Patent Document

FIELD OF THE INVENTION  
         [0001]    The present invention relates to transporting a particulate material through an auger which pressure isolates the inlet of the auger from the outlet of the auger.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many processes involve transporting particulate material by entraining the particulate material in an air stream and/or gases stream to move the particulate material to a collection area. Some kind of conveying devices operate to move the particulate material from the collection area to another desired location such as a discharge bin, transport vehicle, conveyor or the like. A typical installation may move particulate material from a bin or storage area into a transport vehicle such as a truck. During the movement of the particulate material from the storage bin to its final destination, the particulate material is often entrained in an air stream and is discharged into a cyclone or the like for separating the air from the particulate material in the cyclone. The particulate material while being entrained in air will often be moved either under positive pressure or under a vacuum. The air or gas is normally removed in the cyclone and separated from the particulate material. The particulate material is then moved via a conveyor which in this case is a screw auger which functions to firstly move the particulate material to its desired destination, and secondly to isolate the positive and/or negative pressure within the cyclone, hopper, or bin which ever the case may be from the exit end of the auger itself. The isolation of the pressure between the cyclone and the auger exit is critical in order to ensure efficiency in the movement of the particulate matter while entrained in air or other gases. Leakage of air or gases through the auger unit itself reduces the transport efficiency and/or the cyclone efficiency of the particulate matter while entrained in the air or gas.  
         THE PRIOR ART  
         [0003]    Auger conveying devices used in association with material plugs have been described and patented in U.S. Pat. No. 4,225,392 issued to Lelan D. Taylor in a Patent Titled: Pyrolysis Apparatus Issued: Sep. 30, 1980. In this device a feed auger terminates short of a reaction chamber to produce a sealing region (ie. a material plug) to effectively produce a gas tight seal preventing the exit of gaseous reaction products from the reaction chamber.  
           [0004]    The use of material plugs to provide for gas tight sealing together with auger units is also described in U.S. Pat. No. 4,344,723 issued to Ellingson in a Patent Titled: Vacuum Grain Moving Apparatus Issued: Aug. 17, 1982. Material plug sealing systems are also discussed in U.S. Pat. No. 5,871,619 issued to Dana Finley et al. issued on Feb. 16, 1999.  
           [0005]    In addition to the material plug, spring biased exit doors have also been found to be efficient in creating gas tight seals together with the material plug. This technology has been utilized, in particular, in deliquifying liquid slurries through augers and strainer baskets. The deliquification of liquid slurries through augers is discussed and described in U.S. Pat. No. 5,833,851 to Joseph Adams issued on Nov. 10, 1998, and is further discussed in U.S. Pat. No. 4,291,619 Titled: Screw Press With Controllable Rear Door issued to Arthur J. Hunt on Sep. 21, 1981, and is further discussed in U.S. Pat. No. 4,520,724 Titled: Screw Drive Particularly For Plastic Materials issued to Eduardo Costarelli on Jun. 4, 1985.  
           [0006]    In addition to the prior art mentioned above, current methods of pressure isolating particulate conveying systems include rotary valves, feeder valves, star valves, double gate dump valves, and pinch valves, all of which attempt to pressure-isolate the inlet pressure or vacuum from the exit pressure or vacuum of a screw auger conveying device.  
           [0007]    The prior art contemplates the use of a material plug together with a spring biased exit door for the movement of wet slurries in such a way to be able to isolate either negative or positive gas pressures from the entry and exit sides of the auger. This technology, however, has not successfully pressure isolated auger transport units to commercially acceptable levels.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention an auger lock for conveying particulate material there through comprises:  
           [0009]    (a) a cylindrical housing receiving particulate material therein including an auger section, a material plug section, and an exit section;  
           [0010]    (b) in said auger section; a rotatable spiral auger mounted concentrically on a rotatable drive shaft within said housing for conveying particulate material there through;  
           [0011]    (c) in said material plug section; conveyed particulate material is allowed to accumulate and compact to form a material plug to substantially prevent flow of gases through said housing;  
           [0012]    (d) in said exit section; a means for discharging said particulate material.  
           [0013]    Preferably said discharge means includes a biased plunger moveable between a plunger open position and a plunger normally closed position, wherein said closed position said plunger seals off an exit end of said cylindrical housing preventing flow of material and gas through said exit end, and in said open position allowing flow of material through said exit end. Preferably said discharge means includes a means for diverting material radially outward toward the outer diameter of said cylindrical housing as said material approaches said exit end, thereby, ensuring that gases are substantially prevented from flowing past said material plug.  
           [0014]    Preferably said diverting means includes a cylindrical deflector cone mounted concentrically on said drive shaft proximate said plunger, said deflector cone having an inclined deflector surface for diverting material radially outward proximate said exit end of said cylindrical housing.  
           [0015]    Preferably said deflector cone diverts material radially outward prior to material flowing past said exit of said cylindrical housing when said plunger is in said open position.  
           [0016]    Preferably said deflector cone diverts material radially outward prior to material flowing past said exit of said cylindrical housing when said plunger is in closed position.  
           [0017]    Preferably said deflector cone diverts material radially outward only after material has flowed past said exit end when said plunger is in said open position.  
           [0018]    Preferably said inclined deflector surface is angled between 20 and 60 degrees relative to a longitudinal axis taken through said drive shaft.  
           [0019]    Preferably said inclined deflector surface is angled preferably between 30 and 45 degrees, relative to a longitudinal axis taken through said drive shaft.  
           [0020]    Preferably said deflector cone is rigidly attached to said plunger, and in said closed position said plunger and cone remain stationary and in said open position said plunger and cone rotate together in unison with said drive shaft.  
           [0021]    Preferably said plunger further includes means for grinding said material plug and breaking up said material plug into particles when said plunger is in said open position.  
           [0022]    Preferably said grinding means includes agitator pins rigidly connected to said plunger and projecting into said material plug such that when said plunger rotates said agitator pins rotate and grind said material plug, thereby, breaking it down into smaller particles.  
           [0023]    Preferably further comprising a means for selecting and adjusting the length of said cylindrical housing.  
           [0024]    Preferably wherein said adjusting means includes a first auger tube section and a cooperating telescopically extending second auger tube section which can be slidably urged over first auger tube section for selectively adjusting the volume and length of said material plug section.  
           [0025]    Preferably said discharge means includes a biased plunger moveable between a plunger open position and a plunger normally closed position, wherein said closed position said plunger seals off an exit end of said  
           [0026]    cylindrical housing preventing flow of material and gas through said exit end, and in  
           [0027]    said open position allowing flow of material through said exit end. Preferably said discharge means includes a means for diverting material radially outward toward the outer diameter of said cylindrical housing as said material approaches said exit end, thereby, ensuring that gases are substantially prevented from flowing past said material plug.  
           [0028]    Preferably said diverting means includes a cylindrical deflector cone mounted concentrically on said drive shaft proximate said plunger, said deflector cone having an inclined deflector surface for diverting material radially outward proximate said exit end of said cylindrical housing.  
           [0029]    In a presently preferred embodiment the present invention an auger lock for conveying particulate material there through, said auger lock comprises:  
           [0030]    (a) an auger tube receiving particulate material therein including an auger section, a material plug section, and an exit section;  
           [0031]    (b) in said auger section; a means for rotating a rotatable spiral auger mounted concentrically on a rotatable drive shaft within said auger tube for conveying particulate material there through;  
           [0032]    (c) in said material plug section; conveyed particulate material is allowed to accumulate and compact to form a material plug to minimize free flow of gases through said auger tube; and  
           [0033]    (d) in said exit section; a means for discharging said particulate material from said auger tube.  
           [0034]    Preferably including biasing means for biasing said exit door into a closed position, wherein said exit door moveable between a exit door open position and a exit door closed position, wherein said closed position said exit door seals off an exit end of said auger tube preventing flow of material and gas through said exit end, and in said open position allowing flow of material through said exit end.  
           [0035]    Preferably wherein in the closed position said exit door is stationary and in said open position said exit door rotates in unison with said auger.  
           [0036]    Preferably wherein said drive shaft includes a hollow tubular auger shaft for receiving an exit shaft slideably and concentrically within said hollow auger shaft, wherein said door is rigidly attached to said exit shaft, and further including a seal to prevent material from entering into said hollow auger shaft.  
           [0037]    Preferably further including a means for engaging said hollow auger shaft with said exit shaft at a predetermined exit door position.  
           [0038]    Preferably wherein said engaging means includes a pin mounted transversely through said exit shaft and a cooperating slot in said hollow auger shaft for slidably receiving said pin therein at a predetermined exit door position thereby releasably locking together said hollow auger shaft and said exit shaft such that said exit door begins to rotate in unison with said auger shaft, when said exit door has achieved said predetermined position.  
           [0039]    Preferably wherein said biasing means includes a tension spring connected at one end to said hollow auger shaft and at the other end connected to said exit shaft for urging said exit shaft slideably into said auger shaft thereby bringing said exit door into said closed position.  
           [0040]    Preferably wherein said exit door further includes means for grinding said material plug and breaking up said material plug into particles when said exit door is rotating in said open position.  
           [0041]    Preferably wherein said baising means is nested and concentrically disposed within said hollow auger shaft and connected at one end to said exit shaft and at the other end to a shaft end of said auger shaft.  
           [0042]    Preferably wherein said baising means includes a tension spring and also a pretensioning means for preselectively adjusting the tension on the spring, said pretensioning means including a threaded adjusting rod cooperating with a threaded nut proximate a shaft end of auger shaft.  
           [0043]    Preferably further comprising a means for preselectively adjusting the length of said auger tube.  
           [0044]    Preferably wherein said adjusting means includes a first auger tube section and a cooperating telescopically extending second auger tube section which can be cooperatively slidably urged over first auger tube section for selectively adjusting the volume and length of said auger tube and therefore said material plug section. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0045]    The present invention will now be described by example only with reference to the following drawings in which:  
         [0046]    [0046]FIG. 1 is a schematic side cross-sectional view of the auger lock together with a cyclone showing the flow of material through the auger.  
         [0047]    [0047]FIG. 2 is a schematic side cross-sectional view of the auger lock shown in FIG. 1 without showing the material moving through the auger for better viewing of the details with plunger in the closed position.  
         [0048]    [0048]FIG. 3 is schematic cross-sectional side view of the auger lock shown in FIG. 1 without the material present for better view of the details with the plunger in the open position.  
         [0049]    [0049]FIG. 4 is a schematic cross-sectional side view of an alternate embodiment of said auger lock.  
         [0050]    [0050]FIG. 5 is a schematic cross-sectional side view of an alternate embodiment of said auger lock.  
         [0051]    [0051]FIG. 6 is a schematic cross-sectional side view of an alternate embodiment of said auger lock.  
         [0052]    [0052]FIG. 7 is a schematic cross-sectional side view of an alternate embodiment of said auger lock.  
         [0053]    [0053]FIG. 8 is a schematic cross-sectional side view of the presently preferred embodiment of the auger lock in the door open position.  
         [0054]    [0054]FIG. 9 is a schematic cross-sectional view of the presently preferred embodiment of the auger lock in the door closed position.  
         [0055]    [0055]FIG. 10 is a schematic cross-sectional view of the presently preferred embodiment highlighting some aspects of the auger lock. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0056]    The present invention, an auger lock, shown generally as  10  in FIG. 1 includes the following major sections, intake section  11 , auger section  12 , material plug section  14 , and exit section  16 .  
         [0057]    Referring now to FIG. 1 intake section  11  includes a cyclone  28  which also may be a hopper or a storage bin in which material  30  is entrained within a gas. Intake section  11  further includes intake flange  27  which communicates with intake  26  which communicates with auger tube  18 .  
         [0058]    Auger section  12  includes a cylindrical housing; namely, auger tube  18  having mounted therein auger  20  having auger flights  22 . Auger  20  which is mounted on drive shaft  24  which is mounted centrally and longitudinal along longitudinal axis  110  within auger tube  18  as shown in FIG. 1. By way of example only, auger tube  18  may have an outside diameter of five inches, wall thickness of {fraction (3/16)} of an inch and houses an auger  20  having auger flights  22  having an outside diameter of four inches. Auger flights  22  are preferably half pitch flights, meaning a four inch auger would have two inch pitch auger flights  22 . Auger tube  18  has mounted thereon end cap  25  proximate intake section  11 . One end of drive shaft  24  emerges from end cap  25  and has mounted thereon drive pulley  27 . Preferably drive pulley  27  is of the sprocket type, however, other drive arrangements known in the art can also be used including belt driven arrangements. Not shown in FIG. 1 is a motor and drive system connected to drive pulley  27  for rotating drive shaft  24 .  
         [0059]    Auger flights  22  terminate at material plug section  14  wherein only drive shaft  24  and material  30  continue within auger tube  18 . In other words the auger flights  22  terminate and do not enter material plug section  14 . Material  30  within material plug section  14  compacts together forming compacted material  32  within material plug section  14 .  
         [0060]    Exit section  16 , which includes a means for discharging material  30 , includes plunger  34 , rubber seal  36 , agitator pins  38 , deflector cone  40 , two way dogs  44 , spring  46 , shaft bearing  42 , and mounting bracket  48 . FIG. 1 shows plunger  34  in plunger open position  56  wherein two way dogs  44  are in engaged position  54  as shown in FIG. 1.  
         [0061]    In addition, seals  50  located between the inner diameter of deflector cone  40  and the outer diameter of drive shaft  24 , provide for a gas-tight seal between deflector cone  40  and drive shaft  24 . Preferably seals  50  are of the o-ring type, however, brass bushing type seals and/or any other seals known in the art which allow deflector cone  40  to move slidably, longitudinally along drive shaft  24  are acceptable.  
         [0062]    Plunger  34  has mounted thereon rubber seal  36  on the face which contacts the exit end  70  of auger tube  18 , in plunger closed position  58  shown in FIG. 2.  
         [0063]    Exit section  16  which includes plunger  34 , rubber seal  36 , agitator pins  38 , deflector cone  40 , and two way dogs  44  move in unison slidably along drive shaft  24  between a plunger open position  56  shown in FIG. 1, and a plunger closed position  58  shown in FIG. 2.  
         [0064]    In plunger closed position  58  shown in FIG. 2, two way dogs  44  are in dog disengaged position  52  shown in FIG. 2.  
         [0065]    Two way dogs  44  are the type known in the art and preferably are three-toothed dogs which cooperate wherein the engaged position  54 , the two way dogs  44  are meshed together thereby rotating plunger  34 , rubber seal  36 , agitator pins  38 , and deflector cone  40  in unison with drive shaft  24 .  
         [0066]    [0066]FIG. 4, an alternate embodiment of auger lock  10 , schematically illustrates using engaging pins  114  and co-operating engaging pin holes  116  rather than two way dogs  44 . In addition, spring  112  is located exterior of the engaging mechanism.  
         [0067]    Referring to FIGS. 1 through 3 in dogs disengaged position  52  the dog teeth no longer mesh and plunger  34 , rubber seal  36 , agitator pins  38 , and deflector cone  40  no longer rotate in unison with drive shaft  24 , but rather drive shaft  24  rotates freely with plunger  34  left stationary with rubber seal  36  of plunger  34  sealing and mating against exit end  70  of auger tube  18 .  
         [0068]    Spring  46  biases plunger  34  against exit end  70  of auger tube  18 , and maintains plunger  34  in the normally plunger closed position  58  shown in FIG. 2.  
         [0069]    Shaft bearing  42  supports the exit end of drive shaft  24  onto mounting bracket  48  of the type known in the art. Not shown is a frame or other structure to which bracket  48  is mounted.  
         [0070]    Referring now to FIGS. 6 and 7 which schematically illustrates an alternate embodiment of the present invention, an auger lock  10 , which has all of the same components as described above except for modification to auger tube  18  which is comprised of two sections; namely, first auger tube section  130  and second auger tube section  132 , which is coupled together with coupling  134 . First and second auger tube sections  130  and  132  are dimensioned to co-operatively, telescopically slide one over the other in such a manner that the length of the auger tube can be adjusted by slidably urging second auger tube section  132  over first auger tube section  130 , and locking it into a desired position using coupling  134 . In this manner the volume and the length of material plug section  14  containing compacted material  32  can be adjusted by slidably urging second auger tube section  132  telescopically over, first auger tube section  130 . Coupling  134  can be any type known in the art and, for example, a LORENZE™ standard coupling, which is described in U.S. Pat. No. 4,193, 173 and Canadian Patent 1,025,793 can suitably be used.  
         [0071]    In use auger lock  10  as shown in FIG. 1, operates as will be described hereafter.  
         [0072]    Material  30 , which is contained within cyclone  28 , settles to the bottom of cyclone  28  proximate intake flange  27 . Material  30  flows through intake  26  and into auger tube  18  proximate intake section  11 . Auger lock  10  will work with almost any type of dry or wet particulate or granular material and/or bulk solids such as plastic particles (something called rubber regrind), plastic pellets, grain, saw dust, cement dust, rubber powder, and other similar granular materials. Preferably, the material  30  size ranges between  100  mesh and ¾″ in diameter in size. Material  30  can be almost any type of material which is capable of being moved along through auger  20  mounted within auger tube  18 . The interior of cyclone  28  may be under negative and/or positive pressure, and in practice the unit has been tested to be functional between  80  inches of water column pressure and/or  80  inches of water column vacuum using plastic regrind material through the auger. Higher pressures and vacuums are likely achievable. Therefore, auger lock  10  can be utilized with either a negative pressure within cyclone  28  and/or a positive pressure within cyclone  28 .  
         [0073]    As material  30  is transported into auger tube  18 , rotating auger flights  22  of auger  20  move material  30  longitudinally from intake section  11  of auger tube  18  towards exit end  70  of auger tube  18 . Typically drive shaft  24  rotates between 25 to 50 rpm As material  30  is moved into material plug section  14 , the auger flights  22  terminate and material  30  begins to accumulate and compact within material plug section  14 .  
         [0074]    Spring  46  biases plunger  34  against exit end  70  of auger tube  18  preventing any material  30  and gas from exiting from exit end  70  of auger tube  18 .  
         [0075]    Preferably, a rubber seal  36  mounted onto plunger  34  mates with and seals off exit end  70  of auger tube  18 , thereby, preventing material  30  and gas or air from flowing past plunger  34  during the start up of auger lock  10 .  
         [0076]    As auger flights  22  continue to rotate and move more and more material  30  into material plug section  14 , material  30  eventually becomes highly compacted forming compacted material  32  within material plug section  14 . Compacted material  32  is also know as a “material plug” in the art. Compacted material  32  is so highly compacted that it substantially prevents the flow of gases between cyclone  28  and exit end  70  of auger tube  18 . Thereby pressure isolating any positive or negative pressures in cyclone  28  from the ambient pressure found at exit end  70  of auger tube  18 .  
         [0077]    As auger flights  22  continue to rotate, the pressure continually increases increasing the compaction of material  30  within material plug section  14  until the pressure is great enough to overcome the biasing action of spring  46  against plunger  34 . When the pressure of material plug  14  is sufficient to overcome the biasing force of spring  46 , compacted material  32  within material plug section  14  pushes against plunger  34  moving plunger  34  from the plunger closed position  58  to the plunger open position  56 , thereby engaging two way dogs  44  into the engaged position wherein plunger  34  begins rotating in unison with drive shaft  24 .  
         [0078]    During this entire process drive shaft  24  is being rotated by a motor or other means known in the art, via drive pulley  27 . It will be apparent to those skilled in the art that the power required to continually rotate drive shaft  24  will depend among others upon the size of auger tube  18 , and the type of material  30  transported within the auger lock  10 .  
         [0079]    With plunger  34  in the plunger open position  56 , rubber seal  36  no longer contacts exit end  70  of auger tube  18 , therefore breaking the seal between plunger  34  and exit end  70  of auger tube  18 . However, because compacted material  32  is so densely compacted it continues to substantially isolate the pressure and/or vacuum found in cyclone  28  from the ambient air pressure found at exit end  70  of auger tube  18 .  
         [0080]    As two way dogs  44  move into the engaged position  54 , plunger  34  begins to rotate which in turn rotates agitator pins  38 , which are rigidly connected to plunger  34 . Agitator pins  38  are mounted longitudinally and parallel with auger tube  18 , and as depicted can be bolts and/or any rigid projections into the interior of auger tube  18 .  
         [0081]    The length of agitator pins  38  is selected depending upon material  30  consisting and size. By way of example only, finer material  30  requires longer pins, whereas, coarser material  30  requires shorter pins.  
         [0082]    As compact material  32  begins to move outwardly from exit end  70  it makes contact with rotating agitator pins  38  which breaks up compacted material  32 , allowing material  30  (which is broken up) to exit from exit end  70  of auger tube  18 .  
         [0083]    Finally, deflector cone  40 , a cone-shaped deflector mounted on drive shaft  24 , directs material  30  radically outward away from drive shaft  24 , and towards the outer diameter of auger tube  18  and towards agitator pins  38 . In practice it has been found critical to have deflector cone  40  in place in order to provide additional compaction of material  30  as it approaches exit end  70  of auger tube  18 .  
         [0084]    Deflector cone  40  has inclined deflecting surface  118  for deflecting material  30  radially outward.  
         [0085]    By deflecting and moving material radically outward away from the centre of drive shaft  24  and towards the outer diameter of auger tube  18 , additional compaction of material  30  occurs. This additional compaction as material  30  exits from exit end  70  of auger tube  18  is critical to ensure that a gas seal is maintained in material plug section  14  even though plunger  34  no longer seals with rubber seal  36  against exit end  70  of auger tube  18 . The angle theta  72  is the angle between the longitudinal axis  110  which runs parallel along the longitudinal length of drive shaft  24 , and the inclined deflecting surface  118  of deflector cone  40 . Preferably the angle theta  72  is 30 degrees. In practice, angle theta  72  can range between 20 to 60 degrees, however, 30 to 45 degrees is more preferable.  
         [0086]    Referring now to the alternate embodiment shown in FIGS. 6 and 7, the volume and length of material plug section  14  can be adjusted by telescopically urging second auger tube section  132  over first auger tube section  130 , and locking the two auger sections in place with coupling  134 . This is particularly useful when different sized material  30  is fed through auger  20 . By way of example only, finer material  30  being fed through auger  20  requires a smaller material plug section  14 , and therefore, a smaller and shorter material plug. Finer materials tend to compact more easily, and therefore, a more effective material plug can be achieved with finer materials. By reducing material plug section  14  the amount of horsepower required by auger lock  10  is reduced, and the efficiency of auger lock  10  is increased.  
         [0087]    Conversely, as the material  30  becomes coarser in nature, a longer material plug section is required in order to provide for an efficient gas tight seal. Therefore, the courser the material the longer the material plug section  14  would be, and therefore, second auger tube section  132  is urged outwardly extending the length of the auger tube in order to provide for a longer and larger material plug. In this way the operator can fine tune the operation of auger lock  10  by adjusting the length of material plug section  14  according to the size and the consistency of material  30  being fed through auger  20 . In all other aspects, auger lock  10 , as shown in FIGS. 6 and 7, operates in an elegance fashion as auger lock  10  shown in FIGS. 1 through 5 as described here above.  
         [0088]    Presently Preferred Embodiment  
         [0089]    In a presently preferred embodiment of the invention, an auger lock shown generally as  210  in FIG. 8, includes the following major sections. Intake section  211 , drive section  233 , auger section  212 , material plug section  214  and exit section  216 .  
         [0090]    Referring now to FIG. 1, the intake section  211  includes a cyclone  228  which also may be a hopper or storage bin in which material  230  is entrained with a gas. Intake section  211  further includes intake flange  227  which provides for communication between cyclone  228  and auger tube  218 .  
         [0091]    Drive Section  233  includes drive unit  235  mounted to auger tube  218 . Drive unit  235  is driveably connected to drive end shaft  224  and auger shaft  282  which is connected to auger  220  for rotatably driving drive end shaft  224  and auger shaft  282 . Drive unit  235  is a standard type of drive mechanism which can be purchased and is mechanically and/or hydraulically and/or pneumatically connected to drive end shaft  224  through gears, pulleys or belts or other means not shown in FIG. 8. The purpose of drive unit  235  is to rotate a drive end shaft  224  which is connected to auger shaft  282  which in turn rotates auger  220  with its auger flights  222 .  
         [0092]    The reader will note that drive end shaft  224  is hollow and houses therein an adjusting rod  272  connected at the shaft end  225  together with an adjusting nut  273 . Adjusting rod  272  having at the other end a swivel  274  for connecting to one end of spring  245 . The other end of spring  245  is connected to connecting rod  270  which in turn is attached to exit shaft  280 . The tension on spring  245  can be adjusted by threadably turning adjusting nut  273  of adjusting rod  272  which is threaded. By turning adjusting nut  273 , adjusting rod  272  is urged along longitudinal axis  211  thereby selectively increasing or decreasing the tension on spring  245 . Note that drive end shaft  224  is rigidly connected with auger shaft  282 , however, exit shaft  280  which is concentrically housed within auger shaft  282  moves freely and independently of auger shaft  282  and drive end shaft  224 , in the door closed position  292  shown in FIG. 9.  
         [0093]    Exit shaft  280  also has mounted there through laterally a pin  286  which has portions on each side of the pin projecting beyond the diameter of exit shaft  280 . Pin  286  is dimensioned to fit within slot  284  defined in auger shaft  282  for the purpose of driveably connecting auger shaft and drive end shaft with exit shaft  280 .  
         [0094]    Auger lock  210  shown in FIG. 8 is shown in the door open position  290  in which pin  286  has made engagement with slot  284  thereby drive end shaft  224 , auger shaft  282  and exit shaft  280  all rotate in unison due to the coupling of pin  286  with slot  284 .  
         [0095]    Furthermore, seal  236  at the end of auger shaft  282  and near the drive unit  235  seals off material  230  from contaminating the mechanism found within drive end shaft  224 .  
         [0096]    [0096]FIG. 9 shows auger lock  210  in the door closed position  292  in which the tension on spring  245  which is transmitted through exit shaft  280  forces exit door  234  closed against exit end  260  of auger tube  218 . In this position lateral pin  286  does not engage with slot  284  and therefore drive end shaft  224  and auger shaft  282  rotate in unison, however exit shaft  280  rigidly connected to exit door  234  does not rotate unless pin  286  engages with slot  284 .  
         [0097]    Therefore, in the door closed position  292  exit door  234  does not rotate and agitator pins  238  do not impart any forces upon material  230  within auger tube  218 .  
         [0098]    In use, auger lock  210  operates as follows. Material  230  drops out of cyclone  228  through intake flange  227  of intake  226  and into auger tube  218  whereby they encounter the rotating auger flights  222  of auger  220 . The spring tension on spring  245  is adjusted by adjusting nut  273  to impart enough force on exit shaft  280  which transfers this force to exit door  234  thereby keeping it closed and in the door closed position  292  against exit end  260 . Therefore, initially only drive end shaft  224  and auger shaft  282  rotate leaving exit shaft  280  attached to exit door  234  stationary.  
         [0099]    Auger flights  222  continually transport material  230  towards exit end  260  of auger tube  218  until a material plug of material is formed in material plug section  214  of auger tube  218 . A material plug is a conglomeration of material  230  within auger tube  218 . Material  230  is compacted together in this material plug. Once the material plug has obtained sufficient size, it begins imparting forces against exit door  234  thereby pushing open exit door  234  against the tension on spring  245 . Once exit door  234  has opened a predetermined amount, pin  286  engages with slots  284  thereby beginning rotation of exit shaft  280  with exit door  234  attached. Once exit door  234  begins to rotate, agitator pins  238  begin to grind away material  230  from material plug thereby dropping the material into a bin or a hopper below not shown.  
         [0100]    The size of the material plug and the amount that the exit door opens is depended upon the pretension placed on spring  245  and the tension characteristics of spring  245  as well as the amount the exit door must open prior to the engagement of pin  286  with slot  284 . Thereby the characteristics and the size of the material plugs can be adjusted by adjusting the tension on spring  245  as well by selecting the distance between pin  286  and slot  284  in the door closed position  292 .  
         [0101]    The greater the distance between pin  286  and slot  284  in the door closed position  292  the longer the material plug will form prior to exit door  234  rotating and agitator pin  238  grinding away the material plug.  
         [0102]    Referring now to FIG. 10, which is schematic representation of auger lock  210  showing FIGS. 8 and 9, highlighting some aspects of auger lock  210  not shown in FIGS. 8 and 9. Preferably a linear bearing  320  would be mounted onto the end of exit shaft  280  as shown in FIG. 10 in order to provide for support for exit shaft  280 . In addition, a bushing  322  is preferrably used at the shaft end  225  of drive end shaft  224  as shown in FIG. 10.  
         [0103]    Preferably also double pitch flighting  324  on auger  220  would be mounted onto auger shaft  282  approximate the exit end of auger flights  222 .  
         [0104]    In addition to the arrangement shown in FIGS. 8, 9 and  10  for auger lock  210 , additionally the auger tube  218  arrangement shown in FIGS. 6 and 7 for the previous embodiment apply equally well to the presently preferred embodiment namely auger lock  210 . Clarity auger tube  218  could be constructed of two auger tubes sections similar to first auger tube section  130  and second auger tube section  132  shown in FIGS. 6 and 7. A coupling  134  shown in FIG. 7 and FIG. 6 would also be used and this arrangement would enable one to adjust the total length of auger tube  218 , thereby providing very gross and course control of the material plug section  214 .  
         [0105]    For example by extending second auger tubes section  132  over first auger tube section  130  thereby lengthening the total length of auger tube  218 , one can in effect increase the length of new material plug section  214  thereby increase the length of the material plug which is formed. This is useful for example when very course materials are being fed through auger lock  210  in order to provide for a better gas type seal the material plug section  214  would be made greater.  
         [0106]    On the other hand should finer materials or materials be used which provide for better gas tightness in the material plug section, then first auger tube section  130  and second auger tube section  132  could be urged over each other thereby shortening material plug section  214  and in this matter increasing the efficiency of the operation of auger lock  210 .  
         [0107]    It should be apparent to persons skilled in the arts that various modifications and adaptation of this structure described above are possible without departure from the spirit of the invention the scope of which defined in the appended claim.

Technology Category: 7