Patent Publication Number: US-7707754-B2

Title: Auger loading apparatus and machine with same

Description:
TECHNICAL FIELD 
   The present disclosure relates generally to a loading apparatus for a machine such as a scraper, and relates more particularly to a machine such as a scraper having an auger loading apparatus. 
   BACKGROUND 
   A wide variety of building and similar projects require preparatory work such as leveling, grading and filling of underlying soil, gravel or other materials. Highway and building construction, for example, typically requires that a prepared bed of compacted work material be provided upon which pavement, concrete, etc. is to be laid. In some instances, material fill for such purposes must be brought to the work site from another location. In others, material must be removed or redistributed. Foundations for buildings, dams, airports, factories and other construction projects generally present similar issues relating to elevation profile, slope, proper work material type, etc. Virtually all civil, environmental and other construction endeavors require at least some work material transport, and it will thus be readily apparent that the capacity to move relatively large quantities of material in an efficient manner may be paramount for the success of many public and private works projects. 
   To move relatively large volumes of material, construction contractors often utilize machines known as “scrapers” to remove material from one location and transport it to another. The term “scraper” generally refers to the ability of the machine to remove an overlying layer of work material from a work surface. Typical machines employ a scraper blade or cutting edge which may be moved through work material beneath the machine to remove a top layer of material. The removed material is placed into a “bowl” of the scraper, then transported to a different work site or different area of a work site for deposition. Efficient loading and unloading of the bowl in scraper machines has long presented an engineering challenge. 
   Certain scraper machines, known in the art as open bowl scrapers, rely upon forward motion of the machine to urge work material removed with the scraper blade backward and upward into the bowl. This approach generally requires a relatively large and heavy machine to provide sufficient power for driving the machine, removing material, and filling the bowl of the scraper. The challenge is compounded by traction losses of the machine during such operation. In some instances, separate tractor machines are used to push or pull self-propelled and other types of scrapers to enhance their ability to load a desired volume of work material. 
   Engineers have developed certain strategies addressing the loading and unloading challenges experienced with traditional open bowl scrapers. In one design, an elevator apparatus having paddles is used to lift work material from the vicinity of the scraper blade upward, thenceforth dumping the material into the bowl. Elevator designs have met with significant success, however, the relatively large number of moving parts and overall complexity of the apparatus tends to result in high wear and significant maintenance issues. Elevator scrapers also tend to generate significant dust. 
   Another strategy employs one or more augers within the scraper bowl to distribute the work material after it enters the bowl in a more even fashion than that achieved with a conventional open bowl design. In such bowl and auger systems, rotation of a load-distributing auger can lift work material within the bowl and urge work material toward the sides of the bowl such that the scraper machine may more easily push additional work material into the bowl via its forward travel. While systems employing load-distributing augers have various advantages, including some conditioning and mixing of the work material, the auger tends to take up significant space within the volume of the bowl, limiting the carrying capacity of a scraper machine of a given size. Moreover, ejection of material from the bowl tends to be problematic as it must generally be moved around the auger. The ejector system itself can occupy a significant amount of bowl volume. 
   One example of a scraper machine having a load distributing auger is known from U.S. Pat. No. 3,533,174 to Carston. In Carston&#39;s design, an auger is positioned within the bowl of a scraper machine at a generally vertical orientation. The auger receives loosened material within the bowl from a cutting blade as the machine is moved forward. While Carston&#39;s strategy, provides certain advantages over open bowl scrapers, the design is subject to the same limitations mentioned above with respect to the bowl capacity. In other words, Carston&#39; auger takes up a substantial amount of bowl volume that might otherwise be available for carrying work material. Thus, certain of Carston&#39;s potential advantages are at least somewhat overshadowed by the loss in work efficiency. Moreover, because of the auger&#39;s position, the machine still relies largely upon forward travel to push material into the bowl. 
   The present disclosure is directed to one or more of the problems or shortcomings set forth above. 
   SUMMARY OF THE INVENTION 
   In one aspect, the present disclosure provides a machine having a bowl mounted to a frame which defines a load volume. The machine further includes a cutter coupled with the frame and having a cutting edge, and a loading apparatus coupled with the cutter. The loading apparatus includes a chute with a first end disposed outside of the bowl and a second end. The loading apparatus further includes an auger disposed at least partially within the chute, and the auger is configured to move work material between the first and second ends of the chute. 
   In another aspect, the present disclosure provides a loading apparatus for a scraper machine. The loading apparatus includes at least one auger having an axis of rotation, a loading end and a second end opposite the loading end. The at least one auger defines a length dimension aligned with the axis of rotation that extends between the loading end and the second end. The loading apparatus further includes a chute that includes a material feed opening at a first position relative to the length dimension of the at least one auger, and includes at least one material discharge opening separate from the material feed opening and disposed at a second position relative to the length dimension which is different from the first position. The at least one auger is configured to move work material between the material feed opening and the discharge opening in a feed direction aligned generally with the axis of rotation of the at least one feed auger. 
   In still another aspect, the present disclosure provides a method of operating a scraper machine that includes a step of capturing work material at least in part via a step of moving a cutting edge of the scraper machine through the work material. The method further includes a step of moving work material into a chute of the scraper machine at least in part via the moving step, and a step of conveying work material from the guide chute to a bowl at least in part by rotating an auger disposed at least partially within the chute. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partially sectioned side view of a scraper machine according to one embodiment of the present disclosure; 
       FIG. 2  is a top view of a portion of the scraper machine of  FIG. 2 ; 
       FIG. 3  is a bottom perspective view of a loading apparatus suitable for use with the scraper machine of  FIG. 1 ; 
       FIG. 4  is a partial front perspective view of the loading apparatus shown in  FIG. 3 ; and 
       FIG. 5  is a back view of a portion of a loading apparatus according to another embodiment of the present disclosure. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , there is shown a machine  10  according to one embodiment of the present disclosure  10 . Machine  10  may be a self-propelled machine such as a self-propelled scraper machine, or it may be a tow-behind or pushed machine. Machine  10  may include a front frame unit  12  and a back frame unit  14  configured to articulate about an articulation axis J at an articulation joint  26 . Non-articulated configurations are also contemplated herein, however. Machine  10  may further include a cutter  20  coupled to back frame unit  14 , for example, and including a cutting edge  22 . A bowl  18  may be mounted to back frame unit  14 . Work material that is captured at least in part by moving cutter  20  through the work material may be stored for transport and eventual deposition into bowl  18 . A loading apparatus  30 , which may be positioned partially or entirely outside of bowl  18 , may also be mounted to back frame unit  14  and coupled with cutter  20  for loading work material into and out of bowl  18 . 
   Referring also to  FIG. 2 , bowl  18  may include a back side  26 , for example, defined by a movable material ejector assembly  24 , and a front side  29  which may be defined at least in part by loading apparatus  30 , as further described herein. Bowl  18  may further include first and second sides  25  and  27 , together with front side  29  and back side  26  defining a bowl load volume. Loading apparatus  30  may be configured to move work material into and out of bowl  18  for both loading and unloading of bowl  18 . 
   Loading apparatus  30  may include a chute  38  having a first end  32  positioned outside of bowl  18 , and a second end  33  through which work material may be conveyed during loading and/or unloading bowl  18 . Chute  30  may further include an apron  39  extending from a material feed opening  42  outwardly toward cutter  20 . Thus, work material removed from a work surface by cutter  20  may be guided via apron  39  toward and into material feed opening  42 , and thenceforth discharged out of a material discharge opening  36  into bowl  18 . 
   Loading apparatus  30  may still further include at least one auger  34  having an axis of rotation A. The at least one auger  34  is configured to feed work material in a feed direction between first and second ends  32  and  33  of chute  38 . The at least one auger  34  may include first and second augers  34   a  and be  34   b  positioned in parallel. In one embodiment, augers  34   a  and  34   b  may comprise counter-rotating augers having blades  35   a  and  35   b  with overlapping peripheries. The augers are positioned in parallel, and configured to feed work material through chute  38  during either loading or unloading of bowl  18 . An approximate feed direction for loading is shown via arrows B in  FIG. 2 . Unloading may take place generally in a reverse feed direction. Bowl  18  may further define a width W 1  extending between sides  25  and  27 , chute  38  may define an internal width W 2 , which is less than width W 1  but greater than about half of width W 1 . Augers  34   a  and  34   b  may, for example, be driven by bi-directional hydraulic motors  40 , but could be driven by some other means such as an internal combustion engine (not shown) in certain embodiments. 
   Turning to  FIG. 3 , there is shown a back view in perspective of loading apparatus  30 . Chute  38  of loading apparatus  30  may include a floor  43  wherein material discharge opening  36  is disposed. In certain embodiments, floor  43  and material discharge opening  36  may define front side  29  of bowl  18 . During loading or unloading of bowl  18 , material may be transferred through chute  38  either into or out of material discharge opening  36 , and either into or out of bowl  18 . Unloading of bowl  18  with augers  34   a  and  34   b  may be assisted by actuating ejector apparatus  24 . Chute  38  may further include inner peripheral walls  50 , for example, curving inner peripheral walls, extending at least partially about augers  34   a  and  34   b , and further extending for at least a portion of a length dimension L defined by augers  34   a  and  34   b . Inner peripheral walls  50  may define the internal width W 2  of chute  38 , illustrated in  FIG. 2 . 
   Referring also to  FIG. 4 , there is shown a front view of a portion of loading apparatus  30  wherein first ends  37  of augers  34   a  and  34   b , which may be understood as loading ends, are shown disposed hear material feed opening  42 . It should be appreciated that the loading ends  37  of augers  34   a  and  34   b  may be positioned differently relative to material feed opening  42  from the illustrated configuration, for example, extending outwardly therefrom toward cutter  22 . It may also be noted from  FIG. 4  that curving inner peripheral walls  50  may connect with apron  39  approximately at material feed opening  42 . Apron  39  may also include at least one concave portion comprising, for example, first and second curving surfaces  39   a  and  39   b  configured to guide work material from cutter  20  toward material feed opening  42 . In other embodiments, however, apron  39  might comprise a flat panel, for example including sidewalls to assist in guiding work material from cutter  20  toward material feed opening  42 . In still further embodiments, rather than including an apron for guiding material toward material feed opening  42 , an apron might be omitted from the design, and augers  34   a  and  34   b  positioned relatively closer to cutter  20 . 
   In another embodiment of a loading apparatus  130 , shown schematically in  FIG. 5 , a plurality of differently sized material discharge openings  136  may be provided in a chute  138 . In the illustrated embodiment, material discharge openings  136  are relatively smaller closer to an apron  139  than material discharge openings  136  located relatively further from apron  139 . Loading apparatus  138  may be suitable for use where sorting of work material during loading or unloading from a bowl of a scraper machine such as machine  10  is desired. Operation of loading apparatus  138  may be similar to that described herein with regard to the foregoing embodiments, however, work material of certain particle sizes may be fed into, and discharged, disproportionately among the different sized discharge openings of chute  138 . For example, during loading of a bowl such as bowl  18 , relatively larger sized particles, such as relatively large rocks, may be conveyed toward the discharge openings  136  that are spaced relatively further from apron  139 , whereas relatively smaller sized particles may be discharged through the discharge openings relatively closer to apron  139 . As a result, a scraper bowl such as bowl  18  filled with loading apparatus  130  may include material that is relatively smaller in particle, size in one, part of the bowl, and relatively larger in particle size in a different part of the bowl. To optimally sort work material using loading apparatus  130 , in one embodiment it may be configured via a relatively more horizontal inclination to discharge material in a smaller to larger size gradient from a front toward a back, respectively, of the subject bowl. Thus, during unloading, an operator may dispense partial loads at different parts of a work site, or in different layers on a given work surface, the partial loads having different average particle sizes. 
   INDUSTRIAL APPLICABILITY 
   Referring to the drawing Figures generally, during a typical loading operation, machine  10  will be driven across a work surface at as first work area, and cutter  20  and hence cutting edge  22  lowered to a desired vertical position such that cutting edge  22  will pass through work material, dislodging material from the work surface. Continued forward motion of machine  10  will result in additional material dislodged by cutter  20  being pushed upward and backward from cutting edge  22  and into chute  39 , capturing the work material and beginning to load the same. Prior to or upon beginning to move cutter  20  through the work material, rotation of augers  34   a  and  34   b  in first and second directions may be initiated. Because augers  34   a  and  34   b  will typically be counter-oriented, e.g. having respective “left-handed” and “right-handed” helical configurations, they will typically be rotated in opposite directions during loading of bowl  18 , but each urging work material in approximately the same feed direction, toward bowl  18  from cutter  20 . 
   Work material pushed upward and rearward toward and into chute  38  will typically flow generally in two paths defined by curving surfaces  39   a  and  39   b  toward left and right sides of material feed opening  42 . Approximately one half of the work material captured via cutter  20  will generally be fed toward first auger  34   a , and one half fed toward second auger  34   b . At material feed opening  42 , rotation of augers  34   a  and  34   b  will generally rotate a cutting edge  53   a  and  53   b  at the loading ends  37  of each respective auger  34   a  and  34   b  against work material, and the work material will begin being conveyed through the portion of chute  38  defined by peripheral walls  50 . Conveying of work material with augers  34   a  and  34   b  will tend to reduce the power necessary to continue to move machine  10  forward through the work material as compared to certain other designs. In particular, rotation of augers  34   a  and  34   b  performs a substantial portion of the loading work, rather than relying solely or mostly upon forward motion of the machine to push the work material into bowl  18 . 
   When bowl  18  is relatively empty, work material will tend to be discharged via a portion of material discharge opening  36  that is located relatively close to front side  29  and bottom side  28  of bowl  18 . As filling of bowl  18  progresses, material discharge opening  36  will tend to become partially blocked by deposited work material, and additional work material will be discharged relatively more upward and backward in bowl  18 . This phenomenon results at least in part from the relative positioning of loading apparatus  30  in front of bowl  18 , and its relative inclination. In one embodiment, the axis of rotation A of augers  34   a  and  34   b  may be oriented diagonally, for example at approximately a 45° angle, relative to articulation axis J. It is contemplated that an angle of approximately 45° may provide a desired balance between upward lifting force and backward loading force on work material conveyed by loading apparatus  30 . For certain applications, and for certain machine designs, a different angle of inclination of axis A relative to axis J may be appropriate, and the augers may not be oriented in parallel. Where bowl load volume is to be maximized for a particular machine design or size, a loading apparatus  30  may be configured such that augers  34   a  and  34   b  are relatively more vertical, whereas when available power for pushing work material backward in bowl  18  is sought to be maximized, for example, for a relatively less powerful or lighter machine, a relatively more horizontal inclination of axis A may be appropriate. 
   When bowl  18  has been filled to a desired extent, cutter  20  may be lifted to substantially close bowl  18 , and machine  10  will typically be driven to a second work area, for example, where work material is to be deposited. To deposit work material, cutter  20  may be lowered to a height corresponding to a desired lift thickness for deposited material. Machine  10  may then be driven across a work surface at the second work area, and augers  34   a  and  34   b  rotated in opposite directions to those used for loading bowl  18 , to convey work material from bowl  18 , through chute  38 , and onto the work surface. During deposition of work material with machine  10 , ejector apparatus  24  may be used to push work material toward front side  29  of bowl  18 . Unloading of bowl  18  may thus take place in a manner generally the reverse of that occurring during loading. In other words, when bowl  18  is at least partially filled, work material may block a portion of material discharge opening  36 , and thus material initially discharged via material discharge opening  36  will tend to be material that is positioned at relatively higher vertical positions in bowl  18 . As unloading progresses, work material that is positioned progressively lower in bowl  18  will be discharged. 
   The presently disclosed design for a loading apparatus  30 ,  130  for use in a scraper or other material capturing machine  10  improves operating efficiency over known designs such as open bowl scrapers and auger scrapers wherein the augers are positioned within the bowl and thus reduce potentially available bowl volume. Rather than distributing work material within the bowl as in conventional auger-scraper designs such as Carston, augers  34   a  and  34   b  are used to convey work material into and out of the bowl without sacrificing bowl volume. This approach also allows easier loading, as the conveying power provided by augers  34   a  and  34   b  reduces the force necessary to move material into the bowl. Augers  34   a  and  34   b  can also carry material relatively higher into the bowl than conventional designs, as they do not have to overcome remolding forces associated with surrounding work material. In other words, in a design such as Carston, work material once distributed by the auger will tend to move back around the auger as bowl filling progresses, resisting efforts to pile material higher in the bowl, and also providing resistance to rotation of the auger. 
   With regard to conventional elevator scrapers, the present disclosure provides still other advantages. The present disclosure provides a system wherein the work material is better confined during conveying to the bowl, and may thus produce less airborne dust than elevator scraper systems. Moreover, expense, complexity and maintenance problems associated with elevator scraper designs are obviated, as machine  10  and loading apparatus  30 ,  130  may use a relatively smaller number of parts than elevator scrapers having track or chain driven paddles and the like. 
   The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present disclosure in any way. Thus, those skilled in the art will appreciate that various modifications might be made to the presently disclosed embodiments without departing from the full and fair scope of the present disclosure. For example, while the present disclosure is discussed primarily in the context of mobile scraper machines, it is not thereby limited. Those skilled in the art will appreciate that other types of material capturing and/or transfer apparatus such as are used in mining, agriculture and other activities may benefit from the teachings of the present disclosure. It should also be appreciated that while material discharge opening  36  is shown as an elongate, generally rectangular opening, and openings  136  are shown as spaced apart squares, the present disclosure is not thereby limited and slots, circular openings or some other configuration or positioning might be used. Other aspects, features and advantages will be apparent upon an examination of the attached drawings and appended claims.