Abstract:
A magnetic adhesive and braking system for a remote controlled vehicle adapted for traversing across ferromagnetic surfaces of a steel shipping container including the vertical walls and ceiling. The magnetic wheel system allows the vehicle to traverse vertical grades. The magnetic braking system both securely holds the vehicle when stopped on a vertical surface, and exerts enough attractive force between the vehicle and the shipping container to allow a vehicle mounted drill to operate. The magnetic brake design uses mechanical advantage such that the force required to roll the vehicle vertically downward is heightened to the force required to detach the vehicle in a perpendicular vector from the container&#39;s surface.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a remote controlled vehicle adapted for traversing across the surfaces of a steel shipping container. It is capable of carrying a plethora of investigative equipment such as sniffers, cameras, fibre optics, drills and the such. 
         [0002]    Even with homeland security measures heightened the majority of shipping containers reaching American international ports go uninspected. The volume of cargo containers is beyond what the authorities can handle. It is a time consuming task and often dangerous when the contents of a shipping container have shifted and opened. While leaking contents may be visible most chemical spills remain of an unknown nature. Remote controlled vehicles have been extensively used in scientific and police work where it is impractical, impossible or too hazardous to send a person. 
         [0003]    Henceforth, a remote controlled reconnaissance vehicle for use on a steel shipping container would fulfill a long felt need in the inspection industry. This new invention utilizes and combines known and new technologies in a unique and novel configuration to overcome the aforementioned problems and accomplish this. 
       SUMMARY OF THE INVENTION 
       [0004]    The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a remote controlled vehicle with magnetic wheels and a magnetic braking system to affix the vehicle to a steel surface strong enough so as to enable a drill on the vehicle to exert enough force between the vehicle and the steel surface to pierce the steel surface. 
         [0005]    It has many of the advantages mentioned heretofore and many novel features that result in a new remote controlled reconnaissance vehicle with the ability for vertical and inverted overhead travel on these steel containers and with the capability for sampling the atmosphere or viewing the container contents from any vantage point of the container which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art, either alone or in any combination thereof. 
         [0006]    In accordance with the invention, an object of the present invention is to provide a remote controlled vehicle for traversing all orientations of metal surfaces. 
         [0007]    It is a further objective of the present invention to provide a remote controlled vehicle for traversing all orientations of metal surfaces having magnetic wheels. 
         [0008]    It is another objective of the present invention to provide a remote controlled vehicle for traversing all orientations of metal surfaces and capable of carrying reconnaissance equipment. 
         [0009]    It is still another objective of the present invention to provide a remote controlled vehicle for traversing all orientations of metal surfaces and capable of utilizing a magnetic brake and magnetic wheels to secure the vehicle for drilling operations from the vehicle. 
         [0010]    It is a final objective of the present invention to provide a remote controlled vehicle for traversing all orientations of metal surfaces, having a magnetic brake to prevent rollback of the vehicle when stopped on a vertical surface. 
         [0011]    The subject matter of the present invention is particularly pointed out and distinctly claimed in the concluding portion of this specification. However, both the organization and method of operation, together with further advantages and objects thereof, may best be understood by reference to the following description taken in connection with accompanying drawings wherein like reference characters refer to like elements. Other objects, features and aspects of the present invention are discussed in greater detail below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of the preferred embodiment six wheeled mag vehicle showing the general arrangement of all components; 
           [0013]      FIG. 2  is a side view of the preferred embodiment six wheeled mag vehicle showing an articulation of the trailer when climbing up a vertical wall; 
           [0014]      FIG. 3  is a side view of the preferred embodiment six wheeled mag vehicle showing an articulation of the trailer when climbing down a vertical wall; 
           [0015]      FIG. 4  is a side view of the preferred embodiment six wheeled mag vehicle showing the vehicle on a vertical wall with the magnetic brake engaged; 
           [0016]      FIG. 5  is a perspective view of the alternate embodiment four wheeled mag vehicle showing the general arrangement of all components; 
           [0017]      FIG. 6  is a side view of the alternate embodiment four wheeled mag vehicle with the magnetic brake disengaged; 
           [0018]      FIG. 7  is a perspective view of the alternate embodiment four wheeled mag vehicle with the magnetic brake engaged; 
           [0019]      FIG. 8  is a side view of the alternate embodiment four wheeled mag vehicle with the magnetic brake engaged; 
           [0020]      FIG. 9  is a perspective view of a wheel rim; 
           [0021]      FIG. 10  is a perspective view of a foam insert; 
           [0022]      FIG. 11  is a perspective view of a tire; 
           [0023]      FIG. 12  is a perspective view of a magnetic retention ring with the magnets removed; 
           [0024]      FIG. 13  is a perspective view of a magnetic retention ring with the magnets installed; 
           [0025]      FIG. 14  is a perspective view of the magnetic brake in the disengaged position; 
           [0026]      FIG. 15  is a side view of the magnetic brake in the disengaged position; 
           [0027]      FIG. 16  is a top view of the magnetic brake in the disengaged position; 
           [0028]      FIG. 17  is a side view of the magnetic brake in the engaged position; 
           [0029]      FIG. 18  is a perspective view of the magnetic brake&#39;s magnet barrel; 
           [0030]      FIG. 19  is a side cross sectional view of the magnetic brake&#39;s magnet barrel; 
           [0031]      FIG. 20  is a perspective view of the brake housing without the magnet barrel installed; 
           [0032]      FIG. 21  is a side view of the magnetic brake in the disengaged position; and 
           [0033]      FIG. 22  is a side view of the magnetic brake in the engaged position. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
         [0035]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting. 
         [0036]    Looking at  FIGS. 1 to 4  a six wheel version of a magnetic shipping container crawling apparatus  2  can best be seen. A four wheel magnetic shipping container apparatus  4  is best illustrated in  FIGS. 5 to 8 . These two versions differ only by the addition of a two wheeled tractor  6  that is pivotally mounted to the four wheel version  4  which becomes a trailer. The two wheeled tractor  6  and the four wheel trailer  4  are connected by a length of adjoined chain links with a biaxial pivot at one end that allows horizontal and vertical articulation simultaneously to accommodate travel over any surface. This type of connection is well known in the art and is not illustrated. This accommodates the transition between horizontal and vertical surfaces ( FIG. 2 ) and vertical and horizontal surfaces ( FIG. 3 ). 
         [0037]    The preferential size of each vehicle is ⅛ scale although other sizes such as ⅙ and 1/10 scale have been utilized for specific operations. The frame is connected to the magnetic wheel assemblies  8  by a set of spring and strut limiters to allow ease of multi plane articulation. The vehicles have a battery powered RF signal receiver adapted for use with a battery powered RF signal transmitter operated by the user from a remote location that serves to actuate the drive system, the magnetic braking system  20  and any reconnaissance equipment as is well known in the industry. The wheel assemblies  8  of all magnetic vehicles  4  are all driven and all steer. The magnetic wheel assemblies  8  of the tractor  6  are identical in all respects to the magnetic wheel assemblies  8  of the four wheel magnetic vehicle  4  and their frames are substantially similar in design. 
         [0038]    It is to be noted that none of the illustrations reflect the reconnaissance equipment that the vehicles are designed to carry, the drive system, the batteries and the remote control receiver and transmitter. These are not within the scope of the claimed invention and are well known in the art. For ease of illustration these have been eliminated from the drawings. While the remote operation means and the drive system of the vehicles remain essentially off the shelf, it is the wheel design that allows the vehicles to traverse in any orientation along ferromagnetic surfaces. The magnetic wheel assembly  8  has a solid wheel rim  12  ( FIG. 9 ) upon which a foam ring  14  ( FIG. 10 ) is mounted. The wheel rim  12  is journaled for rotation about a shaft or axle coupled to the vehicle&#39;s frame and drive system. The foam ring  14  resides between the wheel rim  12  and the magnetic retention ring  16  ( FIG. 12 ) and lends support to the magnet retention ring  16  which houses a uniform series of identical permanent magnets  18  ( FIG. 13 ) arranged about the retention ring&#39;s exterior periphery. A flexible, soft tire  22  ( FIG. 11 ) that is frictionally affixed to the wheel rim  12  and encases the foam ring  14 , the magnet retention ring  16  with permanent magnets of the rare earth variety  18 , completes the wheel assembly  8 . The tire  22  and magnet retention ring  16  are each formed as unitary pieces from a suitable elastomeric material. 
         [0039]    The magnets  18  reside at approximate 20 degree intervals about the magnet retention ring  16  being held there in matingly conformed magnet recesses  20  by friction and by a flexible cement. Opposing poles are placed adjacent to each other. In the preferred embodiment the magnets each are capable of a 50 pound attraction based on a force exerted perpendicular to the ferromagnetic surface. The force required to turn the wheels is much less as the magnetic forces are incrementally removed while the wheels turn. Although there is a plethora of suitable glues an epoxy system of a silica epoxy resin with a polyamide resin hardener has been shown to work well. 
         [0040]    The outer half of the magnet  18  is exposed to allow friction with the inside of the tire  22 . The magnetic wheel assembly  8  is not pressurized. When assembled the portion of the soft tire  22  that lies between the ferromagnetic surface being traversed and the magnet retention ring  16  deforms under the weight of the vehicle and the magnetic affinity of the magnet laden ring  16  so as to minimize the distance between the magnets  18  and the surface, thereby maximizing the adhesive holding forces of the vehicle. In this manner a magnetic contact is maintained while the wheel assemblies  8  roll along the ferromagnetic surface. 
         [0041]    The exterior surface of the tires  22  have a tread formation  24  to maximize traction on painted ferromagmetic surfaces, although the exterior surface could be modified for increased traction on wet or oily surfaces by the application of solvents, traction rings/chains or a different tread formation. 
         [0042]    The disposition of the magnets  18  at approximate 20 degree intervals about the magnet retention ring  16  has shown to be an optimal spacing configuration when driving over a corrugated shipping container as more of the magnets  18  are exerting a strong magnetic field toward the ferromagnetic surface when the wheel is residing in the bottom trough of a corrugation. (Conventional corrugation of a shipping container has 3 inch wide parallel crests and troughs 1.5 inches apart with 45 degree sloped connecting walls.) It is known that smaller or larger magnets may be used with different spacing for different sized wheels and for different purposes. Generally on a flat ferromagnetic surface there is a minimum of one magnet  18  per wheel assembly in strong magnetic contact with the surface. With the 20 degree magnet spacing on a ⅛ scale wheel assembly when traversing a corrugated trough there is a minimum of six magnets  18  per wheel assembly in strong magnetic contact with the surface. It is to be noted that 10 degree interval spacing has been used with larger diameter wheels or smaller magnets. The wheel assemblies  8  are pivotally connected to a remotely controlled steering mechanism as is well known in the art and is not illustrated herein. 
         [0043]    In operation, as the tire  22  flexes and compresses at the contact plane between the wheel assembly  8  and the ferromagnetic surface, the magnet retention ring  16  is allowed to come into close enough contact with the surface to effect a strong gripping force. During rolling contact a strong magnetic attraction is maintained orthogonally between the magnetic wheel assemblies  8  and the ferromagnetic surface. A multi wheeled shipping container crawling apparatus in the referenced scale sizes with the above wheel assembly configuration is able to ascend and descend vertical walls as well as traverse inverted on horizontal surfaces and make the transition from horizontal to vertical travel and vice versa. 
         [0044]    Each of the 18 magnets  18  in the magnet retention ring  16  has approximately two and a half times the holding strength of the total weight of a six wheeled vehicle (with the weight of all wheels included) when on a flat ferromagnetic surface. I.E. for a ⅛ scale vehicle with a weight of 20 pounds, each of the magnets in the magnet ring can lift 50 pounds vertically in air. Since a minimum of two magnets are always in magnetic contact with the surface because of the deformation of the tires  22 , with six wheels on a flat surface the holding power of the vehicle is 600 pounds. On a corrugated surface this holding power may increase by as much as three times up to 1800 lbs depending upon the actual location of each wheel. For this reason when traversing corrugated steel shipping containers there is no need for the use of the magnetic brake system  20 . Testing has shown that the drive system requires a motor to drive train gearing of 1:70 to 1:90 through a set of worm or pinion and spur gears to develop the extra torque required when traversing a corrugated shipping container wherein there is approximately 3 times the holding force generated by each wheel. 
         [0045]    The magnetic braking system  20  retractably pivots a brake magnet  64  housed in a cylindrical brake magnet inner housing  60 , downward from the approximate center of a magnetic shipping container crawling apparatus  2  into close proximity to the ferromagnetic surface that the crawling apparatus is traversing. The brake magnet inner housing  60  is positioned on the end of a brake arm  46  dimensioned so that its longitudinal axis forms an upwardly inclined acute angle with the ferromagnetic surface when the magnetic brake is engaged. In this configuration an integrated vehicle braking system is engaged. ( FIG. 4 ) First, the additional magnetic attraction between the brake magnet  64  and the ferromagnetic surface acts to hold the vehicle in place. Second, the acute angle design transfers the downward vertical gravitational pull on the vehicle to a horizontal pull between all of the wheel assemblies  8  sand the ferromagnetic surface. When the vehicle resides on a horizontal surface, pulling the vehicle perpendicularly off of that ferromagnetic surface requires much more force than rolling the vehicle downward as would be the case if the acute angle formed between the brake arm  46  and the surface were downwardly inclined. In the preferred embodiment the brake magnets  64  each have 170 pounds of attractive force. Thus with two magnetic brakes applied there will be 340 pounds of magnetic attraction to hold the 20 pound vehicle in place and when drilling, another 600 pounds is available from each of the magnetic wheel assemblies  20 . This additional 600 pounds being applied by virtue of the brake arm&#39;s acute upward angle. 
         [0046]    The magnetic braking system  20  has a housing  26  ( FIG. 14 ) that mechanically supports remote controlled motor  28  through mechanical fasteners  30 . The motor&#39;s drive shaft  32  has a small drive gear  34  ( FIG. 21 ) thereon that meshingly engages a larger driven gear  36  having a drive peg  38  extending normally therefrom. The drive peg  38  extents through an arced slot  48  in brake arm  46 . ( FIG. 17 ) The driven gear  36  and brake arm  46  are pivotally supported on stub axle  40  which is held in position by an inner parallel plate  42  and an outer parallel plate  44  of the housing  26  ( FIG. 16 ) and mechanically affixed to the plates at its distal and proximate ends. A spring means  50  is attached to the stub axle  40  so as to present a counterclockwise torsional force on the stub axle  40 . ( FIG. 22 ) Although the spring means  50  is illustrated as a torsional spring, a retraction coil spring could also be connected to accomplish the same result. At the inner end of the brake arm  46  is an upper stop protrusion  52  and a lower stop protrusion  54  that limit the rotation of the brake arm  46  by abutting the side of the housing  26 . ( FIG. 17 ) The outer end of the brake arm  46  is mechanically connected to the brake magnet outer housing  56  and has a central bore formed therein that supports pivot shaft  58  which is connected to brake magnet inner housing  60  by plate  62 . ( FIG. 18 ) The brake magnet inner housing  60  is a hollow cylinder rotatably housed within cylindrical brake magnet outer housing  56 . The brake magnet inner housing  60  has a section of removed housing material  63  (magnet recess) in which the brake magnet  64  resides and is affixed. ( FIGS. 18 ,  19  and  20 ) A end cap not illustrated encloses the brake magnet inner housing  60  to protect it from harsh elements. A thrust shaft  66  is connected at its ends between drive peg  38  and rotate disc  68  which is affixed to plate  62  via pivot shaft  58 . ( FIGS. 16 and 22 ) The rotate disc  68  is coupled to the thrust shaft by an off centered pin  99  so as to translate the linear motion of the thrust shaft  66  into rotational motion of the brake magnet inner housing  60 . Each end of the thrust shaft is adapted for rotatable engagement. 
         [0047]    In the preferred embodiment there is actually two independent, identical mirror image magnetic braking systems  20  utilized on opposite sides of the vehicle as illustrated best in  FIGS. 1 and 5 . The magnetic strength of each of the brakes is 170 pounds. This is not necessary in all situations but rather is dictated by the amount of downward force exerted off of the vehicle&#39;s platform, such as would be encountered through a vehicle mounted drilling device for boring holes in the surface traversed. 
         [0048]    Looking at  FIGS. 14 ,  15 ,  17 ,  21  and  22  it can be seen how the magnetic brake system  20  works. When not actuated there is no remote drive signal sent to the remote controlled DC powered motor  28  and no rotational torque is generated by the motor  28  to overcome the torsion spring means  50  which applies a counterclockwise torque on the stub axle  40  so as to rotate the brake arm  46  counterclockwise until the upper stop protrusion  52  contacts the side plate of the housing  26  at the same time as the upper end of the actuation shaft  66  is pivoted until the drive peg  38  contacts the upper side of the arced slot  48  and the lower end of the thrust shaft  66  rotates the plate  62  so as to position the brake magnet  64  and brake arm  46  as illustrated in  FIGS. 14 ,  15  and  21 . Here the brake magnet  64  is too far from the ferromagnetic surface to have any holding effect and to prevent the brake magnet  64  from attraction to the magnets  18  in the wheel assembly  8 . 
         [0049]    Operation of the magnetic brake system for engagement or disengagement is a two step process. First the brake magnet  64  must be rotated and then the brake magnet  64  must be lowered or raised. In order to engage the magnetic brake system  20  a remote signal from a remote sending unit is sent to the remote controlled motor  28  from which begins to rotate its drive shaft  32  and attached small drive gear  34  counterclockwise. This in turn rotates larger driven gear  36  clockwise overcoming the counterclockwise force of the spring means  50 . As the drive peg  38  on the larger driven gear  36  rotates clockwise it travels along the arced slot  48  in the brake arm  46  ( FIG. 15 ) and forces the thrust shaft  66  to extend slightly outward from the magnetic brake housing  26  to turn rotate disc  68  which is affixed onto pivot shaft  58  and rotates plate  62  in the direction indicated by directional arrow  70 . Since plate  62  is also affixed to the pivot shaft  58  and is housed in the end of the brake magnet inner housing  60  the inner housing  60  rotates counterclockwise within the brake magnet outer housing  56  so as to move the position of the magnet  64  out of its 9 o&#39;clock position toward the ferromagnetic surface between 90 and 120 degrees to the approximately 5:30 position. This is accomplished when the drive peg  38  contacts the end of the arced slot  48  in the brake arm  46 . Once the drive peg  38  contacts the end of the arced slot  48  the motor  28  continues to exert torque and push the thrust shaft  66  further outward which forces the drive peg  38  to rotate the brake arm  46  clockwise which lowers the other end of the brake arm  46  and the brake magnet  64  into contact with the ferromagnetic surface. With the brake magnet  64  in close proximity to the ferromagnetic surface the remote controlled motor  28  can be shut off. 
         [0050]    It is to be noted that an acute forward (upward if on a vertical surface) angle will always reside between the brake arm  46  and the ferromagnetic surface as the brake arm  46  can only rotate until the lower stop protrusion  54  contacts the side plate of the magnetic brake housing  26 . It is to be noted that depending where the vehicle&#39;s wheel assemblies  8  are physically located on a corrugated container the stop protrusion may not be utilized. 
         [0051]    While the brake magnet  64  is encased within the brake magnet inner housing  60  so as to be protected, it actually sits in the magnet recess  63  which leaves only a thin amount of the brake magnet inner housing cylinder wall between the ferromagnetic surface and the brake magnet  64 . Experimentation has shown that a cylinder wall thickness of 0.010 inch is adequate to withstand the forces and support the brake magnet  64 . 
         [0052]    To disengage the magnetic brake  20  the process is reversed. The remote controlled motor  28  is remotely signaled to reverse its rotation and turn clockwise which first rotates the inner magnetic brake housing  60  approximately 90 to 120 degrees from the 5:30 o&#39;clock position back to the 9 o&#39;clock position to minimize the magnetic attraction between the brake magnet  64  and the ferromagnetic surface. Then when the drive peg  38  contacts the opposite end of the arced slot  48  the motor continues to drive the brake arm  46  to its original position. Once there the motor is shut off and the brake arm  46  is held in position by spring means  50 . 
         [0053]    This sequencing is necessary to be able to use lightweight, inexpensive and conventional components. A lightweight DC powered motor  28  although highly geared for maximum torque could not directly lift the brake arm  46  without some of the magnetic attraction removed. Increasing the motor size requires larger batteries and more mass which is very undesirable. 
         [0054]    In the preferred embodiment, the brake arm  46  rotates over approximately 45 degrees by virtue of the arced slot  48 . The brake magnet inner housing  60  rotates 90 degrees by virtue of the thrust arm travel. 
         [0055]    In another embodiment not shown, the operation of the magnetic braking system  20  works theoretically similar however the rotate disc  68  is relocated 180 degrees such that the drive post  99  resides below pivot shaft  58 . This configuration however, places the brake magnet  64  when retracted at the 3o&#39;clock position which is closer to the magnetic wheels  8  and will cause more torque to be exerted to overcome the magnetic attraction between the brake magnet  64  and the wheel magnets  18 , but under certain situations may offer mechanical operation advantages. 
         [0056]    The above description will enable any person skilled in the art to make and use this invention. It also sets forth the best modes for carrying out this invention. There are numerous variations and modifications thereof that will also remain readily apparent to others skilled in the art, now that the general principles of the present invention have been disclosed. As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.