of the front beam  2  in greater detail. The front beam  2  has a plurality of digging cable shackles  21  and drag cable shackles  22  attached thereto by welding. Each shackle  21 ,  22  is defined by an opposing pair of links or lugs having aligned apertures defined therein for receiving a shackle bolt or pin. It will be noted that the drag cable shackles  22  have two pairs of apertures defined therein, the upper pair for receiving a drag cable, the lower pair for receiving a digging cable. The digging cable shackles  21  may have a half-moon support  410  welded below the aperture for supporting the shackle pin, and the drag cable shackles  22  may have a similar half-moon support  420  welded below the aperture for the same purpose. The digging cable shackles  21  and drag cable shackles  22  are mounted in alternating fashion and are staggered or offset radially in order to facilitate insertion and removal of the shackle pins for quick removal and replacement of the cables, while permitting close placement of adjacent cables. 
     As best shown in  FIGS. 2 and 3 , the top of the frame  1  is supported by the diagonal braces  10 , 11  extending from the center of front beam  2  to the rear corners of the upper frame. The diagonal braces  10 ,  11  are supported by the drag cable support beam  12  and the digging cable support beam  13 , which extend between upper side beams  4  and  5 . Drag lift cables  122  are attached to drag cable support beam  12 , while digging lift cables  132  are attached to digging cable support beam  13 . The drag lift cables  122  and digging lift cables  132  will prevent the drag cables  220  and digging cables  110 , respectively, from flaring out in front of the front beam  2  and possibly missing a ground mine if a mine is detonated under the assembly and top plate  40 . 
     To help dig through soil and rock, the digging cables  110  are sufficiently flexible to accommodate corrections to the right or left made by the prime mover. The digging cables  110  move upward and downward to follow the contour of the ground. Referring to  FIG. 3 , the digging cables  110  are detachably secured to the front beam  2  by the digging cable shackles  21  and the lower apertures (not numbered) of the drag cable shackles  22 . One of each pair of the digging cables  110  is attached to a corresponding digging cable shackle  21 , while the other of each pair is attached to the lower aperture of an adjacent corresponding drag cable shackle  22 . There are thirty-one pairs of digging cables  110  secured by 1¼″ pins  120  through the apertures in the shackles  21 , 22  for a ten foot long front beam  2 . The digging cables  110  are offset to permit the removal of the pins  120  for replacing digging cables  110  that are damaged by mine explosions, as described above. 
     Each digging cable  110 , being of 3″ diameter, is welded to digging cable head  124  by digging cable head cap  126 . The welding is effected by use of stainless steel, such as “308-16” rods. The ground end of each digging cable  110  has an end cap  112  welded to the cable  110 , and welded to the end cap  112  is a digger blade  114  and an upper blade  116 . As needed or desired, extra weight (not shown) may be added to each digging cable  110  to permit the digging cables  110  to perform effectively in hard, rough or muddy terrains. An example would be adding a block or weighted sleeve, such as a ½″, ¾″ or 1″ steel sleeve, or a bar, such as a 2″ by 4″ steel bar, to each end cap  112 . 
     The digger blade  114  needs to be of sufficient length and thickness, such as eight inches long by ¾″ thick, to effectively penetrate into and dig below the ground or ground level in order to make contact with and exhume, expose and/or explode mines that lie below the ground or ground level. When desired, such as when there are no known anti-tank mines in a minefield, and explosion of anti-personnel mines is all that is required, the digging cables  110  can be turned over to allow the upper blade  116  to engage the ground directly. 
     The upper blade  116  is cut back at the angle α of about 40° with respect to an axis normal to end cap  112  in order to reduce stresses when going through brush or high grass, and to allow the digging cables  110  to reach the ground and any hidden detonators. At the end of each digging cable  110 , there is a lift cable eye  118 , to which a corresponding digging lift cable  132  is attached. The digging lift cables  132  are intended to keep the digging cables  110  under the front beam  2  despite any tilting or stress placed upon the anti-mine unit  100 . 
     Similar to the digging cables  110 , the drag cables  220  are sufficiently flexible to accommodate corrections to the right or left made by the prime mover, and move upward and downward to follow the contour of the ground. The drag cables  220  generally do not push soil or rock, and can work in mud or underwater. 
     The drag cables  220  are used in pairs, and each of the fifteen pairs is detachably secured to the front beam  2  by a pin  120  through the upper aperture (not numbered) of a corresponding drag cable shackle  22 . A blade or lug  240  fits between the pair of apertures in each drag cable shackle  22 , and is welded to two arms  242 , which are in turn welded to two caps  246 , which are in turn welded to the cables of the pair of drag cables  220 . The drag cables  220  may be a little thinner, e.g., two inches in diameter, than the digging cables  110 , but welds are still by stainless 308-16 stock material or welding rods. 
     Three steel sleeves  224 , 226 , 228 , of ½″ thickness, are positioned upon each drag cable  220 , and each sleeve  224 , 226 , 228  has ground engaging blades  230 , 232 , 234 , which are intended to contact the ground and any detonators at or slightly below ground level. On the other side of the ground blades  230 , 232 , 234 , a grass blade  236  is welded upon each sleeve  224 , 226 , 228  to permit the drag cables  220  to be turned over for penetration of high grass, brush or hay, and is recessed at an angle α of about 40° in order to better penetrate. 
     A drag lift cable  122  is attached to an aperture in one of the grass blades  236  of a drag cable  220  in order to ensure that the drag cables  220  maintain appropriate orientation. As needed or desired, extra weight (not shown) may be added to each drag cable  220  to permit the drag cables  220  to perform effectively in hard, rough or muddy terrains. An example would be adding a block or weighted sleeve, such as a ½″, ¾″ or 1″ steel sleeve, or a bar, such as a 2″ by 4″ steel bar, to one of the sleeves  224 , 226 , 228  of each drag cable  220 . 
     As shown in  FIGS. 1-2  and  6 - 8 , both of the sides and the rear of the anti-mine unit  100  have a curtain (not numbered) of 2″ curtain cables  330  in close proximity to one another. These curtain cables  330  provide protection to the prime mover and personnel in the vicinity from shrapnel and flying dirt and rocks caused by mine explosions beneath the top plate  40  by keeping the dangers in a confined area. The right and left side curtains are mounted upon the upper side beams  4 , 5 , respectively, using the side curtain hangers  33 , and the rear side curtain is mounted upon the upper rear beam  8  using the rear curtain hangers  35 . 
     Extended pin  332  mounts the curtain cables  330 , which are each welded to an elbow  336 . Elbow  336  is of ¾″ steel sheet cut to size and shape. Washers  338  are welded to elbows  336  to space the cables  330  and allow free rotation of the elbows  336 . Five curtain cables  330  are placed every ten inches. As the curtain cables  330  will be placed under strain during explosions, they will be expected to fly outward. As shown in  FIG. 8 , a heavy tube  34 , which may be a solid rod, may be welded to the upper side beams  4 , 5 , and will keep the curtain cables  330  at or below 70° from vertical and facilitate shrapnel being forced into the ground and the recovery of the curtain cables  330 . The curtain cables  330  will generally flex when they come in contact with the ground or rocks. 
     Just in front of the track or tires of the prime mover are the deflector cables  370 L, 371 L (as best shown in FIGS.  4  and  5 ), which are 3″ cables that are intended to sweep exhumed and unexploded anti-tank mines from the path of the track/wheels of the prime mover. The deflector cables  370 L, 371 L are sufficiently flexible to accommodate corrections to the right or left made by the prime mover. 
     The upper rear beam  8  has deflector cable shackles  37  welded thereto. The deflector cables  370 L, 371 L are welded to caps  384 , which are in turn welded to arms  382 , which are in turn welded to blade or lug  380 , the blade  380  being affixed to the shackle  37  by a pin (not numbered) similar to the pin  120  mentioned above. The deflector cables  370 L,  371 L are relatively hefty and stiff but have end caps  374  welded thereto. Plows  376 , 378  are welded to the end caps  374 . Unlike ground plows, plows  376 , 378  are not intended to turn earth, but are generally trapezoidal with a horizontal, linear bottom edge for scraping the earth to move any exhumed land mines, especially anti-tank mines, away from the tracks or wheels of the prime mover. 
     A pair of deflector cables  370 L, 371 L are mounted on each side of the rear of frame  1  to provide the greatest possible protection for the prime mover. It is preferred that each pair of deflector cables  370 L, 371 L are bolted together at the bottom to prevent the pair from spreading apart. 
       FIGS. 9 and 10  are directed to wire cutters  31  which may optionally be mounted to front beam  2 . Wire cutters are seen to be important, as most mine barriers are surrounded by wire to keep people out (false minefields, wire with signs only, will often be very successful in keeping enemy assaults from being sent through very accessible terrain). Inexpensive and versatile, a wire cutter  31  is comprised of a blade holder having right and left sides  310 , 312  and a blade  314 . Wire cutter mounts  302 , 304 , 306  are mounted upon the front beam  2 . Cutter braces  316 , 318  are welded to the rear of the blade holders and removably attached to the mounts  302 , 304 , 306  by a long bolt  308 , while the blade  314  of the wire cutter  31  is removably attached to the blade holder by a plurality of bolts  320 . 
     As shown in  FIGS. 1 and 12 , the top plate  40  is rigidly secured, such as by welding, upon the top of the frame  1  such that the top plate  40  is prevented from flying off of the assembly after a mine explosion. The top plate  40  substantially or entirely covers the top of the frame  1 , and may be of a size, such as 5′ by 10′, that fits within the area defined by the lifting eyes  16 , as shown in FIG.  2 . The top plate  40  has a plurality of holes  42 , preferably about two inches in diameter, to permit damaged digging and drag cables  110 , 220  to be detached and replaced without difficulty, and to allow chains or cables to be passed therethrough for lifting the drag cables  220 . Steel washers (not shown), about ½″ thick, may be welded to the underside or on top of the holes  42  to prevent the holes  42  from being damaged or split after a mine explosion. The top plate  40  may be ¾″ thick and will be effective in reducing shrapnel and “bouncing betty” type mines from injuring nearby personnel. 
     This anti-mine unit  100 , mounted upon a tracked or wheeled prime mover, is able to quickly and easily reduce a minefield of anti-personnel mines. Anti-tank mines can be exhumed and gathered, easily and safely. Any anti-tank mines that are booby-trapped to explode upon removal can be exploded under a very hefty and stout assembly that will yield with the blast and still retain integrity, even if some of the individual cables are damaged. Though it is advisable to provide a prime mover with armored cab, to protect the operator, very little shrapnel or blast debris should cause damage to personnel to the rear or sides, even though they should be removed by at least fifty yards or meters. 
     Though the anti-mine unit  100  is designed to not miss any mines by the overlap of the various cables, the minefield should be swept by other personnel. It goes without saying that with the anti-mine unit  100  detonating the vast majority of mines in the field, if not all, risk to sweeping personnel is greatly reduced. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Technology Classification (CPC): 5