Abstract:
Apparatuses designed to provide support to a conveyor belt in a new manner. In a first illustrative embodiment, a conveyor belt is supported by a number of magnets. A first set of magnets are disposed on the edges of the conveyor belt, and a second set of magnets are disposed on a support apparatus for the conveyor belt. The first and second sets of magnets interact to create repulsive forces that provide both lateral and vertical support to the conveyor belt. Tension provided by the lateral forces can help the belt move smoothly and with less wear than the support provided by existing support idlers.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional of U.S. application Ser. No. 10/732,718, filed Dec. 10, 2003 now U.S. Pat. No. 6,971,507, the entire disclosure of which is incorporated herein by reference. 

   FIELD 
   The present invention is related to the field of materials conveyance. More particularly, the present invention relates to the field of conveyer devices. 
   BACKGROUND 
   Conveyor belts are used to move materials in a wide variety of industries and environments. Some such conveyor belts are used, for example, in moving ore within a mine, gravel or rocks within a quarry, and in a variety of industrial applications where bulk materials are moved. 
     FIG. 1  illustrates a prior art conveyor. The conveyor includes a conveyor framework  2  which may be made, for example, using channel, angle-iron, trusswork, or a variety of other configurations. A conveyor belt  4  is supported by support idler frames  6  which include a number of support idler rollers  8 . Driving force may be applied by any number of methods/apparatuses, including, for example, creating a turning force at the rollers shown on the end of the framework  2 , or by application of force using magnets on the conveyor belt  4  itself which interact with stators placed relative the edges of the conveyor belt  4 . 
     FIG. 2  shows a closer, cut-away view of a prior art conveyor, highlighting the conveyor belt  4 , idler support  6 , and idler rollers  8 . As shown, the idler rollers  8  are angled with respect to one another such that the conveyor belt  4  forms a trough in which a material to be conveyed rests during transport. The idler supports  6  are secured relative the conveyor framework  2 . There is a slight sag between the rollers  8 , and it can be seen that the conveyor belt  4  does not pass smoothly over the rollers  8 , instead being shaped thereby with slight angular form. 
   The conveyor belt  4  is typically constructed as a relatively flat, flexible member having a first end and a second end, where the ends are secured together to create a loop by the use of a securing apparatus. In a simplest form, the conveyor belt  4  has two ends coupled together by interacting teeth or interleaved loops, where a wire, for example, is passed through the interleaved loops to secure the first end of the conveyor belt  4  to the second end of the conveyor belt  4 . Other forms, such as vulcanized “endless” belts may also be used. Any number of individual sections may be pieced together in this or another suitable manner to build the conveyor belt  4 . 
   One of the limitations of such prior art conveyor support designs is that the supportive force of the rollers  8  causes localized strain on the conveyor belt  4 , wearing the conveyor belt  4 . Further, the rollers  8  are subject to wear and degradation, and require periodic replacement. The rollers  8  include internal bearings that occasionally wear out, and with the large number of moving parts, the overall system is subject to failure in harsh environments. 
   SUMMARY 
   The present invention, in an illustrative embodiment, includes apparatuses designed to provide support to a conveyor belt in a new manner. In a first illustrative embodiment, a conveyor belt is supported by a number of magnets. A first set of magnets are disposed on the edges of the conveyor belt, and a second set of magnets are disposed on a support apparatus for the conveyor belt. The first and second sets of magnets interact to create repulsive forces that provide both lateral and vertical force to the conveyor belt. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an illustrative prior art conveyor; 
       FIG. 2  is a cutaway view highlighting a portion of the illustrative prior art conveyor of  FIG. 1 ; 
       FIG. 3  is a perspective view of a first embodiment of a magnetically supported conveyor system; 
       FIG. 4  is a section view of an illustrative embodiment showing greater detail of the supporting framework for a magnetically supported conveyor system; 
       FIG. 5  is a cross-sectional view of an illustrative support framework; 
       FIG. 6  is a cross-sectional view of another illustrative support framework; 
       FIG. 7  is a cross-sectional view of yet another illustrative support framework; 
       FIG. 8  illustrates in detail a magnetic layout for a magnetically supported conveyor system; 
       FIG. 9  illustrates in detail another magnetic layout for a magnetically supported conveyor system; 
       FIG. 10  illustrates a rectangular magnetic layout for a magnetically supported conveyor system; 
       FIG. 11  shows, in side view, a portion of a magnetically supported conveyor system; 
       FIG. 12  is a cross-sectional view of another illustrative support framework; and 
       FIG. 13  is a side view of another illustrative conveyor system. 
   

   DETAILED DESCRIPTION 
   The following detailed description should be read with reference to the drawings. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the invention. 
     FIG. 3  is a perspective view of a first embodiment of a magnetically supported conveyor system. The system includes a conveyor framework  52  that is used with a conveyor belt  54 . The system includes tension members  60  and several support arms  62  that are secured to the conveyor framework  52  by several support pivot mounts  64 . Several upper pivot mounts  66  are also included. 
   The conveyor belt  54  is at least partly supported by the use of magnetic forces. In particular, a number of outer magnet housings  70  are secured to the conveyor belt  54 . The conveyor belt  54  is then suspended between two inner magnet housings  72 . As illustrated in greater detail below, the outer magnet housings  70  and inner magnet housings  72  interact magnetically. Repulsive forces between the outer magnet housings  70  and inner magnet housings  72  support the conveyor belt  54 . 
     FIG. 4  is a section view of an illustrative embodiment showing greater detail of the supporting framework for a magnetically supported conveyor system. The conveyor framework  52  is secured by a lower pivot mount  68  to the tension member  60 , which is in turn secured to the support arm  62  by the upper pivot mount  66 . The support arm  62  is also secured to the conveyor framework by support pivot mounts  64 . 
   As can be seen, the outer magnet housings  70  wrap around the inner magnet housing  72  so that both lateral and vertical support is provided to the conveyor belt  54 . The conveyor belt  54  is held in position under lateral tension. The weight of whatever material is carried the conveyor belt  54  will cause the conveyor belt  54  to sag in the middle. As the conveyor belt  54  sags, more material can be carried by the conveyor up to a point, however, too much sag can reduce capacity and cause excessive wear on the conveyor belt  54 . To prevent too much sag from occurring, tension members  60  are provided between the support arms  62 . If the conveyor belt  54  is empty, less wear on the conveyor belt  54  occurs when it runs flat, so the tension members  60  are also adapted to cause the conveyor belt  54  to run flat when empty, yet allow some sag to occur as the conveyor belt  54  is loaded. The tension members  60  may include a stop preventing too much sag from occurring, for example, to keep the conveyor belt  54  from coming into contact with the tension members  60 . If desired or necessary, additional support devices may be used in conjunction with the magnetic support provided by the magnet housings  70 ,  72 . The several pivot mounts  64 ,  66 ,  68  allow the conveyor belt  54  to go from a sagging configuration to a flat position (and the reverse) smoothly and easily. 
     FIG. 5  is a cross-sectional view of an illustrative support framework. The cross section shows how the tension members  60  cross from the lower pivot mounts  68  to the upper pivot mounts  66  to provide lateral support to the support arms  62 . The support pivot mounts  64  allow the support arms  62  to move with respect to the conveyor framework  52 , allowing the conveyor belt  54  to have lateral flexibility. 
   Also illustrated is how the outer magnet housing  70  at least partly surrounds the inner magnet housing  72 . The outer magnet housing  70  contains outer magnets  76 , which interact with inner magnets  74  contained by the inner magnet housing  72 . The outer magnets  76  are all aligned in similar polarity, as are the inner magnets  74 , such that the outer magnets  76  collectively repel the inner magnets  74 . The conveyor belt  54  thus moves on a cushion of air with decreased wear and friction. 
   While the preferred embodiments of the present invention include magnets  74 ,  76  that create a cushion of air between the inner and outer housings, other configurations are also contemplated. For example, frictional contact between the inner and outer housings may be allowed in some embodiments. If desired a lubricant (wet or dry) may be provided between the inner and outer housings to make movement with contact easier. 
   Additionally, the magnets  74 ,  76  may provide primary or supplemental support to a conveyor belt. For example, if desired, the magnets  74 ,  76  may be sufficient to provide guiding forces to a belt, wherein the magnets  74 ,  76  and tension members  60  are sufficient to keep the belt relatively flat while the belt is running empty, but when the belt is loaded the belt is allowed to deform and move generally as shown in  FIG. 1 , with rollers disposed longitudinally between the tension members. By allowing the belt to run relatively flat while unloaded, friction and wear are reduced, while rollers may be provided to give additional support when the belt is heavily loaded. 
   In several embodiments additional support devices may be provided as well. For example, an impact cradle or bed such as an impact slider bed may be provided beneath the belt  54  at a location corresponding to a hopper or loading area. The impact slider bed may include, for example, a slippery hard plastic upper layer over a cushioned layer. One example impact slider bed includes a number of elongate members that run longitudinally beneath a portion of the belt  54 , each elongate member having at least two layers, with the upper layer being a slippery plastic about ⅓ the thickness of the member, and a lower layer made up of a relatively soft, cushioning rubber that covers approximately ⅔ of the thickness of the member. If desired, a spring or rigid support, such as a piece of iron or steel, may hold up the elongate members. 
     FIG. 6  is a cross-sectional view of another illustrative support framework. Again, the tension members  60  are coupled to the support legs  62  and conveyor framework  52  using upper and lower pivot mounts  66 ,  68 . The support legs  62  themselves are coupled to the conveyor framework by the support pivot mounts  64 . The main difference from  FIG. 5  to  FIG. 6  is in the shape of the outer magnet housing  70 ′ and inner magnet housing  72 ′. Rather than a curved shape (as shown by the magnet housings  70 ,  72  in  FIG. 5 ), the magnet housings  70 ′,  72 ′ in  FIG. 6  are rectangular. By using the rectangular shape, the inner magnets  74 ′ may be disposed differently, for example, the upper magnet of the inner magnets  74 ′ may have a N/S polarity where the N pole is up, and the lower magnet may have the same alignment, so that the upper and lower magnets of the inner magnet attract one another and hold each other in place, yet repel the outer magnets  76 ′. 
     FIG. 7  is a cross-sectional view of yet another illustrative support framework. A conveyor framework  152  is used to support a conveyor belt  154  as follows. Support arms  162  are secured to the conveyor framework by support pivot mounts  164 . A tension member  160  is coupled to the support arms  162  using arm pivot mounts  166 . The tension member  160  is configured to push the support arms  162  apart, keeping the conveyor belt  154  under tension. The tension member  160  configured as shown simplifies the overall design, however, as illustrated, the conveyor belt  154  is not allowed to sag as far as it otherwise might, since the tension member  160  is in the way. 
   The conveyor belt  154  is coupled to the support arms  162  by the use of an outer magnet housing  170  that is disposed about an inner magnet housing  172 . The repulsive magnetic forces between the inner magnets  174  and outer magnets  176  creates an air gap that allows the conveyor belt  154  to move without significant friction caused either by support along its edges or friction creating by passage over idler rollers. 
     FIG. 8  illustrates in detail a magnetic layout for a magnetically supported conveyor system. The configuration corresponds to that illustrated in  FIG. 5 . The tension member  60  pushes the arm  62  outward through its connection to the upper pivot mount  66 . In turn, the arm transmits both vertical and lateral forces to the inner magnet housing  72  containing a number of inner magnets  74 . Preferably, each of the inner magnets  74  is orientated with the same field polarity facing outside. The outer magnet housing  70  contains several outer magnets  76 , which preferably are orientated to each have the same field polarity facing inside. The field polarity facing inside for the outer magnets  76  is preferably the same as the field polarity facing outside for the inner magnets  74 , such that the outer magnets  76  and inner magnets  74  repel one another. 
     FIG. 9  illustrates in detail another magnetic layout for a magnetically supported conveyor system. The inner magnets  74  comprise a single magnet, and the outer magnets  76  are also a single magnet. If desired, one or both of the magnets may be an electro-magnet that is coupled to a source of electricity such that, when the electricity is on, the magnetic field generated by at least one of the magnets  74 ,  76  is boosted. Then, if desired, the electricity could be cut off when the belt  54  is not moving, reducing the resting tension on the belt  54 . 
     FIG. 10  illustrates a rectangular magnetic layout for a magnetically supported conveyor system. The outer magnet housing  70 ′ is shaped to preserve an air cushion around the inner magnet housing  72 ′. The inner magnets  74 ′ are oriented and disposed to provide a repulsive force with respect to the outer magnets  76 ′. 
     FIG. 11  shows, in side view, a portion of a magnetically supported conveyor system. The system may include a number of outer housing structures  70  disposed about an inner housing structure  72  to support the conveyor belt  54 . The conveyor belt  54  is supported over a conveyor framework  52  by the use of several support arms  62  that may be spaced or alternated as shown. The support arms  62  are secured between the conveyor framework  52  and the conveyor belt  54  by support pivot mounts  64 . Tension members  60  may attach to the support arms  62  as noted above. 
   The conveyor belt  54  may be motivated by any suitable mechanism or device. Pulley and/or roller systems, along with geared devices having teeth that engage the conveyor belt  54  may be used. Several magnet and stator systems may also be used, for example. 
     FIG. 12  is a cross-sectional view of another illustrative support framework. The support framework supports a conveyor belt  100  using outer magnetic housings  102  and inner magnetic housings  104 . The housings  102 ,  104  may be as outlined above. The support arms  106  are tensioned, laterally, by a tension member  108 . Rather than two side-by-side frame members having a number of cross members therebetween (such a support framework would be used with several of the above embodiments), the illustrative framework in  FIG. 12  makes use of a single central member  110 . Because the support arms  106  angle outward with respect to the central member  110 , the force of gravity creates tension across the conveyor belt  100 . As such the conveyor belt  100  tends to run flat when unloaded. 
   The tension member  108  may provide pushing forces between the support arms  106  when the conveyor belt  100  is heavily loaded. For example, if the conveyor belt  100  is heavily loaded, troughing in the middle will tend to pull the support arms  106  together, so the tension member  108  may provide a pushing force to prevent over-troughing of the conveyor belt  100 . 
     FIG. 13  is a side view of another illustrative conveyor system. The system is similar to that shown in  FIG. 11 , with a first magnetic support structure shown generally at  150  for belt  152 , and a second magnetic support structure shown generally at  154 . Between the magnetic support structures is a roller-type structure, as shown generally at  156 . 
   Those skilled in the art will recognize that the present invention may be manifested in a variety of forms other than the specific embodiments described and contemplated herein. Accordingly, departures in form and detail may be made without departing from the scope and spirit of the present invention as described in the appended claims.