Abstract:
A tire conveyor and lift apparatus for conveying, lifting and orienting fuel tires for injection into a rotating cement kiln by force or by gravity. The apparatus brings tires from a tire source by a variable speed conveyor belt to a gate or alternatively vertical guiding rollers that regulate the flow of tires to the lift. Hooked lift arms engage the tire through the central hole and move vertically along a guide. The linear lift arms are mounted to an endless chain which is supported by upper and lower sprockets which are driven by a motor. The top of the guide is curved and has the curvature that approximates the circumference of the top sprocket. The tire is brought along the guide and released to output rollers connected to a feed chute which is aligned with a rotating kiln.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application claims priority from, and is a 35 U.S.C. §111 (a) continuation of, co-pending PCT international application serial number PCT/US00/35562 filed on Dec. 28, 2000 which designates the U.S. and which claims priority from U.S. application Ser. No. 09/477,917 filed on Dec. 31, 1999, now U.S. Pat. No. 6,231,288, from which priority is also claimed in this application. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    Not Applicable  
         REFERENCE TO A MICROFICHE APPENDIX  
         [0003]    Not Applicable  
         BACKGROUND OF THE INVENTION  
         [0004]    1. Field of the Invention  
           [0005]    This invention pertains generally to devices conveying worn tires for disposal or storage, and more particularly to a conveyor head feed apparatus for conveying, elevating and orienting whole tires for injection into a rotating kiln.  
           [0006]    2. Description of the Background Art  
           [0007]    Disposal of worn automobile tires has become a significant problem for many community landfills with limited available space. Tire shredding and chipping devices were developed, in part, to reduce the volume of material presented to landfills for disposal. However, tire shredding and chipping devices are costly to install and maintain, thus significantly raising the cost of disposal of each tire. Tires are also combustible and pose a threat of fire in landfills as well as transfer and storage facilities.  
           [0008]    One alternative to shredding or landfill disposal is to incinerate the tires or burn the tires as a source of supplemental fuel in rotary kilns. Rubber tires burn extremely hot, and thus make a very good source of supplemental fuel for a rotary kiln.  
           [0009]    Rotating kilns are frequently used in the production of cement. Because such kilns operate at extremely high temperatures, it is possible to burn various forms of liquid and solid combustible waste materials as a source of supplemental fuel. At the high temperatures found in such kilns, which are on the order of 3400 degrees Fahrenheit and above, the waste materials tend to combust fairly completely while producing little or no undesirable gaseous or solid emissions. Therefore, these waste materials can serve as a form a supplemental fuel, thereby reducing the demand for and cost of the primary fuel to fire the kiln.  
           [0010]    In addition, the extremely high temperatures within a cement kiln will cause the rubber tires to burn without any significant liquid, solid or gaseous waste byproducts which might otherwise be detrimental to the environment. Burning worn out tires as secondary fuel in rotary cement kilns helps alleviate the growing problem of tire disposal without appreciably impairing the environment.  
           [0011]    Many conventional feed systems used for injecting tires into a cement kiln require that the tires be cut and processed into “fuel packages” having relatively specific outer dimensions. Predictably, such preparation of used tires increases the overall cost of operating the kiln, and normally requires the use of special equipment and additional manpower to cut the tires and package the resulting pieces into suitably sized packages. Therefore, it is more efficient to inject whole tires into the kiln.  
           [0012]    Whether shredded, incinerated or used as secondary fuel in a cement kiln, the tires need to be efficiently presented to the various devices for processing. A considerable amount of manual handling of the tires is required to properly present the tire to the entrance of the kiln or shredder. This handling normally includes changes in elevation from the tire storage or transfer point to the mouth of the kiln.  
           [0013]    Accordingly, a need exists for an efficient automated apparatus that can change the elevation of a stream of tires and present the tires for injection into the kiln or shredding device at the proper orientation. The present invention satisfies that need, as well as others, and generally overcomes the deficiencies found in existing equipment.  
         BRIEF SUMMARY OF THE INVENTION  
         [0014]    The present invention is an apparatus for changing the elevation of a stream of used tires and sequentially orienting the tires for feeding into a rotating cement kiln, shredding device, incinerator or storage area. One drawback to prior conveyor mechanisms is that a considerable amount of manipulation of the tires is required to present the tire to the mouth of the kiln from the tire source including changes in elevation and positioning at an appropriate angle. The apparatus of the present invention eliminates manual handling of the tires from tire transfer point to the mouth of the kiln or other processing device.  
           [0015]    By way of example, and not of limitation, the invention includes a pair of wheels or sprockets supported by a housing. The first or base sprocket is positioned at ground level, and the second sprocket is positioned at a selected elevation above the base sprocket in the same plane. The second sprocket freely rotates about a central axis. The first sprocket is a drive sprocket attached to a motor or other means of rotation. An endless drive chain or drive belt connects the two wheels or sprockets. Forced rotation of the base drive sprocket produces rotation of the second sprocket and directional movement of the chain. It will be apparent that the drive motor can attached to the top sprocket rather than the base sprocket as an alternative.  
           [0016]    A number of arms project laterally from the chain or belt and are securely fixed to the chain or belt. Arcuate hooks or knobs are present on the distal ends of the arms. The arms travel with the chain around the drive and top wheels or sprockets.  
           [0017]    The outer housing of the conveyor head around the top sprocket includes a set of curved panels and a set of rollers. The panels have a curvature at one end which parallels the circumference of the top sprocket. The arc of the curved panel about the top sprocket is continued with a section in a line of rollers. Preferably the central axis point of each roller is approximately six degrees from the adjoining roller along the arc. This arc is continued until the roller line is at the proper angle that will provide the necessary alignment with the feed chute or mouth of the kiln.  
           [0018]    In use, a stream of tires from a tire source moves along a conventional horizontal conveyor. An intake roller platform sequentially receives individual tires from the horizontal conveyor, preferably through a control gate. The platform may also be angled downwardly to utilize the forces of gravity to move the tire along the rollers. The platform has a notch that will allow the horizontal arm to pass through the center of the platform interdigitally as the chain and arm move vertically upward. Once through the notch in the platform, the arm engages the tire from below and the hook or knob is positioned at the center hole of the tire. As the tire is drawn upward, it pivots and aligns vertically on the arm.  
           [0019]    The tires are in a vertical orientation when moved upwardly by the lift conveyor. As the tire approaches the top of the apparatus, it engages the outer surface of the curved housing panels with the arm passing between the panels. The tire is brought along the housing panels over the top to the rollers. The line of top rollers is notched and the arm passes between the two releasing the tire to the rollers in the process. A feed chute, conveyor or staging area is at the end of the line of rollers.  
           [0020]    To ensure that tires and other materials will be gravity fed into the feed chute for the kiln, the rollers and chute apparatus are oriented on the support frame such that the plane of the feed rollers connected to the feed chute has an angle of inclination between approximately thirty-three degrees and approximately sixty degrees, and preferably forty-seven degrees.  
           [0021]    An object of the invention is to efficiently convey whole tires for injection into the interior area of a rotating kiln.  
           [0022]    Another object of the invention is to provide a conveyor mechanism that can efficiently change the elevation of a stream of waste tires without requiring manual positioning,  
           [0023]    Another object of the invention is to provide a conveyor feed system that is automatically controlled to deliver and orient tires for injection into a rotary kiln or storage area.  
           [0024]    Another object of the invention is to provide a stream of tires for injection into a rotating kiln without creating a bottleneck.  
           [0025]    Another object of the invention is to provide a feed conveyor apparatus for a rotating kiln that feeds tires into the kiln at a desired rate.  
           [0026]    Another object of the invention is to provide a feed chute apparatus for conveying and orienting whole tires for injection into a cement kiln which eliminates the need to cut up or otherwise package the tires for injection.  
           [0027]    Further objects and advantages of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]    The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:  
         [0029]    [0029]FIG. 1 is a perspective view of a tire lift and conveyor apparatus according to the present invention.  
         [0030]    [0030]FIG. 2A is a partial view, in side elevation, of the upper portion of the apparatus shown in FIG. 1, showing a feed chute mechanism and showing a tire at the uppermost section of the apparatus engaging the top rollers.  
         [0031]    [0031]FIG. 2B is a partial view, in side elevation, of the upper portion of the apparatus shown in FIG. 1, showing a feed chute mechanism, showing a tire traveling along the arcuate section of the roller line, and showing the withdrawal of the lift arm.  
         [0032]    [0032]FIG. 2C is a partial view, in side elevation, of the upper portion of the apparatus shown in FIG. 1, showing a feed chute mechanism and showing the position of the tire prior to entry into the feed chute.  
         [0033]    [0033]FIG. 2D is a partial view, in side elevation, of the upper portion of the apparatus shown in FIG. 1, showing the tire in the feed chute to be fed into the kiln.  
         [0034]    [0034]FIG. 3 is a schematic side elevational view of an alternative embodiment of the lift and conveyor head system of the present invention, shown with a feed chute and positioned adjacent to a rotating kiln.  
         [0035]    [0035]FIG. 4 is a perspective view of the tire intake section of the alternative embodiment of the invention shown in FIG. 3 showing the conveyor, idler rollers and vertical centering rollers. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in FIG. 1 through FIG. 4, where like reference numbers denote like parts. It will be appreciated that the apparatus may vary as to configuration and as to details of the parts without departing from the basic inventive concepts disclosed herein.  
         [0037]    Referring first to FIG. 1, the invention comprises a tire conveyor and lift apparatus  10  that provides a stream of fuel tires at the proper elevation and orientation to be injected into a rotating cement kiln. Fuel tires, from a tire source, are transported, using a horizontal feed conveyor belt or the like (not shown), to control rollers  12  and control gate  14 . Advancement of the feed conveyor belt may drive the line of tires to the rollers and control gate  14 . Alternatively, it is preferred that control rollers  12 , control gate  14  and intake rollers  16  are at descending angle so as to utilize gravity to cause the movement of the tires along the line.  
         [0038]    Control gate  14  has a control mechanism  18  which is positioned beneath chute  20  as shown. In the embodiment shown, control mechanism  18  comprises an arm assembly having a pair of opposing and generally parallel arms  22   a,    22   b  which are pivotally coupled at one end to the side walls of the housing using flange bearings or the like. A pair of posts  24   a,    24   b  are positioned at the opposite ends of arms  22   a,    22   b , respectively, in a substantially perpendicular orientation in relation to the arms.  
         [0039]    A pair of gate operators  26   a,    26   b  (not shown) are attached to the undersides of arms  22   a ,  22   b  and impart pivoting motion to the arm assembly. Gate operators  26   a ,  26   b  are typically conventional hydraulic operated piston-type operating mechanisms that can be actuated by a timer or manually. Alternatively, gate operators  26   a,    26   b  could be solenoid operated piston-type mechanisms or the like.  
         [0040]    When control gate  14  is actuated, arms  22   a ,  22   b  pivot downwardly and posts  24   a,    24   b  retract allowing individual tires to move along intake rollers  16  and abut the lower vertical sections  28   a,    28   b  of skirt  30 . Is can be seen, therefore, control gate  14  permits the sequential advancement of tires to intake rollers  16  and thereby controls the rate of tires presented to the idler rollers by timed repetitive starting and stopping events. These starting and stopping events are also preferably coordinated with the rotational speed of the lift conveyor. Intake rollers  16  are separated by a longitudinal slot  32  as shown. The rollers on either side of the slot  32  abut the vertical sections  28   a  and  28   b  of skirt  30 . The distance between the two identical sections of skirt  30  is approximately equal to the width of slot  32 .  
         [0041]    The lift conveyor preferably includes a base sprocket  34  and a top sprocket  36  operably connected to an endless chain  38 . As shown is FIG. 1 and FIG. 3, endless chain  38  simultaneously engages the circumference of sprocket  34  and sprocket  36 . Accordingly, rotation of one sprocket will result in rotation of the other sprocket. An electric drive motor  40  is rotatably connected to base drive sprocket  34  allowing the base and top sprocket  36  and endless chain  38  to move at predetermined speeds.  
         [0042]    Hooked lift arms  42  are secured to endless chain  38  and oriented to be perpendicular to the length of  38 . Each lift arm  42  has a knob or hook  44  at the end of the arm opposite the attachment point with chain  38 .  
         [0043]    The lift conveyor is situated so that the hooked lift arms  42  travel through slot  32  of intake rollers  16  and the two sections of skirt  30  when moving in the vertical plane. Referring also to FIG. 2 and FIG. 3, tire  46  is positioned so that the center hole of the tire is generally centered over longitudinal slot  32 . As each lift arm  42  rises through slot  32 , it engages the bottom side of the tire. Hook  44  is disposed within the center of the generally horizontal tire. Continuing vertically above the intake rollers  16 , tire  46  pivots to a vertical orientation under forces of gravity. Lift arm  42  thus engages tire  46  through the center hole at one engagement point. The tire travels upward in this vertical orientation along skirt  30  toward the top section of skirt  30 .  
         [0044]    Referring particularly to FIG. 2A through FIG. 2D, the upper section of skirt  30  has two arcuate sections  48   a  and  48   b  that are positioned parallel to the outer circumference of top sprocket  36 . The edges of the skirt sections  48   a,    48   b  abut output rollers  50 . Notch  52  in output rollers  50  has a width that is the same as the distance between the members of the slide skirt and a depth that will allow passage of the lift arms.  
         [0045]    The top sections  54   a,    54   b  of output rollers  50  that are joined with sections  48   a,    48   b  of skirt  30  follow the general curvature of sections  48   a  and  48   b.  It is preferred that the center of each roller be aligned approximately six degrees apart with the first roller being placed at approximately ninety degrees from horizontal. Sections  54   a,    54   b  of output rollers  50  preferably follow an approximately thirty degree arc in approximately six degree increments and then continue tangentially in a plane. Accordingly, rollers  50  descend at approximately a thirty degree angle toward opening  60  of a feed chute  56 . Feed chute  56  can simply be a hollow chute, or a feed chute apparatus with the capability to regulate the feed rate into a kiln. To ensure that the tires will be gravity fed into the kiln, the feed chute is oriented on the support frame such that the plane of the internal ramp (bottom wall) has an angle of inclination between approximately 33 degrees and approximately 60 degrees, and preferably 47 degrees. If rate regulation capability is desired, feed chute  56  can be configured in the same way as control gate  14 . Alternatively, the feed chute apparatus with rate regulation capability described in detail in co-pending application Ser. No. 09/448,570 filed on Nov. 23, 1999, which is incorporated herein by reference, can be used.  
         [0046]    As seen in FIG. 2B and FIG. 2C, lift arm  42  retreats from the center of the tire as the tire travels over curved output roller sections  54   a,    54   b  and output rollers  50 . Momentum, gravity and drag in the output conveyor rollers assist the release of the tire from lift arm  42 . Lift arm  42  descends through notch  52  and tire  46  is free to roll down rollers  50  toward the feed chute and kiln. Output rollers  50  are preferably positioned at an angle to allow gravity to cause the motion of the tire down the rollers.  
         [0047]    Note also that, while the angle of output rollers  50  is preferably 30 degrees, any angle between 30 and 60 degrees is suitable. This angle allows the tire to move without assistance down output rollers  50  yet remain in control as the tire reaches the transition rollers and feed chute  56 .  
         [0048]    Referring to FIG. 1 and FIG. 2D, proper positioning of the gravity feed chute apparatus in relation to the kiln is critical in order for the tires to be injected by the force of gravity. Transition rollers  58  at the end of rollers  50  opposite notch  52  are preferably inserted into or positioned immediately adjacent opening  60  of feed chute  56 . The number of transition rollers may vary depending on the change in angle necessary between output rollers  50  and the opening  60  of feed chute  56 .  
         [0049]    In operation, the tires are directed into the feed chute apparatus  56  by gravity. As the kiln rotates, the feed opening of the kiln eventually comes into alignment with the feed chute  56 . At that point, the tire is released from the feed chute and into the kiln since the angle of inclination is sufficient to allow the material to be gravity fed out the end of the feed chute.  
         [0050]    [0050]FIG. 3 shows an alternative embodiment of the invention. In this embodiment, a conveyor belt  62  brings the fuel tires from a tire source to upper idler rollers  64 . The conveyor belt may determine the rate of tires presented to the idler rollers by timed repetitive starting and stopping events. These starting and stopping events are also preferably coordinated with the rotational speed of the lift conveyor.  
         [0051]    Referring also to FIG. 4, a power roller  66 , in line with upper idler rollers  64 , is rotated by a motor  68 . Power roller  66  may be larger in circumference than the idler rollers but the upper surface of power roller  66  should be on the same level as the idler rollers. Lower idler rollers  70  are adjacent to power roller  66  and on the same plane. It is preferred that the line of idler rollers  64 ,  70  and power roller  66  be at an angle of approximately 20 degrees in relation to a horizontal plane. Lower idler rollers  70  are preferably separated by a notch  72  as shown to facilitate the upward movement of hooked lift arms  74  through lower idler rollers  70 .  
         [0052]    Vertical centering rollers or posts  76  are disposed between several lower idler rollers  70  preferably symmetrically with respect to notch  72 . The vertical centering rollers  76  are preferably sequentially arranged to form a point.  
         [0053]    In use, a tire  78  is driven by conveyor belt  62  to upper idler rollers  64 . Power roller  66  facilitates the movement of tire  78  down the line until it engages lower idler rollers  70  and vertical rollers  76 . Tire  78  is oriented directly over notch  72  thereby. Lift arm  74  passes through notch  72  and engages and lifts tire  78  upwardly along slide skirt  80  to output rollers  82 , to feed chute  56  and into kiln  84 .  
         [0054]    Accordingly, it will be seen that this invention provides a simple and effective way of conveying, lifting and orienting waste tires for introduction into a rotating kiln using gravity or injection feed. Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Thus the scope of this invention should be determined by the appended claims and their legal equivalents.