Abstract:
A system and auger assembly for conveying a solid granular material includes a rotatable auger, a first auger tube and a second auger tube telescopically recieved in the first auger tube. A drive mechanism longitudinally moves the second tube between a first position in which the second tube extends from the first tube and over a remaining portion of the length of the auger, and a second position in which the second tube is telescopically recieved within the first auger tube.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a system for the handling of solid granular materials and, more particularly, a system and an auger assembly for the conveying of such materials. 
     Transportable hoppers such as grain carts have been employed in the past for the transport of granular materials such as grain. These grain carts have been unloaded either by the gravity from the bottom of the hopper, or from the top of the hopper by a powered auger screw conveyer which extends from adjacent the bottom of the hopper to adjacent its top where the discharge of the grain may be accurately directed. These powered auger screw conveyors are contained over at least an upper portion of their length by a tube which is stationarily attached, such as by welding, to one of the inclined walls of the hopper. The remaining lower portion of the auger screw toward the bottom of the hopper is covered by a generally flat door which slides on slide rails to cover the lower portion of the auger screw when the grain cart is empty, but to expose the lower portion of the screw when it is desired to unload grain from the hopper. 
     Such sliding cover door assemblies suffer several disadvantages. One disadvantage is that the slide assembly slows unloading. Another disadvantage is that bulky granular material can bridge from the slide assembly to the walls of the hopper, hindering free flow into the auger screw. Still another disadvantage is that the granular material, for example grain, tends to abrade and wear the auger tube itself necessitating that the auger tube must be replaced after time. Such replacement is relatively difficult, expensive and time consuming where the auger tube is stationarily fixed, such as by welding, to a side wall of the grain cart hopper as they have typically been in the past. 
     It is the purpose of the present invention to overcome these several disadvantages. In the present invention, two auger tubes are provided. A first auger tube is provided as in the past which surrounds at least a portion of the auger and is stationarily fixed to an inclined sidewall of the hopper. The second auger tube is moveable telescopically into and out of the first tube between a first position in which the second tube extends from the first tube to cover the auger, and a second position in which the second tube is telescopically withdrawn into the first tube to expose the auger for operation. In the second position the second tube surrounds the auger and is positioned between the auger and the interior wall of the first tube to protect the first tube against abrasion and wear during operation. 
     The telescoping first and second auger tubes of the invention substantially speed the unloading process over the prior sliding door-slide rail constructions, and minimize bridging. In the present invention the need for the door slide rails as in the prior constructions is eliminated, and the second tube lines the first tube and protects it against abrasion. Although abrasion of the second tube may occur, it is not stationarily welded to the inclined sidewall of the hopper as is the first tube, and is much more easily and inexpensively replaced than the difficult to replace tubes which are welded to the side wall. 
     In one principal aspect of the present invention, an auger assembly for conveying a solid granular material comprises an elongate rotatable auger; a first tube at least partially surrounding the auger over a first portion of the length of the elongate auger; and a coupling for coupling the auger to a source of power for transmitting power to the auger to rotate the auger in the first tube. A second tube also at least partially surrounds the auger over a portion of the length of the elongate auger. A drive mechanism longitudinally moves the second tube between a first position in which the second tube extends from the first tube, and substantially over a second portion of the length of the elongate auger, and a second position in which the second tube extends over a substantial amount of the first portion and in which a substantial amount of the second portion of the length of the elongate auger is exposed. 
     In another principal aspect of the present invention, the tubes substantially surround the respective portions of the length of the elongate auger when the second tube is in its respective first and second positions. 
     In still another principal aspect of the present invention, the second tube is moved telescopically relative to the first tube when the second tube is moved between the first and second positions. 
     In still another principal aspect of the present invention, the second tube moves into the first tube and around the auger when it moves to the second position, and the second tube is positioned between the auger and the first tube when the second tube is in the second position. 
     In still another principal aspect of the present invention, the drive mechanism comprises a fluid cylinder, and preferably a hydraulic fluid cylinder. 
     In still another principal aspect of the present invention, the first tube is notched at an end thereof adjacent the second portion of the auger. 
     In still another principal aspect of the present invention, the auger assembly is in a system for the handling of a solid granular material, which system includes a hopper having a top and a bottom and inclined walls which are inclined toward each other toward the bottom of the hopper; the elongate rotatable auger extends from adjacent the bottom to adjacent the top of the hopper; and the first tube at least partially surrounds the auger over a first portion of the length of the elongate auger nearest the top of the hopper. The drive mechanism longitudinally moves the aforementioned second tube between the first position in which the second tube extends toward the bottom of the hopper, and substantially over the second portion of the length of the elongate auger, and the second position in which the second tube extends over a substantial amount of the first portion toward the top of the hopper, and in which a substantial amount of the second portion of the length of the elongate auger is exposed toward the bottom of said hopper. 
     These and other objects, features and advantages of the present invention will be more clearly understood through a consideration of the following detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the course of this description reference will be made to the attached drawings in which: 
     FIG. 1 is an overall perspective view of an empty grain cart having a preferred embodiment of auger assembly of the present invention; 
     FIG. 2 is a broken perspective view of the auger assembly substantially as shown in FIG. 1, and in which the auger tube is shown in a first extended covering position in which substantially all portions of the auger are covered; and 
     FIG. 3 is a broken perspective view of the auger assembly substantially as shown in FIG. 1, but in which the auger tube has been retracted into a second position to expose the auger screw for operation in conveying materials from the grain cart. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A grain cart generally  10  is shown in FIG. 1 for the transport of grain. Such grain carts typically comprise a hopper  12  which is formed by inclined walls, two of which are shown in FIG. 1 as walls  13  and  14  which slope inwardly toward each other toward the bottom  16  generally of the grain cart. The grain cart  10  also includes various other conventional components, such as wheels  18  and a drawbar  19  with tractor hitch  20  which permits the grain cart to be transported between various locations, and a jack  22  which may be employed to support and level the drawbar  19  when the grain cart has been detached from the tractor. 
     Such grain carts  10  as shown in FIG. 1 may include a powered auger conveyor  24  for conveying the grain in the cart to the top  26  and over the side of the cart. As shown in FIG. 1, the auger conveyer  24  comprises a conveyer section  28  which is positioned in the grain cart hopper  12 , and an extension section  30  which is preferably hingedly attached, as by hinge  32 , to the top of the conveyer section  28  in the hopper. The hinge  32  makes it possible to rotate the extension section  30  to a folded transport position as shown in the drawings to facilitate transport, or to an operational position in which the extension section  30  extends in axial alignment with the conveyer section  28 . When rotated to the operational position the auger screws in both sections  28  and  30  will be mechanically coupled to operate in unison and so as to convey grain in the cart to the discharge head  34  of the extension section  30  as seen in FIG.  1 . Rotation of the extension section  30  about hinge  32  may either be done manually or preferably by way of linkage arms  36  and a fluid cylinder  38  as best seen in FIGS. 2 and 3. 
     In the present invention the conveyor section  28  that is within the hopper  12  preferably comprises an auger  40  the shaft of which extends through the bottom  16  of the hopper  12  where it is coupled to a gearbox  41  to drive the auger as seen in FIGS. 2 and 3. The auger  40  is contained in a pair of auger tubes  42  and  44 . Auger tube  42  is typically fixed to the inclined sidewall  14  of the hopper  12 , such as by welding, and includes a flange  46  at its top which carries the hinge  32 . When the extension conveyor section  30  is rotated into its upwardly extending axially aligned operational position, the flange  46  seats against a comparable flange  48  on the extension section  30  to insure a firm coterminous alignment between the top of auger tube  42  and the auger tube of the extension section  30 , and alignment of the drive shafts of the augers in the respective sections so that both augers are driven in unison. 
     Auger tube  42  preferably extends over the greater portion of the length of the auger  40  as best seen in FIGS. 2 and 3. However, it preferably terminates short of the lower end of the auger  40  at the bottom of the hopper  12 . Auger tube  42  may be notched at  50  adjacent its bottom to form a short guide extension  52  to extend further down in partial surrounding relationship to the lower end of the auger  40 . 
     The auger tube  44  is slightly smaller in diameter than the internal diameter of auger tube  42  to permit it to be telescopically received in auger tube  42 . A fluid power cylinder  54 , such as a hydraulic cylinder, is coupled at  55  at one end to the auger tube  42 , and coupled at  56  at its other end to the bottom of cylinder  44 . 
     In accordance with the present invention, the fluid power cylinder  54  is operated to telescopically move the auger tube  44  into and out of the auger tube  42 . As shown in FIG. 2, when the fluid power cylinder  54  is actuated to extend its piston rod, the auger tube  44  will be extended out of the auger tube  42  so as to cover the lower, previously exposed portion of the auger. However, when it is desired to convey grain from the hopper  12  through the auger conveyor  24 , the fluid power cylinder  54  is operated to retract its piston rod and pull the auger tube  44  telescopically into the auger tube  42  as shown in FIG.  3 . In this position, the auger tube  44  will surround the upper portion of the auger within the auger tube  42 , but will be positioned between the auger and the inner wall of the auger tube  42  to protect the inner wall of the auger tube  42  against any abrasion that may occur during the grain conveying process. When the auger tube  44  assumes the position shown in FIG. 3, the bottom few flights of the auger  40  will be exposed to the grain in the hopper  12 , and when the auger is rotated it will convey the grain up through the conveyer section  28  and extension conveyer section  30  to be discharged from the hopper  12 . 
     From the foregoing description it will be seen that the telescopic configuration of the auger tubes of the present invention result in a minimum of components which might obstruct the path of the movement of the grain to be conveyed from the cart  10 . This speeds unloading and reduces the possibility of bridging of the components. The need for the cumbersome and space consuming slide rails and other components of the prior assemblies is avoided. The notch  50  and/or guide extension  52  at the bottom of the tube  42  also facilitate the movement of the tube  44  between its positions, supports the tube  44  when it is in the down position as shown in FIG. 2, and enlarges the size of the opening access to the auger  40  when the tube  44  is in its up operational position as seen in FIG.  3 . 
     Another advantage of the present invention is that the auger tube  42 , which is typically stationarily welded to the inclined wall  14  of the hopper  12 , is protected against abrasion wear during the conveying operation by the auger tube  44  which covers its inner wall. This will greatly extend the life of the stationary fixed auger tube  42  and reduce the need for replacement of this difficult to replace auger tube  42 . On the other hand, the auger tube  44  which will be subject to that abrasion and wear may be much more easily replaced simply by uncoupling the couple  56  of the fluid cylinder  54 , sliding the worn tube  44  out of the auger tube  42 , and replacing it with a new tube. 
     It will be appreciated that although the foregoing description is directed to a solid granular material handling system which includes a transportable grain cart, the principles of the present invention may be equally applicable to an auger conveyor in other types of installations and for conveying other forms of granular material. 
     It will also be understood that the preferred embodiment of the present invention which has been described is merely illustrative of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.